From b112d42ad60551a075d0bf4c06667f11e7aa976d Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Fri, 22 May 2009 22:40:26 -0700 Subject: [PATCH] add hmac.NewSHA1 and hmac.NewMD5. fix Reset bug in sha1. add hmac, sha1, md5 tests. document hmac. R=r DELTA=146 (111 added, 6 deleted, 29 changed) OCL=29294 CL=29299 --- src/lib/crypto/hmac/hmac.go | 54 +++++++++++++------ src/lib/crypto/hmac/hmac_test.go | 93 ++++++++++++++++++++++++++++---- src/lib/crypto/md5/md5_test.go | 13 +++-- src/lib/crypto/sha1/sha1.go | 2 + src/lib/crypto/sha1/sha1_test.go | 13 +++-- 5 files changed, 140 insertions(+), 35 deletions(-) diff --git a/src/lib/crypto/hmac/hmac.go b/src/lib/crypto/hmac/hmac.go index ccecc15d20..0b9a08012d 100644 --- a/src/lib/crypto/hmac/hmac.go +++ b/src/lib/crypto/hmac/hmac.go @@ -2,22 +2,34 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. -// TODO(rsc): comments - +// The hmac package implements the Keyed-Hash Message Authentication Code (HMAC) +// as defined in U.S. Federal Information Processing Standards Publication 198. +// An HMAC is a cryptographic hash attesting that uses a key to sign a message. +// The receiver verifies the hash by recomputing it using the same key. package hmac import ( + "crypto/md5"; + "crypto/sha1"; "hash"; "os"; ) -// k0 = key -// ipad = 0x36 byte repeated to key len -// opad = 0x5c byte repeated to key len -// hmac = -// H((k0 ^ opad) || H((k0 ^ ipad) || text)) +// FIPS 198: +// http://csrc.nist.gov/publications/fips/fips198/fips-198a.pdf + +// key is zero padded to 64 bytes +// ipad = 0x36 byte repeated to 64 bytes +// opad = 0x5c byte repeated to 64 bytes +// hmac = H([key ^ opad] H([key ^ ipad] text)) const ( + // NOTE(rsc): This constant is actually the + // underlying hash function's block size. + // HMAC is only conventionally used with + // MD5 and SHA1, and both use 64-byte blocks. + // The hash.Hash interface doesn't provide a + // way to find out the block size. padSize = 64; ) @@ -37,11 +49,6 @@ func (h *hmac) tmpPad(xor byte) { } } -func (h *hmac) init() { - h.tmpPad(0x36); - h.inner.Write(h.tmp[0:padSize]); -} - func (h *hmac) Sum() []byte { h.tmpPad(0x5c); sum := h.inner.Sum(); @@ -63,10 +70,17 @@ func (h *hmac) Size() int { func (h *hmac) Reset() { h.inner.Reset(); - h.init(); + h.tmpPad(0x36); + h.inner.Write(h.tmp[0:padSize]); } -func HMAC(h hash.Hash, key []byte) hash.Hash { +// New returns a new HMAC hash using the given hash and key. +func New(h hash.Hash, key []byte) hash.Hash { + if len(key) > padSize { + // If key is too big, hash it. + h.Write(key); + key = h.Sum(); + } hm := new(hmac); hm.inner = h; hm.size = h.Size(); @@ -75,6 +89,16 @@ func HMAC(h hash.Hash, key []byte) hash.Hash { hm.key[i] = k; } hm.tmp = make([]byte, padSize + hm.size); - hm.init(); + hm.Reset(); return hm; } + +// NewMD5 returns a new HMAC-MD5 hash using the given key. +func NewMD5(key []byte) hash.Hash { + return New(md5.New(), key); +} + +// NewSHA1 returns a new HMAC-SHA1 hash using the given key. +func NewSHA1(key []byte) hash.Hash { + return New(sha1.New(), key); +} diff --git a/src/lib/crypto/hmac/hmac_test.go b/src/lib/crypto/hmac/hmac_test.go index 47bf6b609d..01e532d9fd 100644 --- a/src/lib/crypto/hmac/hmac_test.go +++ b/src/lib/crypto/hmac/hmac_test.go @@ -7,21 +7,94 @@ package hmac // TODO(rsc): better test import ( + "hash"; "crypto/hmac"; - "crypto/md5"; "io"; "fmt"; "testing"; ) -func TestHMAC_MD5(t *testing.T) { - // presotto's test - inner := md5.New(); - h := HMAC(inner, io.StringBytes("Jefe")); - io.WriteString(h, "what do ya want for nothing?"); - s := fmt.Sprintf("%x", h.Sum()); - answer := "750c783e6ab0b503eaa86e310a5db738"; - if s != answer { - t.Error("have", s, "\nwant", answer); +type hmacTest struct { + hash func([]byte) hash.Hash; + key []byte; + in []byte; + out string; +} + +// Tests from US FIPS 198 +// http://csrc.nist.gov/publications/fips/fips198/fips-198a.pdf +var hmacTests = []hmacTest { + hmacTest { + NewSHA1, + []byte { + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, + 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, + 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, + 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, + 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, + 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, + 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, + 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, + }, + io.StringBytes("Sample #1"), + "4f4ca3d5d68ba7cc0a1208c9c61e9c5da0403c0a", + }, + hmacTest { + NewSHA1, + []byte { + 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, + 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, + 0x40, 0x41, 0x42, 0x43, + }, + io.StringBytes("Sample #2"), + "0922d3405faa3d194f82a45830737d5cc6c75d24", + }, + hmacTest { + NewSHA1, + []byte { + 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, + 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, + 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, + 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, + 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, + 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, + 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, + 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, + 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, + 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, + 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, + 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, + 0xb0, 0xb1, 0xb2, 0xb3, + }, + io.StringBytes("Sample #3"), + "bcf41eab8bb2d802f3d05caf7cb092ecf8d1a3aa", + }, + + // Test from Plan 9. + hmacTest { + NewMD5, + io.StringBytes("Jefe"), + io.StringBytes("what do ya want for nothing?"), + "750c783e6ab0b503eaa86e310a5db738", + } +} + +func TestHMAC(t *testing.T) { + for i, tt := range hmacTests { + h := tt.hash(tt.key); + for j := 0; j < 2; j++ { + n, err := h.Write(tt.in); + if n != len(tt.in) || err != nil { + t.Errorf("test %d.%d: Write(%d) = %d, %v", i, j, len(tt.in), n, err); + continue; + } + sum := fmt.Sprintf("%x", h.Sum()); + if sum != tt.out { + t.Errorf("test %d.%d: have %s want %s\n", i, j, sum, tt.out); + } + + // Second iteration: make sure reset works. + h.Reset(); + } } } diff --git a/src/lib/crypto/md5/md5_test.go b/src/lib/crypto/md5/md5_test.go index e557742cc7..f610f1143b 100644 --- a/src/lib/crypto/md5/md5_test.go +++ b/src/lib/crypto/md5/md5_test.go @@ -54,11 +54,14 @@ func TestGolden(t *testing.T) { for i := 0; i < len(golden); i++ { g := golden[i]; c := New(); - io.WriteString(c, g.in); - s := fmt.Sprintf("%x", c.Sum()); - if s != g.out { - t.Errorf("md5(%s) = %s want %s", g.in, s, g.out); - t.FailNow(); + for j := 0; j < 2; j++ { + io.WriteString(c, g.in); + s := fmt.Sprintf("%x", c.Sum()); + if s != g.out { + t.Errorf("md5[%d](%s) = %s want %s", j, g.in, s, g.out); + t.FailNow(); + } + c.Reset(); } } } diff --git a/src/lib/crypto/sha1/sha1.go b/src/lib/crypto/sha1/sha1.go index c5f702264f..a4cccd7a37 100644 --- a/src/lib/crypto/sha1/sha1.go +++ b/src/lib/crypto/sha1/sha1.go @@ -37,6 +37,8 @@ func (d *digest) Reset() { d.h[2] = _Init2; d.h[3] = _Init3; d.h[4] = _Init4; + d.nx = 0; + d.len = 0; } // New returns a Hash computing the SHA1 checksum. diff --git a/src/lib/crypto/sha1/sha1_test.go b/src/lib/crypto/sha1/sha1_test.go index 3ac9a47ec2..381cc76ee5 100644 --- a/src/lib/crypto/sha1/sha1_test.go +++ b/src/lib/crypto/sha1/sha1_test.go @@ -56,11 +56,14 @@ func TestGolden(t *testing.T) { for i := 0; i < len(golden); i++ { g := golden[i]; c := New(); - io.WriteString(c, g.in); - s := fmt.Sprintf("%x", c.Sum()); - if s != g.out { - t.Errorf("sha1(%s) = %s want %s", g.in, s, g.out); - t.FailNow(); + for j := 0; j < 2; j++ { + io.WriteString(c, g.in); + s := fmt.Sprintf("%x", c.Sum()); + if s != g.out { + t.Errorf("sha1[%d](%s) = %s want %s", j, g.in, s, g.out); + t.FailNow(); + } + c.Reset(); } } }