Line data Source code
1 : /**************************** sha1.c ***************************/
2 : /***************** See RFC 6234 for details. *******************/
3 : /* Copyright (c) 2011 IETF Trust and the persons identified as */
4 : /* authors of the code. All rights reserved. */
5 : /* See sha.h for terms of use and redistribution. */
6 :
7 : /*
8 : * Description:
9 : * This file implements the Secure Hash Algorithm SHA-1
10 : * as defined in the U.S. National Institute of Standards
11 : * and Technology Federal Information Processing Standards
12 : * Publication (FIPS PUB) 180-3 published in October 2008
13 : * and formerly defined in its predecessors, FIPS PUB 180-1
14 : * and FIP PUB 180-2.
15 : *
16 : * A combined document showing all algorithms is available at
17 : * http://csrc.nist.gov/publications/fips/
18 : * fips180-3/fips180-3_final.pdf
19 : *
20 : * The SHA-1 algorithm produces a 160-bit message digest for a
21 : * given data stream that can serve as a means of providing a
22 : * "fingerprint" for a message.
23 : *
24 : * Portability Issues:
25 : * SHA-1 is defined in terms of 32-bit "words". This code
26 : * uses <stdint.h> (included via "sha.h") to define 32- and
27 : * 8-bit unsigned integer types. If your C compiler does
28 : * not support 32-bit unsigned integers, this code is not
29 : * appropriate.
30 : *
31 : * Caveats:
32 : * SHA-1 is designed to work with messages less than 2^64 bits
33 : * long. This implementation uses SHA1Input() to hash the bits
34 : * that are a multiple of the size of an 8-bit octet, and then
35 : * optionally uses SHA1FinalBits() to hash the final few bits of
36 : * the input.
37 : */
38 :
39 : #include "sha.h"
40 : #include "sha-private.h"
41 :
42 : /*
43 : * Define the SHA1 circular left shift macro
44 : */
45 : #define SHA1_ROTL(bits,word) \
46 : (((word) << (bits)) | ((word) >> (32-(bits))))
47 :
48 : /*
49 : * Add "length" to the length.
50 : * Set Corrupted when overflow has occurred.
51 : */
52 : static uint32_t addTemp;
53 : #define SHA1AddLength(context, length) \
54 : (addTemp = (context)->Length_Low, \
55 : (context)->Corrupted = \
56 : (((context)->Length_Low += (length)) < addTemp) && \
57 : (++(context)->Length_High == 0) ? shaInputTooLong \
58 : : (context)->Corrupted )
59 :
60 : /* Local Function Prototypes */
61 : static void SHA1ProcessMessageBlock(SHA1Context *context);
62 : static void SHA1Finalize(SHA1Context *context, uint8_t Pad_Byte);
63 : static void SHA1PadMessage(SHA1Context *context, uint8_t Pad_Byte);
64 :
65 : /*
66 : * SHA1Reset
67 : *
68 : * Description:
69 : * This function will initialize the SHA1Context in preparation
70 : * for computing a new SHA1 message digest.
71 : *
72 : * Parameters:
73 : * context: [in/out]
74 : * The context to reset.
75 : *
76 : * Returns:
77 : * sha Error Code.
78 : *
79 : */
80 341 : int SHA1Reset(SHA1Context *context)
81 : {
82 341 : if (!context) return shaNull;
83 :
84 341 : context->Length_High = context->Length_Low = 0;
85 341 : context->Message_Block_Index = 0;
86 :
87 : /* Initial Hash Values: FIPS 180-3 section 5.3.1 */
88 341 : context->Intermediate_Hash[0] = 0x67452301;
89 341 : context->Intermediate_Hash[1] = 0xEFCDAB89;
90 341 : context->Intermediate_Hash[2] = 0x98BADCFE;
91 341 : context->Intermediate_Hash[3] = 0x10325476;
92 341 : context->Intermediate_Hash[4] = 0xC3D2E1F0;
93 :
94 341 : context->Computed = 0;
95 341 : context->Corrupted = shaSuccess;
96 :
97 341 : return shaSuccess;
98 : }
99 :
100 : /*
101 : * SHA1Input
102 : *
103 : * Description:
104 : * This function accepts an array of octets as the next portion
105 : * of the message.
