60 lines
1.4 KiB
Go
60 lines
1.4 KiB
Go
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// Copyright 2016 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package aes
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import (
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"crypto/cipher"
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)
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// Assert that aesCipherAsm implements the cbcEncAble and cbcDecAble interfaces.
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var _ cbcEncAble = (*aesCipherAsm)(nil)
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var _ cbcDecAble = (*aesCipherAsm)(nil)
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type cbc struct {
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b *aesCipherAsm
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c code
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iv [BlockSize]byte
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}
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func (b *aesCipherAsm) NewCBCEncrypter(iv []byte) cipher.BlockMode {
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var c cbc
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c.b = b
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c.c = b.function
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copy(c.iv[:], iv)
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return &c
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}
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func (b *aesCipherAsm) NewCBCDecrypter(iv []byte) cipher.BlockMode {
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var c cbc
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c.b = b
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c.c = b.function + 128 // decrypt function code is encrypt + 128
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copy(c.iv[:], iv)
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return &c
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}
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func (x *cbc) BlockSize() int { return BlockSize }
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// cryptBlocksChain invokes the cipher message with chaining (KMC) instruction
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// with the given function code. The length must be a multiple of BlockSize (16).
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//go:noescape
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func cryptBlocksChain(c code, iv, key, dst, src *byte, length int)
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func (x *cbc) CryptBlocks(dst, src []byte) {
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if len(src)%BlockSize != 0 {
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panic("crypto/cipher: input not full blocks")
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}
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if len(dst) < len(src) {
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panic("crypto/cipher: output smaller than input")
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}
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cryptBlocksChain(x.c, &x.iv[0], &x.b.key[0], &dst[0], &src[0], len(src))
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}
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func (x *cbc) SetIV(iv []byte) {
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if len(iv) != BlockSize {
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panic("cipher: incorrect length IV")
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}
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copy(x.iv[:], iv)
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}
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