Removed old mbedtls, replacing with submodule.

1 files changed, 0 insertions, 2814 deletions

diff --git a/lib/mbedtls-2.27.0/library/rsa.c b/lib/mbedtls-2.27.0/library/rsa.c
deleted file mode 100644
index 268d025..0000000
--- a/lib/mbedtls-2.27.0/library/rsa.c
+++ /dev/null
@@ -1,2814 +0,0 @@
-/*
- *  The RSA public-key cryptosystem
- *
- *  Copyright The Mbed TLS Contributors
- *  SPDX-License-Identifier: Apache-2.0
- *
- *  Licensed under the Apache License, Version 2.0 (the "License"); you may
- *  not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *  http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- */
-
-/*
- *  The following sources were referenced in the design of this implementation
- *  of the RSA algorithm:
- *
- *  [1] A method for obtaining digital signatures and public-key cryptosystems
- *      R Rivest, A Shamir, and L Adleman
- *      http://people.csail.mit.edu/rivest/pubs.html#RSA78
- *
- *  [2] Handbook of Applied Cryptography - 1997, Chapter 8
- *      Menezes, van Oorschot and Vanstone
- *
- *  [3] Malware Guard Extension: Using SGX to Conceal Cache Attacks
- *      Michael Schwarz, Samuel Weiser, Daniel Gruss, Clémentine Maurice and
- *      Stefan Mangard
- *      https://arxiv.org/abs/1702.08719v2
- *
- */
-
-#include "common.h"
-
-#if defined(MBEDTLS_RSA_C)
-
-#include "mbedtls/rsa.h"
-#include "mbedtls/rsa_internal.h"
-#include "mbedtls/oid.h"
-#include "mbedtls/platform_util.h"
-#include "mbedtls/error.h"
-
-#include <string.h>
-
-#if defined(MBEDTLS_PKCS1_V21)
-#include "mbedtls/md.h"
-#endif
-
-#if defined(MBEDTLS_PKCS1_V15) && !defined(__OpenBSD__) && !defined(__NetBSD__)
-#include <stdlib.h>
-#endif
-
-#if defined(MBEDTLS_PLATFORM_C)
-#include "mbedtls/platform.h"
-#else
-#include <stdio.h>
-#define mbedtls_printf printf
-#define mbedtls_calloc calloc
-#define mbedtls_free   free
-#endif
-
-#if !defined(MBEDTLS_RSA_ALT)
-
-/* Parameter validation macros */
-#define RSA_VALIDATE_RET( cond )                                       \
-    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_RSA_BAD_INPUT_DATA )
-#define RSA_VALIDATE( cond )                                           \
-    MBEDTLS_INTERNAL_VALIDATE( cond )
-
-#if defined(MBEDTLS_PKCS1_V15)
-/* constant-time buffer comparison */
-static inline int mbedtls_safer_memcmp( const void *a, const void *b, size_t n )
-{
-    size_t i;
-    const unsigned char *A = (const unsigned char *) a;
-    const unsigned char *B = (const unsigned char *) b;
-    unsigned char diff = 0;
-
-    for( i = 0; i < n; i++ )
-        diff |= A[i] ^ B[i];
-
-    return( diff );
-}
-#endif /* MBEDTLS_PKCS1_V15 */
-
-int mbedtls_rsa_import( mbedtls_rsa_context *ctx,
-                        const mbedtls_mpi *N,
-                        const mbedtls_mpi *P, const mbedtls_mpi *Q,
-                        const mbedtls_mpi *D, const mbedtls_mpi *E )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    RSA_VALIDATE_RET( ctx != NULL );
-
-    if( ( N != NULL && ( ret = mbedtls_mpi_copy( &ctx->N, N ) ) != 0 ) ||
-        ( P != NULL && ( ret = mbedtls_mpi_copy( &ctx->P, P ) ) != 0 ) ||
-        ( Q != NULL && ( ret = mbedtls_mpi_copy( &ctx->Q, Q ) ) != 0 ) ||
-        ( D != NULL && ( ret = mbedtls_mpi_copy( &ctx->D, D ) ) != 0 ) ||
-        ( E != NULL && ( ret = mbedtls_mpi_copy( &ctx->E, E ) ) != 0 ) )
-    {
-        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
-    }
-
-    if( N != NULL )
-        ctx->len = mbedtls_mpi_size( &ctx->N );
-
-    return( 0 );
-}
-
-int mbedtls_rsa_import_raw( mbedtls_rsa_context *ctx,
-                            unsigned char const *N, size_t N_len,
-                            unsigned char const *P, size_t P_len,
-                            unsigned char const *Q, size_t Q_len,
-                            unsigned char const *D, size_t D_len,
-                            unsigned char const *E, size_t E_len )
-{
-    int ret = 0;
-    RSA_VALIDATE_RET( ctx != NULL );
-
-    if( N != NULL )
-    {
-        MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->N, N, N_len ) );
-        ctx->len = mbedtls_mpi_size( &ctx->N );
-    }
-
-    if( P != NULL )
-        MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->P, P, P_len ) );
-
-    if( Q != NULL )
-        MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->Q, Q, Q_len ) );
-
-    if( D != NULL )
-        MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->D, D, D_len ) );
-
-    if( E != NULL )
-        MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->E, E, E_len ) );
-
-cleanup:
-
-    if( ret != 0 )
-        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
-
-    return( 0 );
-}
-
-/*
- * Checks whether the context fields are set in such a way
- * that the RSA primitives will be able to execute without error.
- * It does *not* make guarantees for consistency of the parameters.
- */
-static int rsa_check_context( mbedtls_rsa_context const *ctx, int is_priv,
-                              int blinding_needed )
-{
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    /* blinding_needed is only used for NO_CRT to decide whether
-     * P,Q need to be present or not. */
-    ((void) blinding_needed);
-#endif
-
-    if( ctx->len != mbedtls_mpi_size( &ctx->N ) ||
-        ctx->len > MBEDTLS_MPI_MAX_SIZE )
-    {
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-    }
-
-    /*
-     * 1. Modular exponentiation needs positive, odd moduli.
-     */
-
-    /* Modular exponentiation wrt. N is always used for
-     * RSA public key operations. */
-    if( mbedtls_mpi_cmp_int( &ctx->N, 0 ) <= 0 ||
-        mbedtls_mpi_get_bit( &ctx->N, 0 ) == 0  )
-    {
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-    }
-
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    /* Modular exponentiation for P and Q is only
-     * used for private key operations and if CRT
-     * is used. */
-    if( is_priv &&
-        ( mbedtls_mpi_cmp_int( &ctx->P, 0 ) <= 0 ||
-          mbedtls_mpi_get_bit( &ctx->P, 0 ) == 0 ||
-          mbedtls_mpi_cmp_int( &ctx->Q, 0 ) <= 0 ||
-          mbedtls_mpi_get_bit( &ctx->Q, 0 ) == 0  ) )
-    {
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-    }
-#endif /* !MBEDTLS_RSA_NO_CRT */
-
-    /*
-     * 2. Exponents must be positive
-     */
-
-    /* Always need E for public key operations */
-    if( mbedtls_mpi_cmp_int( &ctx->E, 0 ) <= 0 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-#if defined(MBEDTLS_RSA_NO_CRT)
-    /* For private key operations, use D or DP & DQ
-     * as (unblinded) exponents. */
-    if( is_priv && mbedtls_mpi_cmp_int( &ctx->D, 0 ) <= 0 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-#else
-    if( is_priv &&
-        ( mbedtls_mpi_cmp_int( &ctx->DP, 0 ) <= 0 ||
-          mbedtls_mpi_cmp_int( &ctx->DQ, 0 ) <= 0  ) )
-    {
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-    }
-#endif /* MBEDTLS_RSA_NO_CRT */
-
-    /* Blinding shouldn't make exponents negative either,
-     * so check that P, Q >= 1 if that hasn't yet been
-     * done as part of 1. */
-#if defined(MBEDTLS_RSA_NO_CRT)
-    if( is_priv && blinding_needed &&
-        ( mbedtls_mpi_cmp_int( &ctx->P, 0 ) <= 0 ||
-          mbedtls_mpi_cmp_int( &ctx->Q, 0 ) <= 0 ) )
-    {
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-    }
-#endif
-
-    /* It wouldn't lead to an error if it wasn't satisfied,
-     * but check for QP >= 1 nonetheless. */
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    if( is_priv &&
-        mbedtls_mpi_cmp_int( &ctx->QP, 0 ) <= 0 )
-    {
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-    }
-#endif
-
-    return( 0 );
-}
-
-int mbedtls_rsa_complete( mbedtls_rsa_context *ctx )
-{
-    int ret = 0;
-    int have_N, have_P, have_Q, have_D, have_E;
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    int have_DP, have_DQ, have_QP;
-#endif
-    int n_missing, pq_missing, d_missing, is_pub, is_priv;
-
-    RSA_VALIDATE_RET( ctx != NULL );
-
-    have_N = ( mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 );
-    have_P = ( mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 );
-    have_Q = ( mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 );
-    have_D = ( mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 );
-    have_E = ( mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0 );
-
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    have_DP = ( mbedtls_mpi_cmp_int( &ctx->DP, 0 ) != 0 );
-    have_DQ = ( mbedtls_mpi_cmp_int( &ctx->DQ, 0 ) != 0 );
-    have_QP = ( mbedtls_mpi_cmp_int( &ctx->QP, 0 ) != 0 );
-#endif
-
-    /*
-     * Check whether provided parameters are enough
-     * to deduce all others. The following incomplete
-     * parameter sets for private keys are supported:
-     *
-     * (1) P, Q missing.
-     * (2) D and potentially N missing.
-     *
-     */
-
-    n_missing  =              have_P &&  have_Q &&  have_D && have_E;
-    pq_missing =   have_N && !have_P && !have_Q &&  have_D && have_E;
-    d_missing  =              have_P &&  have_Q && !have_D && have_E;
-    is_pub     =   have_N && !have_P && !have_Q && !have_D && have_E;
-
-    /* These three alternatives are mutually exclusive */
-    is_priv = n_missing || pq_missing || d_missing;
-
-    if( !is_priv && !is_pub )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    /*
-     * Step 1: Deduce N if P, Q are provided.
-     */
-
-    if( !have_N && have_P && have_Q )
-    {
-        if( ( ret = mbedtls_mpi_mul_mpi( &ctx->N, &ctx->P,
-                                         &ctx->Q ) ) != 0 )
-        {
-            return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
-        }
-
-        ctx->len = mbedtls_mpi_size( &ctx->N );
-    }
-
-    /*
-     * Step 2: Deduce and verify all remaining core parameters.
-     */
-
-    if( pq_missing )
-    {
-        ret = mbedtls_rsa_deduce_primes( &ctx->N, &ctx->E, &ctx->D,
-                                         &ctx->P, &ctx->Q );
-        if( ret != 0 )
-            return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
-
-    }
-    else if( d_missing )
-    {
-        if( ( ret = mbedtls_rsa_deduce_private_exponent( &ctx->P,
-                                                         &ctx->Q,
-                                                         &ctx->E,
-                                                         &ctx->D ) ) != 0 )
-        {
-            return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
-        }
-    }
-
-    /*
-     * Step 3: Deduce all additional parameters specific
-     *         to our current RSA implementation.
