1/* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements.  See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License.  You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16/*
17 * FILE:        sha2.c
18 * AUTHOR:      Aaron D. Gifford <me@aarongifford.com>
19 *
20 * A licence was granted to the ASF by Aaron on 4 November 2003.
21 */
22
23#include <string.h>     /* memcpy()/memset() or bcopy()/bzero() */
24#include <assert.h>     /* assert() */
25#include "sha2.h"
26
27/*
28 * ASSERT NOTE:
29 * Some sanity checking code is included using assert().  On my FreeBSD
30 * system, this additional code can be removed by compiling with NDEBUG
31 * defined.  Check your own systems manpage on assert() to see how to
32 * compile WITHOUT the sanity checking code on your system.
33 *
34 * UNROLLED TRANSFORM LOOP NOTE:
35 * You can define SHA2_UNROLL_TRANSFORM to use the unrolled transform
36 * loop version for the hash transform rounds (defined using macros
37 * later in this file).  Either define on the command line, for example:
38 *
39 *   cc -DSHA2_UNROLL_TRANSFORM -o sha2 sha2.c sha2prog.c
40 *
41 * or define below:
42 *
43 *   #define SHA2_UNROLL_TRANSFORM
44 *
45 */
46
47/*** SHA-256/384/512 Machine Architecture Definitions *****************/
48typedef apr_byte_t   sha2_byte;         /* Exactly 1 byte */
49typedef apr_uint32_t sha2_word32;       /* Exactly 4 bytes */
50typedef apr_uint64_t sha2_word64;       /* Exactly 8 bytes */
51
52/*** SHA-256/384/512 Various Length Definitions ***********************/
53/* NOTE: Most of these are in sha2.h */
54#define SHA256_SHORT_BLOCK_LENGTH       (SHA256_BLOCK_LENGTH - 8)
55
56
57/*** ENDIAN REVERSAL MACROS *******************************************/
58#if !APR_IS_BIGENDIAN
59#define REVERSE32(w,x)  { \
60        sha2_word32 tmp = (w); \
61        tmp = (tmp >> 16) | (tmp << 16); \
62        (x) = ((tmp & 0xff00ff00UL) >> 8) | ((tmp & 0x00ff00ffUL) << 8); \
63}
64#define REVERSE64(w,x)  { \
65        sha2_word64 tmp = (w); \
66        tmp = (tmp >> 32) | (tmp << 32); \
67        tmp = ((tmp & APR_UINT64_C(0xff00ff00ff00ff00)) >> 8) | \
68              ((tmp & APR_UINT64_C(0x00ff00ff00ff00ff)) << 8); \
69        (x) = ((tmp & APR_UINT64_C(0xffff0000ffff0000)) >> 16) | \
70              ((tmp & APR_UINT64_C(0x0000ffff0000ffff)) << 16); \
71}
72#endif /* !APR_IS_BIGENDIAN */
73
74/*
75 * Macro for incrementally adding the unsigned 64-bit integer n to the
76 * unsigned 128-bit integer (represented using a two-element array of
77 * 64-bit words):
78 */
79#define ADDINC128(w,n)  { \
80        (w)[0] += (sha2_word64)(n); \
81        if ((w)[0] < (n)) { \
82                (w)[1]++; \
83        } \
84}
85
86/*
87 * Macros for copying blocks of memory and for zeroing out ranges
88 * of memory.  Using these macros makes it easy to switch from
89 * using memset()/memcpy() and using bzero()/bcopy().
90 *
91 * Please define either SHA2_USE_MEMSET_MEMCPY or define
92 * SHA2_USE_BZERO_BCOPY depending on which function set you
93 * choose to use:
94 */
95#if !defined(SHA2_USE_MEMSET_MEMCPY) && !defined(SHA2_USE_BZERO_BCOPY)
96/* Default to memset()/memcpy() if no option is specified */
97#define SHA2_USE_MEMSET_MEMCPY  1
98#endif
99#if defined(SHA2_USE_MEMSET_MEMCPY) && defined(SHA2_USE_BZERO_BCOPY)
100/* Abort with an error if BOTH options are defined */
101#error Define either SHA2_USE_MEMSET_MEMCPY or SHA2_USE_BZERO_BCOPY, not both!
