diff options
Diffstat (limited to 'lib/mbedtls-2.27.0/library/ecdsa.c')
| -rw-r--r-- | lib/mbedtls-2.27.0/library/ecdsa.c | 1012 |
1 files changed, 0 insertions, 1012 deletions
diff --git a/lib/mbedtls-2.27.0/library/ecdsa.c b/lib/mbedtls-2.27.0/library/ecdsa.c deleted file mode 100644 index 640eb24..0000000 --- a/lib/mbedtls-2.27.0/library/ecdsa.c +++ /dev/null @@ -1,1012 +0,0 @@ -/* - * Elliptic curve DSA - * - * 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. - */ - -/* - * References: - * - * SEC1 http://www.secg.org/index.php?action=secg,docs_secg - */ - -#include "common.h" - -#if defined(MBEDTLS_ECDSA_C) - -#include "mbedtls/ecdsa.h" -#include "mbedtls/asn1write.h" - -#include <string.h> - -#if defined(MBEDTLS_ECDSA_DETERMINISTIC) -#include "mbedtls/hmac_drbg.h" -#endif - -#if defined(MBEDTLS_PLATFORM_C) -#include "mbedtls/platform.h" -#else -#include <stdlib.h> -#define mbedtls_calloc calloc -#define mbedtls_free free -#endif - -#include "mbedtls/platform_util.h" -#include "mbedtls/error.h" - -/* Parameter validation macros based on platform_util.h */ -#define ECDSA_VALIDATE_RET( cond ) \ - MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA ) -#define ECDSA_VALIDATE( cond ) \ - MBEDTLS_INTERNAL_VALIDATE( cond ) - -#if defined(MBEDTLS_ECP_RESTARTABLE) - -/* - * Sub-context for ecdsa_verify() - */ -struct mbedtls_ecdsa_restart_ver -{ - mbedtls_mpi u1, u2; /* intermediate values */ - enum { /* what to do next? */ - ecdsa_ver_init = 0, /* getting started */ - ecdsa_ver_muladd, /* muladd step */ - } state; -}; - -/* - * Init verify restart sub-context - */ -static void ecdsa_restart_ver_init( mbedtls_ecdsa_restart_ver_ctx *ctx ) -{ - mbedtls_mpi_init( &ctx->u1 ); - mbedtls_mpi_init( &ctx->u2 ); - ctx->state = ecdsa_ver_init; -} - -/* - * Free the components of a verify restart sub-context - */ -static void ecdsa_restart_ver_free( mbedtls_ecdsa_restart_ver_ctx *ctx ) -{ - if( ctx == NULL ) - return; - - mbedtls_mpi_free( &ctx->u1 ); - mbedtls_mpi_free( &ctx->u2 ); - - ecdsa_restart_ver_init( ctx ); -} - -/* - * Sub-context for ecdsa_sign() - */ -struct mbedtls_ecdsa_restart_sig -{ - int sign_tries; - int key_tries; - mbedtls_mpi k; /* per-signature random */ - mbedtls_mpi r; /* r value */ - enum { /* what to do next? */ - ecdsa_sig_init = 0, /* getting started */ - ecdsa_sig_mul, /* doing ecp_mul() */ - ecdsa_sig_modn, /* mod N computations */ - } state; -}; - -/* - * Init verify sign sub-context - */ -static void ecdsa_restart_sig_init( mbedtls_ecdsa_restart_sig_ctx *ctx ) -{ - ctx->sign_tries = 0; - ctx->key_tries = 0; - mbedtls_mpi_init( &ctx->k ); - mbedtls_mpi_init( &ctx->r ); - ctx->state = ecdsa_sig_init; -} - -/* - * Free the components of a sign restart sub-context - */ -static void ecdsa_restart_sig_free( mbedtls_ecdsa_restart_sig_ctx *ctx ) -{ - if( ctx == NULL ) - return; - - mbedtls_mpi_free( &ctx->k ); - mbedtls_mpi_free( &ctx->r ); -} - -#if defined(MBEDTLS_ECDSA_DETERMINISTIC) -/* - * Sub-context for ecdsa_sign_det() - */ -struct mbedtls_ecdsa_restart_det -{ - mbedtls_hmac_drbg_context rng_ctx; /* DRBG state */ - enum { /* what to do next? */ - ecdsa_det_init = 0, /* getting started */ - ecdsa_det_sign, /* make signature */ - } state; -}; - -/* - * Init verify sign_det sub-context - */ -static void ecdsa_restart_det_init( mbedtls_ecdsa_restart_det_ctx *ctx ) -{ - mbedtls_hmac_drbg_init( &ctx->rng_ctx ); - ctx->state = ecdsa_det_init; -} - -/* - * Free the components of a sign_det restart sub-context - */ -static void