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fdb119ef JF |
1 | /*\r |
2 | * sha1.c\r | |
3 | *\r | |
4 | * Description:\r | |
5 | * This file implements the Secure Hashing Algorithm 1 as\r | |
6 | * defined in FIPS PUB 180-1 published April 17, 1995.\r | |
7 | *\r | |
8 | * The SHA-1, produces a 160-bit message digest for a given\r | |
9 | * data stream. It should take about 2**n steps to find a\r | |
10 | * message with the same digest as a given message and\r | |
11 | * 2**(n/2) to find any two messages with the same digest,\r | |
12 | * when n is the digest size in bits. Therefore, this\r | |
13 | * algorithm can serve as a means of providing a\r | |
14 | * "fingerprint" for a message.\r | |
15 | *\r | |
16 | * Portability Issues:\r | |
17 | * SHA-1 is defined in terms of 32-bit "words". This code\r | |
18 | * uses <stdint.h> (included via "sha1.h" to define 32 and 8\r | |
19 | * bit unsigned integer types. If your C compiler does not\r | |
20 | * support 32 bit unsigned integers, this code is not\r | |
21 | * appropriate.\r | |
22 | *\r | |
23 | * Caveats:\r | |
24 | * SHA-1 is designed to work with messages less than 2^64 bits\r | |
25 | * long. Although SHA-1 allows a message digest to be generated\r | |
26 | * for messages of any number of bits less than 2^64, this\r | |
27 | * implementation only works with messages with a length that is\r | |
28 | * a multiple of the size of an 8-bit character.\r | |
29 | *\r | |
30 | */\r | |
31 | \r | |
32 | #include "sha1.h"\r | |
33 | \r | |
34 | /*\r | |
35 | * Define the SHA1 circular left shift macro\r | |
36 | */\r | |
37 | #define SHA1CircularShift(bits,word) \\r | |
38 | (((word) << (bits)) | ((word) >> (32-(bits))))\r | |
39 | \r | |
40 | /* Local Function Prototyptes */\r | |
41 | void SHA1PadMessage(SHA1Context *);\r | |
42 | void SHA1ProcessMessageBlock(SHA1Context *);\r | |
43 | \r | |
44 | /*\r | |
45 | * SHA1Reset\r | |
46 | *\r | |
47 | * Description:\r | |
48 | * This function will initialize the SHA1Context in preparation\r | |
49 | * for computing a new SHA1 message digest.\r | |
50 | *\r | |
51 | * Parameters:\r | |
52 | * context: [in/out]\r | |
53 | * The context to reset.\r | |
54 | *\r | |
55 | * Returns:\r | |
56 | * sha Error Code.\r | |
57 | *\r | |
58 | */\r | |
59 | int SHA1Reset(SHA1Context *context)\r | |
60 | {\r | |
61 | if (!context)\r | |
62 | {\r | |
63 | return shaNull;\r | |
64 | }\r | |
65 | \r | |
66 | context->Length_Low = 0;\r | |
67 | context->Length_High = 0;\r | |
68 | context->Message_Block_Index = 0;\r | |
69 | \r | |
70 | context->Intermediate_Hash[0] = 0x67452301;\r | |
71 | context->Intermediate_Hash[1] = 0xEFCDAB89;\r | |
72 | context->Intermediate_Hash[2] = 0x98BADCFE;\r | |
73 | context->Intermediate_Hash[3] = 0x10325476;\r | |
74 | context->Intermediate_Hash[4] = 0xC3D2E1F0;\r | |
75 | \r | |
76 | context->Computed = 0;\r | |
77 | context->Corrupted = 0;\r | |
78 | \r | |
79 | return shaSuccess;\r | |
80 | }\r | |
81 | \r | |
82 | /*\r | |
83 | * SHA1Result\r | |
84 | *\r | |
85 | * Description:\r | |
86 | * This function will return the 160-bit message digest into the\r | |
87 | * Message_Digest array provided by the caller.\r | |
