| // Copyright 2012 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 amd64 arm64 |
| |
| package aes |
| |
| import ( |
| "crypto/cipher" |
| "crypto/internal/subtle" |
| "internal/cpu" |
| ) |
| |
| import "crypto/internal/boring" |
| |
| // defined in asm_*.s |
| |
| //go:noescape |
| func encryptBlockAsm(nr int, xk *uint32, dst, src *byte) |
| |
| //go:noescape |
| func decryptBlockAsm(nr int, xk *uint32, dst, src *byte) |
| |
| //go:noescape |
| func expandKeyAsm(nr int, key *byte, enc *uint32, dec *uint32) |
| |
| type aesCipherAsm struct { |
| aesCipher |
| } |
| |
| var supportsAES = cpu.X86.HasAES || cpu.ARM64.HasAES |
| var supportsGFMUL = cpu.X86.HasPCLMULQDQ || cpu.ARM64.HasPMULL |
| |
| func newCipher(key []byte) (cipher.Block, error) { |
| if !supportsAES { |
| return newCipherGeneric(key) |
| } |
| n := len(key) + 28 |
| c := aesCipherAsm{aesCipher{make([]uint32, n), make([]uint32, n)}} |
| var rounds int |
| switch len(key) { |
| case 128 / 8: |
| rounds = 10 |
| case 192 / 8: |
| rounds = 12 |
| case 256 / 8: |
| rounds = 14 |
| } |
| |
| expandKeyAsm(rounds, &key[0], &c.enc[0], &c.dec[0]) |
| if supportsAES && supportsGFMUL { |
| return &aesCipherGCM{c}, nil |
| } |
| return &c, nil |
| } |
| |
| func (c *aesCipherAsm) BlockSize() int { return BlockSize } |
| |
| func (c *aesCipherAsm) Encrypt(dst, src []byte) { |
| boring.Unreachable() |
| if len(src) < BlockSize { |
| panic("crypto/aes: input not full block") |
| } |
| if len(dst) < BlockSize { |
| panic("crypto/aes: output not full block") |
| } |
| if subtle.InexactOverlap(dst[:BlockSize], src[:BlockSize]) { |
| panic("crypto/aes: invalid buffer overlap") |
| } |
| encryptBlockAsm(len(c.enc)/4-1, &c.enc[0], &dst[0], &src[0]) |
| } |
| |
| func (c *aesCipherAsm) Decrypt(dst, src []byte) { |
| boring.Unreachable() |
| if len(src) < BlockSize { |
| panic("crypto/aes: input not full block") |
| } |
| if len(dst) < BlockSize { |
| panic("crypto/aes: output not full block") |
| } |
| if subtle.InexactOverlap(dst[:BlockSize], src[:BlockSize]) { |
| panic("crypto/aes: invalid buffer overlap") |
| } |
| decryptBlockAsm(len(c.dec)/4-1, &c.dec[0], &dst[0], &src[0]) |
| } |
| |
| // expandKey is used by BenchmarkExpand to ensure that the asm implementation |
| // of key expansion is used for the benchmark when it is available. |
| func expandKey(key []byte, enc, dec []uint32) { |
| if supportsAES { |
| rounds := 10 // rounds needed for AES128 |
| switch len(key) { |
| case 192 / 8: |
| rounds = 12 |
| case 256 / 8: |
| rounds = 14 |
| } |
| expandKeyAsm(rounds, &key[0], &enc[0], &dec[0]) |
| } else { |
| expandKeyGo(key, enc, dec) |
| } |
| } |