Enable support for psa opaque ECDHE-PSK key exchange on the client side

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
This commit is contained in:
Przemek Stekiel 2022-04-14 08:29:31 +02:00
parent 51a1f36be0
commit 19b80f8151
3 changed files with 54 additions and 36 deletions

View file

@ -5093,11 +5093,13 @@ static int ssl_compute_master( mbedtls_ssl_handshake_params *handshake,
}
#endif /* MBEDTLS_SSL_EXTENDED_MS_ENABLED */
#if defined(MBEDTLS_USE_PSA_CRYPTO) && \
( defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) )
#if defined(MBEDTLS_USE_PSA_CRYPTO) && \
( defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) )
if( ( handshake->ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
handshake->ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ) &&
handshake->ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
handshake->ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ) &&
ssl_use_opaque_psk( ssl ) == 1 )
{
/* Perform PSK-to-MS expansion in a single step. */
@ -5120,15 +5122,23 @@ static int ssl_compute_master( mbedtls_ssl_handshake_params *handshake,
size_t other_secret_len = 0;
unsigned char* other_secret = NULL;
if ( handshake->ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
switch( handshake->ciphersuite_info->key_exchange )
{
/* Provide other key as other secret.
* For RSA-PKS other key length is always 48 bytes.
/* Provide other secret.
* Other secret is stored in premaster, where first 2 bytes hold the
* length of the other key. Skip them.
* length of the other key.
*/
other_secret_len = 48;
other_secret = handshake->premaster + 2;
case MBEDTLS_KEY_EXCHANGE_RSA_PSK:
/* For RSA-PKS other key length is always 48 bytes. */
other_secret_len = 48;
other_secret = handshake->premaster + 2;
break;
case MBEDTLS_KEY_EXCHANGE_ECDHE_PSK:
other_secret_len = MBEDTLS_GET_UINT16_BE(handshake->premaster, 0);
other_secret = handshake->premaster + 2;
break;
default:
break;
}
status = setup_psa_key_derivation( &derivation, psk, alg,

View file

@ -2959,10 +2959,6 @@ ecdh_calc_secret:
* ciphersuites we offered, so this should never happen. */
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
/* Opaque PSKs are currently only supported for PSK-only suites. */
if( ssl_conf_has_static_raw_psk( ssl->conf ) == 0 )
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
/* uint16 to store content length */
const size_t content_len_size = 2;
@ -3068,30 +3064,40 @@ ecdh_calc_secret:
MBEDTLS_PUT_UINT16_BE( zlen, pms, 0 );
pms += zlen_size + zlen;
const unsigned char *psk = NULL;
size_t psk_len = 0;
/* In case of opaque psk skip writting psk to pms.
* Opaque key will be handled later. */
if( ssl_conf_has_static_raw_psk( ssl->conf ) == 1 )
{
const unsigned char *psk = NULL;
size_t psk_len = 0;
if( mbedtls_ssl_get_psk( ssl, &psk, &psk_len )
== MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED )
/*
* This should never happen because the existence of a PSK is always
* checked before calling this function
*/
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
if( mbedtls_ssl_get_psk( ssl, &psk, &psk_len )
== MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED )
/*
* This should never happen because the existence of a PSK is always
* checked before calling this function
*/
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
/* opaque psk<0..2^16-1>; */
if( (size_t)( pms_end - pms ) < ( 2 + psk_len ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
/* opaque psk<0..2^16-1>; */
if( (size_t)( pms_end - pms ) < ( 2 + psk_len ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
/* Write the PSK length as uint16 */
MBEDTLS_PUT_UINT16_BE( psk_len, pms, 0 );
pms += 2;
/* Write the PSK length as uint16 */
MBEDTLS_PUT_UINT16_BE( psk_len, pms, 0 );
pms += 2;
/* Write the PSK itself */
memcpy( pms, psk, psk_len );
pms += psk_len;
/* Write the PSK itself */
memcpy( pms, psk, psk_len );
pms += psk_len;
ssl->handshake->pmslen = pms - ssl->handshake->premaster;
ssl->handshake->pmslen = pms - ssl->handshake->premaster;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "skip PMS generation for opaque ECDHE-PSK" ) );
}
}
else
#endif /* MBEDTLS_USE_PSA_CRYPTO &&

View file

@ -1406,11 +1406,13 @@ int main( int argc, char *argv[] )
#if defined (MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
if( opt.psk_opaque != 0 )
{
/* Ensure that the chosen ciphersuite is PSK-only or rsa-psk; we must know
* the ciphersuite in advance to set the correct policy for the
/* Ensure that the chosen ciphersuite is PSK-only, rsa-psk
or ecdhe-psk; we must know the ciphersuite in
advance to set the correct policy for the
* PSK key slot. This limitation might go away in the future. */
if( ( ciphersuite_info->key_exchange != MBEDTLS_KEY_EXCHANGE_PSK &&
ciphersuite_info->key_exchange != MBEDTLS_KEY_EXCHANGE_RSA_PSK ) ||
ciphersuite_info->key_exchange != MBEDTLS_KEY_EXCHANGE_RSA_PSK &&
ciphersuite_info->key_exchange != MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ) ||
opt.min_version != MBEDTLS_SSL_MINOR_VERSION_3 )
{
mbedtls_printf( "opaque PSKs are only supported in conjunction \