commit 8e80504b46764c2a590a6290cccc5716ff51ea79
author Neil Armstrong <narmstrong@baylibre.com> Wed Mar 16 15:30:31 2022 +0100
committer Neil Armstrong <narmstrong@baylibre.com> Wed Mar 16 15:30:31 2022 +0100
tree 697020a884b93c29229ed720c93762bb4f76a548
parent 169e61add63d5ee2f5df158f10c7068204abd932

Simplify padding check and get rid of psa_sig_md in rsa_decrypt_wrap()

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

library/pk_wrap.c

diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index d5d57aa..c4d715c 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -227,24 +227,14 @@
     int key_len;
     unsigned char buf[MBEDTLS_PK_RSA_PRV_DER_MAX_BYTES];
     mbedtls_pk_info_t pk_info = mbedtls_rsa_info;
-    psa_algorithm_t psa_sig_md;
 
     ((void) f_rng);
     ((void) p_rng);
 
 #if !defined(MBEDTLS_RSA_ALT)
-    switch( rsa->padding )
-    {
-        case MBEDTLS_RSA_PKCS_V15:
-            psa_sig_md = PSA_ALG_RSA_PKCS1V15_CRYPT;
-            break;
-
-        default:
-            return( MBEDTLS_ERR_RSA_INVALID_PADDING );
-    }
-#else
-    psa_sig_md = PSA_ALG_RSA_PKCS1V15_CRYPT;
-#endif
+    if( rsa->padding != MBEDTLS_RSA_PKCS_V15 )
+        return( MBEDTLS_ERR_RSA_INVALID_PADDING );
+#endif /* !MBEDTLS_RSA_ALT */
 
     if( ilen != mbedtls_rsa_get_len( rsa ) )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
@@ -259,7 +249,7 @@
 
     psa_set_key_type( &attributes, PSA_KEY_TYPE_RSA_KEY_PAIR );
     psa_set_key_usage_flags( &attributes, PSA_KEY_USAGE_DECRYPT );
-    psa_set_key_algorithm( &attributes, psa_sig_md );
+    psa_set_key_algorithm( &attributes, PSA_ALG_RSA_PKCS1V15_CRYPT );
 
     status = psa_import_key( &attributes,
                              buf + sizeof( buf ) - key_len, key_len,
@@ -270,8 +260,10 @@
         goto cleanup;
     }
 
-    status = psa_asymmetric_decrypt( key_id, psa_sig_md, input, ilen,
-                                     NULL, 0, output, osize, olen );
+    status = psa_asymmetric_decrypt( key_id, PSA_ALG_RSA_PKCS1V15_CRYPT,
+                                     input, ilen,
+                                     NULL, 0,
+                                     output, osize, olen );
     if( status != PSA_SUCCESS )
     {
         ret = mbedtls_pk_error_from_psa_rsa( status );