更新

md2/digest.go

@@ -0,0 +1,124 @@
+package md2
+
+import (
+    "bytes"
+)
+
+// The size of an MD2 checksum in bytes.
+const Size = 16
+
+// The blocksize of MD2 in bytes.
+const BlockSize = 16
+
+// digest represents the partial evaluation of a checksum.
+type digest struct {
+    s   [48]byte        // state, 48 ints
+    x   [BlockSize]byte // temp storage buffer, 16 bytes
+    nx  int             // how many bytes are there in the buffer
+    len uint64
+
+    digest [Size]byte // the digest, Size
+}
+
+func newDigest() *digest {
+    d := new(digest)
+    d.Reset()
+    return d
+}
+
+func (d *digest) Reset() {
+    d.digest = [Size]byte{}
+    d.s = [48]byte{}
+    d.x = [BlockSize]byte{}
+
+    d.nx = 0
+    d.len = 0
+}
+
+func (d *digest) Size() int {
+    return Size
+}
+
+func (d *digest) BlockSize() int {
+    return BlockSize
+}
+
+// Write is the interface for IO Writer
+func (d *digest) Write(p []byte) (nn int, err error) {
+    nn = len(p)
+
+    plen := len(p)
+
+    for d.nx + plen >= BlockSize {
+        xx := BlockSize - d.nx
+
+        copy(d.x[d.nx:], p)
+
+        d.block(d.x[:])
+
+        plen -= xx
+        d.len += uint64(xx)
+
+        p = p[xx:]
+        d.nx = 0
+    }
+
+    copy(d.x[d.nx:], p)
+    d.nx += plen
+    d.len += uint64(plen)
+
+    return
+}
+
+func (d *digest) Sum(in []byte) []byte {
+    // Make a copy of d so that caller can keep writing and summing.
+    d0 := *d
+    hash := d0.checkSum()
+    return append(in, hash[:]...)
+}
+
+func (d *digest) checkSum() []byte {
+    padding := BlockSize - d.nx
+    tmp := bytes.Repeat([]byte{byte(padding)}, padding)
+    d.Write(tmp)
+
+    // At this state we should have nothing left in buffer
+    if d.nx != 0 {
+        panic("d.nx != 0")
+    }
+
+    d.Write(d.digest[:])
+
+    // At this state we should have nothing left in buffer
+    if d.nx != 0 {
+        panic("d.nx != 0")
+    }
+
+    return d.s[:16]
+}
+
+func (d *digest) block(p []byte) {
+    var t, i, j uint8
+    t = 0
+
+    for i = 0; i < 16; i++ {
+        d.s[i+16] = p[i]
+        d.s[i+32] = byte(p[i] ^ d.s[i])
+    }
+
+    for i = 0; i < 18; i++ {
+        for j = 0; j < 48; j++ {
+            d.s[j] = byte(d.s[j] ^ sbox[t])
+            t = d.s[j]
+        }
+        t = byte(t + i)
+    }
+
+    t = d.digest[15]
+
+    for i = 0; i < 16; i++ {
+        d.digest[i] = byte(d.digest[i] ^ sbox[p[i]^t])
+        t = d.digest[i]
+    }
+}
+

md2/md2.go

@@ -4,33 +4,9 @@ import (
     "hash"
 )
 
-// The size of an MD2 checksum in bytes.
-const Size = 16
-
-// The blocksize of MD2 in bytes.
-const BlockSize = 16
-
-const _Chunk = 16
-
-var PI_SUBST = []uint8{
-    41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
-    19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
-    76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
-    138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
-    245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
-    148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
-    39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
-    181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
-    150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
-    112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
-    96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
-    85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
-    234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
-    129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
-    8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
-    203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
-    166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
-    31, 26, 219, 153, 141, 51, 159, 17, 131, 20,
+// New returns a new hash.Hash computing the MD2 checksum.
+func New() hash.Hash {
+    return newDigest()
 }
 