ecdsa_restart_det_free( mbedtls_ecdsa_restart_det_ctx *ctx ) -{ - if( ctx == NULL ) - return; - - mbedtls_hmac_drbg_free( &ctx->rng_ctx ); - - ecdsa_restart_det_init( ctx ); -} -#endif /* MBEDTLS_ECDSA_DETERMINISTIC */ - -#define ECDSA_RS_ECP ( rs_ctx == NULL ? NULL : &rs_ctx->ecp ) - -/* Utility macro for checking and updating ops budget */ -#define ECDSA_BUDGET( ops ) \ - MBEDTLS_MPI_CHK( mbedtls_ecp_check_budget( grp, ECDSA_RS_ECP, ops ) ); - -/* Call this when entering a function that needs its own sub-context */ -#define ECDSA_RS_ENTER( SUB ) do { \ - /* reset ops count for this call if top-level */ \ - if( rs_ctx != NULL && rs_ctx->ecp.depth++ == 0 ) \ - rs_ctx->ecp.ops_done = 0; \ - \ - /* set up our own sub-context if needed */ \ - if( mbedtls_ecp_restart_is_enabled() && \ - rs_ctx != NULL && rs_ctx->SUB == NULL ) \ - { \ - rs_ctx->SUB = mbedtls_calloc( 1, sizeof( *rs_ctx->SUB ) ); \ - if( rs_ctx->SUB == NULL ) \ - return( MBEDTLS_ERR_ECP_ALLOC_FAILED ); \ - \ - ecdsa_restart_## SUB ##_init( rs_ctx->SUB ); \ - } \ -} while( 0 ) - -/* Call this when leaving a function that needs its own sub-context */ -#define ECDSA_RS_LEAVE( SUB ) do { \ - /* clear our sub-context when not in progress (done or error) */ \ - if( rs_ctx != NULL && rs_ctx->SUB != NULL && \ - ret != MBEDTLS_ERR_ECP_IN_PROGRESS ) \ - { \ - ecdsa_restart_## SUB ##_free( rs_ctx->SUB ); \ - mbedtls_free( rs_ctx->SUB ); \ - rs_ctx->SUB = NULL; \ - } \ - \ - if( rs_ctx != NULL ) \ - rs_ctx->ecp.depth--; \ -} while( 0 ) - -#else /* MBEDTLS_ECP_RESTARTABLE */ - -#define ECDSA_RS_ECP NULL - -#define ECDSA_BUDGET( ops ) /* no-op; for compatibility */ - -#define ECDSA_RS_ENTER( SUB ) (void) rs_ctx -#define ECDSA_RS_LEAVE( SUB ) (void) rs_ctx - -#endif /* MBEDTLS_ECP_RESTARTABLE */ - -#if defined(MBEDTLS_ECDSA_DETERMINISTIC) || \ - !defined(MBEDTLS_ECDSA_SIGN_ALT) || \ - !defined(MBEDTLS_ECDSA_VERIFY_ALT) -/* - * Derive a suitable integer for group grp from a buffer of length len - * SEC1 4.1.3 step 5 aka SEC1 4.1.4 step 3 - */ -static int derive_mpi( const mbedtls_ecp_group *grp, mbedtls_mpi *x, - const unsigned char *buf, size_t blen ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - size_t n_size = ( grp->nbits + 7 ) / 8; - size_t use_size = blen > n_size ? n_size : blen; - - MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( x, buf, use_size ) ); - if( use_size * 8 > grp->nbits ) - MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( x, use_size * 8 - grp->nbits ) ); - - /* While at it, reduce modulo N */ - if( mbedtls_mpi_cmp_mpi( x, &grp->N ) >= 0 ) - MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( x, x, &grp->N ) ); - -cleanup: - return( ret ); -} -#endif /* ECDSA_DETERMINISTIC || !ECDSA_SIGN_ALT || !ECDSA_VERIFY_ALT */ - -#if !defined(MBEDTLS_ECDSA_SIGN_ALT) -/* - * Compute ECDSA signature of a hashed message (SEC1 4.1.3) - * Obviously, compared to SEC1 4.1.3, we skip step 4 (hash message) - */ -static int ecdsa_sign_restartable( mbedtls_ecp_group *grp, - mbedtls_mpi *r, mbedtls_mpi *s, - const mbedtls_mpi *d, const unsigned char *buf, size_t blen, - int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, - int (*f_rng_blind)(void *, unsigned char *, size_t), - void *p_rng_blind, - mbedtls_ecdsa_restart_ctx *rs_ctx ) -{ - int ret, key_tries, sign_tries; - int *p_sign_tries = &sign_tries, *p_key_tries = &key_tries; - mbedtls_ecp_point R; - mbedtls_mpi k, e, t; - mbedtls_mpi *pk = &k, *pr = r; - - /* Fail cleanly on curves such as Curve25519 that can't be used for ECDSA */ - if( ! mbedtls_ecdsa_can_do( grp->id ) || grp->N.p == NULL ) - return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); - - /* Make sure d is in range 1..n-1 */ - if( mbedtls_mpi_cmp_int( d, 1 ) < 0 || mbedtls_mpi_cmp_mpi( d, &grp->N ) >= 0 ) - return( MBEDTLS_ERR_ECP_INVALID_KEY ); - - mbedtls_ecp_point_init( &R ); - mbedtls_mpi_init( &k ); mbedtls_mpi_init( &e ); mbedtls_mpi_init( &t ); - - ECDSA_RS_ENTER( sig ); - -#if defined(MBEDTLS_ECP_RESTARTABLE) - if( rs_ctx != NULL && rs_ctx->sig != NULL ) - { - /* redirect to our context */ - p_sign_tries = &rs_ctx->sig->sign_tries; - p_key_tries = &rs_ctx->sig->key_tries; - pk = &rs_ctx->sig->k; - pr = &rs_ctx->sig->r; - - /* jump to current step */ - if( rs_ctx->sig->state == ecdsa_sig_mul ) - goto mul; - if( rs_ctx->sig->state == ecdsa_sig_modn ) - goto modn; - } -#endif /* MBEDTLS_ECP_RESTARTABLE */ - - *p_sign_tries = 0; - do - { - if( (*p_sign_tries)++ > 10 ) - { - ret = MBEDTLS_ERR_ECP_RANDOM_FAILED; - goto cleanup; - } - - /* - * Steps 1-3: generate a suitable ephemeral keypair - * and set r = xR mod n - */ - *p_key_tries = 0; - do - { - if( (*p_key_tries)++ > 10 ) - { - ret = MBEDTLS_ERR_ECP_RANDOM_FAILED; - goto cleanup; - } - - MBEDTLS_MPI_CHK( mbedtls_ecp_gen_privkey( grp, pk, f_rng, p_rng ) ); - -#if defined(MBEDTLS_ECP_RESTARTABLE) - if( rs_ctx != NULL && rs_ctx->sig != NULL ) - rs_ctx->sig->state = ecdsa_sig_mul; - -mul: -#endif - MBEDTLS_MPI_CHK( mbedtls_ecp_mul_restartable( grp, &R, pk, &grp->G, - f_rng_blind, - p_rng_blind, - ECDSA_RS_ECP ) ); - MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( pr, &R.X, &grp->N ) ); - } - while( mbedtls_mpi_cmp_int( pr, 0 ) == 0 ); - -#if defined(MBEDTLS_ECP_RESTARTABLE) - if( rs_ctx != NULL && rs_ctx->sig != NULL ) - rs_ctx->sig->state = ecdsa_sig_modn; - -modn: -#endif - /* - * Accounting for everything up to the end of the loop - * (step 6, but checking now avoids saving e and t) - */ - ECDSA_BUDGET( MBEDTLS_ECP_OPS_INV + 4 ); - - /* - * Step 5: derive MPI from hashed message - */ - MBEDTLS_MPI_CHK( derive_mpi( grp, &e, buf, blen ) ); - - /* - * Generate a random value to blind inv_mod in next step, - * avoiding a potential timing leak. - */ - MBEDTLS_MPI_CHK( mbedtls_ecp_gen_privkey( grp, &t, f_rng_blind, - p_rng_blind ) ); - - /* - * Step 6: compute s = (e + r * d) / k = t (e + rd) / (kt) mod n - */ - MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( s, pr, d ) ); - MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &e, &e, s ) ); - MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &e, &e, &t ) ); - MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( pk, pk, &t ) ); - MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( pk, pk, &grp->N ) ); - MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( s, pk, &grp->N ) ); - MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( s, s, &e ) ); - MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( s, s, &grp->N ) ); - } - while( mbedtls_mpi_cmp_int( s, 0 ) == 0 ); - -#if defined(MBEDTLS_ECP_RESTARTABLE) - if( rs_ctx != NULL && rs_ctx->sig != NULL ) - mbedtls_mpi_copy( r, pr ); -#endif - -cleanup: - mbedtls_ecp_point_free( &R ); - mbedtls_mpi_free( &k ); mbedtls_mpi_free( &e ); mbedtls_mpi_free( &t ); - - ECDSA_RS_LEAVE( sig ); - - return( ret ); -} - -int mbedtls_ecdsa_can_do( mbedtls_ecp_group_id gid ) -{ - switch( gid ) - { -#ifdef MBEDTLS_ECP_DP_CURVE25519_ENABLED - case MBEDTLS_ECP_DP_CURVE25519: return 0; -#endif -#ifdef MBEDTLS_ECP_DP_CURVE448_ENABLED - case MBEDTLS_ECP_DP_CURVE448: return 0; -#endif - default: return 1; - } -} - -/* - * Compute ECDSA signature of a hashed message - */ -int mbedtls_ecdsa_sign( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s, - const mbedtls_mpi *d, const unsigned char *buf, size_t blen, - int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ) -{ - ECDSA_VALIDATE_RET( grp != NULL ); - ECDSA_VALIDATE_RET( r != NULL ); - ECDSA_VALIDATE_RET( s != NULL ); - ECDSA_VALIDATE_RET( d != NULL ); - ECDSA_VALIDATE_RET( f_rng != NULL ); - ECDSA_VALIDATE_RET( buf != NULL || blen == 0 ); - - /* Use the same RNG for both blinding and ephemeral key generation */ - return( ecdsa_sign_restartable( grp, r, s, d, buf, blen, - f_rng, p_rng, f_rng, p_rng, NULL ) ); -} -#endif /* !MBEDTLS_ECDSA_SIGN_ALT */ - -#if defined(MBEDTLS_ECDSA_DETERMINISTIC) -/* - * Deterministic signature wrapper - */ -static int ecdsa_sign_det_restartable( mbedtls_ecp_group *grp, - mbedtls_mpi *r, mbedtls_mpi *s, - const mbedtls_mpi *d, const unsigned char *buf, size_t blen, - mbedtls_md_type_t md_alg, - int (*f_rng_blind)(void *, unsigned char *, size_t), - void *p_rng_blind, - mbedtls_ecdsa_restart_ctx *rs_ctx ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - mbedtls_hmac_drbg_context rng_ctx; - mbedtls_hmac_drbg_context *p_rng = &rng_ctx; - unsigned char data[2 * MBEDTLS_ECP_MAX_BYTES]; - size_t grp_len = ( grp->nbits + 7 ) / 8; - const mbedtls_md_info_t *md_info; - mbedtls_mpi h; - - if( ( md_info = mbedtls_md_info_from_type( md_alg ) ) == NULL ) - return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); - - mbedtls_mpi_init( &h ); - mbedtls_hmac_drbg_init( &rng_ctx ); - - ECDSA_RS_ENTER( det ); - -#if defined(MBEDTLS_ECP_RESTARTABLE) - if( rs_ctx != NULL && rs_ctx->det != NULL ) - { - /* redirect to our context */ - p_rng = &rs_ctx->det->rng_ctx; - - /* jump to current step */ - if( rs_ctx->det->state == ecdsa_det_sign ) - goto sign; - } -#endif /* MBEDTLS_ECP_RESTARTABLE */ - - /* Use private key and message hash (reduced) to initialize HMAC_DRBG */ - MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( d, data, grp_len ) ); - MBEDTLS_MPI_CHK( derive_mpi( grp, &h, buf, blen ) ); - MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &h, data + grp_len, grp_len ) ); - mbedtls_hmac_drbg_seed_buf( p_rng, md_info, data, 2 * grp_len ); - -#if defined(MBEDTLS_ECP_RESTARTABLE) - if( rs_ctx != NULL && rs_ctx->det != NULL ) - rs_ctx->det->state = ecdsa_det_sign; - -sign: -#endif -#if defined(MBEDTLS_ECDSA_SIGN_ALT) - (void) f_rng_blind; - (void) p_rng_blind; - ret = mbedtls_ecdsa_sign( grp, r, s, d, buf, blen, - mbedtls_hmac_drbg_random, p_rng ); -#else - if( f_rng_blind != NULL ) - ret = ecdsa_sign_restartable( grp, r, s, d, buf, blen, - mbedtls_hmac_drbg_random, p_rng, - f_rng_blind, p_rng_blind, rs_ctx ); - else - { - mbedtls_hmac_drbg_context *p_rng_blind_det; - -#if !defined(MBEDTLS_ECP_RESTARTABLE) - /* - * To avoid reusing rng_ctx and risking incorrect behavior we seed a - * second HMAC-DRBG with the same seed. We also apply a label to avoid - * reusing the bits of the ephemeral key for blinding and eliminate the - * risk that they leak this way. - */ - const char* blind_label = "BLINDING CONTEXT"; - mbedtls_hmac_drbg_context rng_ctx_blind; - - mbedtls_hmac_drbg_init( &rng_ctx_blind ); - p_rng_blind_det = &rng_ctx_blind; - mbedtls_hmac_drbg_seed_buf( p_rng_blind_det, md_info, - data, 2 * grp_len ); - ret = mbedtls_hmac_drbg_update_ret( p_rng_blind_det, - (const unsigned char*) blind_label, - strlen( blind_label ) ); - if( ret != 0 ) - { - mbedtls_hmac_drbg_free( &rng_ctx_blind ); - goto cleanup; - } -#else - /* - * In the case of restartable computations we would either need to store - * the second RNG in the restart context too or set it up at every - * restart. The first option would penalize the correct application of - * the function and the second would defeat the purpose of the - * restartable feature. - * - * Therefore in this case we reuse the original RNG. This comes with the - * price that the resulting signature might not be a valid deterministic - * ECDSA signature with a very low probability (same magnitude as - * successfully guessing the private key). However even then it is still - * a valid ECDSA signature. - */ - p_rng_blind_det = p_rng; -#endif /* MBEDTLS_ECP_RESTARTABLE */ - - /* - * Since the output of the RNGs is always the same for the same key and - * message, this limits the efficiency of blinding and leaks information - * through side channels. After mbedtls_ecdsa_sign_det() is removed NULL - * won't be a valid value for f_rng_blind anymore. Therefore it should - * be checked by the caller and this branch and check can be removed. - */ - ret = ecdsa_sign_restartable( grp, r, s, d, buf, blen, - mbedtls_hmac_drbg_random, p_rng, - mbedtls_hmac_drbg_random, p_rng_blind_det, - rs_ctx ); - -#if !defined(MBEDTLS_ECP_RESTARTABLE) - mbedtls_hmac_drbg_free( &rng_ctx_blind ); -#endif - } -#endif /* MBEDTLS_ECDSA_SIGN_ALT */ - -cleanup: - mbedtls_hmac_drbg_free( &rng_ctx ); - mbedtls_mpi_free( &h ); - - ECDSA_RS_LEAVE( det ); - - return( ret ); -} - -/* - * Deterministic signature wrappers - */ - -#if !defined(MBEDTLS_DEPRECATED_REMOVED) -int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, - mbedtls_mpi *s, const mbedtls_mpi *d, - const unsigned char *buf, size_t blen, - mbedtls_md_type_t md_alg ) -{ - ECDSA_VALIDATE_RET( grp != NULL ); - ECDSA_VALIDATE_RET( r != NULL ); - ECDSA_VALIDATE_RET( s != NULL ); - ECDSA_VALIDATE_RET( d != NULL ); - ECDSA_VALIDATE_RET( buf != NULL || blen == 0 ); - - return( ecdsa_sign_det_restartable( grp, r, s, d, buf, blen, md_alg, - NULL, NULL, NULL ) ); -} -#endif /* MBEDTLS_DEPRECATED_REMOVED */ - -int mbedtls_ecdsa_sign_det_ext( mbedtls_ecp_group *grp, mbedtls_mpi *r, - mbedtls_mpi *s, const mbedtls_mpi *d, - const unsigned char *buf, size_t blen, - mbedtls_md_type_t md_alg, - int (*f_rng_blind)(void *, unsigned char *, - size_t), - void *p_rng_blind ) -{ - ECDSA_VALIDATE_RET( grp != NULL ); - ECDSA_VALIDATE_RET( r != NULL ); - ECDSA_VALIDATE_RET( s != NULL ); - ECDSA_VALIDATE_RET( d != NULL ); - ECDSA_VALIDATE_RET( buf != NULL || blen == 0 ); - ECDSA_VALIDATE_RET( f_rng_blind != NULL ); - - return( ecdsa_sign_det_restartable( grp, r, s, d, buf, blen, md_alg, - f_rng_blind, p_rng_blind, NULL ) ); -} -#endif /* MBEDTLS_ECDSA_DETERMINISTIC */ - -#if !defined(MBEDTLS_ECDSA_VERIFY_ALT) -/* - * Verify ECDSA signature of hashed message (SEC1 4.1.4) - * Obviously, compared to SEC1 4.1.3, we skip step 2 (hash message) - */ -static int ecdsa_verify_restartable( mbedtls_ecp_group *grp, - const unsigned char *buf, size_t blen, - const mbedtls_ecp_point *Q, - const mbedtls_mpi *r, const mbedtls_mpi *s, - mbedtls_ecdsa_restart_ctx *rs_ctx ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - mbedtls_mpi e, s_inv, u1, u2; - mbedtls_ecp_point R; - mbedtls_mpi *pu1 = &u1, *pu2 = &u2; - - mbedtls_ecp_point_init( &R ); - mbedtls_mpi_init( &e ); mbedtls_mpi_init( &s_inv ); - mbedtls_mpi_init( &u1 ); mbedtls_mpi_init( &u2 ); - - /* Fail cleanly on curves such as Curve25519 that can't be used