102#endif
103
104#ifdef SHA2_USE_MEMSET_MEMCPY
105#define MEMSET_BZERO(p,l)       memset((p), 0, (l))
106#define MEMCPY_BCOPY(d,s,l)     memcpy((d), (s), (l))
107#endif
108#ifdef SHA2_USE_BZERO_BCOPY
109#define MEMSET_BZERO(p,l)       bzero((p), (l))
110#define MEMCPY_BCOPY(d,s,l)     bcopy((s), (d), (l))
111#endif
112
113
114/*** THE SIX LOGICAL FUNCTIONS ****************************************/
115/*
116 * Bit shifting and rotation (used by the six SHA-XYZ logical functions:
117 *
118 *   NOTE:  The naming of R and S appears backwards here (R is a SHIFT and
119 *   S is a ROTATION) because the SHA-256/384/512 description document
120 *   (see http://csrc.nist.gov/cryptval/shs/sha256-384-512.pdf) uses this
121 *   same "backwards" definition.
122 */
123/* Shift-right (used in SHA-256, SHA-384, and SHA-512): */
124#define R(b,x)          ((x) >> (b))
125/* 32-bit Rotate-right (used in SHA-256): */
126#define S32(b,x)        (((x) >> (b)) | ((x) << (32 - (b))))
127/* 64-bit Rotate-right (used in SHA-384 and SHA-512): */
128#define S64(b,x)        (((x) >> (b)) | ((x) << (64 - (b))))
129
130/* Two of six logical functions used in SHA-256, SHA-384, and SHA-512: */
131#define Ch(x,y,z)       (((x) & (y)) ^ ((~(x)) & (z)))
132#define Maj(x,y,z)      (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
133
134/* Four of six logical functions used in SHA-256: */
135#define Sigma0_256(x)   (S32(2,  (x)) ^ S32(13, (x)) ^ S32(22, (x)))
136#define Sigma1_256(x)   (S32(6,  (x)) ^ S32(11, (x)) ^ S32(25, (x)))
137#define sigma0_256(x)   (S32(7,  (x)) ^ S32(18, (x)) ^ R(3 ,   (x)))
138#define sigma1_256(x)   (S32(17, (x)) ^ S32(19, (x)) ^ R(10,   (x)))
139
140/* Four of six logical functions used in SHA-384 and SHA-512: */
141#define Sigma0_512(x)   (S64(28, (x)) ^ S64(34, (x)) ^ S64(39, (x)))
142#define Sigma1_512(x)   (S64(14, (x)) ^ S64(18, (x)) ^ S64(41, (x)))
143#define sigma0_512(x)   (S64( 1, (x)) ^ S64( 8, (x)) ^ R( 7,   (x)))
144#define sigma1_512(x)   (S64(19, (x)) ^ S64(61, (x)) ^ R( 6,   (x)))
145
146/*** INTERNAL FUNCTION PROTOTYPES *************************************/
147/* NOTE: These should not be accessed directly from outside this
148 * library -- they are intended for private internal visibility/use
149 * only.
