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Diffstat (limited to 'lib/mbedtls-2.27.0/library/ssl_tls13_keys.h')
| -rw-r--r-- | lib/mbedtls-2.27.0/library/ssl_tls13_keys.h | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/lib/mbedtls-2.27.0/library/ssl_tls13_keys.h b/lib/mbedtls-2.27.0/library/ssl_tls13_keys.h new file mode 100644 index 0000000..7089049 --- /dev/null +++ b/lib/mbedtls-2.27.0/library/ssl_tls13_keys.h @@ -0,0 +1,274 @@ +/* + * TLS 1.3 key schedule + * + * 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. + */ +#if !defined(MBEDTLS_SSL_TLS1_3_KEYS_H) +#define MBEDTLS_SSL_TLS1_3_KEYS_H + +/* This requires MBEDTLS_SSL_TLS1_3_LABEL( idx, name, string ) to be defined at + * the point of use. See e.g. the definition of mbedtls_ssl_tls1_3_labels_union + * below. */ +#define MBEDTLS_SSL_TLS1_3_LABEL_LIST \ + MBEDTLS_SSL_TLS1_3_LABEL( finished , "finished" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( resumption , "resumption" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( traffic_upd , "traffic upd" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( exporter , "exporter" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( key , "key" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( iv , "iv" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( c_hs_traffic, "c hs traffic" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( c_ap_traffic, "c ap traffic" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( c_e_traffic , "c e traffic" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( s_hs_traffic, "s hs traffic" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( s_ap_traffic, "s ap traffic" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( s_e_traffic , "s e traffic" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( e_exp_master, "e exp master" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( res_master , "res master" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( exp_master , "exp master" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( ext_binder , "ext binder" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( res_binder , "res binder" ) \ + MBEDTLS_SSL_TLS1_3_LABEL( derived , "derived" ) + +#define MBEDTLS_SSL_TLS1_3_LABEL( name, string ) \ + const unsigned char name [ sizeof(string) - 1 ]; + +union mbedtls_ssl_tls1_3_labels_union +{ + MBEDTLS_SSL_TLS1_3_LABEL_LIST +}; +struct mbedtls_ssl_tls1_3_labels_struct +{ + MBEDTLS_SSL_TLS1_3_LABEL_LIST +}; +#undef MBEDTLS_SSL_TLS1_3_LABEL + +extern const struct mbedtls_ssl_tls1_3_labels_struct mbedtls_ssl_tls1_3_labels; + +#define MBEDTLS_SSL_TLS1_3_LBL_WITH_LEN( LABEL ) \ + mbedtls_ssl_tls1_3_labels.LABEL, \ + sizeof(mbedtls_ssl_tls1_3_labels.LABEL) + +#define MBEDTLS_SSL_TLS1_3_KEY_SCHEDULE_MAX_LABEL_LEN \ + sizeof( union mbedtls_ssl_tls1_3_labels_union ) + +/* The maximum length of HKDF contexts used in the TLS 1.3 standard. + * Since contexts are always hashes of message transcripts, this can + * be approximated from above by the maximum hash size. */ +#define MBEDTLS_SSL_TLS1_3_KEY_SCHEDULE_MAX_CONTEXT_LEN \ + MBEDTLS_MD_MAX_SIZE + +/* Maximum desired length for expanded key material generated + * by HKDF-Expand-Label. + * + * Warning: If this ever needs to be increased, the implementation + * ssl_tls1_3_hkdf_encode_label() in ssl_tls13_keys.c needs to be + * adjusted since it currently assumes that HKDF key expansion + * is never used with more than 255 Bytes of output. */ +#define MBEDTLS_SSL_TLS1_3_KEY_SCHEDULE_MAX_EXPANSION_LEN 255 + +/** + * \brief The \c HKDF-Expand-Label function from + * the TLS 1.3 standard RFC 8446. + * + * <tt> + * HKDF-Expand-Label( Secret, Label, Context, Length ) = + * HKDF-Expand( Secret, HkdfLabel, Length ) + * </tt> + * + * \param hash_alg The identifier for the hash algorithm to use. + * \param secret The \c Secret argument to \c HKDF-Expand-Label. + * This must be a readable buffer of length \p slen Bytes. + * \param slen The length of \p secret in Bytes. + * \param label The \c Label argument to \c HKDF-Expand-Label. + * This must be a readable buffer of length \p llen Bytes. + * \param llen The length of \p label in Bytes. + * \param ctx The \c Context argument to \c HKDF-Expand-Label. + * This must be a readable buffer of length \p clen Bytes. + * \param clen The length of \p context in Bytes. + * \param buf The destination buffer to hold the expanded secret. + * This must be a writable buffer of length \p blen Bytes. + * \param blen The desired size of the expanded secret in Bytes. + * + * \returns \c 0 on success. + * \return A negative error code on failure. + */ + +int mbedtls_ssl_tls1_3_hkdf_expand_label( + mbedtls_md_type_t hash_alg, + const unsigned char *secret, size_t slen, + const unsigned char *label, size_t llen, + const unsigned char *ctx, size_t clen, + unsigned char *buf, size_t blen ); + +/** + * \brief This function is part of the TLS 1.3 key schedule. + * It extracts key and IV for the actual client/server traffic + * from the client/server traffic secrets. + * + * From RFC 8446: + * + * <tt> + * [sender]_write_key = HKDF-Expand-Label(Secret, "key", "", key_length) + * [sender]_write_iv = HKDF-Expand-Label(Secret, "iv", "", iv_length)* + * </tt> + * + * \param hash_alg The identifier for the hash algorithm to be used + * for the HKDF-based expansion of the secret. + * \param client_secret The client traffic secret. + * This must be a readable buffer of size \p slen Bytes + * \param server_secret The server traffic secret. + * This must be a readable buffer of size \p slen Bytes + * \param slen Length of the secrets \p client_secret and + * \p server_secret in Bytes. + * \param key_len The desired length of the key to be extracted in Bytes. + * \param iv_len The desired length of the IV to be extracted in Bytes. + * \param keys The address of the structure holding the generated + * keys and IVs. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ + +int mbedtls_ssl_tls1_3_make_traffic_keys( + mbedtls_md_type_t hash_alg, + const unsigned char *client_secret, + const unsigned char *server_secret, + size_t slen, size_t key_len, size_t iv_len, + mbedtls_ssl_key_set *keys ); + + +#define MBEDTLS_SSL_TLS1_3_CONTEXT_UNHASHED 0 +#define MBEDTLS_SSL_TLS1_3_CONTEXT_HASHED 1 + +/** + * \brief The \c Derive-Secret function from the TLS 1.3 standard RFC 8446. + * + * <tt> + * Derive-Secret( Secret, Label, Messages ) = + * HKDF-Expand-Label( Secret, Label, + * Hash( Messages ), + * Hash.Length ) ) + * </tt> + * + * \param hash_alg The identifier for the hash function used for the + * applications of HKDF. + * \param secret The \c Secret argument to the \c Derive-Secret function. + * This must be a readable buffer of length \p slen Bytes. + * \param slen The length of \p secret in Bytes. + * \param label The \c Label argument to the \c Derive-Secret function. + * This must be a readable buffer of length \p llen Bytes. + * \param llen The length of \p label in Bytes. + * \param ctx The hash of the \c Messages argument to the + * \c Derive-Secret function, or the \c Messages argument + * itself, depending on \p context_already_hashed. + * \param clen The length of \p hash. + * \param ctx_hashed This indicates whether the \p ctx contains the hash of + * the \c Messages argument in the application of the + * \c Derive-Secret function + * (value MBEDTLS_SSL_TLS1_3_CONTEXT_HASHED), or whether + * it is the content of \c Messages itself, in which case + * the function takes care of the hashing + * (value MBEDTLS_SSL_TLS1_3_CONTEXT_UNHASHED). + * \param dstbuf The target buffer to write the output of + * \c Derive-Secret to. This must be a writable buffer of + * size \p buflen Bytes. + * \param buflen The length of \p dstbuf in Bytes. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ +int mbedtls_ssl_tls1_3_derive_secret( + mbedtls_md_type_t hash_alg, + const unsigned char *secret, size_t slen, + const unsigned char *label, size_t llen, + const unsigned char *ctx, size_t clen, + int ctx_hashed, + unsigned char *dstbuf, size_t buflen ); + +/** + * \brief Compute the next secret in the TLS 1.3 key schedule + * + * The TLS 1.3 key schedule proceeds as follows to compute + * the three main secrets during the handshake: The early + * secret for early data, the handshake secret for all + * other encrypted handshake messages, and the master + * secret for all application traffic. + * + * <tt> + * 0 + * | + * v + * PSK -> HKDF-Extract = Early Secret + * | + * v + * Derive-Secret( ., "derived", "" ) + * | + * v + * (EC)DHE -> HKDF-Extract = Handshake Secret + * | + * v + * Derive-Secret( ., "derived", "" ) + * | + * v + * 0 -> HKDF-Extract = Master Secret + * </tt> + * + * Each of the three secrets in turn is the basis for further + * key derivations, such as the derivation of traffic keys and IVs; + * see e.g. mbedtls_ssl_tls1_3_make_traffic_keys(). + * + * This function implements one step in this evolution of secrets: + * + * <tt> + * old_secret + * | + * v + * Derive-Secret( ., "derived", "" ) + * | + * v + * input -> HKDF-Extract = new_secret + * </tt> + * + * \param hash_alg The identifier for the hash function used for the + * applications of HKDF. + * \param secret_old The address of the buffer holding the old secret + * on function entry. If not \c NULL, this must be a + * readable buffer whose size matches the output size + * of the hash function represented by \p hash_alg. + * If \c NULL, an all \c 0 array will be used instead. + * \param input The address of the buffer holding the additional + * input for the key derivation (e.g., the PSK or the + * ephemeral (EC)DH secret). If not \c NULL, this must be + * a readable buffer whose size \p input_len Bytes. + * If \c NULL, an all \c 0 array will be used instead. + * \param input_len The length of \p input in Bytes. + * \param secret_new The address of the buffer holding the new secret + * on function exit. This must be a writable buffer + * whose size matches the output size of the hash + * function represented by \p hash_alg. + * This may be the same as \p secret_old. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ + +int mbedtls_ssl_tls1_3_evolve_secret( + mbedtls_md_type_t hash_alg, + const unsigned char *secret_old, + const unsigned char *input, size_t input_len, + unsigned char *secret_new ); + +#endif /* MBEDTLS_SSL_TLS1_3_KEYS_H */ |