88 | * NOTE: The first octet of hash is stored in the 0th element,\r | |
89 | * the last octet of hash in the 19th element.\r | |
90 | *\r | |
91 | * Parameters:\r | |
92 | * context: [in/out]\r | |
93 | * The context to use to calculate the SHA-1 hash.\r | |
94 | * Message_Digest: [out]\r | |
95 | * Where the digest is returned.\r | |
96 | *\r | |
97 | * Returns:\r | |
98 | * sha Error Code.\r | |
99 | *\r | |
100 | */\r | |
101 | int SHA1Result( SHA1Context *context,\r | |
102 | uint8_t Message_Digest[SHA1HashSize])\r | |
103 | {\r | |
104 | int i;\r | |
105 | \r | |
106 | if (!context || !Message_Digest)\r | |
107 | {\r | |
108 | return shaNull;\r | |
109 | }\r | |
110 | \r | |
111 | if (context->Corrupted)\r | |
112 | {\r | |
113 | return context->Corrupted;\r | |
114 | }\r | |
115 | \r | |
116 | if (!context->Computed)\r | |
117 | {\r | |
118 | SHA1PadMessage(context);\r | |
119 | for(i=0; i<64; ++i)\r | |
120 | {\r | |
121 | /* message may be sensitive, clear it out */\r | |
122 | context->Message_Block[i] = 0;\r | |
123 | }\r | |
124 | context->Length_Low = 0; /* and clear length */\r | |
125 | context->Length_High = 0;\r | |
126 | context->Computed = 1;\r | |
127 | \r | |
128 | }\r | |
129 | \r | |
130 | for(i = 0; i < SHA1HashSize; ++i)\r | |
131 | {\r | |
132 | Message_Digest[i] = context->Intermediate_Hash[i>>2]\r | |
133 | >> 8 * ( 3 - ( i & 0x03 ) );\r | |
134 | }\r | |
135 | \r | |
136 | return shaSuccess;\r | |
137 | }\r | |
138 | \r | |
139 | /*\r | |
140 | * SHA1Input\r | |
141 | *\r | |
142 | * Description:\r | |
143 | * This function accepts an array of octets as the next portion\r | |
144 | * of the message.\r | |
145 | *\r | |
146 | * Parameters:\r | |
147 | * context: [in/out]\r | |
148 | * The SHA context to update\r | |
149 | * message_array: [in]\r | |
150 | * An array of characters representing the next portion of\r | |
151 | * the message.\r | |
152 | * length: [in]\r | |
153 | * The length of the message in message_array\r | |
154 | *\r | |
155 | * Returns:\r | |
156 | * sha Error Code.\r | |
157 | *\r | |
158 | */\r | |
159 | int SHA1Input( SHA1Context *context,\r | |
160 | const uint8_t *message_array,\r | |
161 | unsigned length)\r | |
162 | {\r | |
163 | if (!length)\r | |
164 | {\r | |
165 | return shaSuccess;\r | |
166 | }\r | |
167 | \r | |
168 | if (!context || !message_array)\r | |
169 | {\r | |
170 | return shaNull;\r | |
171 | }\r | |
172 | \r | |
173 | if (context->Computed)\r | |
174 | {\r | |
175 | context->Corrupted = shaStateError;\r | |
176 | \r | |
177 | return shaStateError;\r | |
178 | }\r | |
179 | \r | |
180 | if (context->Corrupted)\r | |
181 | {\r | |
182 | return context->Corrupted;\r | |
183 | }\r | |
184 | while(length-- && !context->Corrupted)\r | |
185 | {\r | |
186 | context->Message_Block[context->Message_Block_Index++] =\r | |
187 | (*message_array & 0xFF);\r | |
188 | \r | |
189 | context->Length_Low += 8;\r | |
190 | if (context->Length_Low == 0)\r | |
191 | {\r | |
192 | context->Length_High++;\r | |
193 | if (context->Length_High == 0)\r | |
194 | {\r | |
195 | /* Message is too long */\r | |
196 | context->Corrupted = 1;\r | |
197 | }\r | |
198 | }\r | |
199 | \r | |
200 | if (context->Message_Block_Index == 64)\r | |
