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Crypto modes: CBC, CFB, ECB.

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Not ready to link into build yet.

Delta says 1272 lines but only 474
if you subtract the test files,
which are mostly data.

R=r
DELTA=1252  (1249 added, 0 deleted, 3 changed)
OCL=29013
CL=29037
This commit is contained in:
Russ Cox 2009-05-19 14:01:03 -07:00
parent da49bfe664
commit b0608c1391
9 changed files with 1260 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

75
src/lib/crypto/block/cbc.go Normal file
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// Copyright 2009 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.
// Cipher block chaining (CBC) mode.
// CBC provides confidentiality by xoring (chaining) each plaintext block
// with the previous ciphertext block before applying the block cipher.
// See NIST SP 800-38A, pp 10-11
package block
import (
"crypto/block";
"io";
)
type cbcCipher struct {
c Cipher;
blockSize int;
iv []byte;
tmp []byte;
}
func newCBC(c Cipher, iv []byte) *cbcCipher {
n := c.BlockSize();
x := new(cbcCipher);
x.c = c;
x.blockSize = n;
x.iv = copy(iv);
x.tmp = make([]byte, n);
return x;
}
func (x *cbcCipher) BlockSize() int {
return x.blockSize;
}
func (x *cbcCipher) Encrypt(src, dst []byte) {
for i := 0; i < x.blockSize; i++ {
x.iv[i] ^= src[i];
}
x.c.Encrypt(x.iv, x.iv);
for i := 0; i < x.blockSize; i++ {
dst[i] = x.iv[i];
}
}
func (x *cbcCipher) Decrypt(src, dst []byte) {
x.c.Decrypt(src, x.tmp);
for i := 0; i < x.blockSize; i++ {
x.tmp[i] ^= x.iv[i];
x.iv[i] = src[i];
dst[i] = x.tmp[i];
}
}
// NewCBCDecrypter returns a reader that reads data from r and decrypts it using c
// in cipher block chaining (CBC) mode with the initialization vector iv.
// The returned Reader does not buffer or read ahead except
// as required by the cipher's block size.
func NewCBCDecrypter(c Cipher, iv []byte, r io.Reader) io.Reader {
return NewECBDecrypter(newCBC(c, iv), r);
}
// NewCBCEncrypter returns a writer that encrypts data using c
// in cipher block chaining (CBC) mode with the initialization vector iv
// and writes the encrypted data to w.
// The returned Writer does no buffering except as required
// by the cipher's block size, so there is no need for a Flush method.
func NewCBCEncrypter(c Cipher, iv []byte, w io.Writer) io.Writer {
return NewECBEncrypter(newCBC(c, iv), w);
}

107
src/lib/crypto/block/cbc_aes_test.go Normal file
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// Copyright 2009 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.
// CBC AES test vectors.
// See U.S. National Institute of Standards and Technology (NIST)
// Special Publication 800-38A, ``Recommendation for Block Cipher
// Modes of Operation,'' 2001 Edition, pp. 24-29.
package block
// gobuild: $GC ecb_aes_test.go
import (
"crypto/aes";
"crypto/block";
"io";
"os";
"testing";
"./ecb_aes_test";
)
type cbcTest struct {
name string;
key []byte;
iv []byte;
in []byte;
out []byte;
}
var cbcAESTests = []cbcTest {
// NIST SP 800-38A pp 27-29
cbcTest {
"CBC-AES128",
commonKey128,
commonIV,
commonInput,
[]byte {
0x76, 0x49, 0xab, 0xac, 0x81, 0x19, 0xb2, 0x46, 0xce, 0xe9, 0x8e, 0x9b, 0x12, 0xe9, 0x19, 0x7d,
0x50, 0x86, 0xcb, 0x9b, 0x50, 0x72, 0x19, 0xee, 0x95, 0xdb, 0x11, 0x3a, 0x91, 0x76, 0x78, 0xb2,
0x73, 0xbe, 0xd6, 0xb8, 0xe3, 0xc1, 0x74, 0x3b, 0x71, 0x16, 0xe6, 0x9e, 0x22, 0x22, 0x95, 0x16,
0x3f, 0xf1, 0xca, 0xa1, 0x68, 0x1f, 0xac, 0x09, 0x12, 0x0e, 0xca, 0x30, 0x75, 0x86, 0xe1, 0xa7,
},
},
cbcTest {
"CBC-AES192",
commonKey192,
commonIV,
commonInput,
[]byte {
0x4f, 0x02, 0x1d, 0xb2, 0x43, 0xbc, 0x63, 0x3d, 0x71, 0x78, 0x18, 0x3a, 0x9f, 0xa0, 0x71, 0xe8,
0xb4, 0xd9, 0xad, 0xa9, 0xad, 0x7d, 0xed, 0xf4, 0xe5, 0xe7, 0x38, 0x76, 0x3f, 0x69, 0x14, 0x5a,
