lib/sha1.nit

   1 # This file is part of NIT (http://www.nitlanguage.org).
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #                http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 # Provides methods to compute the SHA1 hash of a String
  16 module sha1
  17
  18 in "C Header" `{
  19
  20         /* This code is public-domain - it is based on libcrypt
  21          * placed in the public domain by Wei Dai and other contributors.
  22          */
  23
  24         #include <stdint.h>
  25         #include <string.h>
  26
  27         #define HASH_LENGTH 20
  28         #define BLOCK_LENGTH 64
  29
  30         union _buffer {
  31                 uint8_t b[BLOCK_LENGTH];
  32                 uint32_t w[BLOCK_LENGTH/4];
  33         };
  34
  35         union _state {
  36                 uint8_t b[HASH_LENGTH];
  37                 uint32_t w[HASH_LENGTH/4];
  38         };
  39
  40         typedef struct sha1nfo {
  41                 union _buffer buffer;
  42                 uint8_t bufferOffset;
  43                 union _state state;
  44                 uint32_t byteCount;
  45                 uint8_t keyBuffer[BLOCK_LENGTH];
  46                 uint8_t innerHash[HASH_LENGTH];
  47         } sha1nfo;
  48
  49         /**
  50          */
  51         void sha1_init(sha1nfo *s);
  52         /**
  53          */
  54         void sha1_writebyte(sha1nfo *s, uint8_t data);
  55         /**
  56          */
  57         void sha1_write(sha1nfo *s, const char *data, size_t len);
  58         /**
  59          */
  60         uint8_t* sha1_result(sha1nfo *s);
  61         /**
  62          */
  63         void sha1_initHmac(sha1nfo *s, const uint8_t* key, int keyLength);
  64         /**
  65          */
  66         uint8_t* sha1_resultHmac(sha1nfo *s);
  67 `}
  68
  69 `{
  70         #define SHA1_K0 0x5a827999
  71         #define SHA1_K20 0x6ed9eba1
  72         #define SHA1_K40 0x8f1bbcdc
  73         #define SHA1_K60 0xca62c1d6
  74
  75         const uint8_t sha1InitState[] = {
  76                 0x01,0x23,0x45,0x67, // H0
  77                 0x89,0xab,0xcd,0xef, // H1
  78                 0xfe,0xdc,0xba,0x98, // H2
  79                 0x76,0x54,0x32,0x10, // H3
  80                 0xf0,0xe1,0xd2,0xc3     // H4
  81         };
  82
  83         void sha1_init(sha1nfo *s) {
  84                 memcpy(s->state.b,sha1InitState,HASH_LENGTH);
  85                 s->byteCount = 0;
  86                 s->bufferOffset = 0;
  87         }
  88
  89         uint32_t sha1_rol32(uint32_t number, uint8_t bits) {
  90                 return ((number << bits) | (number >> (32-bits)));
  91         }
  92
  93         void sha1_hashBlock(sha1nfo *s) {
  94                 uint8_t i;
  95                 uint32_t a,b,c,d,e,t;
  96
  97                 a=s->state.w[0];
  98                 b=s->state.w[1];
  99                 c=s->state.w[2];
 100                 d=s->state.w[3];
 101                 e=s->state.w[4];
 102                 for (i=0; i<80; i++) {
 103                         if (i>=16) {
 104                                 t = s->buffer.w[(i+13)&15] ^ s->buffer.w[(i+8)&15] ^ s->buffer.w[(i+2)&15] ^ s->buffer.w[i&15];
 105                                 s->buffer.w[i&15] = sha1_rol32(t,1);
 106                         }
 107                         if (i<20) {
 108                                 t = (d ^ (b & (c ^ d))) + SHA1_K0;
 109                         } else if (i<40) {
 110                                 t = (b ^ c ^ d) + SHA1_K20;
 111                         } else if (i<60) {
 112                                 t = ((b & c) | (d & (b | c))) + SHA1_K40;
 113                         } else {
 114                                 t = (b ^ c ^ d) + SHA1_K60;
 115                         }
 116                         t+=sha1_rol32(a,5) + e + s->buffer.w[i&15];
 117                         e=d;
 118                         d=c;
 119                         c=sha1_rol32(b,30);
 120                         b=a;
 121                         a=t;
 122                 }
 123                 s->state.w[0] += a;
 124                 s->state.w[1] += b;
 125                 s->state.w[2] += c;
 126                 s->state.w[3] += d;
 127                 s->state.w[4] += e;
 128         }
 129
 130         void sha1_addUncounted(sha1nfo *s, uint8_t data) {
 131                 s->buffer.b[s->bufferOffset ^ 3] = data;
 132                 s->bufferOffset++;
 133                 if (s->bufferOffset == BLOCK_LENGTH) {
 134                         sha1_hashBlock(s);
 135                         s->bufferOffset = 0;
 136                 }
 137         }
 138
 139         void sha1_writebyte(sha1nfo *s, uint8_t data) {
 140                 ++s->byteCount;
 141                 sha1_addUncounted(s, data);
 142         }
 143
 144         void sha1_write(sha1nfo *s, const char *data, size_t len) {
 145                 for (;len--;) sha1_writebyte(s, (uint8_t) *data++);
 146         }
 147
 148         void sha1_pad(sha1nfo *s) {
 149                 // Implement SHA-1 padding (fips180-2 §5.1.1)
 150
 151                 // Pad with 0x80 followed by 0x00 until the end of the block
 152                 sha1_addUncounted(s, 0x80);
 153                 while (s->bufferOffset != 56) sha1_addUncounted(s, 0x00);
 154
 155                 // Append length in the last 8 bytes
 156                 sha1_addUncounted(s, 0); // We're only using 32 bit lengths
 157                 sha1_addUncounted(s, 0); // But SHA-1 supports 64 bit lengths
 158                 sha1_addUncounted(s, 0); // So zero pad the top bits
 159                 sha1_addUncounted(s, s->byteCount >> 29); // Shifting to multiply by 8
 160                 sha1_addUncounted(s, s->byteCount >> 21); // as SHA-1 supports bitstreams as well as
 161                 sha1_addUncounted(s, s->byteCount >> 13); // byte.