-     */
-
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    if( is_priv && ! ( have_DP && have_DQ && have_QP ) )
-    {
-        ret = mbedtls_rsa_deduce_crt( &ctx->P,  &ctx->Q,  &ctx->D,
-                                      &ctx->DP, &ctx->DQ, &ctx->QP );
-        if( ret != 0 )
-            return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
-    }
-#endif /* MBEDTLS_RSA_NO_CRT */
-
-    /*
-     * Step 3: Basic sanity checks
-     */
-
-    return( rsa_check_context( ctx, is_priv, 1 ) );
-}
-
-int mbedtls_rsa_export_raw( const mbedtls_rsa_context *ctx,
-                            unsigned char *N, size_t N_len,
-                            unsigned char *P, size_t P_len,
-                            unsigned char *Q, size_t Q_len,
-                            unsigned char *D, size_t D_len,
-                            unsigned char *E, size_t E_len )
-{
-    int ret = 0;
-    int is_priv;
-    RSA_VALIDATE_RET( ctx != NULL );
-
-    /* Check if key is private or public */
-    is_priv =
-        mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
-        mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
-        mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
-        mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 &&
-        mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0;
-
-    if( !is_priv )
-    {
-        /* If we're trying to export private parameters for a public key,
-         * something must be wrong. */
-        if( P != NULL || Q != NULL || D != NULL )
-            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    }
-
-    if( N != NULL )
-        MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->N, N, N_len ) );
-
-    if( P != NULL )
-        MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->P, P, P_len ) );
-
-    if( Q != NULL )
-        MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->Q, Q, Q_len ) );
-
-    if( D != NULL )
-        MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->D, D, D_len ) );
-
-    if( E != NULL )
-        MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->E, E, E_len ) );
-
-cleanup:
-
-    return( ret );
-}
-
-int mbedtls_rsa_export( const mbedtls_rsa_context *ctx,
-                        mbedtls_mpi *N, mbedtls_mpi *P, mbedtls_mpi *Q,
-                        mbedtls_mpi *D, mbedtls_mpi *E )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    int is_priv;
-    RSA_VALIDATE_RET( ctx != NULL );
-
-    /* Check if key is private or public */
-    is_priv =
-        mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
-        mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
-        mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
-        mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 &&
-        mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0;
-
-    if( !is_priv )
-    {
-        /* If we're trying to export private parameters for a public key,
-         * something must be wrong. */
-        if( P != NULL || Q != NULL || D != NULL )
-            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    }
-
-    /* Export all requested core parameters. */
-
-    if( ( N != NULL && ( ret = mbedtls_mpi_copy( N, &ctx->N ) ) != 0 ) ||
-        ( P != NULL && ( ret = mbedtls_mpi_copy( P, &ctx->P ) ) != 0 ) ||
-        ( Q != NULL && ( ret = mbedtls_mpi_copy( Q, &ctx->Q ) ) != 0 ) ||
-        ( D != NULL && ( ret = mbedtls_mpi_copy( D, &ctx->D ) ) != 0 ) ||
-        ( E != NULL && ( ret = mbedtls_mpi_copy( E, &ctx->E ) ) != 0 ) )
-    {
-        return( ret );
-    }
-
-    return( 0 );
-}
-
-/*
- * Export CRT parameters
- * This must also be implemented if CRT is not used, for being able to
- * write DER encoded RSA keys. The helper function mbedtls_rsa_deduce_crt
- * can be used in this case.
- */
-int mbedtls_rsa_export_crt( const mbedtls_rsa_context *ctx,
-                            mbedtls_mpi *DP, mbedtls_mpi *DQ, mbedtls_mpi *QP )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    int is_priv;
-    RSA_VALIDATE_RET( ctx != NULL );
-
-    /* Check if key is private or public */
-    is_priv =
-        mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
-        mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
-        mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
-        mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 &&
-        mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0;
-
-    if( !is_priv )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    /* Export all requested blinding parameters. */
-    if( ( DP != NULL && ( ret = mbedtls_mpi_copy( DP, &ctx->DP ) ) != 0 ) ||
-        ( DQ != NULL && ( ret = mbedtls_mpi_copy( DQ, &ctx->DQ ) ) != 0 ) ||
-        ( QP != NULL && ( ret = mbedtls_mpi_copy( QP, &ctx->QP ) ) != 0 ) )
-    {
-        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
-    }
-#else
-    if( ( ret = mbedtls_rsa_deduce_crt( &ctx->P, &ctx->Q, &ctx->D,
-                                        DP, DQ, QP ) ) != 0 )
-    {
-        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_BAD_INPUT_DATA, ret ) );
-    }
-#endif
-
-    return( 0 );
-}
-
-/*
- * Initialize an RSA context
- */
-void mbedtls_rsa_init( mbedtls_rsa_context *ctx,
-               int padding,
-               int hash_id )
-{
-    RSA_VALIDATE( ctx != NULL );
-    RSA_VALIDATE( padding == MBEDTLS_RSA_PKCS_V15 ||
-                  padding == MBEDTLS_RSA_PKCS_V21 );
-
-    memset( ctx, 0, sizeof( mbedtls_rsa_context ) );
-
-    mbedtls_rsa_set_padding( ctx, padding, hash_id );
-
-#if defined(MBEDTLS_THREADING_C)
-    /* Set ctx->ver to nonzero to indicate that the mutex has been
-     * initialized and will need to be freed. */
-    ctx->ver = 1;
-    mbedtls_mutex_init( &ctx->mutex );
-#endif
-}
-
-/*
- * Set padding for an existing RSA context
- */
-void mbedtls_rsa_set_padding( mbedtls_rsa_context *ctx, int padding,
-                              int hash_id )
-{
-    RSA_VALIDATE( ctx != NULL );
-    RSA_VALIDATE( padding == MBEDTLS_RSA_PKCS_V15 ||
-                  padding == MBEDTLS_RSA_PKCS_V21 );
-
-    ctx->padding = padding;
-    ctx->hash_id = hash_id;
-}
-
-/*
- * Get length in bytes of RSA modulus
- */
-
-size_t mbedtls_rsa_get_len( const mbedtls_rsa_context *ctx )
-{
-    return( ctx->len );
-}
-
-
-#if defined(MBEDTLS_GENPRIME)
-
-/*
- * Generate an RSA keypair
- *
- * This generation method follows the RSA key pair generation procedure of
- * FIPS 186-4 if 2^16 < exponent < 2^256 and nbits = 2048 or nbits = 3072.
- */
-int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
-                 int (*f_rng)(void *, unsigned char *, size_t),
-                 void *p_rng,
-                 unsigned int nbits, int exponent )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    mbedtls_mpi H, G, L;
-    int prime_quality = 0;
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( f_rng != NULL );
-
-    /*
-     * If the modulus is 1024 bit long or shorter, then the security strength of
-     * the RSA algorithm is less than or equal to 80 bits and therefore an error
-     * rate of 2^-80 is sufficient.
-     */
-    if( nbits > 1024 )
-        prime_quality = MBEDTLS_MPI_GEN_PRIME_FLAG_LOW_ERR;
-
-    mbedtls_mpi_init( &H );
-    mbedtls_mpi_init( &G );
-    mbedtls_mpi_init( &L );
-
-    if( nbits < 128 || exponent < 3 || nbits % 2 != 0 )
-    {
-        ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
-        goto cleanup;
-    }
-
-    /*
-     * find primes P and Q with Q < P so that:
-     * 1.  |P-Q| > 2^( nbits / 2 - 100 )
-     * 2.  GCD( E, (P-1)*(Q-1) ) == 1
-     * 3.  E^-1 mod LCM(P-1, Q-1) > 2^( nbits / 2 )
-     */
-    MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->E, exponent ) );
-
-    do
-    {
-        MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->P, nbits >> 1,
-                                                prime_quality, f_rng, p_rng ) );
-
-        MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->Q, nbits >> 1,
-                                                prime_quality, f_rng, p_rng ) );
-
-        /* make sure the difference between p and q is not too small (FIPS 186-4 §B.3.3 step 5.4) */
-        MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &H, &ctx->P, &ctx->Q ) );
-        if( mbedtls_mpi_bitlen( &H ) <= ( ( nbits >= 200 ) ? ( ( nbits >> 1 ) - 99 ) : 0 ) )
-            continue;
-
-        /* not required by any standards, but some users rely on the fact that P > Q */
-        if( H.s < 0 )
-            mbedtls_mpi_swap( &ctx->P, &ctx->Q );
-
-        /* Temporarily replace P,Q by P-1, Q-1 */
-        MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &ctx->P, &ctx->P, 1 ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &ctx->Q, &ctx->Q, 1 ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &H, &ctx->P, &ctx->Q ) );
-
-        /* check GCD( E, (P-1)*(Q-1) ) == 1 (FIPS 186-4 §B.3.1 criterion 2(a)) */
-        MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->E, &H  ) );
-        if( mbedtls_mpi_cmp_int( &G, 1 ) != 0 )
-            continue;
-
-        /* compute smallest possible D = E^-1 mod LCM(P-1, Q-1) (FIPS 186-4 §B.3.1 criterion 3(b)) */
-        MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->P, &ctx->Q ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( &L, NULL, &H, &G ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->D, &ctx->E, &L ) );
-
-        if( mbedtls_mpi_bitlen( &ctx->D ) <= ( ( nbits + 1 ) / 2 ) ) // (FIPS 186-4 §B.3.1 criterion 3(a))
-            continue;
-
-        break;
-    }
-    while( 1 );
-
-    /* Restore P,Q */
-    MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &ctx->P,  &ctx->P, 1 ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &ctx->Q,  &ctx->Q, 1 ) );
-
-    MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->N, &ctx->P, &ctx->Q ) );
-
-    ctx->len = mbedtls_mpi_size( &ctx->N );
-
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    /*
-     * DP = D mod (P - 1)
-     * DQ = D mod (Q - 1)
-     * QP = Q^-1 mod P
-     */
-    MBEDTLS_MPI_CHK( mbedtls_rsa_deduce_crt( &ctx->P, &ctx->Q, &ctx->D,
-                                             &ctx->DP, &ctx->DQ, &ctx->QP ) );
-#endif /* MBEDTLS_RSA_NO_CRT */
-
-    /* Double-check */
-    MBEDTLS_MPI_CHK( mbedtls_rsa_check_privkey( ctx ) );
-
-cleanup:
-
-    mbedtls_mpi_free( &H );
-    mbedtls_mpi_free( &G );
-    mbedtls_mpi_free( &L );
-
-    if( ret != 0 )
-    {
-        mbedtls_rsa_free( ctx );
-
-        if( ( -ret & ~0x7f ) == 0 )
-            ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_KEY_GEN_FAILED, ret );
-        return( ret );
-    }
-
-    return( 0 );
-}
-
-#endif /* MBEDTLS_GENPRIME */
-
-/*
- * Check a public RSA key
- */
-int mbedtls_rsa_check_pubkey( const mbedtls_rsa_context *ctx )
-{
-    RSA_VALIDATE_RET( ctx != NULL );
-
-    if( rsa_check_context( ctx, 0 /* public */, 0 /* no blinding */ ) != 0 )
-        return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
-
-    if( mbedtls_mpi_bitlen( &ctx->N ) < 128 )
-    {
-        return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
-    }
-
-    if( mbedtls_mpi_get_bit( &ctx->E, 0 ) == 0 ||
-        mbedtls_mpi_bitlen( &ctx->E )     < 2  ||
-        mbedtls_mpi_cmp_mpi( &ctx->E, &ctx->N ) >= 0 )
-    {
-        return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
-    }
-
-    return( 0 );
-}
-
-/*
- * Check for the consistency of all fields in an RSA private key context
- */
-int mbedtls_rsa_check_privkey( const mbedtls_rsa_context *ctx )
-{
-    RSA_VALIDATE_RET( ctx != NULL );
-
-    if( mbedtls_rsa_check_pubkey( ctx ) != 0 ||
-        rsa_check_context( ctx, 1 /* private */, 1 /* blinding */ ) != 0 )
-    {
-        return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
-    }
-
-    if( mbedtls_rsa_validate_params( &ctx->N, &ctx->P, &ctx->Q,
-                                     &ctx->D, &ctx->E, NULL, NULL ) != 0 )
-    {
-        return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
-    }
-
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    else if( mbedtls_rsa_validate_crt( &ctx->P, &ctx->Q, &ctx->D,
-                                       &ctx->DP, &ctx->DQ, &ctx->QP ) != 0 )
-    {
-        return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
-    }
-#endif
-
-    return( 0 );
-}
-
-/*
- * Check if contexts holding a public and private key match
- */
-int mbedtls_rsa_check_pub_priv( const mbedtls_rsa_context *pub,
-                                const mbedtls_rsa_context *prv )
-{
-    RSA_VALIDATE_RET( pub != NULL );
-    RSA_VALIDATE_RET( prv != NULL );
-
-    if( mbedtls_rsa_check_pubkey( pub )  != 0 ||
-        mbedtls_rsa_check_privkey( prv ) != 0 )
-    {
-        return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
-    }
-
-    if( mbedtls_mpi_cmp_mpi( &pub->N, &prv->N ) != 0 ||
-        mbedtls_mpi_cmp_mpi( &pub->E, &prv->E ) != 0 )
-    {
-        return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
-    }
-
-    return( 0 );
-}
-
-/*
- * Do an RSA public key operation
- */
-int mbedtls_rsa_public( mbedtls_rsa_context *ctx,
-                const unsigned char *input,
-                unsigned char *output )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    size_t olen;
-    mbedtls_mpi T;
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( input != NULL );
-    RSA_VALIDATE_RET( output != NULL );
-
-    if( rsa_check_context( ctx, 0 /* public */, 0 /* no blinding */ ) )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    mbedtls_mpi_init( &T );
-
-#if defined(MBEDTLS_THREADING_C)
-    if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
-        return( ret );
-#endif
-
-    MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &T, input, ctx->len ) );
-
-    if( mbedtls_mpi_cmp_mpi( &T, &ctx->N ) >= 0 )
-    {
-        ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
-        goto cleanup;
-    }
-
-    olen = ctx->len;
-    MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T, &T, &ctx->E, &ctx->N, &ctx->RN ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &T, output, olen ) );
-
-cleanup:
-#if defined(MBEDTLS_THREADING_C)
-    if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
-        return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
-#endif
-
-    mbedtls_mpi_free( &T );
-
-    if( ret != 0 )
-        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_PUBLIC_FAILED, ret ) );
-
-    return( 0 );
-}
-
-/*
- * Generate or update blinding values, see section 10 of:
- *  KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA,
- *  DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer
- *  Berlin Heidelberg, 1996. p. 104-113.