0x57, 0x1b, 0x24, 0x20, 0x12, 0xfb, 0x7a, 0xe0, 0x7f, 0xa9, 0xba, 0xac, 0x3d, 0xf1, 0x02, 0xe0,
0x08, 0xb0, 0xe2, 0x79, 0x88, 0x59, 0x88, 0x81, 0xd9, 0x20, 0xa9, 0xe6, 0x4f, 0x56, 0x15, 0xcd,
},
},
cbcTest {
"CBC-AES256",
commonKey256,
commonIV,
commonInput,
[]byte {
0xf5, 0x8c, 0x4c, 0x04, 0xd6, 0xe5, 0xf1, 0xba, 0x77, 0x9e, 0xab, 0xfb, 0x5f, 0x7b, 0xfb, 0xd6,
0x9c, 0xfc, 0x4e, 0x96, 0x7e, 0xdb, 0x80, 0x8d, 0x67, 0x9f, 0x77, 0x7b, 0xc6, 0x70, 0x2c, 0x7d,
0x39, 0xf2, 0x33, 0x69, 0xa9, 0xd9, 0xba, 0xcf, 0xa5, 0x30, 0xe2, 0x63, 0x04, 0x23, 0x14, 0x61,
0xb2, 0xeb, 0x05, 0xe2, 0xc3, 0x9b, 0xe9, 0xfc, 0xda, 0x6c, 0x19, 0x07, 0x8c, 0x6a, 0x9d, 0x1b,
},
},
}
func TestCBC_AES(t *testing.T) {
for i, tt := range cbcAESTests {
test := tt.name;
c, err := aes.NewCipher(tt.key);
if err != nil {
t.Errorf("%s: NewCipher(%d bytes) = %s", test, len(tt.key), err);
continue;
}
var crypt io.ByteBuffer;
w := NewCBCEncrypter(c, tt.iv, &crypt);
var r io.Reader = io.NewByteReader(tt.in);
n, err := io.Copy(r, w);
if n != int64(len(tt.in)) || err != nil {
t.Errorf("%s: CBCEncrypter io.Copy = %d, %v want %d, nil", test, n, err, len(tt.in));
} else if d := crypt.Data(); !same(tt.out, d) {
t.Errorf("%s: CBCEncrypter\nhave %x\nwant %x", test, d, tt.out);
}
var plain io.ByteBuffer;
r = NewCBCDecrypter(c, tt.iv, io.NewByteReader(tt.out));
w = &plain;
n, err = io.Copy(r, w);
if n != int64(len(tt.out)) || err != nil {
t.Errorf("%s: CBCDecrypter io.Copy = %d, %v want %d, nil", test, n, err, len(tt.out));
} else if d := plain.Data(); !same(tt.in, d) {
t.Errorf("%s: CBCDecrypter\nhave %x\nwant %x", test, d, tt.in);
}
if t.Failed() {
break;
}
}
}

100
src/lib/crypto/block/cfb.go Normal file
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// Copyright 2009 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.
// Cipher feedback (CFB) mode.
// CFB provides confidentiality by feeding a fraction of
// the previous ciphertext in as the plaintext for the next
// block operation.
// See NIST SP 800-38A, pp 11-13
package block
import (
"crypto/block";
"io";
)
type cfbCipher struct {
c Cipher;
blockSize int; // our block size (s/8)
cipherSize int; // underlying cipher block size
iv []byte;
tmp []byte;
}
func newCFB(c Cipher, s int, iv []byte) *cfbCipher {
if s == 0 || s % 8 != 0 {
panicln("invalid CFB mode", s);
}
b := c.BlockSize();
x := new(cfbCipher);
x.c = c;
x.blockSize = s/8;
x.cipherSize = b;
x.iv = copy(iv);
x.tmp = make([]byte, b);
return x;
}
func (x *cfbCipher) BlockSize() int {
return x.blockSize;
}
func (x *cfbCipher) Encrypt(src, dst []byte) {
// Encrypt old IV and xor prefix with src to make dst.
x.c.Encrypt(x.iv, x.tmp);
for i := 0; i < x.blockSize; i++ {
dst[i] = src[i] ^ x.tmp[i];
}
// Slide unused IV pieces down and insert dst at end.
for i := 0; i < x.cipherSize - x.blockSize; i++ {
x.iv[i] = x.iv[i + x.blockSize];
}
off := x.cipherSize - x.blockSize;
for i := off; i < x.cipherSize; i++ {
x.iv[i] = dst[i - off];
}
}
func (x *cfbCipher) Decrypt(src, dst []byte) {
// Encrypt [sic] old IV and xor prefix with src to make dst.
x.c.Encrypt(x.iv, x.tmp);
for i := 0; i < x.blockSize; i++ {
dst[i] = src[i] ^ x.tmp[i];
}
// Slide unused IV pieces down and insert src at top.
for i := 0; i < x.cipherSize - x.blockSize; i++ {
x.iv[i] = x.iv[i + x.blockSize];
}
off := x.cipherSize - x.blockSize;
for i := off; i < x.cipherSize; i++ {
// Reconstruct src = dst ^ x.tmp
// in case we overwrote src (src == dst).
x.iv[i] = dst[i - off] ^ x.tmp[i - off];
}
}
// NewCFBDecrypter returns a reader that reads data from r and decrypts it using c
// in s-bit cipher feedback (CFB) mode with the initialization vector iv.
// The returned Reader does not buffer or read ahead except
// as required by the cipher's block size.
