From 79befe0e3139e3c54f19766c64d7e610fcc69346 Mon Sep 17 00:00:00 2001
From: Tom Stellard <tstellar@redhat.com>
Date: Sep 11 2019 03:10:28 +0000
Subject: Add fallback to VerifyPKCS1v15() when input is already a hashed value


This change is not FIPS compliant but will allow existing applications
to continue to run correctly while they migrate to using the crytp APIs
in a FIPS compliant manner.

---

diff --git a/src/crypto/rsa/pkcs1v15.go b/src/crypto/rsa/pkcs1v15.go
index 26aac57..e73c0fa 100644
--- a/src/crypto/rsa/pkcs1v15.go
+++ b/src/crypto/rsa/pkcs1v15.go
@@ -323,6 +323,15 @@ func VerifyPKCS1v15(pub *PublicKey, hash crypto.Hash, hashed []byte, sig []byte)
 		if err != nil {
 			return err
 		}
+		if hash == 0 {
+			// TODO: Emit a warning here.
+			// FIXME: Relax FIPS requirements to support existing applications.
+			// FIXME: Do we need to pad the encrypted value here?
+			hashed, err = boring.EncryptRSAPKCS1(bkey, sig)
+			if err != nil {
+				return err
+			}
+		}
 		if err := boring.VerifyRSAPKCS1v15(bkey, hash, hashed, sig); err != nil {
 			return ErrVerification
 		}