50 lines
1.5 KiB
Go
50 lines
1.5 KiB
Go
|
// Copyright 2018 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.
|
||
|
|
|
||
|
|
// +build s390x,go1.11,!gccgo,!appengine
|
||
|
|
|
||
|
|
package poly1305
|
||
|
|
|
||
|
|
// hasVectorFacility reports whether the machine supports
|
||
|
|
// the vector facility (vx).
|
||
|
|
func hasVectorFacility() bool
|
||
|
|
|
||
|
|
// hasVMSLFacility reports whether the machine supports
|
||
|
|
// Vector Multiply Sum Logical (VMSL).
|
||
|
|
func hasVMSLFacility() bool
|
||
|
|
|
||
|
|
var hasVX = hasVectorFacility()
|
||
|
|
var hasVMSL = hasVMSLFacility()
|
||
|
|
|
||
|
|
// poly1305vx is an assembly implementation of Poly1305 that uses vector
|
||
|
|
// instructions. It must only be called if the vector facility (vx) is
|
||
|
|
// available.
|
||
|
|
//go:noescape
|
||
|
|
func poly1305vx(out *[16]byte, m *byte, mlen uint64, key *[32]byte)
|
||
|
|
|
||
|
|
// poly1305vmsl is an assembly implementation of Poly1305 that uses vector
|
||
|
|
// instructions, including VMSL. It must only be called if the vector facility (vx) is
|
||
|
|
// available and if VMSL is supported.
|
||
|
|
//go:noescape
|
||
|
|
func poly1305vmsl(out *[16]byte, m *byte, mlen uint64, key *[32]byte)
|
||
|
|
|
||
|
|
// Sum generates an authenticator for m using a one-time key and puts the
|
||
|
|
// 16-byte result into out. Authenticating two different messages with the same
|
||
|
|
// key allows an attacker to forge messages at will.
|
||
|
|
func Sum(out *[16]byte, m []byte, key *[32]byte) {
|
||
|
|
if hasVX {
|
||
|
|
var mPtr *byte
|
||
|
|
if len(m) > 0 {
|
||
|
|
mPtr = &m[0]
|
||
|
|
}
|
||
|
|
if hasVMSL && len(m) > 256 {
|
||
|
|
poly1305vmsl(out, mPtr, uint64(len(m)), key)
|
||
|
|
} else {
|
||
|
|
poly1305vx(out, mPtr, uint64(len(m)), key)
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
sumGeneric(out, m, key)
|
||
|
|
}
|
||
|
|
}
|