// Modes for s not a multiple of 8 are unimplemented.
func NewCFBDecrypter(c Cipher, s int, iv []byte, r io.Reader) io.Reader {
return NewECBDecrypter(newCFB(c, s, iv), r);
}
// NewCFBEncrypter returns a writer that encrypts data using c
// in s-bit cipher feedback (CFB) mode with the initialization vector iv
// and writes the encrypted data to w.
// The returned Writer does no buffering except as required
// by the cipher's block size, so there is no need for a Flush method.
// Modes for s not a multiple of 8 are unimplemented.
func NewCFBEncrypter(c Cipher, s int, iv []byte, w io.Writer) io.Writer {
return NewECBEncrypter(newCFB(c, s, iv), w);
}

316
src/lib/crypto/block/cfb_aes_test.go Normal file
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// Copyright 2009 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.
// CFB AES test vectors.
// See U.S. National Institute of Standards and Technology (NIST)
// Special Publication 800-38A, ``Recommendation for Block Cipher
// Modes of Operation,'' 2001 Edition, pp. 29-52.
package block
// gobuild: $GC ecb_aes_test.go
import (
"crypto/aes";
"crypto/block";
"io";
"os";
"testing";
"./ecb_aes_test";
)
type cfbTest struct {
name string;
s int;
key []byte;
iv []byte;
in []byte;
out []byte;
}
var cfbAESTests = []cfbTest {
cfbTest {
"CFB1-AES128",
1,
commonKey128,
commonIV,
[]byte{
0<<7 | 1<<6 | 1<<5 | 0<<4 | 1<<3 | 0<<2 | 1<<1,
1<<7 | 1<<6 | 0<<5 | 0<<4 | 0<<3 | 0<<2 | 0<<1,
},
[]byte{
0<<7 | 1<<6 | 1<<5 | 0<<4 | 1<<3 | 0<<2 | 0<<1,
1<<7 | 0<<6 | 1<<5 | 1<<4 | 0<<3 | 0<<2 | 1<<1,
},
},
cfbTest {
"CFB1-AES192",
1,
commonKey192,
commonIV,
[]byte{
0<<7 | 1<<6 | 1<<5 | 0<<4 | 1<<3 | 0<<2 | 1<<1,
1<<7 | 1<<6 | 0<<5 | 0<<4 | 0<<3 | 0<<2 | 0<<1,
},
[]byte{
1<<7 | 0<<6 | 0<<5 | 1<<4 | 0<<3 | 0<<2 | 1<<1,
0<<7 | 1<<6 | 0<<5 | 1<<4 | 1<<3 | 0<<2 | 0<<1,
},
},
cfbTest {
"CFB1-AES256",
1,
commonKey256,
commonIV,
[]byte{
0<<7 | 1<<6 | 1<<5 | 0<<4 | 1<<3 | 0<<2 | 1<<1,
1<<7 | 1<<6 | 0<<5 | 0<<4 | 0<<3 | 0<<2 | 0<<1,
},
[]byte{
1<<7 | 0<<6 | 0<<5 | 1<<4 | 0<<3 | 0<<2 | 0<<1,
0<<7 | 0<<6 | 1<<5 | 0<<4 | 1<<3 | 0<<2 | 0<<1,
},
},
cfbTest {
"CFB8-AES128",
8,
commonKey128,
commonIV,
[]byte{
0x6b,
0xc1,
0xbe,
0xe2,
0x2e,
0x40,
0x9f,
0x96,
0xe9,
0x3d,
0x7e,
0x11,
0x73,
0x93,
0x17,
0x2a,
0xae,
0x2d,
},
[]byte{
0x3b,
0x79,
0x42,
0x4c,
0x9c,
0x0d,
0xd4,
0x36,
0xba,
0xce,
0x9e,
0x0e,
0xd4,
0x58,
0x6a,
0x4f,
0x32,
0xb9,
},
},
cfbTest {
"CFB8-AES192",
8,
commonKey192,
commonIV,
[]byte{
0x6b,
0xc1,
0xbe,
0xe2,
0x2e,
0x40,
0x9f,
0x96,
0xe9,
0x3d,
0x7e,
0x11,
0x73,
0x93,
0x17,
0x2a,
0xae,
0x2d,
},
[]byte{
0xcd,
0xa2,
0x52,
0x1e,
0xf0,
0xa9,
0x05,
0xca,
0x44,
0xcd,
0x05,
0x7c,
0xbf,
0x0d,
0x47,
0xa0,
0x67,
0x8a,
},
},
cfbTest {
"CFB8-AES256",
8,
commonKey256,
commonIV,
[]byte{
0x6b,
0xc1,
0xbe,
0xe2,
0x2e,
0x40,
0x9f,
0x96,
0xe9,
0x3d,
0x7e,
0x11,
0x73,
0x93,
0x17,
0x2a,
0xae,
0x2d,
},
[]byte{
0xdc,
0x1f,
0x1a,
0x85,
0x20,
0xa6,
0x4d,
0xb5,
0x5f,
0xcc,
0x8a,
0xc5,
0x54,
0x84,
0x4e,
0x88,
0x97,
0x00,
},
},
cfbTest {
"CFB128-AES128",
128,
commonKey128,
commonIV,
[]byte{
0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
},
[]byte{
0x3b, 0x3f, 0xd9, 0x2e, 0xb7, 0x2d, 0xad, 0x20, 0x33, 0x34, 0x49, 0xf8, 0xe8, 0x3c, 0xfb, 0x4a,
0xc8, 0xa6, 0x45, 0x37, 0xa0, 0xb3, 0xa9, 0x3f, 0xcd, 0xe3, 0xcd, 0xad, 0x9f, 0x1c, 0xe5, 0x8b,
