boringssl/ssl/test/runner/deterministic.go
David Benjamin 2e045a980c Add a deterministic PRNG for runner.
It's useful, when combined with patching crypto/rand/deterministic.c in, for
debugging things. Also if we want to record fuzzer transcripts again, this
probably should be on.

Change-Id: I109cf27ebab64f01a13466f0d960def3257d8750
Reviewed-on: https://boringssl-review.googlesource.com/8192
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 20:15:48 +00:00

38 lines
1.2 KiB
Go

// Copyright (c) 2016, Google Inc.
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
package runner
import (
"encoding/binary"
)
// Use a different key from crypto/rand/deterministic.c.
var deterministicRandKey = []byte("runner deterministic key 0123456")
type deterministicRand struct {
numCalls uint64
}
func (d *deterministicRand) Read(buf []byte) (int, error) {
for i := range buf {
buf[i] = 0
}
var nonce [12]byte
binary.LittleEndian.PutUint64(nonce[:8], d.numCalls)
chaCha20(buf, buf, deterministicRandKey, nonce[:], 0)
d.numCalls++
return len(buf), nil
}