Enable support for psa opaque DHE-PSK key exchange on the client side
Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index c60a856..294ed48 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -5099,7 +5099,8 @@
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_ECDHE_PSK ) &&
+ handshake->ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
+ handshake->ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ) &&
ssl_use_opaque_psk( ssl ) == 1 )
{
/* Perform PSK-to-MS expansion in a single step. */
@@ -5134,6 +5135,7 @@
other_secret = handshake->premaster + 2;
break;
case MBEDTLS_KEY_EXCHANGE_ECDHE_PSK:
+ case MBEDTLS_KEY_EXCHANGE_DHE_PSK:
other_secret_len = MBEDTLS_GET_UINT16_BE(handshake->premaster, 0);
other_secret = handshake->premaster + 2;
break;
@@ -5383,21 +5385,27 @@
unsigned char *end = p + sizeof( ssl->handshake->premaster );
const unsigned char *psk = NULL;
size_t psk_len = 0;
+ int psk_ret = mbedtls_ssl_get_psk( ssl, &psk, &psk_len );
#if defined(MBEDTLS_USE_PSA_CRYPTO) && \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
(void) key_ex;
#endif /* MBEDTLS_USE_PSA_CRYPTO && MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
- if( mbedtls_ssl_get_psk( ssl, &psk, &psk_len )
- == MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED )
+ if( psk_ret == MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED )
{
/*
* This should never happen because the existence of a PSK is always
- * checked before calling this function
+ * checked before calling this function.
+ *
+ * The exception is opaque DHE-PSK. For DHE-PSK fill premaster with
+ * the the shared secret without PSK.
*/
- MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
- return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+ if ( key_ex != MBEDTLS_KEY_EXCHANGE_DHE_PSK )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+ }
}
/*
@@ -5458,6 +5466,14 @@
p += 2 + len;
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K );
+
+ /* For opaque PSK fill premaster with the the shared secret without PSK. */
+ if( psk_ret == MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1,
+ ( "skip PMS generation for opaque DHE-PSK" ) );
+ return( 0 );
+ }
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
diff --git a/library/ssl_tls12_client.c b/library/ssl_tls12_client.c
index 2868a84..f6a21cb 100644
--- a/library/ssl_tls12_client.c
+++ b/library/ssl_tls12_client.c
@@ -3153,12 +3153,6 @@
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK )
{
-#if defined(MBEDTLS_USE_PSA_CRYPTO)
- /* 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 );
-#endif /* MBEDTLS_USE_PSA_CRYPTO */
-
/*
* ClientDiffieHellmanPublic public (DHM send G^X mod P)
*/
diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 5ab13be..2f33d8f 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -1406,22 +1406,6 @@
#if defined (MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
if( opt.psk_opaque != 0 )
{
- /* 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_ECDHE_PSK ) ||
- opt.min_version != MBEDTLS_SSL_MINOR_VERSION_3 )
- {
- mbedtls_printf( "opaque PSKs are only supported in conjunction \
- with forcing TLS 1.2 and a PSK-only, RSA-PSK \
- ciphersuites through the 'force_ciphersuite' option.\n" );
- ret = 2;
- goto usage;
- }
-
/* Determine KDF algorithm the opaque PSK will be used in. */
#if defined(MBEDTLS_SHA384_C)
if( ciphersuite_info->mac == MBEDTLS_MD_SHA384 )