Add negative tests for opaque mixed-PSK (server)

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 705a632..64e78a9 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -4270,7 +4270,10 @@
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
         /* Opaque PSKs are currently only supported for PSK-only. */
         if( ssl_use_opaque_psk( ssl ) == 1 )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "opaque PSK not supported with RSA-PSK" ) );
             return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
+        }
 #endif
 
         if( ( ret = ssl_parse_encrypted_pms( ssl, p, end, 2 ) ) != 0 )
@@ -4305,7 +4308,10 @@
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
         /* Opaque PSKs are currently only supported for PSK-only. */
         if( ssl_use_opaque_psk( ssl ) == 1 )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "opaque PSK not supported with DHE-PSK" ) );
             return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
+        }
 #endif
 
         if( p != end )
@@ -4342,7 +4348,10 @@
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
         /* Opaque PSKs are currently only supported for PSK-only. */
         if( ssl_use_opaque_psk( ssl ) == 1 )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "opaque PSK not supported with ECDHE-PSK" ) );
             return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
+        }
 #endif
 
         MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index d45c0ed..6169a37 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -2162,17 +2162,6 @@
 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
         if( opt.psk_opaque != 0 || opt.psk_list_opaque != 0 )
         {
-            /* Ensure that the chosen ciphersuite is PSK-only; 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 ||
-                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 ciphersuite through the 'force_ciphersuite' option.\n" );
-                ret = 2;
-                goto usage;
-            }
-
             /* Determine KDF algorithm the opaque PSK will be used in. */
 #if defined(MBEDTLS_SHA512_C)
             if( ciphersuite_info->mac == MBEDTLS_MD_SHA384 )
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 545da09..b1a3288 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -1734,6 +1734,39 @@
             -s "error" \
             -c "error"
 
+requires_config_enabled MBEDTLS_USE_PSA_CRYPTO
+run_test    "Opaque psk: server: ECDHE-PSK not supported" \
+            "$P_SRV debug_level=1 psk=abc123 psk_identity=foo psk_opaque=1 \
+            force_version=tls12 \
+            force_ciphersuite=TLS-ECDHE-PSK-WITH-AES-128-CBC-SHA" \
+            "$P_CLI debug_level=1 psk=abc123 psk_identity=foo" \
+            1 \
+            -s "opaque PSK not supported with ECDHE-PSK" \
+            -s "error" \
+            -c "error"
+
+requires_config_enabled MBEDTLS_USE_PSA_CRYPTO
+run_test    "Opaque psk: server: DHE-PSK not supported" \
+            "$P_SRV debug_level=1 psk=abc123 psk_identity=foo psk_opaque=1 \
+            force_version=tls12 \
+            force_ciphersuite=TLS-DHE-PSK-WITH-AES-128-CBC-SHA" \
+            "$P_CLI debug_level=1 psk=abc123 psk_identity=foo" \
+            1 \
+            -s "opaque PSK not supported with DHE-PSK" \
+            -s "error" \
+            -c "error"
+
+requires_config_enabled MBEDTLS_USE_PSA_CRYPTO
+run_test    "Opaque psk: server: RSA-PSK not supported" \
+            "$P_SRV debug_level=1 psk=abc123 psk_identity=foo psk_opaque=1 \
+            force_version=tls12 \
+            force_ciphersuite=TLS-RSA-PSK-WITH-AES-128-CBC-SHA" \
+            "$P_CLI debug_level=1 psk=abc123 psk_identity=foo" \
+            1 \
+            -s "opaque PSK not supported with RSA-PSK" \
+            -s "error" \
+            -c "error"
+
 # Test ciphersuites which we expect to be fully supported by PSA Crypto
 # and check that we don't fall back to Mbed TLS' internal crypto primitives.
 run_test_psa TLS-ECDHE-ECDSA-WITH-AES-128-CCM