- */
-static int rsa_prepare_blinding( mbedtls_rsa_context *ctx,
-                 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
-{
-    int ret, count = 0;
-    mbedtls_mpi R;
-
-    mbedtls_mpi_init( &R );
-
-    if( ctx->Vf.p != NULL )
-    {
-        /* We already have blinding values, just update them by squaring */
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &ctx->Vi ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->N ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vf, &ctx->Vf, &ctx->Vf ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->N ) );
-
-        goto cleanup;
-    }
-
-    /* Unblinding value: Vf = random number, invertible mod N */
-    do {
-        if( count++ > 10 )
-        {
-            ret = MBEDTLS_ERR_RSA_RNG_FAILED;
-            goto cleanup;
-        }
-
-        MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &ctx->Vf, ctx->len - 1, f_rng, p_rng ) );
-
-        /* Compute Vf^-1 as R * (R Vf)^-1 to avoid leaks from inv_mod. */
-        MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &R, ctx->len - 1, f_rng, p_rng ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vf, &R ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->N ) );
-
-        /* At this point, Vi is invertible mod N if and only if both Vf and R
-         * are invertible mod N. If one of them isn't, we don't need to know
-         * which one, we just loop and choose new values for both of them.
-         * (Each iteration succeeds with overwhelming probability.) */
-        ret = mbedtls_mpi_inv_mod( &ctx->Vi, &ctx->Vi, &ctx->N );
-        if( ret != 0 && ret != MBEDTLS_ERR_MPI_NOT_ACCEPTABLE )
-            goto cleanup;
-
-    } while( ret == MBEDTLS_ERR_MPI_NOT_ACCEPTABLE );
-
-    /* Finish the computation of Vf^-1 = R * (R Vf)^-1 */
-    MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &R ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->N ) );
-
-    /* Blinding value: Vi = Vf^(-e) mod N
-     * (Vi already contains Vf^-1 at this point) */
-    MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->Vi, &ctx->Vi, &ctx->E, &ctx->N, &ctx->RN ) );
-
-
-cleanup:
-    mbedtls_mpi_free( &R );
-
-    return( ret );
-}
-
-/*
- * Exponent blinding supposed to prevent side-channel attacks using multiple
- * traces of measurements to recover the RSA key. The more collisions are there,
- * the more bits of the key can be recovered. See [3].
- *
- * Collecting n collisions with m bit long blinding value requires 2^(m-m/n)
- * observations on avarage.
- *
- * For example with 28 byte blinding to achieve 2 collisions the adversary has
- * to make 2^112 observations on avarage.
- *
- * (With the currently (as of 2017 April) known best algorithms breaking 2048
- * bit RSA requires approximately as much time as trying out 2^112 random keys.
- * Thus in this sense with 28 byte blinding the security is not reduced by
- * side-channel attacks like the one in [3])
- *
- * This countermeasure does not help if the key recovery is possible with a
- * single trace.
- */
-#define RSA_EXPONENT_BLINDING 28
-
-/*
- * Do an RSA private key operation
- */
-int mbedtls_rsa_private( mbedtls_rsa_context *ctx,
-                 int (*f_rng)(void *, unsigned char *, size_t),
-                 void *p_rng,
-                 const unsigned char *input,
-                 unsigned char *output )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    size_t olen;
-
-    /* Temporary holding the result */
-    mbedtls_mpi T;
-
-    /* Temporaries holding P-1, Q-1 and the
-     * exponent blinding factor, respectively. */
-    mbedtls_mpi P1, Q1, R;
-
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    /* Temporaries holding the results mod p resp. mod q. */
-    mbedtls_mpi TP, TQ;
-
-    /* Temporaries holding the blinded exponents for
-     * the mod p resp. mod q computation (if used). */
-    mbedtls_mpi DP_blind, DQ_blind;
-
-    /* Pointers to actual exponents to be used - either the unblinded
-     * or the blinded ones, depending on the presence of a PRNG. */
-    mbedtls_mpi *DP = &ctx->DP;
-    mbedtls_mpi *DQ = &ctx->DQ;
-#else
-    /* Temporary holding the blinded exponent (if used). */
-    mbedtls_mpi D_blind;
-
-    /* Pointer to actual exponent to be used - either the unblinded
-     * or the blinded one, depending on the presence of a PRNG. */
-    mbedtls_mpi *D = &ctx->D;
-#endif /* MBEDTLS_RSA_NO_CRT */
-
-    /* Temporaries holding the initial input and the double
-     * checked result; should be the same in the end. */
-    mbedtls_mpi I, C;
-
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( input  != NULL );
-    RSA_VALIDATE_RET( output != NULL );
-
-    if( rsa_check_context( ctx, 1             /* private key checks */,
-                                f_rng != NULL /* blinding y/n       */ ) != 0 )
-    {
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-    }
-
-#if defined(MBEDTLS_THREADING_C)
-    if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
-        return( ret );
-#endif
-
-    /* MPI Initialization */
-    mbedtls_mpi_init( &T );
-
-    mbedtls_mpi_init( &P1 );
-    mbedtls_mpi_init( &Q1 );
-    mbedtls_mpi_init( &R );
-
-    if( f_rng != NULL )
-    {
-#if defined(MBEDTLS_RSA_NO_CRT)
-        mbedtls_mpi_init( &D_blind );
-#else
-        mbedtls_mpi_init( &DP_blind );
-        mbedtls_mpi_init( &DQ_blind );
-#endif
-    }
-
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    mbedtls_mpi_init( &TP ); mbedtls_mpi_init( &TQ );
-#endif
-
-    mbedtls_mpi_init( &I );
-    mbedtls_mpi_init( &C );
-
-    /* End of MPI initialization */
-
-    MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &T, input, ctx->len ) );
-    if( mbedtls_mpi_cmp_mpi( &T, &ctx->N ) >= 0 )
-    {
-        ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
-        goto cleanup;
-    }
-
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &I, &T ) );
-
-    if( f_rng != NULL )
-    {
-        /*
-         * Blinding
-         * T = T * Vi mod N
-         */
-        MBEDTLS_MPI_CHK( rsa_prepare_blinding( ctx, f_rng, p_rng ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &T, &ctx->Vi ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &T, &ctx->N ) );
-
-        /*
-         * Exponent blinding
-         */
-        MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &P1, &ctx->P, 1 ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &Q1, &ctx->Q, 1 ) );
-
-#if defined(MBEDTLS_RSA_NO_CRT)
-        /*
-         * D_blind = ( P - 1 ) * ( Q - 1 ) * R + D
-         */
-        MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &R, RSA_EXPONENT_BLINDING,
-                         f_rng, p_rng ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &D_blind, &P1, &Q1 ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &D_blind, &D_blind, &R ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &D_blind, &D_blind, &ctx->D ) );
-
-        D = &D_blind;
-#else
-        /*
-         * DP_blind = ( P - 1 ) * R + DP
-         */
-        MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &R, RSA_EXPONENT_BLINDING,
-                         f_rng, p_rng ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &DP_blind, &P1, &R ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &DP_blind, &DP_blind,
-                    &ctx->DP ) );
-
-        DP = &DP_blind;
-
-        /*
-         * DQ_blind = ( Q - 1 ) * R + DQ
-         */
-        MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &R, RSA_EXPONENT_BLINDING,
-                         f_rng, p_rng ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &DQ_blind, &Q1, &R ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &DQ_blind, &DQ_blind,
-                    &ctx->DQ ) );
-
-        DQ = &DQ_blind;
-#endif /* MBEDTLS_RSA_NO_CRT */
-    }
-
-#if defined(MBEDTLS_RSA_NO_CRT)
-    MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T, &T, D, &ctx->N, &ctx->RN ) );
-#else
-    /*
-     * Faster decryption using the CRT
-     *
-     * TP = input ^ dP mod P
-     * TQ = input ^ dQ mod Q
-     */
-
-    MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &TP, &T, DP, &ctx->P, &ctx->RP ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &TQ, &T, DQ, &ctx->Q, &ctx->RQ ) );
-
-    /*
-     * T = (TP - TQ) * (Q^-1 mod P) mod P
-     */
-    MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &T, &TP, &TQ ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &TP, &T, &ctx->QP ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &TP, &ctx->P ) );
-
-    /*
-     * T = TQ + T * Q
-     */
-    MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &TP, &T, &ctx->Q ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &T, &TQ, &TP ) );
-#endif /* MBEDTLS_RSA_NO_CRT */
-
-    if( f_rng != NULL )
-    {
-        /*
-         * Unblind
-         * T = T * Vf mod N
-         */
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &T, &ctx->Vf ) );
-        MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &T, &ctx->N ) );
-    }
-
-    /* Verify the result to prevent glitching attacks. */
-    MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &C, &T, &ctx->E,
-                                          &ctx->N, &ctx->RN ) );
-    if( mbedtls_mpi_cmp_mpi( &C, &I ) != 0 )
-    {
-        ret = MBEDTLS_ERR_RSA_VERIFY_FAILED;
-        goto cleanup;
-    }
-
-    olen = ctx->len;
-    MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &T, output, olen ) );
-
-cleanup:
-#if defined(MBEDTLS_THREADING_C)
-    if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
-        return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
-#endif
-
-    mbedtls_mpi_free( &P1 );
-    mbedtls_mpi_free( &Q1 );
-    mbedtls_mpi_free( &R );
-
-    if( f_rng != NULL )
-    {
-#if defined(MBEDTLS_RSA_NO_CRT)
-        mbedtls_mpi_free( &D_blind );
-#else
-        mbedtls_mpi_free( &DP_blind );
-        mbedtls_mpi_free( &DQ_blind );
-#endif
-    }
-
-    mbedtls_mpi_free( &T );
-
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    mbedtls_mpi_free( &TP ); mbedtls_mpi_free( &TQ );
-#endif
-
-    mbedtls_mpi_free( &C );
-    mbedtls_mpi_free( &I );
-
-    if( ret != 0 && ret >= -0x007f )
-        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_PRIVATE_FAILED, ret ) );
-
-    return( ret );
-}
-
-#if defined(MBEDTLS_PKCS1_V21)
-/**
- * Generate and apply the MGF1 operation (from PKCS#1 v2.1) to a buffer.