201 | {\r | |
202 | SHA1ProcessMessageBlock(context);\r | |
203 | }\r | |
204 | \r | |
205 | message_array++;\r | |
206 | }\r | |
207 | \r | |
208 | return shaSuccess;\r | |
209 | }\r | |
210 | \r | |
211 | /*\r | |
212 | * SHA1ProcessMessageBlock\r | |
213 | *\r | |
214 | * Description:\r | |
215 | * This function will process the next 512 bits of the message\r | |
216 | * stored in the Message_Block array.\r | |
217 | *\r | |
218 | * Parameters:\r | |
219 | * None.\r | |
220 | *\r | |
221 | * Returns:\r | |
222 | * Nothing.\r | |
223 | *\r | |
224 | * Comments:\r | |
225 | \r | |
226 | * Many of the variable names in this code, especially the\r | |
227 | * single character names, were used because those were the\r | |
228 | * names used in the publication.\r | |
229 | *\r | |
230 | *\r | |
231 | */\r | |
232 | void SHA1ProcessMessageBlock(SHA1Context *context)\r | |
233 | {\r | |
234 | const uint32_t K[] = { /* Constants defined in SHA-1 */\r | |
235 | 0x5A827999,\r | |
236 | 0x6ED9EBA1,\r | |
237 | 0x8F1BBCDC,\r | |
238 | 0xCA62C1D6\r | |
239 | };\r | |
240 | int t; /* Loop counter */\r | |
241 | uint32_t temp; /* Temporary word value */\r | |
242 | uint32_t W[80]; /* Word sequence */\r | |
243 | uint32_t A, B, C, D, E; /* Word buffers */\r | |
244 | \r | |
245 | /*\r | |
246 | * Initialize the first 16 words in the array W\r | |
247 | */\r | |
248 | for(t = 0; t < 16; t++)\r | |
249 | {\r | |
250 | W[t] = context->Message_Block[t * 4] << 24;\r | |
251 | W[t] |= context->Message_Block[t * 4 + 1] << 16;\r | |
252 | W[t] |= context->Message_Block[t * 4 + 2] << 8;\r | |
253 | W[t] |= context->Message_Block[t * 4 + 3];\r | |
254 | }\r | |
255 | \r | |
256 | for(t = 16; t < 80; t++)\r | |
257 | {\r | |
258 | W[t] = SHA1CircularShift(1,W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);\r | |
259 | }\r | |
260 | \r | |
261 | A = context->Intermediate_Hash[0];\r | |
262 | B = context->Intermediate_Hash[1];\r | |
263 | C = context->Intermediate_Hash[2];\r | |
264 | D = context->Intermediate_Hash[3];\r | |
265 | E = context->Intermediate_Hash[4];\r | |
266 | \r | |
267 | for(t = 0; t < 20; t++)\r | |
268 | {\r | |
269 | temp = SHA1CircularShift(5,A) +\r | |
270 | ((B & C) | ((~B) & D)) + E + W[t] + K[0];\r | |
271 | E = D;\r | |
272 | D = C;\r | |
273 | C = SHA1CircularShift(30,B);\r | |
274 | \r | |
275 | B = A;\r | |
276 | A = temp;\r | |
277 | }\r | |
278 | \r | |
279 | for(t = 20; t < 40; t++)\r | |
280 | {\r | |
281 | temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[1];\r | |
282 | E = D;\r | |
283 | D = C;\r | |
284 | C = SHA1CircularShift(30,B);\r | |
285 | B = A;\r | |
286 | A = temp;\r | |
287 | }\r | |
288 | \r | |
289 | for(t = 40; t < 60; t++)\r | |
290 | {\r | |
291 | temp = SHA1CircularShift(5,A) +\r | |
292 | ((B & C) | (B & D) | (C & D)) + E + W[t] + K[2];\r | |
293 | E = D;\r | |
294 | D = C;\r | |
295 | C = SHA1CircularShift(30,B);\r | |
296 | B = A;\r | |
297 | A = temp;\r | |
298 | }\r | |
299 | \r | |
300 | for(t = 60; t < 80; t++)\r | |
301 | {\r | |
302 | temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[3];\r | |
303 | E = D;\r | |
304 | D = C;\r | |
305 | C = SHA1CircularShift(30,B);\r | |
306 | B = A;\r | |
