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Diffstat (limited to 'library/ssl_tls13_keys.h')
| -rw-r--r-- | library/ssl_tls13_keys.h | 651 |
1 files changed, 651 insertions, 0 deletions
diff --git a/library/ssl_tls13_keys.h b/library/ssl_tls13_keys.h new file mode 100644 index 00000000000..d3a4c6c9926 --- /dev/null +++ b/library/ssl_tls13_keys.h @@ -0,0 +1,651 @@ +/* + * TLS 1.3 key schedule + * + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + */ +#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_tls13_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") \ + MBEDTLS_SSL_TLS1_3_LABEL(client_cv, "TLS 1.3, client CertificateVerify") \ + MBEDTLS_SSL_TLS1_3_LABEL(server_cv, "TLS 1.3, server CertificateVerify") + +#define MBEDTLS_SSL_TLS1_3_CONTEXT_UNHASHED 0 +#define MBEDTLS_SSL_TLS1_3_CONTEXT_HASHED 1 + +#define MBEDTLS_SSL_TLS1_3_PSK_EXTERNAL 0 +#define MBEDTLS_SSL_TLS1_3_PSK_RESUMPTION 1 + +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) + +#define MBEDTLS_SSL_TLS1_3_LABEL(name, string) \ + const unsigned char name [sizeof(string) - 1]; + +union mbedtls_ssl_tls13_labels_union { + MBEDTLS_SSL_TLS1_3_LABEL_LIST +}; +struct mbedtls_ssl_tls13_labels_struct { + MBEDTLS_SSL_TLS1_3_LABEL_LIST +}; +#undef MBEDTLS_SSL_TLS1_3_LABEL + +extern const struct mbedtls_ssl_tls13_labels_struct mbedtls_ssl_tls13_labels; + +#define MBEDTLS_SSL_TLS1_3_LBL_LEN(LABEL) \ + sizeof(mbedtls_ssl_tls13_labels.LABEL) + +#define MBEDTLS_SSL_TLS1_3_LBL_WITH_LEN(LABEL) \ + mbedtls_ssl_tls13_labels.LABEL, \ + MBEDTLS_SSL_TLS1_3_LBL_LEN(LABEL) + +#define MBEDTLS_SSL_TLS1_3_KEY_SCHEDULE_MAX_LABEL_LEN \ + sizeof(union mbedtls_ssl_tls13_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 \ + PSA_HASH_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_tls13_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 secret_len Bytes. + * \param secret_len 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 label_len Bytes. + * \param label_len 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 ctx_len Bytes. + * \param ctx_len 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 buf_len Bytes. + * \param buf_len The desired size of the expanded secret in Bytes. + * + * \returns \c 0 on success. + * \return A negative error code on failure. + */ + +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_hkdf_expand_label( + psa_algorithm_t hash_alg, + const unsigned char *secret, size_t secret_len, + const unsigned char *label, size_t label_len, + const unsigned char *ctx, size_t ctx_len, + unsigned char *buf, size_t buf_len); + +/** + * \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 secret_len Bytes + * \param server_secret The server traffic secret. + * This must be a readable buffer of size + * \p secret_len Bytes + * \param secret_len 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. + */ + +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_make_traffic_keys( + psa_algorithm_t hash_alg, + const unsigned char *client_secret, + const unsigned char *server_secret, size_t secret_len, + size_t key_len, size_t iv_len, + mbedtls_ssl_key_set *keys); + +/** + * \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 secret_len Bytes. + * \param secret_len 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 label_len Bytes. + * \param label_len 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 ctx_hashed. + * \param ctx_len The length of \p ctx in Bytes. + * \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 dtsbuf_len Bytes. + * \param dstbuf_len The length of \p dstbuf in Bytes. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_derive_secret( + psa_algorithm_t hash_alg, + const unsigned char *secret, size_t secret_len, + const unsigned char *label, size_t label_len, + const unsigned char *ctx, size_t ctx_len, + int ctx_hashed, + unsigned char *dstbuf, size_t dstbuf_len); + +/** + * \brief Derive TLS 1.3 early data key material from early secret. + * + * This is a small wrapper invoking mbedtls_ssl_tls13_derive_secret() + * with the appropriate labels. + * + * <tt> + * Early Secret + * | + * +-----> Derive-Secret(., "c e traffic", ClientHello) + * | = client_early_traffic_secret + * | + * +-----> Derive-Secret(., "e exp master", ClientHello) + * . = early_exporter_master_secret + * . + * . + * </tt> + * + * \note To obtain the actual key and