- *
- * \param dst       buffer to mask
- * \param dlen      length of destination buffer
- * \param src       source of the mask generation
- * \param slen      length of the source buffer
- * \param md_ctx    message digest context to use
- */
-static int mgf_mask( unsigned char *dst, size_t dlen, unsigned char *src,
-                      size_t slen, mbedtls_md_context_t *md_ctx )
-{
-    unsigned char mask[MBEDTLS_MD_MAX_SIZE];
-    unsigned char counter[4];
-    unsigned char *p;
-    unsigned int hlen;
-    size_t i, use_len;
-    int ret = 0;
-
-    memset( mask, 0, MBEDTLS_MD_MAX_SIZE );
-    memset( counter, 0, 4 );
-
-    hlen = mbedtls_md_get_size( md_ctx->md_info );
-
-    /* Generate and apply dbMask */
-    p = dst;
-
-    while( dlen > 0 )
-    {
-        use_len = hlen;
-        if( dlen < hlen )
-            use_len = dlen;
-
-        if( ( ret = mbedtls_md_starts( md_ctx ) ) != 0 )
-            goto exit;
-        if( ( ret = mbedtls_md_update( md_ctx, src, slen ) ) != 0 )
-            goto exit;
-        if( ( ret = mbedtls_md_update( md_ctx, counter, 4 ) ) != 0 )
-            goto exit;
-        if( ( ret = mbedtls_md_finish( md_ctx, mask ) ) != 0 )
-            goto exit;
-
-        for( i = 0; i < use_len; ++i )
-            *p++ ^= mask[i];
-
-        counter[3]++;
-
-        dlen -= use_len;
-    }
-
-exit:
-    mbedtls_platform_zeroize( mask, sizeof( mask ) );
-
-    return( ret );
-}
-#endif /* MBEDTLS_PKCS1_V21 */
-
-#if defined(MBEDTLS_PKCS1_V21)
-/*
- * Implementation of the PKCS#1 v2.1 RSAES-OAEP-ENCRYPT function
- */
-int mbedtls_rsa_rsaes_oaep_encrypt( mbedtls_rsa_context *ctx,
-                            int (*f_rng)(void *, unsigned char *, size_t),
-                            void *p_rng,
-                            int mode,
-                            const unsigned char *label, size_t label_len,
-                            size_t ilen,
-                            const unsigned char *input,
-                            unsigned char *output )
-{
-    size_t olen;
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    unsigned char *p = output;
-    unsigned int hlen;
-    const mbedtls_md_info_t *md_info;
-    mbedtls_md_context_t md_ctx;
-
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( output != NULL );
-    RSA_VALIDATE_RET( ilen == 0 || input != NULL );
-    RSA_VALIDATE_RET( label_len == 0 || label != NULL );
-
-    if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    if( f_rng == NULL )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    md_info = mbedtls_md_info_from_type( (mbedtls_md_type_t) ctx->hash_id );
-    if( md_info == NULL )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    olen = ctx->len;
-    hlen = mbedtls_md_get_size( md_info );
-
-    /* first comparison checks for overflow */
-    if( ilen + 2 * hlen + 2 < ilen || olen < ilen + 2 * hlen + 2 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    memset( output, 0, olen );
-
-    *p++ = 0;
-
-    /* Generate a random octet string seed */
-    if( ( ret = f_rng( p_rng, p, hlen ) ) != 0 )
-        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_RNG_FAILED, ret ) );
-
-    p += hlen;
-
-    /* Construct DB */
-    if( ( ret = mbedtls_md( md_info, label, label_len, p ) ) != 0 )
-        return( ret );
-    p += hlen;
-    p += olen - 2 * hlen - 2 - ilen;
-    *p++ = 1;
-    if( ilen != 0 )
-        memcpy( p, input, ilen );
-
-    mbedtls_md_init( &md_ctx );
-    if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
-        goto exit;
-
-    /* maskedDB: Apply dbMask to DB */
-    if( ( ret = mgf_mask( output + hlen + 1, olen - hlen - 1, output + 1, hlen,
-                          &md_ctx ) ) != 0 )
-        goto exit;
-
-    /* maskedSeed: Apply seedMask to seed */
-    if( ( ret = mgf_mask( output + 1, hlen, output + hlen + 1, olen - hlen - 1,
-                          &md_ctx ) ) != 0 )
-        goto exit;
-
-exit:
-    mbedtls_md_free( &md_ctx );
-
-    if( ret != 0 )
-        return( ret );
-
-    return( ( mode == MBEDTLS_RSA_PUBLIC )
-            ? mbedtls_rsa_public(  ctx, output, output )
-            : mbedtls_rsa_private( ctx, f_rng, p_rng, output, output ) );
-}
-#endif /* MBEDTLS_PKCS1_V21 */
-
-#if defined(MBEDTLS_PKCS1_V15)
-/*
- * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-ENCRYPT function
- */
-int mbedtls_rsa_rsaes_pkcs1_v15_encrypt( mbedtls_rsa_context *ctx,
-                                 int (*f_rng)(void *, unsigned char *, size_t),
-                                 void *p_rng,
-                                 int mode, size_t ilen,
-                                 const unsigned char *input,
-                                 unsigned char *output )
-{
-    size_t nb_pad, olen;
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    unsigned char *p = output;
-
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( output != NULL );
-    RSA_VALIDATE_RET( ilen == 0 || input != NULL );
-
-    if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    olen = ctx->len;
-
-    /* first comparison checks for overflow */
-    if( ilen + 11 < ilen || olen < ilen + 11 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    nb_pad = olen - 3 - ilen;
-
-    *p++ = 0;
-    if( mode == MBEDTLS_RSA_PUBLIC )
-    {
-        if( f_rng == NULL )
-            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-        *p++ = MBEDTLS_RSA_CRYPT;
-
-        while( nb_pad-- > 0 )
-        {
-            int rng_dl = 100;
-
-            do {
-                ret = f_rng( p_rng, p, 1 );
-            } while( *p == 0 && --rng_dl && ret == 0 );
-
-            /* Check if RNG failed to generate data */
-            if( rng_dl == 0 || ret != 0 )
-                return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_RNG_FAILED, ret ) );
-
-            p++;
-        }
-    }
-    else
-    {
-        *p++ = MBEDTLS_RSA_SIGN;
-
-        while( nb_pad-- > 0 )
-            *p++ = 0xFF;
-    }
-
-    *p++ = 0;
-    if( ilen != 0 )
-        memcpy( p, input, ilen );
-
-    return( ( mode == MBEDTLS_RSA_PUBLIC )
-            ? mbedtls_rsa_public(  ctx, output, output )
-            : mbedtls_rsa_private( ctx, f_rng, p_rng, output, output ) );
-}
-#endif /* MBEDTLS_PKCS1_V15 */
-
-/*
- * Add the message padding, then do an RSA operation
- */
-int mbedtls_rsa_pkcs1_encrypt( mbedtls_rsa_context *ctx,
-                       int (*f_rng)(void *, unsigned char *, size_t),
-                       void *p_rng,
-                       int mode, size_t ilen,
-                       const unsigned char *input,
-                       unsigned char *output )
-{
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( output != NULL );
-    RSA_VALIDATE_RET( ilen == 0 || input != NULL );
-
-    switch( ctx->padding )
-    {
-#if defined(MBEDTLS_PKCS1_V15)
-        case MBEDTLS_RSA_PKCS_V15:
-            return mbedtls_rsa_rsaes_pkcs1_v15_encrypt( ctx, f_rng, p_rng, mode, ilen,
-                                                input, output );
-#endif
-
-#if defined(MBEDTLS_PKCS1_V21)
-        case MBEDTLS_RSA_PKCS_V21:
-            return mbedtls_rsa_rsaes_oaep_encrypt( ctx, f_rng, p_rng, mode, NULL, 0,
-                                           ilen, input, output );
-#endif
-
-        default:
-            return( MBEDTLS_ERR_RSA_INVALID_PADDING );
-    }
-}
-
-#if defined(MBEDTLS_PKCS1_V21)
-/*
- * Implementation of the PKCS#1 v2.1 RSAES-OAEP-DECRYPT function
- */
-int mbedtls_rsa_rsaes_oaep_decrypt( mbedtls_rsa_context *ctx,
-                            int (*f_rng)(void *, unsigned char *, size_t),
-                            void *p_rng,
-                            int mode,
-                            const unsigned char *label, size_t label_len,
-                            size_t *olen,
-                            const unsigned char *input,
-                            unsigned char *output,
-                            size_t output_max_len )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    size_t ilen, i, pad_len;
-    unsigned char *p, bad, pad_done;
-    unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
-    unsigned char lhash[MBEDTLS_MD_MAX_SIZE];
-    unsigned int hlen;
-    const mbedtls_md_info_t *md_info;
-    mbedtls_md_context_t md_ctx;
-
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( output_max_len == 0 || output != NULL );
-    RSA_VALIDATE_RET( label_len == 0 || label != NULL );
-    RSA_VALIDATE_RET( input != NULL );
-    RSA_VALIDATE_RET( olen != NULL );
-
-    /*
-     * Parameters sanity checks
-     */
-    if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    ilen = ctx->len;
-
-    if( ilen < 16 || ilen > sizeof( buf ) )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    md_info = mbedtls_md_info_from_type( (mbedtls_md_type_t) ctx->hash_id );
-    if( md_info == NULL )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    hlen = mbedtls_md_get_size( md_info );
-
-    // checking for integer underflow
-    if( 2 * hlen + 2 > ilen )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    /*
-     * RSA operation
-     */
-    ret = ( mode == MBEDTLS_RSA_PUBLIC )
-          ? mbedtls_rsa_public(  ctx, input, buf )
-          : mbedtls_rsa_private( ctx, f_rng, p_rng, input, buf );
-
-    if( ret != 0 )
-        goto cleanup;
-
-    /*
-     * Unmask data and generate lHash
-     */
-    mbedtls_md_init( &md_ctx );
-    if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
-    {
-        mbedtls_md_free( &md_ctx );
-        goto cleanup;
-    }
-
-    /* seed: Apply seedMask to maskedSeed */
-    if( ( ret = mgf_mask( buf + 1, hlen, buf + hlen + 1, ilen - hlen - 1,
-                          &md_ctx ) ) != 0 ||
-    /* DB: Apply dbMask to maskedDB */
-        ( ret = mgf_mask( buf + hlen + 1, ilen - hlen - 1, buf + 1, hlen,
-                          &md_ctx ) ) != 0 )
-    {
-        mbedtls_md_free( &md_ctx );
-        goto cleanup;
-    }
-
-    mbedtls_md_free( &md_ctx );
-
-    /* Generate lHash */
-    if( ( ret = mbedtls_md( md_info, label, label_len, lhash ) ) != 0 )
-        goto cleanup;
-
-    /*
-     * Check contents, in "constant-time"
-     */
-    p = buf;
-    bad = 0;
-
-    bad |= *p++; /* First byte must be 0 */
-
-    p += hlen; /* Skip seed */
-
-    /* Check lHash */
-    for( i = 0; i < hlen; i++ )
-        bad |= lhash[i] ^ *p++;
-
-    /* Get zero-padding len, but always read till end of buffer
-     * (minus one, for the 01 byte) */
-    pad_len = 0;
-    pad_done = 0;
-    for( i = 0; i < ilen - 2 * hlen - 2; i++ )
-    {
-        pad_done |= p[i];
-        pad_len += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1;
-    }
-
-    p += pad_len;
-    bad |= *p++ ^ 0x01;
-
-    /*
-     * The only information "leaked" is whether the padding was correct or not
-     * (eg, no data is copied if it was not correct). This meets the
-     * recommendations in PKCS#1 v2.2: an opponent cannot distinguish between
-     * the different error conditions.