0x26, 0x75, 0x1f, 0x67, 0xa3, 0xcb, 0xb1, 0x40, 0xb1, 0x80, 0x8c, 0xf1, 0x87, 0xa4, 0xf4, 0xdf,
0xc0, 0x4b, 0x05, 0x35, 0x7c, 0x5d, 0x1c, 0x0e, 0xea, 0xc4, 0xc6, 0x6f, 0x9f, 0xf7, 0xf2, 0xe6,
},
},
cfbTest {
"CFB128-AES192",
128,
commonKey192,
commonIV,
[]byte{
0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
},
[]byte{
0xcd, 0xc8, 0x0d, 0x6f, 0xdd, 0xf1, 0x8c, 0xab, 0x34, 0xc2, 0x59, 0x09, 0xc9, 0x9a, 0x41, 0x74,
0x67, 0xce, 0x7f, 0x7f, 0x81, 0x17, 0x36, 0x21, 0x96, 0x1a, 0x2b, 0x70, 0x17, 0x1d, 0x3d, 0x7a,
0x2e, 0x1e, 0x8a, 0x1d, 0xd5, 0x9b, 0x88, 0xb1, 0xc8, 0xe6, 0x0f, 0xed, 0x1e, 0xfa, 0xc4, 0xc9,
0xc0, 0x5f, 0x9f, 0x9c, 0xa9, 0x83, 0x4f, 0xa0, 0x42, 0xae, 0x8f, 0xba, 0x58, 0x4b, 0x09, 0xff,
},
},
cfbTest {
"CFB128-AES256",
128,
commonKey256,
commonIV,
[]byte{
0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
},
[]byte{
0xdc, 0x7e, 0x84, 0xbf, 0xda, 0x79, 0x16, 0x4b, 0x7e, 0xcd, 0x84, 0x86, 0x98, 0x5d, 0x38, 0x60,
0x39, 0xff, 0xed, 0x14, 0x3b, 0x28, 0xb1, 0xc8, 0x32, 0x11, 0x3c, 0x63, 0x31, 0xe5, 0x40, 0x7b,
0xdf, 0x10, 0x13, 0x24, 0x15, 0xe5, 0x4b, 0x92, 0xa1, 0x3e, 0xd0, 0xa8, 0x26, 0x7a, 0xe2, 0xf9,
0x75, 0xa3, 0x85, 0x74, 0x1a, 0xb9, 0xce, 0xf8, 0x20, 0x31, 0x62, 0x3d, 0x55, 0xb1, 0xe4, 0x71,
},
},
}
func TestCFB_AES(t *testing.T) {
for i, tt := range cfbAESTests {
test := tt.name;
if tt.s == 1 {
// 1-bit CFB not implemented
continue;
}
c, err := aes.NewCipher(tt.key);
if err != nil {
t.Errorf("%s: NewCipher(%d bytes) = %s", test, len(tt.key), err);
continue;
}
var crypt io.ByteBuffer;
w := NewCFBEncrypter(c, tt.s, tt.iv, &crypt);
var r io.Reader = io.NewByteReader(tt.in);
n, err := io.Copy(r, w);
if n != int64(len(tt.in)) || err != nil {
t.Errorf("%s: CFBEncrypter io.Copy = %d, %v want %d, nil", test, n, err, len(tt.in));
} else if d := crypt.Data(); !same(tt.out, d) {
t.Errorf("%s: CFBEncrypter\nhave %x\nwant %x", test, d, tt.out);
}
var plain io.ByteBuffer;
r = NewCFBDecrypter(c, tt.s, tt.iv, io.NewByteReader(tt.out));
w = &plain;
n, err = io.Copy(r, w);
if n != int64(len(tt.out)) || err != nil {
t.Errorf("%s: CFBDecrypter io.Copy = %d, %v want %d, nil", test, n, err, len(tt.out));
} else if d := plain.Data(); !same(tt.in, d) {
t.Errorf("%s: CFBDecrypter\nhave %x\nwant %x", test, d, tt.in);
}
if t.Failed() {
break;
}
}
}

58
src/lib/crypto/block/cipher.go Normal file
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// Copyright 2009 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.
// The block package implements standard block cipher modes
// that can be wrapped around low-level block cipher implementations.
// See http://csrc.nist.gov/groups/ST/toolkit/BCM/current_modes.html
// and NIST Special Publication 800-38A.
package block
// A Cipher represents an implementation of block cipher
// using a given key. It provides the capability to encrypt
// or decrypt individual blocks. The mode implementations
// extend that capability to streams of blocks.
type Cipher interface {
// BlockSize returns the cipher's block size.
BlockSize() int;
// Encrypt encrypts the first block in src into dst.
// Src and dst may point at the same memory.
Encrypt(src, dst []byte);
// Decrypt decrypts the first block in src into dst.
// Src and dst may point at the same memory.
