gcc/libgo/go/crypto/aes/ctr_s390x.go
Ian Lance Taylor 1a2f01efa6 libgo: update to Go1.10beta1
Update the Go library to the 1.10beta1 release.
    
    Requires a few changes to the compiler for modifications to the map
    runtime code, and to handle some nowritebarrier cases in the runtime.
    
    Reviewed-on: https://go-review.googlesource.com/86455

gotools/:
	* Makefile.am (go_cmd_vet_files): New variable.
	(go_cmd_buildid_files, go_cmd_test2json_files): New variables.
	(s-zdefaultcc): Change from constants to functions.
	(noinst_PROGRAMS): Add vet, buildid, and test2json.
	(cgo$(EXEEXT)): Link against $(LIBGOTOOL).
	(vet$(EXEEXT)): New target.
	(buildid$(EXEEXT)): New target.
	(test2json$(EXEEXT)): New target.
	(install-exec-local): Install all $(noinst_PROGRAMS).
	(uninstall-local): Uninstasll all $(noinst_PROGRAMS).
	(check-go-tool): Depend on $(noinst_PROGRAMS).  Copy down
	objabi.go.
	(check-runtime): Depend on $(noinst_PROGRAMS).
	(check-cgo-test, check-carchive-test): Likewise.
	(check-vet): New target.
	(check): Depend on check-vet.  Look at cmd_vet-testlog.
	(.PHONY): Add check-vet.
	* Makefile.in: Rebuild.

From-SVN: r256365
2018-01-09 01:23:08 +00:00

83 lines
2.4 KiB
Go

// Copyright 2016 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 ignore
package aes
import (
"crypto/cipher"
"unsafe"
)
// Assert that aesCipherAsm implements the ctrAble interface.
var _ ctrAble = (*aesCipherAsm)(nil)
// xorBytes xors the contents of a and b and places the resulting values into
// dst. If a and b are not the same length then the number of bytes processed
// will be equal to the length of shorter of the two. Returns the number
// of bytes processed.
//go:noescape
func xorBytes(dst, a, b []byte) int
// streamBufferSize is the number of bytes of encrypted counter values to cache.
const streamBufferSize = 32 * BlockSize
type aesctr struct {
block *aesCipherAsm // block cipher
ctr [2]uint64 // next value of the counter (big endian)
buffer []byte // buffer for the encrypted counter values
storage [streamBufferSize]byte // array backing buffer slice
}
// NewCTR returns a Stream which encrypts/decrypts using the AES block
// cipher in counter mode. The length of iv must be the same as BlockSize.
func (c *aesCipherAsm) NewCTR(iv []byte) cipher.Stream {
if len(iv) != BlockSize {
panic("cipher.NewCTR: IV length must equal block size")
}
var ac aesctr
ac.block = c
ac.ctr[0] = *(*uint64)(unsafe.Pointer((&iv[0]))) // high bits
ac.ctr[1] = *(*uint64)(unsafe.Pointer((&iv[8]))) // low bits
ac.buffer = ac.storage[:0]
return &ac
}
func (c *aesctr) refill() {
// Fill up the buffer with an incrementing count.
c.buffer = c.storage[:streamBufferSize]
c0, c1 := c.ctr[0], c.ctr[1]
for i := 0; i < streamBufferSize; i += BlockSize {
b0 := (*uint64)(unsafe.Pointer(&c.buffer[i]))
b1 := (*uint64)(unsafe.Pointer(&c.buffer[i+BlockSize/2]))
*b0, *b1 = c0, c1
// Increment in big endian: c0 is high, c1 is low.
c1++
if c1 == 0 {
// add carry
c0++
}
}
c.ctr[0], c.ctr[1] = c0, c1
// Encrypt the buffer using AES in ECB mode.
cryptBlocks(c.block.function, &c.block.key[0], &c.buffer[0], &c.buffer[0], streamBufferSize)
}
func (c *aesctr) XORKeyStream(dst, src []byte) {
if len(src) > 0 {
// Assert len(dst) >= len(src)
_ = dst[len(src)-1]
}
for len(src) > 0 {
if len(c.buffer) == 0 {
c.refill()
}
n := xorBytes(dst, src, c.buffer)
c.buffer = c.buffer[n:]
src = src[n:]
dst = dst[n:]
}
}