 162                 sha1_addUncounted(s, s->byteCount >> 5);
 163                 sha1_addUncounted(s, s->byteCount << 3);
 164         }
 165
 166         uint8_t* sha1_result(sha1nfo *s) {
 167                 int i;
 168                 // Pad to complete the last block
 169                 sha1_pad(s);
 170
 171                 // Swap byte order back
 172                 for (i=0; i<5; i++) {
 173                         uint32_t a,b;
 174                         a=s->state.w[i];
 175                         b=a<<24;
 176                         b|=(a<<8) & 0x00ff0000;
 177                         b|=(a>>8) & 0x0000ff00;
 178                         b|=a>>24;
 179                         s->state.w[i]=b;
 180                 }
 181
 182                 // Return pointer to hash (20 characters)
 183                 return s->state.b;
 184         }
 185
 186         #define HMAC_IPAD 0x36
 187         #define HMAC_OPAD 0x5c
 188
 189         void sha1_initHmac(sha1nfo *s, const uint8_t* key, int keyLength) {
 190                 uint8_t i;
 191                 memset(s->keyBuffer, 0, BLOCK_LENGTH);
 192                 if (keyLength > BLOCK_LENGTH) {
 193                         // Hash long keys
 194                         sha1_init(s);
 195                         for (;keyLength--;) sha1_writebyte(s, *key++);
 196                         memcpy(s->keyBuffer, sha1_result(s), HASH_LENGTH);
 197                 } else {
 198                         // Block length keys are used as is
 199                         memcpy(s->keyBuffer, key, keyLength);
 200                 }
 201                 // Start inner hash
 202                 sha1_init(s);
 203                 for (i=0; i<BLOCK_LENGTH; i++) {
 204                         sha1_writebyte(s, s->keyBuffer[i] ^ HMAC_IPAD);
 205                 }
 206         }
 207
 208         uint8_t* sha1_resultHmac(sha1nfo *s) {
 209                 uint8_t i;
 210                 // Complete inner hash
 211                 memcpy(s->innerHash,sha1_result(s),HASH_LENGTH);
 212                 // Calculate outer hash
 213                 sha1_init(s);
 214                 for (i=0; i<BLOCK_LENGTH; i++) sha1_writebyte(s, s->keyBuffer[i] ^ HMAC_OPAD);
 215                 for (i=0; i<HASH_LENGTH; i++) sha1_writebyte(s, s->innerHash[i]);
 216                 return sha1_result(s);
 217         }
 218 `}
 219
 220 redef class NativeString
 221         private fun sha1_intern(len: Int): NativeString `{
 222                 sha1nfo s;
 223
 224                 sha1_init(&s);
 225                 sha1_write(&s, self, len);
 226                 uint8_t* digest = sha1_result(&s);
 227
 228                 char* digested = malloc(21);
 229
 230                 memcpy(digested, digest, 20);
 231
 232                 digested[20] = '\0';
 233
 234                 return digested;
 235         `}
 236 end
 237
 238 redef class String
 239
 240         # Computes the SHA1 of the receiver
 241         #
 242         # Returns a digest of 20 bytes as a NativeString,
 243         # note that all the characters are not necessarily ASCII.
 244         # If you want the hex string version of the digest, use
 245         # sha1_hexdigest.
 246         #
 247         #     import base64
 248         #     assert "The quick brown fox jumps over the lazy dog".sha1 == [0x2Fu8, 0xD4u8, 0xE1u8, 0xC6u8, 0x7Au8, 0x2Du8, 0x28u8, 0xFCu8, 0xEDu8, 0x84u8, 0x9Eu8, 0xE1u8, 0xBBu8, 0x76u8, 0xE7u8, 0x39u8, 0x1Bu8, 0x93u8, 0xEBu8, 0x12u8]
 249         fun sha1: Bytes do
 250                 return new Bytes(to_cstring.sha1_intern(bytelen), 20, 20)
 251         end
 252
 253         # Computes the SHA1 of the receiver.
 254         #
 255         # Returns a 40 char String containing the Hexadecimal
 256         # Digest in its Char form.
 257         #
 258         #     assert "The quick brown fox jumps over the lazy dog".sha1_hexdigest == "2FD4E1C67A2D28FCED849EE1BB76E7391B93EB12"
 259         fun sha1_hexdigest: String do return sha1.hexdigest
 260 end