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
--- /dev/null
+// 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);
+}
+
--- /dev/null
+// 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;
+ }
+ }
+}
--- /dev/null
+// 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);
+}
+
--- /dev/null
+// 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;
+ }
+ }
+}
--- /dev/null
+// 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;
+}
--- /dev/null
+// 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;
+}
+
--- /dev/null
+// 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;
+ }
+ }
+}
--- /dev/null
+// 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);
+ }
+}
// 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);
}
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
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 {