From 82d34ccf476c3ff3cb5fe8e5f8f0426a533d024d Mon Sep 17 00:00:00 2001
From: XiaokangQian <xiaokang.qian@arm.com>
Date: Wed, 3 Nov 2021 08:51:56 +0000
Subject: [PATCH] Add signature scheme rsa pss

Signed-off-by: XiaokangQian <xiaokang.qian@arm.com>
---
 library/ssl_tls.c           |  6 ++++++
 library/ssl_tls13_generic.c | 27 ++++++++++++++++++++++++++-
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 48a6369b7a..4ada5369b0 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -6370,6 +6370,12 @@ static uint16_t ssl_preset_default_sig_algs[] = {
     MBEDTLS_TLS13_SIG_ECDSA_SECP521R1_SHA512,
 #endif /* MBEDTLS_SHA512_C && MBEDTLS_ECP_DP_SECP521R1_ENABLED */
 #endif /* MBEDTLS_ECDSA_C */
+
+    /* RSA algorithms */
+#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
+    MBEDTLS_TLS13_SIG_RSA_PSS_RSAE_SHA256,
+#endif
+
     MBEDTLS_TLS13_SIG_NONE
 };
 
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 12ef4d58c8..6b7a6f84af 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -320,6 +320,11 @@ static int ssl_tls13_parse_certificate_verify( mbedtls_ssl_context *ssl,
     unsigned char verify_hash[MBEDTLS_MD_MAX_SIZE];
     size_t verify_hash_len;
 
+    void const *opts_ptr = NULL;
+#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
+    mbedtls_pk_rsassa_pss_options opts;
+#endif /* MBEDTLS_X509_RSASSA_PSS_SUPPORT */
+
     /*
      * struct {
      *     SignatureScheme algorithm;
@@ -368,6 +373,13 @@ static int ssl_tls13_parse_certificate_verify( mbedtls_ssl_context *ssl,
             md_alg = MBEDTLS_MD_SHA512;
             sig_alg = MBEDTLS_PK_ECDSA;
             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" ) );
+            md_alg = MBEDTLS_MD_SHA256;
+            sig_alg = MBEDTLS_PK_RSASSA_PSS;
+            break;
+#endif /* MBEDTLS_X509_RSASSA_PSS_SUPPORT */
         default:
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "Certificate Verify: Unknown signature algorithm." ) );
             goto error;
@@ -426,8 +438,21 @@ static int ssl_tls13_parse_certificate_verify( mbedtls_ssl_context *ssl,
     }
 
     MBEDTLS_SSL_DEBUG_BUF( 3, "verify hash", verify_hash, verify_hash_len );
+#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
+    if( sig_alg == MBEDTLS_PK_RSASSA_PSS )
+    {
+        const mbedtls_md_info_t* md_info;
+        opts.mgf1_hash_id = md_alg;
+        if( ( md_info = mbedtls_md_info_from_type( md_alg ) ) == NULL )
+        {
+            return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+        }
+        opts.expected_salt_len = mbedtls_md_get_size( md_info );
+        opts_ptr = (const void*) &opts;
+    }
+#endif /* MBEDTLS_X509_RSASSA_PSS_SUPPORT */
 
-    if( ( ret = mbedtls_pk_verify_ext( sig_alg, NULL,
+    if( ( ret = mbedtls_pk_verify_ext( sig_alg, opts_ptr,
                                        &ssl->session_negotiate->peer_cert->pk,
                                        md_alg, verify_hash, verify_hash_len,
                                        p, signature_len ) ) == 0 )