307 | A = temp;\r | |
308 | }\r | |
309 | \r | |
310 | context->Intermediate_Hash[0] += A;\r | |
311 | context->Intermediate_Hash[1] += B;\r | |
312 | context->Intermediate_Hash[2] += C;\r | |
313 | context->Intermediate_Hash[3] += D;\r | |
314 | context->Intermediate_Hash[4] += E;\r | |
315 | \r | |
316 | context->Message_Block_Index = 0;\r | |
317 | }\r | |
318 | \r | |
319 | /*\r | |
320 | * SHA1PadMessage\r | |
321 | *\r | |
322 | \r | |
323 | * Description:\r | |
324 | * According to the standard, the message must be padded to an even\r | |
325 | * 512 bits. The first padding bit must be a '1'. The last 64\r | |
326 | * bits represent the length of the original message. All bits in\r | |
327 | * between should be 0. This function will pad the message\r | |
328 | * according to those rules by filling the Message_Block array\r | |
329 | * accordingly. It will also call the ProcessMessageBlock function\r | |
330 | * provided appropriately. When it returns, it can be assumed that\r | |
331 | * the message digest has been computed.\r | |
332 | *\r | |
333 | * Parameters:\r | |
334 | * context: [in/out]\r | |
335 | * The context to pad\r | |
336 | * ProcessMessageBlock: [in]\r | |
337 | * The appropriate SHA*ProcessMessageBlock function\r | |
338 | * Returns:\r | |
339 | * Nothing.\r | |
340 | *\r | |
341 | */\r | |
342 | \r | |
343 | void SHA1PadMessage(SHA1Context *context)\r | |
344 | {\r | |
345 | /*\r | |
346 | * Check to see if the current message block is too small to hold\r | |
347 | * the initial padding bits and length. If so, we will pad the\r | |
348 | * block, process it, and then continue padding into a second\r | |
349 | * block.\r | |
350 | */\r | |
351 | if (context->Message_Block_Index > 55)\r | |
352 | {\r | |
353 | context->Message_Block[context->Message_Block_Index++] = 0x80;\r | |
354 | while(context->Message_Block_Index < 64)\r | |
355 | {\r | |
356 | context->Message_Block[context->Message_Block_Index++] = 0;\r | |
357 | }\r | |
358 | \r | |
359 | SHA1ProcessMessageBlock(context);\r | |
360 | \r | |
361 | while(context->Message_Block_Index < 56)\r | |
362 | {\r | |
363 | context->Message_Block[context->Message_Block_Index++] = 0;\r | |
364 | }\r | |
365 | }\r | |
366 | else\r | |
367 | {\r | |
368 | context->Message_Block[context->Message_Block_Index++] = 0x80;\r | |
369 | while(context->Message_Block_Index < 56)\r | |
370 | {\r | |
371 | \r | |
372 | context->Message_Block[context->Message_Block_Index++] = 0;\r | |
373 | }\r | |
374 | }\r | |
375 | \r | |
376 | /*\r | |
377 | * Store the message length as the last 8 octets\r | |
378 | */\r | |
379 | context->Message_Block[56] = context->Length_High >> 24;\r | |
380 | context->Message_Block[57] = context->Length_High >> 16;\r | |
381 | context->Message_Block[58] = context->Length_High >> 8;\r | |
382 | context->Message_Block[59] = context->Length_High;\r | |
383 | context->Message_Block[60] = context->Length_Low >> 24;\r | |
384 | context->Message_Block[61] = context->Length_Low >> 16;\r | |
385 | context->Message_Block[62] = context->Length_Low >> 8;\r | |
386 | context->Message_Block[63] = context->Length_Low;\r | |
387 | \r | |
388 | SHA1ProcessMessageBlock(context);\r | |
389 | }\r |