-     */
-    if( bad != 0 )
-    {
-        ret = MBEDTLS_ERR_RSA_INVALID_PADDING;
-        goto cleanup;
-    }
-
-    if( ilen - ( p - buf ) > output_max_len )
-    {
-        ret = MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE;
-        goto cleanup;
-    }
-
-    *olen = ilen - (p - buf);
-    if( *olen != 0 )
-        memcpy( output, p, *olen );
-    ret = 0;
-
-cleanup:
-    mbedtls_platform_zeroize( buf, sizeof( buf ) );
-    mbedtls_platform_zeroize( lhash, sizeof( lhash ) );
-
-    return( ret );
-}
-#endif /* MBEDTLS_PKCS1_V21 */
-
-#if defined(MBEDTLS_PKCS1_V15)
-/** Turn zero-or-nonzero into zero-or-all-bits-one, without branches.
- *
- * \param value     The value to analyze.
- * \return          Zero if \p value is zero, otherwise all-bits-one.
- */
-static unsigned all_or_nothing_int( unsigned value )
-{
-    /* MSVC has a warning about unary minus on unsigned, but this is
-     * well-defined and precisely what we want to do here */
-#if defined(_MSC_VER)
-#pragma warning( push )
-#pragma warning( disable : 4146 )
-#endif
-    return( - ( ( value | - value ) >> ( sizeof( value ) * 8 - 1 ) ) );
-#if defined(_MSC_VER)
-#pragma warning( pop )
-#endif
-}
-
-/** Check whether a size is out of bounds, without branches.
- *
- * This is equivalent to `size > max`, but is likely to be compiled to
- * to code using bitwise operation rather than a branch.
- *
- * \param size      Size to check.
- * \param max       Maximum desired value for \p size.
- * \return          \c 0 if `size <= max`.
- * \return          \c 1 if `size > max`.
- */
-static unsigned size_greater_than( size_t size, size_t max )
-{
-    /* Return the sign bit (1 for negative) of (max - size). */
-    return( ( max - size ) >> ( sizeof( size_t ) * 8 - 1 ) );
-}
-
-/** Choose between two integer values, without branches.
- *
- * This is equivalent to `cond ? if1 : if0`, but is likely to be compiled
- * to code using bitwise operation rather than a branch.
- *
- * \param cond      Condition to test.
- * \param if1       Value to use if \p cond is nonzero.
- * \param if0       Value to use if \p cond is zero.
- * \return          \c if1 if \p cond is nonzero, otherwise \c if0.
- */
-static unsigned if_int( unsigned cond, unsigned if1, unsigned if0 )
-{
-    unsigned mask = all_or_nothing_int( cond );
-    return( ( mask & if1 ) | (~mask & if0 ) );
-}
-
-/** Shift some data towards the left inside a buffer without leaking
- * the length of the data through side channels.
- *
- * `mem_move_to_left(start, total, offset)` is functionally equivalent to
- * ```
- * memmove(start, start + offset, total - offset);
- * memset(start + offset, 0, total - offset);
- * ```
- * but it strives to use a memory access pattern (and thus total timing)
- * that does not depend on \p offset. This timing independence comes at
- * the expense of performance.
- *
- * \param start     Pointer to the start of the buffer.
- * \param total     Total size of the buffer.
- * \param offset    Offset from which to copy \p total - \p offset bytes.
- */
-static void mem_move_to_left( void *start,
-                              size_t total,
-                              size_t offset )
-{
-    volatile unsigned char *buf = start;
-    size_t i, n;
-    if( total == 0 )
-        return;
-    for( i = 0; i < total; i++ )
-    {
-        unsigned no_op = size_greater_than( total - offset, i );
-        /* The first `total - offset` passes are a no-op. The last
-         * `offset` passes shift the data one byte to the left and
-         * zero out the last byte. */
-        for( n = 0; n < total - 1; n++ )
-        {
-            unsigned char current = buf[n];
-            unsigned char next = buf[n+1];
-            buf[n] = if_int( no_op, current, next );
-        }
-        buf[total-1] = if_int( no_op, buf[total-1], 0 );
-    }
-}
-
-/*
- * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-DECRYPT function
- */
-int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx,
-                                 int (*f_rng)(void *, unsigned char *, size_t),
-                                 void *p_rng,
-                                 int mode, size_t *olen,
-                                 const unsigned char *input,
-                                 unsigned char *output,
-                                 size_t output_max_len )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    size_t ilen, i, plaintext_max_size;
-    unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
-    /* The following variables take sensitive values: their value must
-     * not leak into the observable behavior of the function other than
-     * the designated outputs (output, olen, return value). Otherwise
-     * this would open the execution of the function to
-     * side-channel-based variants of the Bleichenbacher padding oracle
-     * attack. Potential side channels include overall timing, memory
-     * access patterns (especially visible to an adversary who has access
-     * to a shared memory cache), and branches (especially visible to
-     * an adversary who has access to a shared code cache or to a shared
-     * branch predictor). */
-    size_t pad_count = 0;
-    unsigned bad = 0;
-    unsigned char pad_done = 0;
-    size_t plaintext_size = 0;
-    unsigned output_too_large;
-
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( output_max_len == 0 || output != NULL );
-    RSA_VALIDATE_RET( input != NULL );
-    RSA_VALIDATE_RET( olen != NULL );
-
-    ilen = ctx->len;
-    plaintext_max_size = ( output_max_len > ilen - 11 ?
-                           ilen - 11 :
-                           output_max_len );
-
-    if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    if( ilen < 16 || ilen > sizeof( buf ) )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    ret = ( mode == MBEDTLS_RSA_PUBLIC )
-          ? mbedtls_rsa_public(  ctx, input, buf )
-          : mbedtls_rsa_private( ctx, f_rng, p_rng, input, buf );
-
-    if( ret != 0 )
-        goto cleanup;
-
-    /* Check and get padding length in constant time and constant
-     * memory trace. The first byte must be 0. */
-    bad |= buf[0];
-
-    if( mode == MBEDTLS_RSA_PRIVATE )
-    {
-        /* Decode EME-PKCS1-v1_5 padding: 0x00 || 0x02 || PS || 0x00
-         * where PS must be at least 8 nonzero bytes. */
-        bad |= buf[1] ^ MBEDTLS_RSA_CRYPT;
-
-        /* Read the whole buffer. Set pad_done to nonzero if we find
-         * the 0x00 byte and remember the padding length in pad_count. */
-        for( i = 2; i < ilen; i++ )
-        {
-            pad_done  |= ((buf[i] | (unsigned char)-buf[i]) >> 7) ^ 1;
-            pad_count += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1;
-        }
-    }
-    else
-    {
-        /* Decode EMSA-PKCS1-v1_5 padding: 0x00 || 0x01 || PS || 0x00
-         * where PS must be at least 8 bytes with the value 0xFF. */
-        bad |= buf[1] ^ MBEDTLS_RSA_SIGN;
-
-        /* Read the whole buffer. Set pad_done to nonzero if we find
-         * the 0x00 byte and remember the padding length in pad_count.
-         * If there's a non-0xff byte in the padding, the padding is bad. */
-        for( i = 2; i < ilen; i++ )
-        {
-            pad_done |= if_int( buf[i], 0, 1 );
-            pad_count += if_int( pad_done, 0, 1 );
-            bad |= if_int( pad_done, 0, buf[i] ^ 0xFF );
-        }
-    }
-
-    /* If pad_done is still zero, there's no data, only unfinished padding. */
-    bad |= if_int( pad_done, 0, 1 );
-
-    /* There must be at least 8 bytes of padding. */
-    bad |= size_greater_than( 8, pad_count );
-
-    /* If the padding is valid, set plaintext_size to the number of
-     * remaining bytes after stripping the padding. If the padding
-     * is invalid, avoid leaking this fact through the size of the
-     * output: use the maximum message size that fits in the output
-     * buffer. Do it without branches to avoid leaking the padding
-     * validity through timing. RSA keys are small enough that all the
-     * size_t values involved fit in unsigned int. */
-    plaintext_size = if_int( bad,
-                             (unsigned) plaintext_max_size,
-                             (unsigned) ( ilen - pad_count - 3 ) );
-
-    /* Set output_too_large to 0 if the plaintext fits in the output
-     * buffer and to 1 otherwise. */
-    output_too_large = size_greater_than( plaintext_size,
-                                          plaintext_max_size );
-
-    /* Set ret without branches to avoid timing attacks. Return:
-     * - INVALID_PADDING if the padding is bad (bad != 0).
-     * - OUTPUT_TOO_LARGE if the padding is good but the decrypted
-     *   plaintext does not fit in the output buffer.
-     * - 0 if the padding is correct. */
-    ret = - (int) if_int( bad, - MBEDTLS_ERR_RSA_INVALID_PADDING,
-                  if_int( output_too_large, - MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE,
-                          0 ) );
-
-    /* If the padding is bad or the plaintext is too large, zero the
-     * data that we're about to copy to the output buffer.
-     * We need to copy the same amount of data
-     * from the same buffer whether the padding is good or not to
-     * avoid leaking the padding validity through overall timing or
-     * through memory or cache access patterns. */
-    bad = all_or_nothing_int( bad | output_too_large );
-    for( i = 11; i < ilen; i++ )
-        buf[i] &= ~bad;
-
-    /* If the plaintext is too large, truncate it to the buffer size.