 // Sum returns checksum of the data.
@@ -43,150 +19,3 @@ func Sum(data []byte) (sum [Size]byte) {
     copy(sum[:], hash)
     return
 }
-
-// digest represents the partial evaluation of a checksum.
-type digest struct {
-    digest [Size]byte   // the digest, Size
-    state  [48]byte     // state, 48 ints
-    x      [_Chunk]byte // temp storage buffer, 16 bytes, _Chunk
-    nx     uint8        // how many bytes are there in the buffer
-}
-
-// New returns a new hash.Hash computing the MD2 checksum.
-func New() hash.Hash {
-    d := new(digest)
-    d.Reset()
-    return d
-}
-
-func (d *digest) Reset() {
-    for i := range d.digest {
-        d.digest[i] = 0
-    }
-
-    for i := range d.state {
-        d.state[i] = 0
-    }
-
-    for i := range d.x {
-        d.x[i] = 0
-    }
-
-    d.nx = 0
-}
-
-func (d *digest) Size() int {
-    return Size
-}
-
-func (d *digest) BlockSize() int {
-    return BlockSize
-}
-
-// Write is the interface for IO Writer
-func (d *digest) Write(p []byte) (nn int, err error) {
-    nn = len(p)
-    //d.len += uint64(nn)
-
-    // If we have something left in the buffer
-    if d.nx > 0 {
-        n := uint8(len(p))
-
-        var i uint8
-        // try to copy the rest n bytes free of the buffer into the buffer
-        // then hash the buffer
-
-        if (n + d.nx) > _Chunk {
-            n = _Chunk - d.nx
-        }
-
-        for i = 0; i < n; i++ {
-            // copy n bytes to the buffer
-            d.x[d.nx+i] = p[i]
-        }
-
-        d.nx += n
-
-        // if we have exactly 1 block in the buffer then hash that block
-        if d.nx == _Chunk {
-            d.block(d.x[0:_Chunk])
-            d.nx = 0
-        }
-
-        p = p[n:]
-    }
-
-    imax := len(p) / _Chunk
-    // For the rest, try hashing by the blocksize
-    for i := 0; i < imax; i++ {
-        d.block(p[:_Chunk])
-        p = p[_Chunk:]
-    }
-
-    // Then stuff the rest that doesn't add up to a block to the buffer
-    if len(p) > 0 {
-        d.nx = uint8(copy(d.x[:], p))
-    }
-
-    return
-}
-
-func (d *digest) Sum(in []byte) []byte {
-    // Make a copy of d so that caller can keep writing and summing.
-    d0 := *d
-    hash := d0.checkSum()
-    return append(in, hash[:]...)
-}
-
-func (d *digest) checkSum() []byte {
-    // Padding.
-    var tmp [_Chunk]byte
-    //tmp := make([]byte, _Chunk, _Chunk)
-    len := uint8(d.nx)
-
-    for i := range tmp {
-        tmp[i] = _Chunk - len
-    }
-
-    d.Write(tmp[0 : _Chunk-len])
-
-    // At this state we should have nothing left in buffer
-    if d.nx != 0 {
-        panic("d.nx != 0")
-    }
-
-    d.Write(d.digest[0:16])
-
-    // At this state we should have nothing left in buffer
-    if d.nx != 0 {
-        panic("d.nx != 0")
-    }
-
-    return d.state[0:16]
-}
-
-func (dig *digest) block(p []byte) {
-    var t, i, j uint8
-    t = 0
-
-    for i = 0; i < 16; i++ {
-        dig.state[i+16] = p[i]
-        dig.state[i+32] = byte(p[i] ^ dig.state[i])
-    }
-
-    for i = 0; i < 18; i++ {
-        for j = 0; j < 48; j++ {
-            dig.state[j] = byte(dig.state[j] ^ PI_SUBST[t])
-            t = dig.state[j]
-        }
-        t = byte(t + i)
-    }
-
-    t = dig.digest[15]
-
-    for i = 0; i < 16; i++ {
-        dig.digest[i] = byte(dig.digest[i] ^ PI_SUBST[p[i]^t])
-        t = dig.digest[i]
-    }
-}
-

md2/md2_test.go

@@ -26,3 +26,17 @@ func Test_Check(t *testing.T) {
         t.Errorf("Check error. got %x, want %s", out2, check)
     }
 }
+
+func Test_Check2(t *testing.T) {
+    in := []byte("nonce-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")
+    check := "7517531718b62aa9ba3d135a865af776"
+
+    h := New()
+    h.Write(in)
+
+    out := h.Sum(nil)
+
+    if fmt.Sprintf("%x", out) != check {
+        t.Errorf("Check error. got %x, want %s", out, check)
+    }
+}

md2/sbox.go

@@ -0,0 +1,22 @@
+package md2
+
+var sbox = []uint8{
+    41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
+    19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
+    76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
+    138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
+    245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
+    148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
+    39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
+    181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
+    150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
+    112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
+    96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
+    85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
+    234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
+    129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
+    8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
+    203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
+    166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
+    31, 26, 219, 153, 141, 51, 159, 17, 131, 20,
+}