106 : *
107 : * Parameters:
108 : * context: [in/out]
109 : * The SHA context to update.
110 : * message_array[ ]: [in]
111 : * An array of octets representing the next portion of
112 : * the message.
113 : * length: [in]
114 : * The length of the message in message_array.
115 : *
116 : * Returns:
117 : * sha Error Code.
118 : *
119 : */
120 678 : int SHA1Input(SHA1Context *context,
121 : const uint8_t *message_array, unsigned length)
122 : {
123 678 : if (!context) return shaNull;
124 678 : if (!length) return shaSuccess;
125 676 : if (!message_array) return shaNull;
126 676 : if (context->Computed) return context->Corrupted = shaStateError;
127 676 : if (context->Corrupted) return context->Corrupted;
128 :
129 47049 : while (length--) {
130 46373 : context->Message_Block[context->Message_Block_Index++] =
131 46373 : *message_array;
132 :
133 46373 : if ((SHA1AddLength(context, 8) == shaSuccess) &&
134 : (context->Message_Block_Index == SHA1_Message_Block_Size))
135 674 : SHA1ProcessMessageBlock(context);
136 :
137 46373 : message_array++;
138 : }
139 :
140 676 : return context->Corrupted;
141 : }
142 :
143 : /*
144 : * SHA1FinalBits
145 : *
146 : * Description:
147 : * This function will add in any final bits of the message.
148 : *
149 : * Parameters:
150 : * context: [in/out]
151 : * The SHA context to update.
152 : * message_bits: [in]
153 : * The final bits of the message, in the upper portion of the
154 : * byte. (Use 0b###00000 instead of 0b00000### to input the
155 : * three bits ###.)
156 : * length: [in]
157 : * The number of bits in message_bits, between 1 and 7.
158 : *
159 : * Returns:
160 : * sha Error Code.
161 : */
162 0 : int SHA1FinalBits(SHA1Context *context, uint8_t message_bits,
163 : unsigned int length)
164 : {
165 : static uint8_t masks[8] = {
166 : /* 0 0b00000000 */ 0x00, /* 1 0b10000000 */ 0x80,
167 : /* 2 0b11000000 */ 0xC0, /* 3 0b11100000 */ 0xE0,
168 : /* 4 0b11110000 */ 0xF0, /* 5 0b11111000 */ 0xF8,
169 : /* 6 0b11111100 */ 0xFC, /* 7 0b11111110 */ 0xFE
170 : };
171 :
172 : static uint8_t markbit[8] = {
173 : /* 0 0b10000000 */ 0x80, /* 1 0b01000000 */ 0x40,
174 : /* 2 0b00100000 */ 0x20, /* 3 0b00010000 */ 0x10,
175 : /* 4 0b00001000 */ 0x08, /* 5 0b00000100 */ 0x04,
176 : /* 6 0b00000010 */ 0x02, /* 7 0b00000001 */ 0x01
177 : };
178 :
179 0 : if (!context) return shaNull;
180 0 : if (!length) return shaSuccess;
181 0 : if (context->Corrupted) return context->Corrupted;
182 0 : if (context->Computed) return context->Corrupted = shaStateError;
183 0 : if (length >= 8) return context->Corrupted = shaBadParam;
184 :
185 0 : SHA1AddLength(context, length);
186 0 : SHA1Finalize(context,
187 0 : (uint8_t) ((message_bits & masks[length]) | markbit[length]));
188 :
189 0 : return context->Corrupted;
190 : }
191 :
192 : /*
193 : * SHA1Result
194 : *
195 : * Description:
196 : * This function will return the 160-bit message digest
197 : * into the Message_Digest array provided by the caller.
198 : * NOTE:
199 : * The first octet of hash is stored in the element with index 0,
200 : * the last octet of hash in the element with index 19.
201 : *
202 : * Parameters:
203 : * context: [in/out]
204 : * The context to use to calculate the SHA-1 hash.
205 : * Message_Digest[ ]: [out]
206 : * Where the digest is returned.
207 : *
208 : * Returns:
209 : * sha Error Code.