-     * Copy anyway to avoid revealing the length through timing, because
-     * revealing the length is as bad as revealing the padding validity
-     * for a Bleichenbacher attack. */
-    plaintext_size = if_int( output_too_large,
-                             (unsigned) plaintext_max_size,
-                             (unsigned) plaintext_size );
-
-    /* Move the plaintext to the leftmost position where it can start in
-     * the working buffer, i.e. make it start plaintext_max_size from
-     * the end of the buffer. Do this with a memory access trace that
-     * does not depend on the plaintext size. After this move, the
-     * starting location of the plaintext is no longer sensitive
-     * information. */
-    mem_move_to_left( buf + ilen - plaintext_max_size,
-                      plaintext_max_size,
-                      plaintext_max_size - plaintext_size );
-
-    /* Finally copy the decrypted plaintext plus trailing zeros into the output
-     * buffer. If output_max_len is 0, then output may be an invalid pointer
-     * and the result of memcpy() would be undefined; prevent undefined
-     * behavior making sure to depend only on output_max_len (the size of the
-     * user-provided output buffer), which is independent from plaintext
-     * length, validity of padding, success of the decryption, and other
-     * secrets. */
-    if( output_max_len != 0 )
-        memcpy( output, buf + ilen - plaintext_max_size, plaintext_max_size );
-
-    /* Report the amount of data we copied to the output buffer. In case
-     * of errors (bad padding or output too large), the value of *olen
-     * when this function returns is not specified. Making it equivalent
-     * to the good case limits the risks of leaking the padding validity. */
-    *olen = plaintext_size;
-
-cleanup:
-    mbedtls_platform_zeroize( buf, sizeof( buf ) );
-
-    return( ret );
-}
-#endif /* MBEDTLS_PKCS1_V15 */
-
-/*
- * Do an RSA operation, then remove the message padding
- */
-int mbedtls_rsa_pkcs1_decrypt( mbedtls_rsa_context *ctx,
-                       int (*f_rng)(void *, unsigned char *, size_t),
-                       void *p_rng,
-                       int mode, size_t *olen,
-                       const unsigned char *input,
-                       unsigned char *output,
-                       size_t output_max_len)
-{
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( output_max_len == 0 || output != NULL );
-    RSA_VALIDATE_RET( input != NULL );
-    RSA_VALIDATE_RET( olen != NULL );
-
-    switch( ctx->padding )
-    {
-#if defined(MBEDTLS_PKCS1_V15)
-        case MBEDTLS_RSA_PKCS_V15:
-            return mbedtls_rsa_rsaes_pkcs1_v15_decrypt( ctx, f_rng, p_rng, mode, olen,
-                                                input, output, output_max_len );
-#endif
-
-#if defined(MBEDTLS_PKCS1_V21)
-        case MBEDTLS_RSA_PKCS_V21:
-            return mbedtls_rsa_rsaes_oaep_decrypt( ctx, f_rng, p_rng, mode, NULL, 0,
-                                           olen, input, output,
-                                           output_max_len );
-#endif
-
-        default:
-            return( MBEDTLS_ERR_RSA_INVALID_PADDING );
-    }
-}
-
-#if defined(MBEDTLS_PKCS1_V21)
-static int rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
-                         int (*f_rng)(void *, unsigned char *, size_t),
-                         void *p_rng,
-                         int mode,
-                         mbedtls_md_type_t md_alg,
-                         unsigned int hashlen,
-                         const unsigned char *hash,
-                         int saltlen,
-                         unsigned char *sig )
-{
-    size_t olen;
-    unsigned char *p = sig;
-    unsigned char *salt = NULL;
-    size_t slen, min_slen, hlen, offset = 0;
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    size_t msb;
-    const mbedtls_md_info_t *md_info;
-    mbedtls_md_context_t md_ctx;
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
-                        hashlen == 0 ) ||
-                      hash != NULL );
-    RSA_VALIDATE_RET( sig != NULL );
-
-    if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    if( f_rng == NULL )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    olen = ctx->len;
-
-    if( md_alg != MBEDTLS_MD_NONE )
-    {
-        /* Gather length of hash to sign */
-        md_info = mbedtls_md_info_from_type( md_alg );
-        if( md_info == NULL )
-            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-        hashlen = mbedtls_md_get_size( md_info );
-    }
-
-    md_info = mbedtls_md_info_from_type( (mbedtls_md_type_t) ctx->hash_id );
-    if( md_info == NULL )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    hlen = mbedtls_md_get_size( md_info );
-
-    if (saltlen == MBEDTLS_RSA_SALT_LEN_ANY)
-    {
-       /* Calculate the largest possible salt length, up to the hash size.
-        * Normally this is the hash length, which is the maximum salt length
-        * according to FIPS 185-4 §5.5 (e) and common practice. If there is not
-        * enough room, use the maximum salt length that fits. The constraint is
-        * that the hash length plus the salt length plus 2 bytes must be at most
-        * the key length. This complies with FIPS 186-4 §5.5 (e) and RFC 8017
-        * (PKCS#1 v2.2) §9.1.1 step 3. */
-        min_slen = hlen - 2;
-        if( olen < hlen + min_slen + 2 )
-            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-        else if( olen >= hlen + hlen + 2 )
-            slen = hlen;
-        else
-            slen = olen - hlen - 2;
-    }
-    else if ( (saltlen < 0) || (saltlen + hlen + 2 > olen) )
-    {
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-    }
-    else
-    {
-        slen = (size_t) saltlen;
-    }
-
-    memset( sig, 0, olen );
-
-    /* Note: EMSA-PSS encoding is over the length of N - 1 bits */
-    msb = mbedtls_mpi_bitlen( &ctx->N ) - 1;
-    p += olen - hlen - slen - 2;
-    *p++ = 0x01;
-
-    /* Generate salt of length slen in place in the encoded message */
-    salt = p;
-    if( ( ret = f_rng( p_rng, salt, slen ) ) != 0 )
-        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_RSA_RNG_FAILED, ret ) );
-
-    p += slen;
-
-    mbedtls_md_init( &md_ctx );
-    if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
-        goto exit;
-
-    /* Generate H = Hash( M' ) */
-    if( ( ret = mbedtls_md_starts( &md_ctx ) ) != 0 )
-        goto exit;
-    if( ( ret = mbedtls_md_update( &md_ctx, p, 8 ) ) != 0 )
-        goto exit;
-    if( ( ret = mbedtls_md_update( &md_ctx, hash, hashlen ) ) != 0 )
-        goto exit;
-    if( ( ret = mbedtls_md_update( &md_ctx, salt, slen ) ) != 0 )
-        goto exit;
-    if( ( ret = mbedtls_md_finish( &md_ctx, p ) ) != 0 )
-        goto exit;
-
-    /* Compensate for boundary condition when applying mask */
-    if( msb % 8 == 0 )
-        offset = 1;
-
-    /* maskedDB: Apply dbMask to DB */
-    if( ( ret = mgf_mask( sig + offset, olen - hlen - 1 - offset, p, hlen,
-                          &md_ctx ) ) != 0 )
-        goto exit;
-
-    msb = mbedtls_mpi_bitlen( &ctx->N ) - 1;
-    sig[0] &= 0xFF >> ( olen * 8 - msb );
-
-    p += hlen;
-    *p++ = 0xBC;
-
-exit:
-    mbedtls_md_free( &md_ctx );
-
-    if( ret != 0 )
-        return( ret );
-
-    return( ( mode == MBEDTLS_RSA_PUBLIC )
-            ? mbedtls_rsa_public(  ctx, sig, sig )
-            : mbedtls_rsa_private( ctx, f_rng, p_rng, sig, sig ) );
-}
-
-/*
- * Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function with
- * the option to pass in the salt length.
- */
-int mbedtls_rsa_rsassa_pss_sign_ext( mbedtls_rsa_context *ctx,
-                         int (*f_rng)(void *, unsigned char *, size_t),
-                         void *p_rng,
-                         mbedtls_md_type_t md_alg,
-                         unsigned int hashlen,
-                         const unsigned char *hash,
-                         int saltlen,
-                         unsigned char *sig )
-{
-    return rsa_rsassa_pss_sign( ctx, f_rng, p_rng, MBEDTLS_RSA_PRIVATE, md_alg,
-                                hashlen, hash, saltlen, sig );
-}
-
-
-/*
- * Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function
- */
-int mbedtls_rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx,
-                         int (*f_rng)(void *, unsigned char *, size_t),
-                         void *p_rng,
-                         int mode,
-                         mbedtls_md_type_t md_alg,
-                         unsigned int hashlen,
-                         const unsigned char *hash,
-                         unsigned char *sig )
-{
-    return rsa_rsassa_pss_sign( ctx, f_rng, p_rng, mode, md_alg,
-                                hashlen, hash, MBEDTLS_RSA_SALT_LEN_ANY, sig );
-}
-#endif /* MBEDTLS_PKCS1_V21 */
-
-#if defined(MBEDTLS_PKCS1_V15)
-/*
- * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-V1_5-SIGN function
- */
-
-/* Construct a PKCS v1.5 encoding of a hashed message
- *
- * This is used both for signature generation and verification.
- *
- * Parameters:
- * - md_alg:  Identifies the hash algorithm used to generate the given hash;
- *            MBEDTLS_MD_NONE if raw data is signed.
- * - hashlen: Length of hash in case hashlen is MBEDTLS_MD_NONE.
- * - hash:    Buffer containing the hashed message or the raw data.
- * - dst_len: Length of the encoded message.
- * - dst:     Buffer to hold the encoded message.
- *
- * Assumptions:
- * - hash has size hashlen if md_alg == MBEDTLS_MD_NONE.
- * - hash has size corresponding to md_alg if md_alg != MBEDTLS_MD_NONE.
- * - dst points to a buffer of size at least dst_len.
- *
- */
-static int rsa_rsassa_pkcs1_v15_encode( mbedtls_md_type_t md_alg,
-                                        unsigned int hashlen,
-                                        const unsigned char *hash,
-                                        size_t dst_len,
-                                        unsigned char *dst )
-{
-    size_t oid_size  = 0;
-    size_t nb_pad    = dst_len;
-    unsigned char *p = dst;
-    const char *oid  = NULL;
-
-    /* Are we signing hashed or raw data? */
-    if( md_alg != MBEDTLS_MD_NONE )
-    {
-        const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( md_alg );
-        if( md_info == NULL )
-            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-        if( mbedtls_oid_get_oid_by_md( md_alg, &oid, &oid_size ) != 0 )
-            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-        hashlen = mbedtls_md_get_size( md_info );
-
-        /* Double-check that 8 + hashlen + oid_size can be used as a
-         * 1-byte ASN.1 length encoding and that there's no overflow. */
-        if( 8 + hashlen + oid_size  >= 0x80         ||
-            10 + hashlen            <  hashlen      ||
-            10 + hashlen + oid_size <  10 + hashlen )
-            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-        /*
-         * Static bounds check:
-         * - Need 10 bytes for five tag-length pairs.
-         *   (Insist on 1-byte length encodings to protect against variants of
-         *    Bleichenbacher's forgery attack against lax PKCS#1v1.5 verification)
-         * - Need hashlen bytes for hash
-         * - Need oid_size bytes for hash alg OID.
-         */
-        if( nb_pad < 10 + hashlen + oid_size )
-            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-        nb_pad -= 10 + hashlen + oid_size;
-    }
-    else
-    {
-        if( nb_pad < hashlen )
-            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-        nb_pad -= hashlen;
-    }
-
-    /* Need space for signature header and padding delimiter (3 bytes),
-     * and 8 bytes for the minimal padding */
-    if( nb_pad < 3 + 8 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-    nb_pad -= 3;
-
-    /* Now nb_pad is the amount of memory to be filled
-     * with padding, and at least 8 bytes long. */
-
-    /* Write signature header and padding */
-    *p++ = 0;
-    *p++ = MBEDTLS_RSA_SIGN;
-    memset( p, 0xFF, nb_pad );
-    p += nb_pad;
-    *p++ = 0;
-
-    /* Are we signing raw data? */
-    if( md_alg == MBEDTLS_MD_NONE )
-    {
-        memcpy( p, hash, hashlen );
-        return( 0 );
-    }
-
-    /* Signing hashed data, add corresponding ASN.1 structure
-     *
-     * DigestInfo ::= SEQUENCE {
-     *   digestAlgorithm DigestAlgorithmIdentifier,
-     *   digest Digest }
-     * DigestAlgorithmIdentifier ::= AlgorithmIdentifier
-     * Digest ::= OCTET STRING
-     *
-     * Schematic:
-     * TAG-SEQ + LEN [ TAG-SEQ + LEN [ TAG-OID  + LEN [ OID  ]
-     *                                 TAG-NULL + LEN [ NULL ] ]
-     *                 TAG-OCTET + LEN [ HASH ] ]
-     */
-    *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED;
-    *p++ = (unsigned char)( 0x08 + oid_size + hashlen );
-    *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED;
-    *p++ = (unsigned char)( 0x04 + oid_size );
-    *p++ = MBEDTLS_ASN1_OID;
-    *p++ = (unsigned char) oid_size;
-    memcpy( p, oid, oid_size );
-    p += oid_size;
-    *p++ = MBEDTLS_ASN1_NULL;
-    *p++ = 0x00;
-    *p++ = MBEDTLS_ASN1_OCTET_STRING;
-    *p++ = (unsigned char) hashlen;
-    memcpy( p, hash, hashlen );
-    p += hashlen;
-
-    /* Just a sanity-check, should be automatic
-     * after the initial bounds check. */
-    if( p != dst + dst_len )
-    {
-        mbedtls_platform_zeroize( dst, dst_len );
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-    }
-
-    return( 0 );
-}
-
-/*
- * Do an RSA operation to sign the message digest
- */
-int mbedtls_rsa_rsassa_pkcs1_v15_sign( mbedtls_rsa_context *ctx,
-                               int (*f_rng)(void *, unsigned char *, size_t),
-                               void *p_rng,
-                               int mode,
-                               mbedtls_md_type_t md_alg,
-                               unsigned int hashlen,
-                               const unsigned char *hash,
-                               unsigned char *sig )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    unsigned char *sig_try = NULL, *verif = NULL;
-
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
-                        hashlen == 0 ) ||
-                      hash != NULL );
-    RSA_VALIDATE_RET( sig != NULL );
-
-    if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    /*
-     * Prepare PKCS1-v1.5 encoding (padding and hash identifier)
-     */
-
-    if( ( ret = rsa_rsassa_pkcs1_v15_encode( md_alg, hashlen, hash,
-                                             ctx->len, sig ) ) != 0 )
-        return( ret );
-
-    /*
-     * Call respective RSA primitive
-     */
-
-    if( mode == MBEDTLS_RSA_PUBLIC )
-    {
-        /* Skip verification on a public key operation */
-        return( mbedtls_rsa_public( ctx, sig, sig ) );
-    }
-
-    /* Private key operation
-     *
-     * In order to prevent Lenstra's attack, make the signature in a
-     * temporary buffer and check it before returning it.