Decrypt(src, dst []byte);
}
// Utility routines
func shift1(src, dst []byte) byte {
var b byte;
for i := len(src)-1; i >= 0; i-- {
bb := src[i]>>7;
dst[i] = src[i]<<1 | b;
b = bb;
}
return b;
}
func same(p, q []byte) bool {
if len(p) != len(q) {
return false;
}
for i := 0; i < len(p); i++ {
if p[i] != q[i] {
return false;
}
}
return true;
}
func copy(p []byte) []byte {
q := make([]byte, len(p));
for i, b := range p {
q[i] = b;
}
return q;
}

271
src/lib/crypto/block/ecb.go Normal file
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@ -0,0 +1,271 @@
// Copyright 2009 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.
// Electronic codebook (ECB) mode.
// ECB is a fancy name for ``encrypt and decrypt each block separately.''
// It's a pretty bad thing to do for any large amount of data (more than one block),
// because the individual blocks can still be identified, duplicated, and reordered.
// The ECB implementation exists mainly to provide buffering for
// the other modes, which wrap it by providing modified Ciphers.
// See NIST SP 800-38A, pp 9-10
package block
import (
"crypto/block";
"io";
"os";
)
type ecbDecrypter struct {
c Cipher;
r io.Reader;
blockSize int; // block size
// Buffered data.
// The buffer buf is used as storage for both
// plain or crypt; at least one of those is nil at any given time.
buf []byte;
plain []byte; // plain text waiting to be read
crypt []byte; // ciphertext waiting to be decrypted
}
// Read into x.crypt until it has a full block or EOF or an error happens.
func (x *ecbDecrypter) fillCrypt() os.Error {
var err os.Error;
for len(x.crypt) < x.blockSize {
off := len(x.crypt);
var m int;
m, err = x.r.Read(x.crypt[off:x.blockSize]);
x.crypt = x.crypt[0:off+m];
if m == 0 {
break;
}
// If an error happened but we got enough
// data to do some decryption, we can decrypt
// first and report the error (with some data) later.
// But if we don't have enough to decrypt,
// have to stop now.
if err != nil && len(x.crypt) < x.blockSize {
break;
}
}
return err;
}
// Read from plain text buffer into p.
func (x *ecbDecrypter) readPlain(p []byte) int {
n := len(x.plain);
if n > len(p) {
n = len(p);
}
for i := 0; i < n; i++ {
p[i] = x.plain[i];
}
if n < len(x.plain) {
x.plain = x.plain[n:len(x.plain)];
} else {
x.plain = nil;
}
return n;
}
func (x *ecbDecrypter) Read(p []byte) (n int, err os.Error) {
if len(p) == 0 {
return;
}
// If there's no plaintext waiting and p is not big enough
// to hold a whole cipher block, we'll have to work in the
// cipher text buffer. Set it to non-nil so that the
// code below will fill it.
if x.plain == nil && len(p) < x.blockSize && x.crypt == nil {
x.crypt = x.buf[0:0];
}
// If there is a leftover cipher text buffer,
// try to accumulate a full block.
if x.crypt != nil {
err = x.fillCrypt();
if err != nil || len(x.crypt) == 0 {
return;
}
x.c.Decrypt(x.crypt, x.crypt);
x.plain = x.crypt;
x.crypt = nil;
}
// If there is a leftover plain text buffer, read from it.
if x.plain != nil {
n = x.readPlain(p);
return;
}
// Read and decrypt directly in caller's buffer.
n, err = io.ReadAtLeast(x.r, p, x.blockSize);
if err == io.ErrEOF && n == 0 {
// EOF is okay on block boundary
err = nil;
return;
}
var i int;
for i = 0; i+x.blockSize <= n; i += x.blockSize {
a := p[i:i+x.blockSize];
x.c.Decrypt(a, a);
}
// There might be an encrypted fringe remaining.
// Save it for next time.
if i < n {
p = p[i:n];
for j, v := range p {
x.buf[j] = p[j];
}
x.crypt = x.buf[0:len(p)];
n = i;
}
return;
}
// NewECBDecrypter returns a reader that reads data from r and decrypts it using c.
// It decrypts by calling c.Decrypt on each block in sequence;
// this mode is known as electronic codebook mode, or ECB.
// The returned Reader does not buffer or read ahead except
// as required by the cipher's block size.
func NewECBDecrypter(c Cipher, r io.Reader) io.Reader {
x := new(ecbDecrypter);
x.c = c;
x.r = r;
x.blockSize = c.BlockSize();
x.buf = make([]byte, x.blockSize);
return x;
}
type ecbEncrypter struct {
c Cipher;
w io.Writer;
blockSize int;
// Buffered data.
// The buffer buf is used as storage for both
// plain or crypt. If both are non-nil, plain
// follows crypt in buf.
buf []byte;
plain []byte; // plain text waiting to be encrypted
crypt []byte; // encrypted text waiting to be written
}
// Flush the x.crypt buffer to x.w.
func (x *ecbEncrypter) flushCrypt() os.Error {
if len(x.crypt) == 0 {
return nil;
}
n, err := x.w.Write(x.crypt);
if n < len(x.crypt) {
x.crypt = x.crypt[n:len(x.crypt)];
if err == nil {
err = io.ErrShortWrite;
}
}
if err != nil {
return err;
}
x.crypt = nil;
return nil;
}
// Slide x.plain down to the beginning of x.buf.