150 */
151void apr__SHA256_Transform(SHA256_CTX*, const sha2_word32*);
152
153
154/*** SHA-XYZ INITIAL HASH VALUES AND CONSTANTS ************************/
155/* Hash constant words K for SHA-256: */
156static const sha2_word32 K256[64] = {
157        0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,
158        0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
159        0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL,
160        0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL,
161        0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
162        0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL,
163        0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,
164        0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL,
165        0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL,
166        0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
167        0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL,
168        0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,
169        0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL,
170        0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL,
171        0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
172        0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
173};
174
175/* Initial hash value H for SHA-256: */
176static const sha2_word32 sha256_initial_hash_value[8] = {
177        0x6a09e667UL,
178        0xbb67ae85UL,
179        0x3c6ef372UL,
180        0xa54ff53aUL,
181        0x510e527fUL,
182        0x9b05688cUL,
183        0x1f83d9abUL,
184        0x5be0cd19UL
185};
186
187/*
188 * Constant used by SHA256/384/512_End() functions for converting the
189 * digest to a readable hexadecimal character string:
190 */
191static const char *sha2_hex_digits = "0123456789abcdef";
192
193
194/*** SHA-256: *********************************************************/
195void apr__SHA256_Init(SHA256_CTX* context) {
196        if (context == (SHA256_CTX*)0) {
197                return;
198        }
199        MEMCPY_BCOPY(context->state, sha256_initial_hash_value, SHA256_DIGEST_LENGTH);
200        MEMSET_BZERO(context->buffer, SHA256_BLOCK_LENGTH);
201        context->bitcount = 0;
202}
203
204#ifdef SHA2_UNROLL_TRANSFORM
205
206/* Unrolled SHA-256 round macros: */
207
208#if !APR_IS_BIGENDIAN
209
210#define ROUND256_0_TO_15(a,b,c,d,e,f,g,h)       \
211        REVERSE32(*data++, W256[j]); \
212        T1 = (h) + Sigma1_256(e) + Ch((e), (f), (g)) + \
213             K256[j] + W256[j]; \
214        (d) += T1; \
215        (h) = T1 + Sigma0_256(a) + Maj((a), (b), (c)); \
216        j++
217
218
219#else /* APR_IS_BIGENDIAN */
220
221#define ROUND256_0_TO_15(a,b,c,d,e,f,g,h)       \
222        T1 = (h) + Sigma1_256(e) + Ch((e), (f), (g)) + \
223             K256[j] + (W256[j] = *data++); \
224        (d) += T1; \
225        (h) = T1 + Sigma0_256(a) + Maj((a), (b), (c)); \
226        j++
227
228#endif /* APR_IS_BIGENDIAN */
229
230#define ROUND256(a,b,c,d,e,f,g,h)       \
231        s0 = W256[(j+1)&0x0f]; \
232        s0 = sigma0_256(s0); \
233        s1 = W256[(j+14)&0x0f]; \
234        s1 = sigma1_256(s1); \
235        T1 = (h) + Sigma1_256(e) + Ch((e), (f), (g)) + K256[j] + \
236             (W256[j&0x0f] += s1 + W256[(j+9)&0x0f] + s0); \
237        (d) += T1; \
238        (h) = T1 + Sigma0_256(a) + Maj((a), (b), (c)); \
239        j++
240
241void apr__SHA256_Transform(SHA256_CTX* context, const sha2_word32* data) {
242        sha2_word32     a, b, c, d, e, f, g, h, s0, s1;
243        sha2_word32     T1, *W256;
244        int             j;
245
246        W256 = (sha2_word32*)context->buffer;
247
248        /* Initialize registers with the prev. intermediate value */
249        a = context->state[0];
250        b = context->state[1];
251        c = context->state[2];
252        d = context->state[3];
253        e = context->state[4];
254        f = context->state[5];
255        g = context->state[6];
256        h = context->state[7];
257
258        j = 0;
259        do {
260                /* Rounds 0 to 15 (unrolled): */
261                ROUND256_0_TO_15(a,b,c,d,e,f,g,h);
262                ROUND256_0_TO_15(h,a,b,c,d,e,f,g);
263                ROUND256_0_TO_15(g,h,a,b,c,d,e,f);
264                ROUND256_0_TO_15(f,g,h,a,b,c,d,e);
265                ROUND256_0_TO_15(e,f,g,h,a,b,c,d);
266                ROUND256_0_TO_15(d,e,f,g,h,a,b,c);
267                ROUND256_0_TO_15(c,d,e,f,g,h,a,b);
268                ROUND256_0_TO_15(b,c,d,e,f,g,h,a);
269        } while (j < 16);
270