-     */
-
-    sig_try = mbedtls_calloc( 1, ctx->len );
-    if( sig_try == NULL )
-        return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
-
-    verif = mbedtls_calloc( 1, ctx->len );
-    if( verif == NULL )
-    {
-        mbedtls_free( sig_try );
-        return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
-    }
-
-    MBEDTLS_MPI_CHK( mbedtls_rsa_private( ctx, f_rng, p_rng, sig, sig_try ) );
-    MBEDTLS_MPI_CHK( mbedtls_rsa_public( ctx, sig_try, verif ) );
-
-    if( mbedtls_safer_memcmp( verif, sig, ctx->len ) != 0 )
-    {
-        ret = MBEDTLS_ERR_RSA_PRIVATE_FAILED;
-        goto cleanup;
-    }
-
-    memcpy( sig, sig_try, ctx->len );
-
-cleanup:
-    mbedtls_free( sig_try );
-    mbedtls_free( verif );
-
-    return( ret );
-}
-#endif /* MBEDTLS_PKCS1_V15 */
-
-/*
- * Do an RSA operation to sign the message digest
- */
-int mbedtls_rsa_pkcs1_sign( mbedtls_rsa_context *ctx,
-                    int (*f_rng)(void *, unsigned char *, size_t),
-                    void *p_rng,
-                    int mode,
-                    mbedtls_md_type_t md_alg,
-                    unsigned int hashlen,
-                    const unsigned char *hash,
-                    unsigned char *sig )
-{
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
-                        hashlen == 0 ) ||
-                      hash != NULL );
-    RSA_VALIDATE_RET( sig != NULL );
-
-    switch( ctx->padding )
-    {
-#if defined(MBEDTLS_PKCS1_V15)
-        case MBEDTLS_RSA_PKCS_V15:
-            return mbedtls_rsa_rsassa_pkcs1_v15_sign( ctx, f_rng, p_rng, mode, md_alg,
-                                              hashlen, hash, sig );
-#endif
-
-#if defined(MBEDTLS_PKCS1_V21)
-        case MBEDTLS_RSA_PKCS_V21:
-            return mbedtls_rsa_rsassa_pss_sign( ctx, f_rng, p_rng, mode, md_alg,
-                                        hashlen, hash, sig );
-#endif
-
-        default:
-            return( MBEDTLS_ERR_RSA_INVALID_PADDING );
-    }
-}
-
-#if defined(MBEDTLS_PKCS1_V21)
-/*
- * Implementation of the PKCS#1 v2.1 RSASSA-PSS-VERIFY function
- */
-int mbedtls_rsa_rsassa_pss_verify_ext( mbedtls_rsa_context *ctx,
-                               int (*f_rng)(void *, unsigned char *, size_t),
-                               void *p_rng,
-                               int mode,
-                               mbedtls_md_type_t md_alg,
-                               unsigned int hashlen,
-                               const unsigned char *hash,
-                               mbedtls_md_type_t mgf1_hash_id,
-                               int expected_salt_len,
-                               const unsigned char *sig )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    size_t siglen;
-    unsigned char *p;
-    unsigned char *hash_start;
-    unsigned char result[MBEDTLS_MD_MAX_SIZE];
-    unsigned char zeros[8];
-    unsigned int hlen;
-    size_t observed_salt_len, msb;
-    const mbedtls_md_info_t *md_info;
-    mbedtls_md_context_t md_ctx;
-    unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
-
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( sig != NULL );
-    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
-                        hashlen == 0 ) ||
-                      hash != NULL );
-
-    if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    siglen = ctx->len;
-
-    if( siglen < 16 || siglen > sizeof( buf ) )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    ret = ( mode == MBEDTLS_RSA_PUBLIC )
-          ? mbedtls_rsa_public(  ctx, sig, buf )
-          : mbedtls_rsa_private( ctx, f_rng, p_rng, sig, buf );
-
-    if( ret != 0 )
-        return( ret );
-
-    p = buf;
-
-    if( buf[siglen - 1] != 0xBC )
-        return( MBEDTLS_ERR_RSA_INVALID_PADDING );
-
-    if( md_alg != MBEDTLS_MD_NONE )
-    {
-        /* Gather length of hash to sign */
-        md_info = mbedtls_md_info_from_type( md_alg );
-        if( md_info == NULL )
-            return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-        hashlen = mbedtls_md_get_size( md_info );
-    }
-
-    md_info = mbedtls_md_info_from_type( mgf1_hash_id );
-    if( md_info == NULL )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    hlen = mbedtls_md_get_size( md_info );
-
-    memset( zeros, 0, 8 );
-
-    /*
-     * Note: EMSA-PSS verification is over the length of N - 1 bits
-     */
-    msb = mbedtls_mpi_bitlen( &ctx->N ) - 1;
-
-    if( buf[0] >> ( 8 - siglen * 8 + msb ) )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    /* Compensate for boundary condition when applying mask */
-    if( msb % 8 == 0 )
-    {
-        p++;
-        siglen -= 1;
-    }
-
-    if( siglen < hlen + 2 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-    hash_start = p + siglen - hlen - 1;
-
-    mbedtls_md_init( &md_ctx );
-    if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 )
-        goto exit;
-
-    ret = mgf_mask( p, siglen - hlen - 1, hash_start, hlen, &md_ctx );
-    if( ret != 0 )
-        goto exit;
-
-    buf[0] &= 0xFF >> ( siglen * 8 - msb );
-
-    while( p < hash_start - 1 && *p == 0 )
-        p++;
-
-    if( *p++ != 0x01 )
-    {
-        ret = MBEDTLS_ERR_RSA_INVALID_PADDING;
-        goto exit;
-    }
-
-    observed_salt_len = hash_start - p;
-
-    if( expected_salt_len != MBEDTLS_RSA_SALT_LEN_ANY &&
-        observed_salt_len != (size_t) expected_salt_len )
-    {
-        ret = MBEDTLS_ERR_RSA_INVALID_PADDING;
-        goto exit;
-    }
-
-    /*
-     * Generate H = Hash( M' )
-     */
-    ret = mbedtls_md_starts( &md_ctx );
-    if ( ret != 0 )
-        goto exit;
-    ret = mbedtls_md_update( &md_ctx, zeros, 8 );
-    if ( ret != 0 )
-        goto exit;
-    ret = mbedtls_md_update( &md_ctx, hash, hashlen );
-    if ( ret != 0 )
-        goto exit;
-    ret = mbedtls_md_update( &md_ctx, p, observed_salt_len );
-    if ( ret != 0 )
-        goto exit;
-    ret = mbedtls_md_finish( &md_ctx, result );
-    if ( ret != 0 )
-        goto exit;
-
-    if( memcmp( hash_start, result, hlen ) != 0 )
-    {
-        ret = MBEDTLS_ERR_RSA_VERIFY_FAILED;
-        goto exit;
-    }
-
-exit:
-    mbedtls_md_free( &md_ctx );
-
-    return( ret );
-}
-
-/*
- * Simplified PKCS#1 v2.1 RSASSA-PSS-VERIFY function
- */
-int mbedtls_rsa_rsassa_pss_verify( mbedtls_rsa_context *ctx,
-                           int (*f_rng)(void *, unsigned char *, size_t),
-                           void *p_rng,
-                           int mode,
-                           mbedtls_md_type_t md_alg,
-                           unsigned int hashlen,
-                           const unsigned char *hash,
-                           const unsigned char *sig )
-{
-    mbedtls_md_type_t mgf1_hash_id;
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( sig != NULL );
-    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
-                        hashlen == 0 ) ||
-                      hash != NULL );
-
-    mgf1_hash_id = ( ctx->hash_id != MBEDTLS_MD_NONE )
-                             ? (mbedtls_md_type_t) ctx->hash_id
-                             : md_alg;
-
-    return( mbedtls_rsa_rsassa_pss_verify_ext( ctx, f_rng, p_rng, mode,
-                                       md_alg, hashlen, hash,
-                                       mgf1_hash_id, MBEDTLS_RSA_SALT_LEN_ANY,
-                                       sig ) );
-
-}
-#endif /* MBEDTLS_PKCS1_V21 */
-
-#if defined(MBEDTLS_PKCS1_V15)
-/*
- * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-v1_5-VERIFY function
- */
-int mbedtls_rsa_rsassa_pkcs1_v15_verify( mbedtls_rsa_context *ctx,
-                                 int (*f_rng)(void *, unsigned char *, size_t),
-                                 void *p_rng,
-                                 int mode,
-                                 mbedtls_md_type_t md_alg,
-                                 unsigned int hashlen,
-                                 const unsigned char *hash,
-                                 const unsigned char *sig )
-{
-    int ret = 0;
-    size_t sig_len;
-    unsigned char *encoded = NULL, *encoded_expected = NULL;
-
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( sig != NULL );
-    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
-                        hashlen == 0 ) ||
-                      hash != NULL );
-
-    sig_len = ctx->len;
-
-    if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
-        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
-
-    /*
-     * Prepare expected PKCS1 v1.5 encoding of hash.
-     */
-
-    if( ( encoded          = mbedtls_calloc( 1, sig_len ) ) == NULL ||
-        ( encoded_expected = mbedtls_calloc( 1, sig_len ) ) == NULL )
-    {
-        ret = MBEDTLS_ERR_MPI_ALLOC_FAILED;
-        goto cleanup;
-    }
-
-    if( ( ret = rsa_rsassa_pkcs1_v15_encode( md_alg, hashlen, hash, sig_len,
-                                             encoded_expected ) ) != 0 )
-        goto cleanup;
-
-    /*
-     * Apply RSA primitive to get what should be PKCS1 encoded hash.