for ECDSA */ - if( ! mbedtls_ecdsa_can_do( grp->id ) || grp->N.p == NULL ) - return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA ); - - ECDSA_RS_ENTER( ver ); - -#if defined(MBEDTLS_ECP_RESTARTABLE) - if( rs_ctx != NULL && rs_ctx->ver != NULL ) - { - /* redirect to our context */ - pu1 = &rs_ctx->ver->u1; - pu2 = &rs_ctx->ver->u2; - - /* jump to current step */ - if( rs_ctx->ver->state == ecdsa_ver_muladd ) - goto muladd; - } -#endif /* MBEDTLS_ECP_RESTARTABLE */ - - /* - * Step 1: make sure r and s are in range 1..n-1 - */ - if( mbedtls_mpi_cmp_int( r, 1 ) < 0 || mbedtls_mpi_cmp_mpi( r, &grp->N ) >= 0 || - mbedtls_mpi_cmp_int( s, 1 ) < 0 || mbedtls_mpi_cmp_mpi( s, &grp->N ) >= 0 ) - { - ret = MBEDTLS_ERR_ECP_VERIFY_FAILED; - goto cleanup; - } - - /* - * Step 3: derive MPI from hashed message - */ - MBEDTLS_MPI_CHK( derive_mpi( grp, &e, buf, blen ) ); - - /* - * Step 4: u1 = e / s mod n, u2 = r / s mod n - */ - ECDSA_BUDGET( MBEDTLS_ECP_OPS_CHK + MBEDTLS_ECP_OPS_INV + 2 ); - - MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &s_inv, s, &grp->N ) ); - - MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( pu1, &e, &s_inv ) ); - MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( pu1, pu1, &grp->N ) ); - - MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( pu2, r, &s_inv ) ); - MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( pu2, pu2, &grp->N ) ); - -#if defined(MBEDTLS_ECP_RESTARTABLE) - if( rs_ctx != NULL && rs_ctx->ver != NULL ) - rs_ctx->ver->state = ecdsa_ver_muladd; - -muladd: -#endif - /* - * Step 5: R = u1 G + u2 Q - */ - MBEDTLS_MPI_CHK( mbedtls_ecp_muladd_restartable( grp, - &R, pu1, &grp->G, pu2, Q, ECDSA_RS_ECP ) ); - - if( mbedtls_ecp_is_zero( &R ) ) - { - ret = MBEDTLS_ERR_ECP_VERIFY_FAILED; - goto cleanup; - } - - /* - * Step 6: convert xR to an integer (no-op) - * Step 7: reduce xR mod n (gives v) - */ - MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &R.X, &R.X, &grp->N ) ); - - /* - * Step 8: check if v (that is, R.X) is equal to r - */ - if( mbedtls_mpi_cmp_mpi( &R.X, r ) != 0 ) - { - ret = MBEDTLS_ERR_ECP_VERIFY_FAILED; - goto cleanup; - } - -cleanup: - mbedtls_ecp_point_free( &R ); - mbedtls_mpi_free( &e ); mbedtls_mpi_free( &s_inv ); - mbedtls_mpi_free( &u1 ); mbedtls_mpi_free( &u2 ); - - ECDSA_RS_LEAVE( ver ); - - return( ret ); -} - -/* - * Verify ECDSA signature of hashed message - */ -int mbedtls_ecdsa_verify( mbedtls_ecp_group *grp, - const unsigned char *buf, size_t blen, - const mbedtls_ecp_point *Q, - const mbedtls_mpi *r, - const mbedtls_mpi *s) -{ - ECDSA_VALIDATE_RET( grp != NULL ); - ECDSA_VALIDATE_RET( Q != NULL ); - ECDSA_VALIDATE_RET( r != NULL ); - ECDSA_VALIDATE_RET( s != NULL ); - ECDSA_VALIDATE_RET( buf != NULL || blen == 0 ); - - return( ecdsa_verify_restartable( grp, buf, blen, Q, r, s, NULL ) ); -} -#endif /* !MBEDTLS_ECDSA_VERIFY_ALT */ - -/* - * Convert a signature (given by context) to ASN.1 - */ -static int ecdsa_signature_to_asn1( const mbedtls_mpi *r, const mbedtls_mpi *s, - unsigned char *sig, size_t *slen ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - unsigned char buf[MBEDTLS_ECDSA_MAX_LEN] = {0}; - unsigned char *p = buf + sizeof( buf ); - size_t len = 0; - - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &p, buf, s ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &p, buf, r ) ); - - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, buf, len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, buf, - MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ); - - memcpy( sig, p, len ); - *slen = len; - - return( 0 ); -} - -/* - * Compute and write signature - */ -int mbedtls_ecdsa_write_signature_restartable( mbedtls_ecdsa_context *ctx, - mbedtls_md_type_t md_alg, - const unsigned char *hash, size_t hlen, - unsigned char *sig, size_t *slen, - int (*f_rng)(void *, unsigned char *, size_t), - void *p_rng, - mbedtls_ecdsa_restart_ctx *rs_ctx ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - mbedtls_mpi r, s; - ECDSA_VALIDATE_RET( ctx != NULL ); - ECDSA_VALIDATE_RET( hash != NULL ); - ECDSA_VALIDATE_RET( sig != NULL ); - ECDSA_VALIDATE_RET( slen != NULL ); - - mbedtls_mpi_init( &r ); - mbedtls_mpi_init( &s ); - -#if defined(MBEDTLS_ECDSA_DETERMINISTIC) - MBEDTLS_MPI_CHK( ecdsa_sign_det_restartable( &ctx->grp, &r, &s, &ctx->d, - hash, hlen, md_alg, f_rng, - p_rng, rs_ctx ) ); -#else - (void) md_alg; - -#if defined(MBEDTLS_ECDSA_SIGN_ALT) - (void) rs_ctx; - - MBEDTLS_MPI_CHK( mbedtls_ecdsa_sign( &ctx->grp, &r, &s, &ctx->d, - hash, hlen, f_rng, p_rng ) ); -#else - /* Use the same RNG for both blinding and ephemeral key generation */ - MBEDTLS_MPI_CHK( ecdsa_sign_restartable( &ctx->grp, &r, &s, &ctx->d, - hash, hlen, f_rng, p_rng, f_rng, - p_rng, rs_ctx ) ); -#endif /* MBEDTLS_ECDSA_SIGN_ALT */ -#endif /* MBEDTLS_ECDSA_DETERMINISTIC */ - - MBEDTLS_MPI_CHK( ecdsa_signature_to_asn1( &r, &s, sig, slen ) ); - -cleanup: - mbedtls_mpi_free( &r ); - mbedtls_mpi_free( &s ); - - return( ret ); -} - -/* - * Compute and write signature - */ -int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx, - mbedtls_md_type_t md_alg, - const unsigned char *hash, size_t hlen, - unsigned char *sig, size_t *slen, - int (*f_rng)(void *, unsigned char *, size_t), - void *p_rng ) -{ - ECDSA_VALIDATE_RET( ctx != NULL ); - ECDSA_VALIDATE_RET( hash != NULL ); - ECDSA_VALIDATE_RET( sig != NULL ); - ECDSA_VALIDATE_RET( slen != NULL ); - return( mbedtls_ecdsa_write_signature_restartable( - ctx, md_alg, hash, hlen, sig, slen, f_rng, p_rng, NULL ) ); -} - -#if !defined(MBEDTLS_DEPRECATED_REMOVED) && \ - defined(MBEDTLS_ECDSA_DETERMINISTIC) -int mbedtls_ecdsa_write_signature_det( mbedtls_ecdsa_context *ctx, - const unsigned char *hash, size_t hlen, - unsigned char *sig, size_t *slen, - mbedtls_md_type_t md_alg ) -{ - ECDSA_VALIDATE_RET( ctx != NULL ); - ECDSA_VALIDATE_RET( hash != NULL ); - ECDSA_VALIDATE_RET( sig != NULL ); - ECDSA_VALIDATE_RET( slen != NULL ); - return( mbedtls_ecdsa_write_signature( ctx, md_alg, hash, hlen, sig, slen, - NULL, NULL ) ); -} -#endif - -/* - * Read and check signature - */ -int mbedtls_ecdsa_read_signature( mbedtls_ecdsa_context *ctx, - const unsigned char *hash, size_t hlen, - const unsigned char *sig, size_t slen ) -{ - ECDSA_VALIDATE_RET( ctx != NULL ); - ECDSA_VALIDATE_RET( hash != NULL ); - ECDSA_VALIDATE_RET( sig != NULL ); - return( mbedtls_ecdsa_read_signature_restartable( - ctx, hash, hlen, sig, slen, NULL ) ); -} - -/* - * Restartable read and check signature - */ -int mbedtls_ecdsa_read_signature_restartable( mbedtls_ecdsa_context *ctx, - const unsigned char *hash, size_t hlen, - const unsigned char *sig, size_t slen, - mbedtls_ecdsa_restart_ctx *rs_ctx ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - unsigned char *p = (unsigned char *) sig; - const unsigned char *end = sig + slen; - size_t len; - mbedtls_mpi r, s; - ECDSA_VALIDATE_RET( ctx != NULL ); - ECDSA_VALIDATE_RET( hash != NULL ); - ECDSA_VALIDATE_RET( sig != NULL ); - - mbedtls_mpi_init( &r ); - mbedtls_mpi_init( &s ); - - if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, - MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) - { - ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA; - goto cleanup; - } - - if( p + len != end ) - { - ret = MBEDTLS_ERROR_ADD( MBEDTLS_ERR_ECP_BAD_INPUT_DATA, - MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); - goto cleanup; - } - - if( ( ret = mbedtls_asn1_get_mpi( &p, end, &r ) ) != 0 || - ( ret = mbedtls_asn1_get_mpi( &p, end, &s ) ) != 0 ) - { - ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA; - goto cleanup; - } -#if defined(MBEDTLS_ECDSA_VERIFY_ALT) - (void) rs_ctx; - - if( ( ret = mbedtls_ecdsa_verify( &ctx->grp, hash, hlen, - &ctx->Q, &r, &s ) ) != 0 ) - goto cleanup; -#else - if( ( ret = ecdsa_verify_restartable( &ctx->grp, hash, hlen, - &ctx->Q, &r, &s, rs_ctx ) ) != 0 ) - goto cleanup; -#endif /* MBEDTLS_ECDSA_VERIFY_ALT */ - - /* At this point we know that the buffer starts with a valid signature. - * Return 0 if the buffer just contains the signature, and a specific - * error code if the valid signature is followed by more data. */ - if( p != end ) - ret = MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH; - -cleanup: - mbedtls_mpi_free( &r ); - mbedtls_mpi_free( &s ); - - return( ret ); -} - -#if !defined(MBEDTLS_ECDSA_GENKEY_ALT) -/* - * Generate key pair - */ -int mbedtls_ecdsa_genkey( mbedtls_ecdsa_context *ctx, mbedtls_ecp_group_id gid, - int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ) -{ - int ret = 0; - ECDSA_VALIDATE_RET( ctx != NULL ); - ECDSA_VALIDATE_RET( f_rng != NULL ); - - ret = mbedtls_ecp_group_load( &ctx->grp, gid ); - if( ret != 0 ) - return( ret ); - - return( mbedtls_ecp_gen_keypair( &ctx->grp, &ctx->d, - &ctx->Q, f_rng, p_rng ) ); -} -#endif /* !MBEDTLS_ECDSA_GENKEY_ALT */ - -/* - * Set context from an mbedtls_ecp_keypair - */ -int mbedtls_ecdsa_from_keypair( mbedtls_ecdsa_context *ctx, const mbedtls_ecp_keypair *key ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - ECDSA_VALIDATE_RET( ctx != NULL ); - ECDSA_VALIDATE_RET( key != NULL ); - - if( ( ret = mbedtls_ecp_group_copy( &ctx->grp, &key->grp ) ) != 0 || - ( ret = mbedtls_mpi_copy( &ctx->d, &key->d ) ) != 0 || - ( ret = mbedtls_ecp_copy( &ctx->Q, &key->Q ) ) != 0 ) - { - mbedtls_ecdsa_free( ctx ); - } - - return( ret ); -} - -/* - * Initialize context - */ -void mbedtls_ecdsa_init( mbedtls_ecdsa_context *ctx ) -{ - ECDSA_VALIDATE( ctx != NULL ); - - mbedtls_ecp_keypair_init( ctx ); -} - -/* - * Free context - */ -void mbedtls_ecdsa_free( mbedtls_ecdsa_context *ctx ) -{ - if( ctx == NULL ) - return; - - mbedtls_ecp_keypair_free( ctx ); -} - -#if defined(MBEDTLS_ECP_RESTARTABLE) -/* - * Initialize a restart context - */ -void mbedtls_ecdsa_restart_init( mbedtls_ecdsa_restart_ctx *ctx ) -{ - ECDSA_VALIDATE( ctx != NULL ); - - mbedtls_ecp_restart_init( &ctx->ecp ); - - ctx->ver = NULL; - ctx->sig = NULL; -#if defined(MBEDTLS_ECDSA_DETERMINISTIC) - ctx->det = NULL; -#endif -} - -/* - * Free the components of a restart context - */ -void mbedtls_ecdsa_restart_free( mbedtls_ecdsa_restart_ctx *ctx ) -{ - if( ctx == NULL ) - return; - - mbedtls_ecp_restart_free( &ctx->ecp ); - - ecdsa_restart_ver_free( ctx->ver ); - mbedtls_free( ctx->ver ); - ctx->ver = NULL; - - ecdsa_restart_sig_free( ctx->sig ); - mbedtls_free( ctx->sig ); - ctx->sig = NULL; - -#if defined(MBEDTLS_ECDSA_DETERMINISTIC) - ecdsa_restart_det_free( ctx->det ); - mbedtls_free( ctx->det ); - ctx->det = NULL; -#endif -} -#endif /* MBEDTLS_ECP_RESTARTABLE */ - -#endif /* MBEDTLS_ECDSA_C */ |