210 : *
211 : */
212 341 : int SHA1Result(SHA1Context *context,
213 : uint8_t Message_Digest[SHA1HashSize])
214 : {
215 : int i;
216 :
217 341 : if (!context) return shaNull;
218 341 : if (!Message_Digest) return shaNull;
219 341 : if (context->Corrupted) return context->Corrupted;
220 :
221 341 : if (!context->Computed)
222 341 : SHA1Finalize(context, 0x80);
223 :
224 7161 : for (i = 0; i < SHA1HashSize; ++i)
225 6820 : Message_Digest[i] = (uint8_t) (context->Intermediate_Hash[i>>2]
226 6820 : >> (8 * ( 3 - ( i & 0x03 ) )));
227 :
228 : return shaSuccess;
229 : }
230 :
231 : /*
232 : * SHA1ProcessMessageBlock
233 : *
234 : * Description:
235 : * This helper function will process the next 512 bits of the
236 : * message stored in the Message_Block array.
237 : *
238 : * Parameters:
239 : * context: [in/out]
240 : * The SHA context to update.
241 : *
242 : * Returns:
243 : * Nothing.
244 : *
245 : * Comments:
246 : * Many of the variable names in this code, especially the
247 : * single character names, were used because those were the
248 : * names used in the Secure Hash Standard.
249 : */
250 1015 : static void SHA1ProcessMessageBlock(SHA1Context *context)
251 : {
252 : /* Constants defined in FIPS 180-3, section 4.2.1 */
253 : const uint32_t K[4] = {
254 : 0x5A827999, 0x6ED9EBA1, 0x8F1BBCDC, 0xCA62C1D6
255 : };
256 : int t; /* Loop counter */
257 : uint32_t temp; /* Temporary word value */
258 : uint32_t W[80]; /* Word sequence */
259 : uint32_t A, B, C, D, E; /* Word buffers */
260 :
261 : /*
262 : * Initialize the first 16 words in the array W
263 : */
264 17255 : for (t = 0; t < 16; t++) {
265 16240 : W[t] = ((uint32_t)context->Message_Block[t * 4]) << 24;
266 16240 : W[t] |= ((uint32_t)context->Message_Block[t * 4 + 1]) << 16;
267 16240 : W[t] |= ((uint32_t)context->Message_Block[t * 4 + 2]) << 8;
268 16240 : W[t] |= ((uint32_t)context->Message_Block[t * 4 + 3]);
269 : }
270 :
271 65975 : for (t = 16; t < 80; t++)
272 64960 : W[t] = SHA1_ROTL(1, W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);
273 :
274 1015 : A = context->Intermediate_Hash[0];
275 1015 : B = context->Intermediate_Hash[1];
276 1015 : C = context->Intermediate_Hash[2];
277 1015 : D = context->Intermediate_Hash[3];
278 1015 : E = context->Intermediate_Hash[4];
279 :
280 21315 : for (t = 0; t < 20; t++) {
281 20300 : temp = SHA1_ROTL(5,A) + SHA_Ch(B, C, D) + E + W[t] + K[0];
282 : E = D;
283 : D = C;
284 20300 : C = SHA1_ROTL(30,B);
285 : B = A;
286 : A = temp;
287 : }
288 :
289 21315 : for (t = 20; t < 40; t++) {
290 20300 : temp = SHA1_ROTL(5,A) + SHA_Parity(B, C, D) + E + W[t] + K[1];
291 : E = D;
292 : D = C;
293 20300 : C = SHA1_ROTL(30,B);
294 : B = A;
295 : A = temp;
296 : }
297 :
298 21315 : for (t = 40; t < 60; t++) {
299 20300 : temp = SHA1_ROTL(5,A) + SHA_Maj(B, C, D) + E + W[t] + K[2];
300 : E = D;
301 : D = C;
302 20300 : C = SHA1_ROTL(30,B);
303 : B = A;
304 : A = temp;
305 : }
306 :
307 21315 : for (t = 60; t < 80; t++) {
308 20300 : temp = SHA1_ROTL(5,A) + SHA_Parity(B, C, D) + E + W[t] + K[3];
309 : E = D;
310 : D = C;
311 20300 : C = SHA1_ROTL(30,B);
312 : B = A;
313 : A = temp;
314 : }
315 :
316 1015 : context->Intermediate_Hash[0] += A;
317 1015 : context->Intermediate_Hash[1] += B;
318 1015 : context->Intermediate_Hash[2] += C;
319 1015 : context->Intermediate_Hash[3] += D;
320 1015 : context->Intermediate_Hash[4] += E;
321 1015 : context->Message_Block_Index = 0;
322 1015 : }
323 :
324 : /*
325 : * SHA1Finalize
326 : *
327 : * Description:
328 : * This helper function finishes off the digest calculations.
