--- a/security/nss/lib/freebl/shvfy.c
+++ b/security/nss/lib/freebl/shvfy.c
@@ -115,17 +115,17 @@ BLAPI_SHVerify(const char *name, PRFuncP
     SECItem hash;
     int bytesRead, offset;
     SECStatus rv;
     DSAPublicKey key;
     int count;
 
     PRBool result = PR_FALSE; /* if anything goes wrong,
 			       * the signature does not verify */
-    unsigned char buf[512];
+    unsigned char buf[4096];
     unsigned char hashBuf[SHA1_LENGTH];
 
     PORT_Memset(&key,0,sizeof(key));
     hash.data = hashBuf;
     hash.len = sizeof(hashBuf);
 
     if (!shName) {
 	goto loser;