tls13: add generate handshake keys

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
This commit is contained in:
Jerry Yu 2021-09-16 18:59:08 +08:00
parent f7946a6210
commit 61e35e0047
3 changed files with 155 additions and 21 deletions

View file

@ -508,6 +508,27 @@ struct mbedtls_ssl_key_set
};
typedef struct mbedtls_ssl_key_set mbedtls_ssl_key_set;
typedef struct
{
unsigned char binder_key [ MBEDTLS_MD_MAX_SIZE ];
unsigned char client_early_traffic_secret [ MBEDTLS_MD_MAX_SIZE ];
unsigned char early_exporter_master_secret[ MBEDTLS_MD_MAX_SIZE ];
} mbedtls_ssl_tls1_3_early_secrets;
typedef struct
{
unsigned char client_handshake_traffic_secret[ MBEDTLS_MD_MAX_SIZE ];
unsigned char server_handshake_traffic_secret[ MBEDTLS_MD_MAX_SIZE ];
} mbedtls_ssl_tls1_3_handshake_secrets;
typedef struct
{
unsigned char client_application_traffic_secret_N[ MBEDTLS_MD_MAX_SIZE ];
unsigned char server_application_traffic_secret_N[ MBEDTLS_MD_MAX_SIZE ];
unsigned char exporter_master_secret [ MBEDTLS_MD_MAX_SIZE ];
unsigned char resumption_master_secret [ MBEDTLS_MD_MAX_SIZE ];
} mbedtls_ssl_tls1_3_application_secrets;
/*
* This structure contains the parameters only needed during handshake.
*/
@ -715,6 +736,8 @@ struct mbedtls_ssl_handshake_params
unsigned char handshake[MBEDTLS_TLS1_3_MD_MAX_SIZE];
unsigned char app [MBEDTLS_TLS1_3_MD_MAX_SIZE];
} tls1_3_master_secrets;
mbedtls_ssl_tls1_3_handshake_secrets tls1_3_hs_secrets;
#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)

View file

@ -846,4 +846,121 @@ int mbedtls_ssl_tls1_3_key_schedule_stage_early( mbedtls_ssl_context *ssl )
return( 0 );
}
/* mbedtls_ssl_tls1_3_generate_handshake_keys() generates keys necessary for
* protecting the handshake messages, as described in Section 7 of TLS 1.3. */
int mbedtls_ssl_tls1_3_generate_handshake_keys( mbedtls_ssl_context *ssl,
mbedtls_ssl_key_set *traffic_keys )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_md_type_t md_type;
mbedtls_md_info_t const *md_info;
size_t md_size;
unsigned char transcript[MBEDTLS_MD_MAX_SIZE];
size_t transcript_len;
mbedtls_cipher_info_t const *cipher_info;
size_t keylen, ivlen;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_tls1_3_generate_handshake_keys" ) );
cipher_info = mbedtls_cipher_info_from_type(
ssl->handshake->ciphersuite_info->cipher );
keylen = cipher_info->key_bitlen >> 3;
ivlen = cipher_info->iv_size;
md_type = ssl->handshake->ciphersuite_info->mac;
md_info = mbedtls_md_info_from_type( md_type );
md_size = mbedtls_md_get_size( md_info );
ret = mbedtls_ssl_get_handshake_transcript( ssl, md_type,
transcript,
sizeof( transcript ),
&transcript_len );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1,
"mbedtls_ssl_get_handshake_transcript",
ret );
return( ret );
}
ret = mbedtls_ssl_tls1_3_derive_handshake_secrets( md_type,
ssl->handshake->tls1_3_master_secrets.handshake,
transcript, transcript_len,
&ssl->handshake->tls1_3_hs_secrets );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls1_3_derive_handshake_secrets",
ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_BUF( 4, "Client handshake traffic secret",
ssl->handshake->tls1_3_hs_secrets.client_handshake_traffic_secret,
md_size );
MBEDTLS_SSL_DEBUG_BUF( 4, "Server handshake traffic secret",
ssl->handshake->tls1_3_hs_secrets.server_handshake_traffic_secret,
md_size );
/*
* Export client handshake traffic secret
*/
#if defined(MBEDTLS_SSL_EXPORT_KEYS)
if( ssl->f_export_keys != NULL )
{
ssl->f_export_keys( ssl->p_export_keys,
MBEDTLS_SSL_KEY_EXPORT_TLS13_CLIENT_HANDSHAKE_TRAFFIC_SECRET,
ssl->handshake->tls1_3_hs_secrets.client_handshake_traffic_secret,
md_size,
ssl->handshake->randbytes + 32,
ssl->handshake->randbytes,
MBEDTLS_SSL_TLS_PRF_NONE /* TODO: FIX! */ );
ssl->f_export_keys( ssl->p_export_keys,
MBEDTLS_SSL_KEY_EXPORT_TLS13_SERVER_HANDSHAKE_TRAFFIC_SECRET,
ssl->handshake->tls1_3_hs_secrets.server_handshake_traffic_secret,
md_size,
ssl->handshake->randbytes + 32,
ssl->handshake->randbytes,
MBEDTLS_SSL_TLS_PRF_NONE /* TODO: FIX! */ );
}
#endif /* MBEDTLS_SSL_EXPORT_KEYS */
ret = mbedtls_ssl_tls1_3_make_traffic_keys( md_type,
ssl->handshake->tls1_3_hs_secrets.client_handshake_traffic_secret,
ssl->handshake->tls1_3_hs_secrets.server_handshake_traffic_secret,
md_size,
keylen, ivlen, traffic_keys );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls1_3_make_traffic_keys", ret );
goto exit;
}
MBEDTLS_SSL_DEBUG_BUF( 4, "client_handshake write_key",
traffic_keys->client_write_key,
traffic_keys->key_len);
MBEDTLS_SSL_DEBUG_BUF( 4, "server_handshake write_key",
traffic_keys->server_write_key,
traffic_keys->key_len);
MBEDTLS_SSL_DEBUG_BUF( 4, "client_handshake write_iv",
traffic_keys->client_write_iv,
traffic_keys->iv_len);
MBEDTLS_SSL_DEBUG_BUF( 4, "server_handshake write_iv",
traffic_keys->server_write_iv,
traffic_keys->iv_len);
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= mbedtls_ssl_tls1_3_generate_handshake_keys" ) );
exit:
return( ret );
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */

View file

@ -70,27 +70,6 @@ extern const struct mbedtls_ssl_tls1_3_labels_struct mbedtls_ssl_tls1_3_labels;
#define MBEDTLS_SSL_TLS1_3_KEY_SCHEDULE_MAX_CONTEXT_LEN \
MBEDTLS_MD_MAX_SIZE
typedef struct
{
unsigned char binder_key [ MBEDTLS_MD_MAX_SIZE ];
unsigned char client_early_traffic_secret [ MBEDTLS_MD_MAX_SIZE ];
unsigned char early_exporter_master_secret[ MBEDTLS_MD_MAX_SIZE ];
} mbedtls_ssl_tls1_3_early_secrets;
typedef struct
{
unsigned char client_handshake_traffic_secret[ MBEDTLS_MD_MAX_SIZE ];
unsigned char server_handshake_traffic_secret[ MBEDTLS_MD_MAX_SIZE ];
} mbedtls_ssl_tls1_3_handshake_secrets;
typedef struct
{
unsigned char client_application_traffic_secret_N[ MBEDTLS_MD_MAX_SIZE ];
unsigned char server_application_traffic_secret_N[ MBEDTLS_MD_MAX_SIZE ];
unsigned char exporter_master_secret [ MBEDTLS_MD_MAX_SIZE ];
unsigned char resumption_master_secret [ MBEDTLS_MD_MAX_SIZE ];
} mbedtls_ssl_tls1_3_application_secrets;
/* Maximum desired length for expanded key material generated
* by HKDF-Expand-Label.
*
@ -553,4 +532,19 @@ int mbedtls_ssl_tls13_populate_transform( mbedtls_ssl_transform *transform,
*/
int mbedtls_ssl_tls1_3_key_schedule_stage_early( mbedtls_ssl_context *ssl );
/**
* \brief Compute TLS 1.3 handshake traffic keys.
*
* \param ssl The SSL context to operate on. This must be in
* key schedule stage \c Handshake, see
* mbedtls_ssl_tls13_key_schedule_stage_handshake().
* \param traffic_keys The address at which to store the handshake traffic key
* keys. This must be writable but may be uninitialized.
*
* \returns \c 0 on success.
* \returns A negative error code on failure.
*/
int mbedtls_ssl_tls1_3_generate_handshake_keys( mbedtls_ssl_context *ssl,
mbedtls_ssl_key_set *traffic_keys );
#endif /* MBEDTLS_SSL_TLS1_3_KEYS_H */