329 : *
330 : * Parameters:
331 : * context: [in/out]
332 : * The SHA context to update.
333 : * Pad_Byte: [in]
334 : * The last byte to add to the message block before the 0-padding
335 : * and length. This will contain the last bits of the message
336 : * followed by another single bit. If the message was an
337 : * exact multiple of 8-bits long, Pad_Byte will be 0x80.
338 : *
339 : * Returns:
340 : * sha Error Code.
341 : *
342 : */
343 341 : static void SHA1Finalize(SHA1Context *context, uint8_t Pad_Byte)
344 : {
345 : int i;
346 341 : SHA1PadMessage(context, Pad_Byte);
347 : /* message may be sensitive, clear it out */
348 22165 : for (i = 0; i < SHA1_Message_Block_Size; ++i)
349 21824 : context->Message_Block[i] = 0;
350 341 : context->Length_High = 0; /* and clear length */
351 341 : context->Length_Low = 0;
352 341 : context->Computed = 1;
353 341 : }
354 :
355 : /*
356 : * SHA1PadMessage
357 : *
358 : * Description:
359 : * According to the standard, the message must be padded to the next
360 : * even multiple of 512 bits. The first padding bit must be a '1'.
361 : * The last 64 bits represent the length of the original message.
362 : * All bits in between should be 0. This helper function will pad
363 : * the message according to those rules by filling the Message_Block
364 : * array accordingly. When it returns, it can be assumed that the
365 : * message digest has been computed.
366 : *
367 : * Parameters:
368 : * context: [in/out]
369 : * The context to pad.
370 : * Pad_Byte: [in]
371 : * The last byte to add to the message block before the 0-padding
372 : * and length. This will contain the last bits of the message
373 : * followed by another single bit. If the message was an
374 : * exact multiple of 8-bits long, Pad_Byte will be 0x80.
375 : *
376 : * Returns:
377 : * Nothing.
378 : */
379 341 : static void SHA1PadMessage(SHA1Context *context, uint8_t Pad_Byte)
380 : {
381 : /*
382 : * Check to see if the current message block is too small to hold
383 : * the initial padding bits and length. If so, we will pad the
384 : * block, process it, and then continue padding into a second
385 : * block.
386 : */
387 341 : if (context->Message_Block_Index >= (SHA1_Message_Block_Size - 8)) {
388 0 : context->Message_Block[context->Message_Block_Index++] = Pad_Byte;
389 0 : while (context->Message_Block_Index < SHA1_Message_Block_Size)
390 0 : context->Message_Block[context->Message_Block_Index++] = 0;
391 :
392 0 : SHA1ProcessMessageBlock(context);
393 : } else
394 341 : context->Message_Block[context->Message_Block_Index++] = Pad_Byte;
395 :
396 15859 : while (context->Message_Block_Index < (SHA1_Message_Block_Size - 8))
397 15518 : context->Message_Block[context->Message_Block_Index++] = 0;
398 :
399 : /*
400 : * Store the message length as the last 8 octets
401 : */
402 341 : context->Message_Block[56] = (uint8_t) (context->Length_High >> 24);
403 341 : context->Message_Block[57] = (uint8_t) (context->Length_High >> 16);
404 341 : context->Message_Block[58] = (uint8_t) (context->Length_High >> 8);
405 341 : context->Message_Block[59] = (uint8_t) (context->Length_High);
406 341 : context->Message_Block[60] = (uint8_t) (context->Length_Low >> 24);
407 341 : context->Message_Block[61] = (uint8_t) (context->Length_Low >> 16);
408 341 : context->Message_Block[62] = (uint8_t) (context->Length_Low >> 8);
409 341 : context->Message_Block[63] = (uint8_t) (context->Length_Low);
410 :
411 341 : SHA1ProcessMessageBlock(context);
412 341 : }
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