271        /* Now for the remaining rounds to 64: */
272        do {
273                ROUND256(a,b,c,d,e,f,g,h);
274                ROUND256(h,a,b,c,d,e,f,g);
275                ROUND256(g,h,a,b,c,d,e,f);
276                ROUND256(f,g,h,a,b,c,d,e);
277                ROUND256(e,f,g,h,a,b,c,d);
278                ROUND256(d,e,f,g,h,a,b,c);
279                ROUND256(c,d,e,f,g,h,a,b);
280                ROUND256(b,c,d,e,f,g,h,a);
281        } while (j < 64);
282
283        /* Compute the current intermediate hash value */
284        context->state[0] += a;
285        context->state[1] += b;
286        context->state[2] += c;
287        context->state[3] += d;
288        context->state[4] += e;
289        context->state[5] += f;
290        context->state[6] += g;
291        context->state[7] += h;
292
293        /* Clean up */
294        a = b = c = d = e = f = g = h = T1 = 0;
295}
296
297#else /* SHA2_UNROLL_TRANSFORM */
298
299void apr__SHA256_Transform(SHA256_CTX* context, const sha2_word32* data) {
300        sha2_word32     a, b, c, d, e, f, g, h, s0, s1;
301        sha2_word32     T1, T2, *W256;
302        int             j;
303
304        W256 = (sha2_word32*)context->buffer;
305
306        /* Initialize registers with the prev. intermediate value */
307        a = context->state[0];
308        b = context->state[1];
309        c = context->state[2];
310        d = context->state[3];
311        e = context->state[4];
312        f = context->state[5];
313        g = context->state[6];
314        h = context->state[7];
315
316        j = 0;
317        do {
318#if !APR_IS_BIGENDIAN
319                /* Copy data while converting to host byte order */
320                REVERSE32(*data++,W256[j]);
321                /* Apply the SHA-256 compression function to update a..h */
322                T1 = h + Sigma1_256(e) + Ch(e, f, g) + K256[j] + W256[j];
323#else /* APR_IS_BIGENDIAN */
324                /* Apply the SHA-256 compression function to update a..h with copy */
325                T1 = h + Sigma1_256(e) + Ch(e, f, g) + K256[j] + (W256[j] = *data++);
326#endif /* APR_IS_BIGENDIAN */
327                T2 = Sigma0_256(a) + Maj(a, b, c);
328                h = g;
329                g = f;
330                f = e;
331                e = d + T1;
332                d = c;
333                c = b;
334                b = a;
335                a = T1 + T2;
336
337                j++;
338        } while (j < 16);
339
340        do {
341                /* Part of the message block expansion: */
342                s0 = W256[(j+1)&0x0f];
343                s0 = sigma0_256(s0);
344                s1 = W256[(j+14)&0x0f];
345                s1 = sigma1_256(s1);
346
347                /* Apply the SHA-256 compression function to update a..h */
348                T1 = h + Sigma1_256(e) + Ch(e, f, g) + K256[j] +
349                     (W256[j&0x0f] += s1 + W256[(j+9)&0x0f] + s0);
350                T2 = Sigma0_256(a) + Maj(a, b, c);
351                h = g;
352                g = f;
353                f = e;
354                e = d + T1;
355                d = c;
356                c = b;
357                b = a;
358                a = T1 + T2;
359
360                j++;
361        } while (j < 64);
362
363        /* Compute the current intermediate hash value */
364        context->state[0] += a;
365        context->state[1] += b;
366        context->state[2] += c;
367        context->state[3] += d;
368        context->state[4] += e;
369        context->state[5] += f;
370        context->state[6] += g;
371        context->state[7] += h;
372
373        /* Clean up */
374        a = b = c = d = e = f = g = h = T1 = T2 = 0;
375}
376
377#endif /* SHA2_UNROLL_TRANSFORM */
378
379void apr__SHA256_Update(SHA256_CTX* context, const sha2_byte *data, size_t len) {
380        unsigned int    freespace, usedspace;
381
382        if (len == 0) {
383                /* Calling with no data is valid - we do nothing */
384                return;
385        }
386
387        /* Sanity check: */
388        assert(context != (SHA256_CTX*)0 && data != (sha2_byte*)0);
389
390        usedspace = (unsigned int)((context->bitcount >> 3)
391                                 % SHA256_BLOCK_LENGTH);
392        if (usedspace > 0) {
393                /* Calculate how much free space is available in the buffer */
394                freespace = SHA256_BLOCK_LENGTH - usedspace;
395
396                if (len >= freespace) {
397                        /* Fill the buffer completely and process it */
398                        MEMCPY_BCOPY(&context->buffer[usedspace], data, freespace);
