tls13: Share write ecdh_key_exchange function

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
This commit is contained in:
Jerry Yu 2022-03-30 22:43:29 +08:00
parent 3bf2c6449d
commit 89e103c54c
4 changed files with 83 additions and 68 deletions

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@ -1781,6 +1781,16 @@ int mbedtls_ssl_tls13_write_change_cipher_spec( mbedtls_ssl_context *ssl );
int mbedtls_ssl_reset_transcript_for_hrr( mbedtls_ssl_context *ssl );
#if defined(MBEDTLS_ECDH_C)
int mbedtls_ssl_tls13_generate_and_write_ecdh_key_exchange(
mbedtls_ssl_context *ssl,
uint16_t named_group,
unsigned char *buf,
unsigned char *end,
size_t *out_len );
#endif /* MBEDTLS_ECDH_C */
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)

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@ -204,65 +204,6 @@ static int ssl_tls13_reset_key_share( mbedtls_ssl_context *ssl )
/*
* Functions for writing key_share extension.
*/
#if defined(MBEDTLS_ECDH_C)
static int ssl_tls13_generate_and_write_ecdh_key_exchange(
mbedtls_ssl_context *ssl,
uint16_t named_group,
unsigned char *buf,
unsigned char *end,
size_t *out_len )
{
psa_status_t status = PSA_ERROR_GENERIC_ERROR;
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
psa_key_attributes_t key_attributes;
size_t own_pubkey_len;
mbedtls_ssl_handshake_params *handshake = ssl->handshake;
size_t ecdh_bits = 0;
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Perform PSA-based ECDH computation." ) );
/* Convert EC group to PSA key type. */
if( ( handshake->ecdh_psa_type =
mbedtls_psa_parse_tls_ecc_group( named_group, &ecdh_bits ) ) == 0 )
return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
ssl->handshake->ecdh_bits = ecdh_bits;
key_attributes = psa_key_attributes_init();
psa_set_key_usage_flags( &key_attributes, PSA_KEY_USAGE_DERIVE );
psa_set_key_algorithm( &key_attributes, PSA_ALG_ECDH );
psa_set_key_type( &key_attributes, handshake->ecdh_psa_type );
psa_set_key_bits( &key_attributes, handshake->ecdh_bits );
/* Generate ECDH private key. */
status = psa_generate_key( &key_attributes,
&handshake->ecdh_psa_privkey );
if( status != PSA_SUCCESS )
{
ret = psa_ssl_status_to_mbedtls( status );
MBEDTLS_SSL_DEBUG_RET( 1, "psa_generate_key", ret );
return( ret );
}
/* Export the public part of the ECDH private key from PSA. */
status = psa_export_public_key( handshake->ecdh_psa_privkey,
buf, (size_t)( end - buf ),
&own_pubkey_len );
if( status != PSA_SUCCESS )
{
ret = psa_ssl_status_to_mbedtls( status );
MBEDTLS_SSL_DEBUG_RET( 1, "psa_export_public_key", ret );
return( ret );
}
*out_len = own_pubkey_len;
return( 0 );
}
#endif /* MBEDTLS_ECDH_C */
static int ssl_tls13_get_default_group_id( mbedtls_ssl_context *ssl,
uint16_t *group_id )
{
@ -367,8 +308,8 @@ static int ssl_tls13_write_key_share_ext( mbedtls_ssl_context *ssl,
*/
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 4 );
p += 4;
ret = ssl_tls13_generate_and_write_ecdh_key_exchange( ssl, group_id, p, end,
&key_exchange_len );
ret = mbedtls_ssl_tls13_generate_and_write_ecdh_key_exchange(
ssl, group_id, p, end, &key_exchange_len );
p += key_exchange_len;
if( ret != 0 )
return( ret );

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@ -1535,6 +1535,63 @@ int mbedtls_ssl_tls13_read_public_ecdhe_share( mbedtls_ssl_context *ssl,
return( 0 );
}
int mbedtls_ssl_tls13_generate_and_write_ecdh_key_exchange(
mbedtls_ssl_context *ssl,
uint16_t named_group,
unsigned char *buf,
unsigned char *end,
size_t *out_len )
{
psa_status_t status = PSA_ERROR_GENERIC_ERROR;
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
psa_key_attributes_t key_attributes;
size_t own_pubkey_len;
mbedtls_ssl_handshake_params *handshake = ssl->handshake;
size_t ecdh_bits = 0;
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Perform PSA-based ECDH computation." ) );
/* Convert EC group to PSA key type. */
if( ( handshake->ecdh_psa_type =
mbedtls_psa_parse_tls_ecc_group( named_group, &ecdh_bits ) ) == 0 )
return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
ssl->handshake->ecdh_bits = ecdh_bits;
key_attributes = psa_key_attributes_init();
psa_set_key_usage_flags( &key_attributes, PSA_KEY_USAGE_DERIVE );
psa_set_key_algorithm( &key_attributes, PSA_ALG_ECDH );
psa_set_key_type( &key_attributes, handshake->ecdh_psa_type );
psa_set_key_bits( &key_attributes, handshake->ecdh_bits );
/* Generate ECDH private key. */
status = psa_generate_key( &key_attributes,
&handshake->ecdh_psa_privkey );
if( status != PSA_SUCCESS )
{
ret = psa_ssl_status_to_mbedtls( status );
MBEDTLS_SSL_DEBUG_RET( 1, "psa_generate_key", ret );
return( ret );
}
/* Export the public part of the ECDH private key from PSA. */
status = psa_export_public_key( handshake->ecdh_psa_privkey,
buf, (size_t)( end - buf ),
&own_pubkey_len );
if( status != PSA_SUCCESS )
{
ret = psa_ssl_status_to_mbedtls( status );
MBEDTLS_SSL_DEBUG_RET( 1, "psa_export_public_key", ret );
return( ret );
}
*out_len = own_pubkey_len;
return( 0 );
}
#endif /* MBEDTLS_ECDH_C */
#endif /* MBEDTLS_SSL_TLS_C && MBEDTLS_SSL_PROTO_TLS1_3 */

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@ -822,20 +822,27 @@ static int ssl_tls13_key_share_encapsulate( mbedtls_ssl_context *ssl,
size_t *out_len )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
((void) ssl);
((void) named_group);
((void) buf);
((void) end);
((void) out_len);
#if defined(MBEDTLS_ECDH_C)
if( mbedtls_ssl_tls13_named_group_is_ecdhe( named_group ) )
{
ret = mbedtls_ecdh_tls13_make_params( &ssl->handshake->ecdh_ctx,
out_len, buf, end - buf, ssl->conf->f_rng, ssl->conf->p_rng );
ret = mbedtls_ssl_tls13_generate_and_write_ecdh_key_exchange(
ssl, named_group, buf, end, out_len );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_make_tls13_params", ret );
MBEDTLS_SSL_DEBUG_RET(
1, "mbedtls_ssl_tls13_generate_and_write_ecdh_key_exchange",
ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx, MBEDTLS_DEBUG_ECDH_Q );
}
else if( 0 /* Other kinds of KEMs */ )
else
#endif /* MBEDTLS_ECDH_C */
if( 0 /* Other kinds of KEMs */ )
{
}
else