-     */
-
-    ret = ( mode == MBEDTLS_RSA_PUBLIC )
-          ? mbedtls_rsa_public(  ctx, sig, encoded )
-          : mbedtls_rsa_private( ctx, f_rng, p_rng, sig, encoded );
-    if( ret != 0 )
-        goto cleanup;
-
-    /*
-     * Compare
-     */
-
-    if( ( ret = mbedtls_safer_memcmp( encoded, encoded_expected,
-                                      sig_len ) ) != 0 )
-    {
-        ret = MBEDTLS_ERR_RSA_VERIFY_FAILED;
-        goto cleanup;
-    }
-
-cleanup:
-
-    if( encoded != NULL )
-    {
-        mbedtls_platform_zeroize( encoded, sig_len );
-        mbedtls_free( encoded );
-    }
-
-    if( encoded_expected != NULL )
-    {
-        mbedtls_platform_zeroize( encoded_expected, sig_len );
-        mbedtls_free( encoded_expected );
-    }
-
-    return( ret );
-}
-#endif /* MBEDTLS_PKCS1_V15 */
-
-/*
- * Do an RSA operation and check the message digest
- */
-int mbedtls_rsa_pkcs1_verify( mbedtls_rsa_context *ctx,
-                      int (*f_rng)(void *, unsigned char *, size_t),
-                      void *p_rng,
-                      int mode,
-                      mbedtls_md_type_t md_alg,
-                      unsigned int hashlen,
-                      const unsigned char *hash,
-                      const unsigned char *sig )
-{
-    RSA_VALIDATE_RET( ctx != NULL );
-    RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
-                      mode == MBEDTLS_RSA_PUBLIC );
-    RSA_VALIDATE_RET( sig != NULL );
-    RSA_VALIDATE_RET( ( md_alg  == MBEDTLS_MD_NONE &&
-                        hashlen == 0 ) ||
-                      hash != NULL );
-
-    switch( ctx->padding )
-    {
-#if defined(MBEDTLS_PKCS1_V15)
-        case MBEDTLS_RSA_PKCS_V15:
-            return mbedtls_rsa_rsassa_pkcs1_v15_verify( ctx, f_rng, p_rng, mode, md_alg,
-                                                hashlen, hash, sig );
-#endif
-
-#if defined(MBEDTLS_PKCS1_V21)
-        case MBEDTLS_RSA_PKCS_V21:
-            return mbedtls_rsa_rsassa_pss_verify( ctx, f_rng, p_rng, mode, md_alg,
-                                          hashlen, hash, sig );
-#endif
-
-        default:
-            return( MBEDTLS_ERR_RSA_INVALID_PADDING );
-    }
-}
-
-/*
- * Copy the components of an RSA key
- */
-int mbedtls_rsa_copy( mbedtls_rsa_context *dst, const mbedtls_rsa_context *src )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    RSA_VALIDATE_RET( dst != NULL );
-    RSA_VALIDATE_RET( src != NULL );
-
-    dst->len = src->len;
-
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->N, &src->N ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->E, &src->E ) );
-
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->D, &src->D ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->P, &src->P ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->Q, &src->Q ) );
-
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->DP, &src->DP ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->DQ, &src->DQ ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->QP, &src->QP ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RP, &src->RP ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RQ, &src->RQ ) );
-#endif
-
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RN, &src->RN ) );
-
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->Vi, &src->Vi ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->Vf, &src->Vf ) );
-
-    dst->padding = src->padding;
-    dst->hash_id = src->hash_id;
-
-cleanup:
-    if( ret != 0 )
-        mbedtls_rsa_free( dst );
-
-    return( ret );
-}
-
-/*
- * Free the components of an RSA key
- */
-void mbedtls_rsa_free( mbedtls_rsa_context *ctx )
-{
-    if( ctx == NULL )
-        return;
-
-    mbedtls_mpi_free( &ctx->Vi );
-    mbedtls_mpi_free( &ctx->Vf );
-    mbedtls_mpi_free( &ctx->RN );
-    mbedtls_mpi_free( &ctx->D  );
-    mbedtls_mpi_free( &ctx->Q  );
-    mbedtls_mpi_free( &ctx->P  );
-    mbedtls_mpi_free( &ctx->E  );
-    mbedtls_mpi_free( &ctx->N  );
-
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    mbedtls_mpi_free( &ctx->RQ );
-    mbedtls_mpi_free( &ctx->RP );
-    mbedtls_mpi_free( &ctx->QP );
-    mbedtls_mpi_free( &ctx->DQ );
-    mbedtls_mpi_free( &ctx->DP );
-#endif /* MBEDTLS_RSA_NO_CRT */
-
-#if defined(MBEDTLS_THREADING_C)
-    /* Free the mutex, but only if it hasn't been freed already. */
-    if( ctx->ver != 0 )
-    {
-        mbedtls_mutex_free( &ctx->mutex );
-        ctx->ver = 0;
-    }
-#endif
-}
-
-#endif /* !MBEDTLS_RSA_ALT */
-
-#if defined(MBEDTLS_SELF_TEST)
-
-#include "mbedtls/sha1.h"
-
-/*
- * Example RSA-1024 keypair, for test purposes
- */
-#define KEY_LEN 128
-
-#define RSA_N   "9292758453063D803DD603D5E777D788" \
-                "8ED1D5BF35786190FA2F23EBC0848AEA" \
-                "DDA92CA6C3D80B32C4D109BE0F36D6AE" \
-                "7130B9CED7ACDF54CFC7555AC14EEBAB" \
-                "93A89813FBF3C4F8066D2D800F7C38A8" \
-                "1AE31942917403FF4946B0A83D3D3E05" \
-                "EE57C6F5F5606FB5D4BC6CD34EE0801A" \
-                "5E94BB77B07507233A0BC7BAC8F90F79"
-
-#define RSA_E   "10001"
-
-#define RSA_D   "24BF6185468786FDD303083D25E64EFC" \
-                "66CA472BC44D253102F8B4A9D3BFA750" \
-                "91386C0077937FE33FA3252D28855837" \
-                "AE1B484A8A9A45F7EE8C0C634F99E8CD" \
-                "DF79C5CE07EE72C7F123142198164234" \
-                "CABB724CF78B8173B9F880FC86322407" \
-                "AF1FEDFDDE2BEB674CA15F3E81A1521E" \
-                "071513A1E85B5DFA031F21ECAE91A34D"
-
-#define RSA_P   "C36D0EB7FCD285223CFB5AABA5BDA3D8" \
-                "2C01CAD19EA484A87EA4377637E75500" \
-                "FCB2005C5C7DD6EC4AC023CDA285D796" \
-                "C3D9E75E1EFC42488BB4F1D13AC30A57"
-
-#define RSA_Q   "C000DF51A7C77AE8D7C7370C1FF55B69" \
-                "E211C2B9E5DB1ED0BF61D0D9899620F4" \
-                "910E4168387E3C30AA1E00C339A79508" \
-                "8452DD96A9A5EA5D9DCA68DA636032AF"
-
-#define PT_LEN  24
-#define RSA_PT  "\xAA\xBB\xCC\x03\x02\x01\x00\xFF\xFF\xFF\xFF\xFF" \
-                "\x11\x22\x33\x0A\x0B\x0C\xCC\xDD\xDD\xDD\xDD\xDD"
-
-#if defined(MBEDTLS_PKCS1_V15)
-static int myrand( void *rng_state, unsigned char *output, size_t len )
-{
-#if !defined(__OpenBSD__) && !defined(__NetBSD__)
-    size_t i;
-
-    if( rng_state != NULL )
-        rng_state  = NULL;
-
-    for( i = 0; i < len; ++i )
-        output[i] = rand();
-#else
-    if( rng_state != NULL )
-        rng_state = NULL;
-
-    arc4random_buf( output, len );
-#endif /* !OpenBSD && !NetBSD */
-
-    return( 0 );
-}
-#endif /* MBEDTLS_PKCS1_V15 */
-
-/*
- * Checkup routine
- */
-int mbedtls_rsa_self_test( int verbose )
-{
-    int ret = 0;
-#if defined(MBEDTLS_PKCS1_V15)
-    size_t len;
-    mbedtls_rsa_context rsa;
-    unsigned char rsa_plaintext[PT_LEN];
-    unsigned char rsa_decrypted[PT_LEN];
-    unsigned char rsa_ciphertext[KEY_LEN];
-#if defined(MBEDTLS_SHA1_C)
-    unsigned char sha1sum[20];
-#endif
-
-    mbedtls_mpi K;
-
-    mbedtls_mpi_init( &K );
-    mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 );
-
-    MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_N  ) );
-    MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, &K, NULL, NULL, NULL, NULL ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_P  ) );
-    MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, NULL, &K, NULL, NULL, NULL ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_Q  ) );
-    MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, NULL, NULL, &K, NULL, NULL ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_D  ) );
-    MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, NULL, NULL, NULL, &K, NULL ) );
-    MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_E  ) );
-    MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, NULL, NULL, NULL, NULL, &K ) );
-
-    MBEDTLS_MPI_CHK( mbedtls_rsa_complete( &rsa ) );
-
-    if( verbose != 0 )
-        mbedtls_printf( "  RSA key validation: " );
-
-    if( mbedtls_rsa_check_pubkey(  &rsa ) != 0 ||
-        mbedtls_rsa_check_privkey( &rsa ) != 0 )
-    {
-        if( verbose != 0 )
-            mbedtls_printf( "failed\n" );
-
-        ret = 1;
-        goto cleanup;
-    }
-
-    if( verbose != 0 )
-        mbedtls_printf( "passed\n  PKCS#1 encryption : " );
-
-    memcpy( rsa_plaintext, RSA_PT, PT_LEN );
-
-    if( mbedtls_rsa_pkcs1_encrypt( &rsa, myrand, NULL, MBEDTLS_RSA_PUBLIC,
-                                   PT_LEN, rsa_plaintext,
-                                   rsa_ciphertext ) != 0 )
-    {
-        if( verbose != 0 )
-            mbedtls_printf( "failed\n" );
-
-        ret = 1;
-        goto cleanup;
-    }
-
-    if( verbose != 0 )
-        mbedtls_printf( "passed\n  PKCS#1 decryption : " );
-
-    if( mbedtls_rsa_pkcs1_decrypt( &rsa, myrand, NULL, MBEDTLS_RSA_PRIVATE,
-                                   &len, rsa_ciphertext, rsa_decrypted,
-                                   sizeof(rsa_decrypted) ) != 0 )
-    {
-        if( verbose != 0 )
-            mbedtls_printf( "failed\n" );
-
-        ret = 1;
-        goto cleanup;
-    }
-
-    if( memcmp( rsa_decrypted, rsa_plaintext, len ) != 0 )
-    {
-        if( verbose != 0 )
-            mbedtls_printf( "failed\n" );
-
-        ret = 1;
-        goto cleanup;
-    }
-
-    if( verbose != 0 )
-        mbedtls_printf( "passed\n" );
-
-#if defined(MBEDTLS_SHA1_C)
-    if( verbose != 0 )
-        mbedtls_printf( "  PKCS#1 data sign  : " );
-
-    if( mbedtls_sha1_ret( rsa_plaintext, PT_LEN, sha1sum ) != 0 )
-    {
-        if( verbose != 0 )
-            mbedtls_printf( "failed\n" );
-
-        return( 1 );
-    }
-
-    if( mbedtls_rsa_pkcs1_sign( &rsa, myrand, NULL,
-                                MBEDTLS_RSA_PRIVATE, MBEDTLS_MD_SHA1, 0,
-                                sha1sum, rsa_ciphertext ) != 0 )
-    {
-        if( verbose != 0 )
-            mbedtls_printf( "failed\n" );
-
-        ret = 1;
-        goto cleanup;
-    }
-
-    if( verbose != 0 )
-        mbedtls_printf( "passed\n  PKCS#1 sig. verify: " );
-
-    if( mbedtls_rsa_pkcs1_verify( &rsa, NULL, NULL,
-                                  MBEDTLS_RSA_PUBLIC, MBEDTLS_MD_SHA1, 0,
-                                  sha1sum, rsa_ciphertext ) != 0 )
-    {
-        if( verbose != 0 )
-            mbedtls_printf( "failed\n" );
-
-        ret = 1;
-        goto cleanup;
-    }
-
-    if( verbose != 0 )
-        mbedtls_printf( "passed\n" );
-#endif /* MBEDTLS_SHA1_C */
-
-    if( verbose != 0 )
-        mbedtls_printf( "\n" );
-
-cleanup:
-    mbedtls_mpi_free( &K );
-    mbedtls_rsa_free( &rsa );
-#else /* MBEDTLS_PKCS1_V15 */
-    ((void) verbose);
-#endif /* MBEDTLS_PKCS1_V15 */
-    return( ret );
-}
-
-#endif /* MBEDTLS_SELF_TEST */
-
-#endif /* MBEDTLS_RSA_C */