// Plain is known to have less than one block of data,
// so this is cheap enough.
func (x *ecbEncrypter) slidePlain() {
if len(x.plain) == 0 {
x.plain = x.buf[0:0];
} else if cap(x.plain) < cap(x.buf) {
// plain and buf share same data,
// but buf is before plain, so forward loop is correct
for i := 0; i < len(x.plain); i++ {
x.buf[i] = x.plain[i];
}
x.plain = x.buf[0:len(x.plain)];
}
}
// Fill x.plain from the data in p.
// Return the number of bytes copied.
func (x *ecbEncrypter) fillPlain(p []byte) int {
off := len(x.plain);
n := len(p);
if max := cap(x.plain) - off; n > max {
n = max;
}
x.plain = x.plain[0:off+n];
for i := 0; i < n; i++ {
x.plain[off + i] = p[i];
}
return n;
}
// Encrypt x.plain; record encrypted range as x.crypt.
func (x *ecbEncrypter) encrypt() {
var i int;
n := len(x.plain);
for i = 0; i+x.blockSize <= n; i += x.blockSize {
a := x.plain[i:i+x.blockSize];
x.c.Encrypt(a, a);
}
x.crypt = x.plain[0:i];
x.plain = x.plain[i:n];
}
func (x *ecbEncrypter) Write(p []byte) (n int, err os.Error) {
for {
// If there is data waiting to be written, write it.
// This can happen on the first iteration
// if a write failed in an earlier call.
if err = x.flushCrypt(); err != nil {
return;
}
// Now that encrypted data is gone (flush ran),
// perhaps we need to slide the plaintext down.
x.slidePlain();
// Fill plaintext buffer from p.
m := x.fillPlain(p);
if m == 0 {
break;
}
n += m;
p = p[m:len(p)];
// Encrypt, adjusting crypt and plain.
x.encrypt();
// Write x.crypt.
if err = x.flushCrypt(); err != nil {
break;
}
}
return;
}
// NewECBEncrypter returns a writer that encrypts data using c and writes it to w.
// It encrypts by calling c.Encrypt on each block in sequence;
// this mode is known as electronic codebook mode, or ECB.
// The returned Writer does no buffering except as required
// by the cipher's block size, so there is no need for a Flush method.
func NewECBEncrypter(c Cipher, w io.Writer) io.Writer {
x := new(ecbEncrypter);
x.c = c;
x.w = w;
x.blockSize = c.BlockSize();
// Create a buffer that is an integral number of blocks.
x.buf = make([]byte, 8192/x.blockSize * x.blockSize);
return x;
}

136
src/lib/crypto/block/ecb_aes_test.go Normal file
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@ -0,0 +1,136 @@
// Copyright 2009 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.
// ECB AES test vectors.
// See U.S. National Institute of Standards and Technology (NIST)
// Special Publication 800-38A, ``Recommendation for Block Cipher
// Modes of Operation,'' 2001 Edition, pp. 24-27.
package block
import (
"crypto/aes";
"crypto/block";
"io";
"os";
"testing";
)
type ecbTest struct {
name string;
key []byte;
in []byte;
out []byte;
}
var commonInput = []byte {
0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
}
var commonKey128 = []byte {
0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c,
}
var commonKey192 = []byte {
0x8e, 0x73, 0xb0, 0xf7, 0xda, 0x0e, 0x64, 0x52, 0xc8, 0x10, 0xf3, 0x2b, 0x80, 0x90, 0x79, 0xe5,
0x62, 0xf8, 0xea, 0xd2, 0x52, 0x2c, 0x6b, 0x7b,
}
var commonKey256 = []byte {
0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe, 0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7, 0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4,
}
var commonIV = []byte {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
}
var ecbAESTests = []ecbTest {
// FIPS 197, Appendix B, C
ecbTest {
"FIPS-197 Appendix B",
commonKey128,
[]byte {
0x32, 0x43, 0xf6, 0xa8, 0x88, 0x5a, 0x30, 0x8d, 0x31, 0x31, 0x98, 0xa2, 0xe0, 0x37, 0x07, 0x34,
},
[]byte {
0x39, 0x25, 0x84, 0x1d, 0x02, 0xdc, 0x09, 0xfb, 0xdc, 0x11, 0x85, 0x97, 0x19, 0x6a, 0x0b, 0x32,
}
},
// NIST SP 800-38A pp 24-27
ecbTest {
"ECB-AES128",
commonKey128,
commonInput,
[]byte {
0x3a, 0xd7, 0x7b, 0xb4, 0x0d, 0x7a, 0x36, 0x60, 0xa8, 0x9e, 0xca, 0xf3, 0x24, 0x66, 0xef, 0x97,