IV for the early data traffic, + * the client secret derived by this function need to be + * further processed by mbedtls_ssl_tls13_make_traffic_keys(). + * + * \note The binder key, which is also generated from the early secret, + * is omitted here. Its calculation is part of the separate routine + * mbedtls_ssl_tls13_create_psk_binder(). + * + * \param hash_alg The hash algorithm associated with the PSK for which + * early data key material is being derived. + * \param early_secret The early secret from which the early data key material + * should be derived. This must be a readable buffer whose + * length is the digest size of the hash algorithm + * represented by \p md_size. + * \param transcript The transcript of the handshake so far, calculated with + * respect to \p hash_alg. This must be a readable buffer + * whose length is the digest size of the hash algorithm + * represented by \p md_size. + * \param derived The address of the structure in which to store + * the early data key material. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_derive_early_secrets( + psa_algorithm_t hash_alg, + unsigned char const *early_secret, + unsigned char const *transcript, size_t transcript_len, + mbedtls_ssl_tls13_early_secrets *derived); + +/** + * \brief Derive TLS 1.3 handshake key material from the handshake secret. + * + * This is a small wrapper invoking mbedtls_ssl_tls13_derive_secret() + * with the appropriate labels from the standard. + * + * <tt> + * Handshake Secret + * | + * +-----> Derive-Secret( ., "c hs traffic", + * | ClientHello...ServerHello ) + * | = client_handshake_traffic_secret + * | + * +-----> Derive-Secret( ., "s hs traffic", + * . ClientHello...ServerHello ) + * . = server_handshake_traffic_secret + * . + * </tt> + * + * \note To obtain the actual key and IV for the encrypted handshake traffic, + * the client and server secret derived by this function need to be + * further processed by mbedtls_ssl_tls13_make_traffic_keys(). + * + * \param hash_alg The hash algorithm associated with the ciphersuite + * that's being used for the connection. + * \param handshake_secret The handshake secret from which the handshake key + * material should be derived. This must be a readable + * buffer whose length is the digest size of the hash + * algorithm represented by \p md_size. + * \param transcript The transcript of the handshake so far, calculated + * with respect to \p hash_alg. This must be a readable + * buffer whose length is the digest size of the hash + * algorithm represented by \p md_size. + * \param derived The address of the structure in which to + * store the handshake key material. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_derive_handshake_secrets( + psa_algorithm_t hash_alg, + unsigned char const *handshake_secret, + unsigned char const *transcript, size_t transcript_len, + mbedtls_ssl_tls13_handshake_secrets *derived); + +/** + * \brief Derive TLS 1.3 application key material from the master secret. + * + * This is a small wrapper invoking mbedtls_ssl_tls13_derive_secret() + * with the appropriate labels from the standard. + * + * <tt> + * Master Secret + * | + * +-----> Derive-Secret( ., "c ap traffic", + * | ClientHello...server Finished ) + * | = client_application_traffic_secret_0 + * | + * +-----> Derive-Secret( ., "s ap traffic", + * | ClientHello...Server Finished ) + * | = server_application_traffic_secret_0 + * | + * +-----> Derive-Secret( ., "exp master", + * . ClientHello...server Finished) + * . = exporter_master_secret + * . + * </tt> + * + * \note To obtain the actual key and IV for the (0-th) application traffic, + * the client and server secret derived by this function need to be + * further processed by mbedtls_ssl_tls13_make_traffic_keys(). + * + * \param hash_alg The hash algorithm associated with the ciphersuite + * that's being used for the connection. + * \param master_secret The master secret from which the application key + * material should be derived. This must be a readable + * buffer whose length is the digest size of the hash + * algorithm represented by \p md_size. + * \param transcript The transcript of the handshake up to and including + * the ServerFinished message, calculated with respect + * to \p hash_alg. This must be a readable buffer whose + * length is the digest size of the hash algorithm + * represented by \p hash_alg. + * \param derived The address of the structure in which to + * store the application key material. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_derive_application_secrets( + psa_algorithm_t hash_alg, + unsigned char const *master_secret, + unsigned char const *transcript, size_t transcript_len, + mbedtls_ssl_tls13_application_secrets *derived); + +/** + * \brief Derive TLS 1.3 resumption master secret from the master secret. + * + * This is a small wrapper invoking mbedtls_ssl_tls13_derive_secret() + * with the appropriate labels from the standard. + * + * \param hash_alg The hash algorithm used in the application for which + * key material is being derived. + * \param application_secret The application secret from which the resumption master + * secret should be derived. This must be a readable + * buffer whose length is the digest size of the hash + * algorithm represented by \p md_size. + * \param transcript The transcript of the handshake up to and including + * the ClientFinished message, calculated with respect + * to \p hash_alg. This must be a readable buffer whose + * length is the digest size of the hash algorithm + * represented by \p hash_alg. + * \param transcript_len The length of \p transcript in Bytes. + * \param derived The address of the structure in which to + * store the resumption master secret. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_derive_resumption_master_secret( + psa_algorithm_t hash_alg, + unsigned char const *application_secret, + unsigned char const *transcript, size_t transcript_len, + mbedtls_ssl_tls13_application_secrets *derived); + +/** + * \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_tls13_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. + */ + +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_evolve_secret( + psa_algorithm_t hash_alg, + const unsigned char *secret_old, + const unsigned char *input, size_t input_len, + unsigned char *secret_new); + +/** + * \brief Calculate a TLS 1.3 PSK binder. + * + * \param ssl The SSL context. This is used for debugging only and may + * be \c NULL if MBEDTLS_DEBUG_C is disabled. + * \param hash_alg The hash algorithm associated to the PSK \p psk. + * \param psk The buffer holding the PSK for which to create a binder. + * \param psk_len The size of \p psk in bytes. + * \param psk_type This indicates whether the PSK \p psk is externally + * provisioned (#MBEDTLS_SSL_TLS1_3_PSK_EXTERNAL) or a + * resumption PSK (#MBEDTLS_SSL_TLS1_3_PSK_RESUMPTION). + * \param transcript The handshake transcript up to the point where the + * PSK binder calculation happens. This must be readable, + * and its size must be equal to the digest size of + * the hash algorithm represented by \p hash_alg. + * \param result The address at which to store the PSK binder on success. + * This must be writable, and its size must be equal to the + * digest size of the hash algorithm represented by + * \p hash_alg. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_create_psk_binder(mbedtls_ssl_context *ssl, + const psa_algorithm_t hash_alg, + unsigned char const *psk, size_t psk_len, + int psk_type, + unsigned char const *transcript, + unsigned char *result); + +/** + * \bref Setup an SSL transform structure representing the + * record protection mechanism used by TLS 1.3 + * + * \param transform The SSL transform structure to be created. This must have + * been initialized through mbedtls_ssl_transform_init() and + * not used in any other way prior to calling this function. + * In particular, this function does not clean up the + * transform structure prior to installing the new keys. + * \param endpoint Indicates whether the transform is for the client + * (value #MBEDTLS_SSL_IS_CLIENT) or the server + * (value #MBEDTLS_SSL_IS_SERVER). + * \param ciphersuite The numerical identifier for the ciphersuite to use. + * This must be one of the identifiers listed in + * ssl_ciphersuites.h. + * \param traffic_keys The key material to use. No reference is stored in + * the SSL transform being generated, and the caller + * should destroy the key material afterwards. + * \param ssl (Debug-only) The SSL context to use for debug output + * in case of failure. This parameter is only needed if + * #MBEDTLS_DEBUG_C is set, and is ignored otherwise. + * + * \return \c 0 on success. In this case, \p transform is ready to + * be used with mbedtls_ssl_transform_decrypt() and + * mbedtls_ssl_transform_encrypt(). + * \return A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_populate_transform(mbedtls_ssl_transform *transform, + int endpoint, + int ciphersuite, + mbedtls_ssl_key_set const *traffic_keys, + mbedtls_ssl_context *ssl); + +/* + * TLS 1.3 key schedule evolutions + * + * Early -> Handshake -> Application + * + * Small wrappers around mbedtls_ssl_tls13_evolve_secret(). + */ + +/** + * \brief Begin TLS 1.3 key schedule by calculating early secret. + * + * The TLS 1.3 key schedule can be viewed as a simple state machine + * with states Initial -> Early -> Handshake -> Application, and + * this function represents the Initial -> Early transition. + * + * \param ssl The SSL context to operate on. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_key_schedule_stage_early(mbedtls_ssl_context *ssl); + +/** + * \brief Compute TLS 1.3 resumption master secret. + * + * \param ssl The SSL context to operate on. This must be in + * key schedule stage \c Application, see + * mbedtls_ssl_tls13_key_schedule_stage_application(). + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_compute_resumption_master_secret(mbedtls_ssl_context *ssl); + +/** + * \brief Calculate the verify_data value for the client or server TLS 1.3 + * Finished message. + * + * \param ssl The SSL context to operate on. This must be in + * key schedule stage \c Handshake, see + * mbedtls_ssl_tls13_key_schedule_stage_application(). + * \param dst The address at which to write the verify_data value. + * \param dst_len The size of \p dst in bytes. + * \param actual_len The address at which to store the amount of data + * actually written to \p dst upon success. + * \param which The message to calculate the `verify_data` for: + * - #MBEDTLS_SSL_IS_CLIENT for the Client's Finished message + * - #MBEDTLS_SSL_IS_SERVER for the Server's Finished message + * + * \note Both client and server call this function twice, once to + * generate their own Finished message, and once to verify the + * peer's Finished message. + + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_calculate_verify_data(mbedtls_ssl_context *ssl, + unsigned char *dst, + size_t dst_len, + size_t *actual_len, + int which); + +#if defined(MBEDTLS_SSL_EARLY_DATA) +/** + * \brief Compute TLS 1.3 early transform + * + * \param ssl The SSL context to operate on. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + * + * \warning The function does not compute the early master secret. Call + * mbedtls_ssl_tls13_key_schedule_stage_early() before to + * call this function to generate the early master secret. + * \note For a client/server endpoint, the function computes only the + * encryption/decryption part of the transform as the decryption/ + * encryption part is not defined by the specification (no early + * traffic from the server to the client). + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_compute_early_transform(mbedtls_ssl_context *ssl); +#endif /* MBEDTLS_SSL_EARLY_DATA */ + +/** + * \brief Compute TLS 1.3 handshake transform + * + * \param ssl The SSL context to operate on. The early secret must have been + * computed. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_compute_handshake_transform(mbedtls_ssl_context *ssl); + +/** + * \brief Compute TLS 1.3 application transform + * + * \param ssl The SSL context to operate on. The early secret must have been + * computed. + * + * \returns \c 0 on success. + * \returns A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_compute_application_transform(mbedtls_ssl_context *ssl); + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) +/** + * \brief Export TLS 1.3 PSK from handshake context + * + * \param[in] ssl The SSL context to operate on. + * \param[out] psk PSK output pointer. + * \param[out] psk_len Length of PSK. + * + * \returns \c 0 if there is a configured PSK and it was exported + * successfully. + * \returns A negative error code on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +int mbedtls_ssl_tls13_export_handshake_psk(mbedtls_ssl_context *ssl, + unsigned char **psk, + size_t *psk_len); +#endif + +#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */ + +#endif /* MBEDTLS_SSL_TLS1_3_KEYS_H */ |