Fix the maximum output size in the call to the external signer.

host/lib/host_signature.c

 /* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  *
  * Host functions for signature generation.
  */
 
 /* TODO: change all 'return 0', 'return 1' into meaningful return codes */
 
 #define OPENSSL_NO_SHA
@@ skipping 248 matching lines @@
   sig = SignatureAlloc(siglen_map[key_algorithm], size);
   if (!sig) {
     Free(signature_digest);
     return NULL;
   }
 
   /* Sign the signature_digest into our output buffer */
   rv = InvokeExternalSigner(signature_digest_len, /* Input length */
                             signature_digest,     /* Input data */
                             GetSignatureData(sig), /* Output sig */
-                            (sizeof(VbSignature) + /* Max Output sig size. */
-                             siglen_map[key_algorithm]) ,
+                            siglen_map[key_algorithm], /* Max Output sig size */
                             key_file,             /* Key file to use */
                             external_signer);     /* External cmd to invoke */
   Free(signature_digest);
 
   if (-1 == rv) {
     VBDEBUG(("SignatureBuf(): RSA_private_encrypt() failed.\n"));
     Free(sig);
     return NULL;
   }
 
   /* Return the signature */
   return sig;
 }