Merge pull request #5202 from xkqian/pr/add_rsa_pkcsv15

Pr/add rsa pkcsv15
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index b07d07a..0d54ae9 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -6376,6 +6376,7 @@
 #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
     MBEDTLS_TLS13_SIG_RSA_PSS_RSAE_SHA256,
 #endif
+    MBEDTLS_TLS13_SIG_RSA_PKCS1_SHA256,
 
     MBEDTLS_TLS13_SIG_NONE
 };
@@ -6395,6 +6396,7 @@
 #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
     MBEDTLS_TLS13_SIG_RSA_PSS_RSAE_SHA256,
 #endif
+    MBEDTLS_TLS13_SIG_RSA_PKCS1_SHA256,
 
     MBEDTLS_TLS13_SIG_NONE
 };
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 2dd5c50..f9ad5da 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -376,7 +376,7 @@
             break;
 #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
         case MBEDTLS_TLS13_SIG_RSA_PSS_RSAE_SHA256:
-            MBEDTLS_SSL_DEBUG_MSG( 4, ( "Certificate Verify: using RSA" ) );
+            MBEDTLS_SSL_DEBUG_MSG( 4, ( "Certificate Verify: using RSA PSS" ) );
             md_alg = MBEDTLS_MD_SHA256;
             sig_alg = MBEDTLS_PK_RSASSA_PSS;
             break;
diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 204b975..214f471 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -1538,6 +1538,10 @@
             {
                 sig_alg_list[i++] = MBEDTLS_TLS13_SIG_RSA_PSS_RSAE_SHA256;
             }
+            else if( strcmp( q, "rsa_pkcs1_sha256" ) == 0 )
+            {
+                sig_alg_list[i++] = MBEDTLS_TLS13_SIG_RSA_PKCS1_SHA256;
+            }
             else
             {
                 mbedtls_printf( "unknown signature algorithm %s\n", q );
@@ -1546,6 +1550,7 @@
                 mbedtls_printf( "ecdsa_secp384r1_sha384 " );
                 mbedtls_printf( "ecdsa_secp521r1_sha512 " );
                 mbedtls_printf( "rsa_pss_rsae_sha256 " );
+                mbedtls_printf( "rsa_pkcs1_sha256 " );
                 mbedtls_printf( "\n" );
                 goto exit;
             }