0xf5, 0xd3, 0xd5, 0x85, 0x03, 0xb9, 0x69, 0x9d, 0xe7, 0x85, 0x89, 0x5a, 0x96, 0xfd, 0xba, 0xaf,
0x43, 0xb1, 0xcd, 0x7f, 0x59, 0x8e, 0xce, 0x23, 0x88, 0x1b, 0x00, 0xe3, 0xed, 0x03, 0x06, 0x88,
0x7b, 0x0c, 0x78, 0x5e, 0x27, 0xe8, 0xad, 0x3f, 0x82, 0x23, 0x20, 0x71, 0x04, 0x72, 0x5d, 0xd4,
}
},
ecbTest {
"ECB-AES192",
commonKey192,
commonInput,
[]byte {
0xbd, 0x33, 0x4f, 0x1d, 0x6e, 0x45, 0xf2, 0x5f, 0xf7, 0x12, 0xa2, 0x14, 0x57, 0x1f, 0xa5, 0xcc,
0x97, 0x41, 0x04, 0x84, 0x6d, 0x0a, 0xd3, 0xad, 0x77, 0x34, 0xec, 0xb3, 0xec, 0xee, 0x4e, 0xef,
0xef, 0x7a, 0xfd, 0x22, 0x70, 0xe2, 0xe6, 0x0a, 0xdc, 0xe0, 0xba, 0x2f, 0xac, 0xe6, 0x44, 0x4e,
0x9a, 0x4b, 0x41, 0xba, 0x73, 0x8d, 0x6c, 0x72, 0xfb, 0x16, 0x69, 0x16, 0x03, 0xc1, 0x8e, 0x0e,
}
},
ecbTest {
"ECB-AES256",
commonKey256,
commonInput,
[]byte {
0xf3, 0xee, 0xd1, 0xbd, 0xb5, 0xd2, 0xa0, 0x3c, 0x06, 0x4b, 0x5a, 0x7e, 0x3d, 0xb1, 0x81, 0xf8,
0x59, 0x1c, 0xcb, 0x10, 0xd4, 0x10, 0xed, 0x26, 0xdc, 0x5b, 0xa7, 0x4a, 0x31, 0x36, 0x28, 0x70,
0xb6, 0xed, 0x21, 0xb9, 0x9c, 0xa6, 0xf4, 0xf9, 0xf1, 0x53, 0xe7, 0xb1, 0xbe, 0xaf, 0xed, 0x1d,
0x23, 0x30, 0x4b, 0x7a, 0x39, 0xf9, 0xf3, 0xff, 0x06, 0x7d, 0x8d, 0x8f, 0x9e, 0x24, 0xec, 0xc7,
}
}
}
func TestECB_AES(t *testing.T) {
for i, tt := range ecbAESTests {
test := tt.name;
c, err := aes.NewCipher(tt.key);
if err != nil {
t.Errorf("%s: NewCipher(%d bytes) = %s", test, len(tt.key), err);
continue;
}
var crypt io.ByteBuffer;
w := NewECBEncrypter(c, &crypt);
var r io.Reader = io.NewByteReader(tt.in);
n, err := io.Copy(r, w);
if n != int64(len(tt.in)) || err != nil {
t.Errorf("%s: ECBReader io.Copy = %d, %v want %d, nil", test, n, err, len(tt.in));
} else if d := crypt.Data(); !same(tt.out, d) {
t.Errorf("%s: ECBReader\nhave %x\nwant %x", test, d, tt.out);
}
var plain io.ByteBuffer;
r = NewECBDecrypter(c, io.NewByteReader(tt.out));
w = &plain;
n, err = io.Copy(r, w);
if n != int64(len(tt.out)) || err != nil {
t.Errorf("%s: ECBWriter io.Copy = %d, %v want %d, nil", test, n, err, len(tt.out));
} else if d := plain.Data(); !same(tt.in, d) {
t.Errorf("%s: ECBWriter\nhave %x\nwant %x", test, d, tt.in);
}
if t.Failed() {
break;
}
}
}

183
src/lib/crypto/block/ecb_test.go Normal file
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@ -0,0 +1,183 @@
// Copyright 2009 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 block
import (
"crypto/block";
"fmt";
"io";
"testing";
"testing/iotest";
)
// Simple Cipher for testing: adds an incrementing amount
// to each byte in each
type IncCipher struct {
blockSize int;
delta byte;
encrypting bool;
}
func (c *IncCipher) BlockSize() int {
return c.blockSize;
}
func (c *IncCipher) Encrypt(src, dst []byte) {
if !c.encrypting {
panicln("encrypt: not encrypting");
}
if len(src) != c.blockSize || len(dst) != c.blockSize {
panicln("encrypt: wrong block size", c.blockSize, len(src), len(dst));
}
c.delta++;
for i, b := range src {
dst[i] = b + c.delta;
}
}
func (c *IncCipher) Decrypt(src, dst []byte) {
if c.encrypting {
panicln("decrypt: not decrypting");
}
if len(src) != c.blockSize || len(dst) != c.blockSize {
panicln("decrypt: wrong block size", c.blockSize, len(src), len(dst));
}
c.delta--;
for i, b := range src {
dst[i] = b + c.delta;
}
}
func TestECBEncrypter(t *testing.T) {
var plain, crypt [256]byte;
for i := 0; i < len(plain); i++ {
plain[i] = byte(i);
}
b := new(io.ByteBuffer);
for block := 1; block <= 64; block *= 2 {
// compute encrypted version
delta := byte(0);
for i := 0; i < len(crypt); i++ {
if i % block == 0 {
delta++;
}
crypt[i] = plain[i] + delta;
}
for frag := 0; frag < 2; frag++ {
c := &IncCipher{block, 0, true};
b.Reset();
r := io.NewByteReader(&plain);
w := NewECBEncrypter(c, b);
// copy plain into w in increasingly large chunks: 1, 1, 2, 4, 8, ...
// if frag != 0, move the 1 to the end to cause fragmentation.
if frag == 0 {
nn, err := io.Copyn(r, w, 1);
if err != nil {
t.Errorf("block=%d frag=0: first Copyn: %s", block, err);
continue;
}
}
for n := 1; n <= len(plain)/2; n *= 2 {
nn, err := io.Copyn(r, w, int64(n));
if err != nil {
t.Errorf("block=%d frag=%d: Copyn %d: %s", block, frag, n, err);
}
}
if frag != 0 {
nn, err := io.Copyn(r, w, 1);
if err != nil {
t.Errorf("block=%d frag=1: last Copyn: %s", block, err);
continue;
}
}
// check output
data := b.Data();
if len(data) != len(crypt) {
t.Errorf("block=%d frag=%d: want %d bytes, got %d", block, frag, len(crypt), len(data));
continue;
}
if string(data) != string(&crypt) {
t.Errorf("block=%d frag=%d: want %x got %x", block, frag, data, crypt);
}
}
}
}
func testECBDecrypter(t *testing.T, maxio int) {
var readers = []func(io.Reader) io.Reader {
func (r io.Reader) io.Reader { return r },
iotest.OneByteReader,
iotest.HalfReader,
};
var plain, crypt [256]byte;
for i := 0; i < len(plain); i++ {
plain[i] = byte(255 - i);
}
b := new(io.ByteBuffer);
for block := 1; block <= 64 && block <= maxio; block *= 2 {
// compute encrypted version
delta := byte(0);
for i := 0; i < len(crypt); i++ {
if i % block == 0 {
delta++;
}
crypt[i] = plain[i] + delta;
}
for mode := 0; mode < len(readers); mode++ {
for frag := 0; frag < 2; frag++ {
test := fmt.Sprintf("block=%d mode=%d frag=%d maxio=%d", block, mode, frag, maxio);
c := &IncCipher{block, 0, false};
b.Reset();
r := NewECBDecrypter(c, readers[mode](io.NewByteReader(crypt[0:maxio])));
// read from crypt in increasingly large chunks: 1, 1, 2, 4, 8, ...
// if frag == 1, move the 1 to the end to cause fragmentation.
if frag == 0 {
nn, err := io.Copyn(r, b, 1);
if err != nil {
t.Errorf("%s: first Copyn: %s", test, err);
continue;
}
}
for n := 1; n <= maxio/2; n *= 2 {
nn, err := io.Copyn(r, b, int64(n));
if err != nil {
t.Errorf("%s: Copyn %d: %s", test, n, err);
}
}
if frag != 0 {
nn, err := io.Copyn(r, b, 1);
if err != nil {
t.Errorf("%s: last Copyn: %s", test, err);
continue;
}
}
// check output
data := b.Data();
if len(data) != maxio {
t.Errorf("%s: want %d bytes, got %d", test, maxio, len(data));
continue;
}
if string(data) != string(plain[0:maxio]) {
t.Errorf("%s: input=%x want %x got %x", test, crypt[0:maxio], plain[0:maxio], data);
}
}
}
}
}
func TestECBDecrypter(t *testing.T) {
// Do shorter I/O sizes first; they're easier to debug.
for n := 1; n <= 256 && !t.Failed(); n *= 2 {
testECBDecrypter(t, n);
}
}

17
src/lib/io/io.go
View File

@ -27,6 +27,9 @@ var ErrShortWrite os.Error = &Error{"short write"}
// Reader is the interface that wraps the basic Read method. // Reader is the interface that wraps the basic Read method.
// An implementation of Read is allowed to use all of p for
// scratch space during the call, even if it eventually returns
// n < len(p).
type Reader interface { type Reader interface {
Read(p []byte) (n int, err os.Error); Read(p []byte) (n int, err os.Error);
} }
@ -80,10 +83,11 @@ func WriteString(w Writer, s string) (n int, err os.Error) {
return w.Write(StringBytes(s)) return w.Write(StringBytes(s))
} }
// FullRead reads r until the buffer buf is full, or until EOF or error. // ReadAtLeast reads r into buf until at least min bytes have been read,
func FullRead(r Reader, buf []byte) (n int, err os.Error) { // or until EOF or error.
func ReadAtLeast(r Reader, buf []byte, min int) (n int, err os.Error) {
n = 0; n = 0;
for n < len(buf) { for n < min {
nn, e := r.Read(buf[n:len(buf)]); nn, e := r.Read(buf[n:len(buf)]);
if nn > 0 { if nn > 0 {
n += nn n += nn
@ -98,6 +102,13 @@ func FullRead(r Reader, buf []byte) (n int, err os.Error) {
return n, nil return n, nil
} }
// FullRead reads r until the buffer buf is full, or until EOF or error.
func FullRead(r Reader, buf []byte) (n int, err os.Error) {
// TODO(rsc): 6g bug prevents obvious return
n, err = ReadAtLeast(r, buf, len(buf));
return;
}
// Convert something that implements Read into something // Convert something that implements Read into something
// whose Reads are always FullReads // whose Reads are always FullReads
type fullRead struct { type fullRead struct {