From 18de9fc6b4ad1454c1d9638b0a304f70f99c66b8 Mon Sep 17 00:00:00 2001
From: Christian Rebischke <chris@shibumi.dev>
Date: Fri, 26 Jun 2020 13:24:20 +0200
Subject: [PATCH] crypto/rsa: add rand initialization for rsa.SignPSS
If nil as random source is being passed to rsa.SignPSS
this is going to lead to a nil pointer dereference and invalid memory
access. This commit intents to this fix via initializing
a secure random source with crypto/rand.Reader
---
src/crypto/rsa/pss.go | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/src/crypto/rsa/pss.go b/src/crypto/rsa/pss.go
index b2adbedb28fa85..b9056976c6dd75 100644
--- a/src/crypto/rsa/pss.go
+++ b/src/crypto/rsa/pss.go
@@ -260,8 +260,14 @@ func (opts *PSSOptions) saltLength() int {
//
// digest must be the result of hashing the input message using the given hash
// function. The opts argument may be nil, in which case sensible defaults are
-// used. If opts.Hash is set, it overrides hash.
+// used. If opts.Hash is set, it overrides hash. The rand argument may be nil
+// if nil rand will get initialized via crypto/rand.Reader
func SignPSS(rand io.Reader, priv *PrivateKey, hash crypto.Hash, digest []byte, opts *PSSOptions) ([]byte, error) {
+ // if no random source has been passed
+ // initialize with secure random from crypto/rand.Reader
+ if rand == nil {
+ rand = rand.Reader
+ }
if opts != nil && opts.Hash != 0 {
hash = opts.Hash
}