Add additional password hash algorithms (closes #5859) (#6023)

vendor/golang.org/x/crypto/argon2/blake2b.go

@@ -0,0 +1,53 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package argon2
+
+import (
+	"encoding/binary"
+	"hash"
+
+	"golang.org/x/crypto/blake2b"
+)
+
+// blake2bHash computes an arbitrary long hash value of in
+// and writes the hash to out.
+func blake2bHash(out []byte, in []byte) {
+	var b2 hash.Hash
+	if n := len(out); n < blake2b.Size {
+		b2, _ = blake2b.New(n, nil)
+	} else {
+		b2, _ = blake2b.New512(nil)
+	}
+
+	var buffer [blake2b.Size]byte
+	binary.LittleEndian.PutUint32(buffer[:4], uint32(len(out)))
+	b2.Write(buffer[:4])
+	b2.Write(in)
+
+	if len(out) <= blake2b.Size {
+		b2.Sum(out[:0])
+		return
+	}
+
+	outLen := len(out)
+	b2.Sum(buffer[:0])
+	b2.Reset()
+	copy(out, buffer[:32])
+	out = out[32:]
+	for len(out) > blake2b.Size {
+		b2.Write(buffer[:])
+		b2.Sum(buffer[:0])
+		copy(out, buffer[:32])
+		out = out[32:]
+		b2.Reset()
+	}
+
+	if outLen%blake2b.Size > 0 { // outLen > 64
+		r := ((outLen + 31) / 32) - 2 // ⌈τ /32⌉-2
+		b2, _ = blake2b.New(outLen-32*r, nil)
+	}
+	b2.Write(buffer[:])
+	b2.Sum(out[:0])
+}