Fixed RSA_X_509 padding.

ykcs11/mechanisms.c

@@ -1,5 +1,6 @@
 #include "mechanisms.h"
 #include "debug.h"
+#include <string.h>
 
 #define F4 "\x01\x00\x01"
 #define PRIME256V1 "\x06\x08\x2a\x86\x48\xce\x3d\x03\x01\x07"
@@ -146,14 +147,9 @@ CK_RV apply_sign_mechanism_init(op_info_t *op_info) {
 
     switch (op_info->mechanism.mechanism) {
     case CKM_RSA_PKCS:
-      // No hash required for this mechanism
-      return CKR_OK;
-
     case CKM_RSA_PKCS_PSS:
-      // No hash required for this mechanism
-      return CKR_OK;
-
     case CKM_RSA_X_509:
+    case CKM_ECDSA:
       // No hash required for this mechanism
       return CKR_OK;
 
@@ -174,10 +170,6 @@ CK_RV apply_sign_mechanism_init(op_info_t *op_info) {
     case CKM_SHA512_RSA_PKCS_PSS:
       return do_md_init(YKCS11_SHA512, &op_info->op.sign.md_ctx);
 
-    case CKM_ECDSA:
-      // No hash required for this mechanism
-      return CKR_OK;
-
     default:
       return CKR_FUNCTION_FAILED;
   }
@@ -196,12 +188,10 @@ CK_RV apply_sign_mechanism_update(op_info_t *op_info, CK_BYTE_PTR in, CK_ULONG i
   case CKM_RSA_PKCS:
   case CKM_RSA_PKCS_PSS:
   case CKM_ECDSA:
+  case CKM_RSA_X_509:
     // Mechanism not suitable for multipart signatures
     return CKR_FUNCTION_FAILED;
 
-  case CKM_RSA_X_509: // TODO: shouldn't this be in the group above?
-    return CKR_OK;
-
   case CKM_SHA1_RSA_PKCS:
   case CKM_SHA256_RSA_PKCS:
   case CKM_SHA384_RSA_PKCS:
@@ -258,6 +248,11 @@ CK_RV apply_sign_mechanism_finalize(op_info_t *op_info) {
     return rv;
 
   case CKM_RSA_X_509:
+    // Padding in this case consists of prepending zeroes
+    len = (op_info->op.sign.key_len / 8) - op_info->buf_len;
+    memmove(op_info->buf + len, op_info->buf, op_info->buf_len);
+    memset(op_info->buf, 0, len);
+    op_info->buf_len = op_info->op.sign.key_len / 8;
     return CKR_OK;
 
   case CKM_SHA1_RSA_PKCS: