From b0608c13914e38e247209f193441a356133dc814 Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Tue, 19 May 2009 14:01:03 -0700 Subject: [PATCH] Crypto modes: CBC, CFB, ECB. 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 --- src/lib/crypto/block/cbc.go | 75 +++++++ src/lib/crypto/block/cbc_aes_test.go | 107 +++++++++ src/lib/crypto/block/cfb.go | 100 +++++++++ src/lib/crypto/block/cfb_aes_test.go | 316 +++++++++++++++++++++++++++ src/lib/crypto/block/cipher.go | 58 +++++ src/lib/crypto/block/ecb.go | 271 +++++++++++++++++++++++ src/lib/crypto/block/ecb_aes_test.go | 136 ++++++++++++ src/lib/crypto/block/ecb_test.go | 183 ++++++++++++++++ src/lib/io/io.go | 17 +- 9 files changed, 1260 insertions(+), 3 deletions(-) create mode 100644 src/lib/crypto/block/cbc.go create mode 100644 src/lib/crypto/block/cbc_aes_test.go create mode 100644 src/lib/crypto/block/cfb.go create mode 100644 src/lib/crypto/block/cfb_aes_test.go create mode 100644 src/lib/crypto/block/cipher.go create mode 100644 src/lib/crypto/block/ecb.go create mode 100644 src/lib/crypto/block/ecb_aes_test.go create mode 100644 src/lib/crypto/block/ecb_test.go diff --git a/src/lib/crypto/block/cbc.go b/src/lib/crypto/block/cbc.go new file mode 100644 index 00000000000..85a746b72b3 --- /dev/null +++ b/src/lib/crypto/block/cbc.go @@ -0,0 +1,75 @@ +// 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); +} + diff --git a/src/lib/crypto/block/cbc_aes_test.go b/src/lib/crypto/block/cbc_aes_test.go new file mode 100644 index 00000000000..4681c1c0717 --- /dev/null +++ b/src/lib/crypto/block/cbc_aes_test.go @@ -0,0 +1,107 @@ +// 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; + } + } +} diff --git a/src/lib/crypto/block/cfb.go b/src/lib/crypto/block/cfb.go new file mode 100644 index 00000000000..827a55ee1c4 --- /dev/null +++ b/src/lib/crypto/block/cfb.go @@ -0,0 +1,100 @@ +// 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); +} + diff --git a/src/lib/crypto/block/cfb_aes_test.go b/src/lib/crypto/block/cfb_aes_test.go new file mode 100644 index 00000000000..6c793dba8ec --- /dev/null +++ b/src/lib/crypto/block/cfb_aes_test.go @@ -0,0 +1,316 @@ +// 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; + } + } +} diff --git a/src/lib/crypto/block/cipher.go b/src/lib/crypto/block/cipher.go new file mode 100644 index 00000000000..8bff1b87820 --- /dev/null +++ b/src/lib/crypto/block/cipher.go @@ -0,0 +1,58 @@ +// 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; +} diff --git a/src/lib/crypto/block/ecb.go b/src/lib/crypto/block/ecb.go new file mode 100644 index 00000000000..141d38cc8dd --- /dev/null +++ b/src/lib/crypto/block/ecb.go @@ -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; +} + diff --git a/src/lib/crypto/block/ecb_aes_test.go b/src/lib/crypto/block/ecb_aes_test.go new file mode 100644 index 00000000000..de8a624b9ff --- /dev/null +++ b/src/lib/crypto/block/ecb_aes_test.go @@ -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; + } + } +} diff --git a/src/lib/crypto/block/ecb_test.go b/src/lib/crypto/block/ecb_test.go new file mode 100644 index 00000000000..968893a9bb6 --- /dev/null +++ b/src/lib/crypto/block/ecb_test.go @@ -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); + } +} diff --git a/src/lib/io/io.go b/src/lib/io/io.go index 91b6ffd8b9b..c120d8d4430 100644 --- a/src/lib/io/io.go +++ b/src/lib/io/io.go @@ -27,6 +27,9 @@ var ErrShortWrite os.Error = &Error{"short write"} // 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 { 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)) } -// 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) { +// ReadAtLeast reads r into buf until at least min bytes have been read, +// or until EOF or error. +func ReadAtLeast(r Reader, buf []byte, min int) (n int, err os.Error) { n = 0; - for n < len(buf) { + for n < min { nn, e := r.Read(buf[n:len(buf)]); if nn > 0 { n += nn @@ -98,6 +102,13 @@ func FullRead(r Reader, buf []byte) (n int, err os.Error) { 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 // whose Reads are always FullReads type fullRead struct {