399                        context->bitcount += freespace << 3;
400                        len -= freespace;
401                        data += freespace;
402                        apr__SHA256_Transform(context, (sha2_word32*)context->buffer);
403                } else {
404                        /* The buffer is not yet full */
405                        MEMCPY_BCOPY(&context->buffer[usedspace], data, len);
406                        context->bitcount += len << 3;
407                        /* Clean up: */
408                        usedspace = freespace = 0;
409                        return;
410                }
411        }
412        while (len >= SHA256_BLOCK_LENGTH) {
413                /* Process as many complete blocks as we can */
414                apr__SHA256_Transform(context, (sha2_word32*)data);
415                context->bitcount += SHA256_BLOCK_LENGTH << 3;
416                len -= SHA256_BLOCK_LENGTH;
417                data += SHA256_BLOCK_LENGTH;
418        }
419        if (len > 0) {
420                /* There's left-overs, so save 'em */
421                MEMCPY_BCOPY(context->buffer, data, len);
422                context->bitcount += len << 3;
423        }
424        /* Clean up: */
425        usedspace = freespace = 0;
426}
427
428void apr__SHA256_Final(sha2_byte digest[SHA256_DIGEST_LENGTH], SHA256_CTX* context) {
429        sha2_word32     *d = (sha2_word32*)digest;
430        unsigned int    usedspace;
431
432        /* Sanity check: */
433        assert(context != (SHA256_CTX*)0);
434
435        /* If no digest buffer is passed, we don't bother doing this: */
436        if (digest != (sha2_byte*)0) {
437                usedspace = (unsigned int)((context->bitcount >> 3)
438                                         % SHA256_BLOCK_LENGTH);
439#if !APR_IS_BIGENDIAN
440                /* Convert FROM host byte order */
441                REVERSE64(context->bitcount,context->bitcount);
442#endif
443                if (usedspace > 0) {
444                        /* Begin padding with a 1 bit: */
445                        context->buffer[usedspace++] = 0x80;
446
447                        if (usedspace <= SHA256_SHORT_BLOCK_LENGTH) {
448                                /* Set-up for the last transform: */
449                                MEMSET_BZERO(&context->buffer[usedspace], SHA256_SHORT_BLOCK_LENGTH - usedspace);
450                        } else {
451                                if (usedspace < SHA256_BLOCK_LENGTH) {
452                                        MEMSET_BZERO(&context->buffer[usedspace], SHA256_BLOCK_LENGTH - usedspace);
453                                }
454                                /* Do second-to-last transform: */
455                                apr__SHA256_Transform(context, (sha2_word32*)context->buffer);
456
457                                /* And set-up for the last transform: */
458                                MEMSET_BZERO(context->buffer, SHA256_SHORT_BLOCK_LENGTH);
459                        }
460                } else {
461                        /* Set-up for the last transform: */
462                        MEMSET_BZERO(context->buffer, SHA256_SHORT_BLOCK_LENGTH);
463
464                        /* Begin padding with a 1 bit: */
465                        *context->buffer = 0x80;
466                }
467                /* Set the bit count: */
468                {
469                        union dummy {
470                                apr_uint64_t bitcount;
471                                apr_byte_t bytes[8];
472                        } bitcount;
473                        bitcount.bitcount = context->bitcount;
474                        MEMCPY_BCOPY(&context->buffer[SHA256_SHORT_BLOCK_LENGTH], bitcount.bytes, 8);
475                }
476
477                /* Final transform: */
478                apr__SHA256_Transform(context, (sha2_word32*)context->buffer);
479
480#if !APR_IS_BIGENDIAN
481                {
482                        /* Convert TO host byte order */
483                        int     j;
484                        for (j = 0; j < 8; j++) {
485                                REVERSE32(context->state[j],context->state[j]);
486                                *d++ = context->state[j];
487                        }
488                }
489#else
490                MEMCPY_BCOPY(d, context->state, SHA256_DIGEST_LENGTH);
491#endif
492        }
493
494        /* Clean up state data: */
495        MEMSET_BZERO(context, sizeof(*context));
496        usedspace = 0;
497}
498
499char *apr__SHA256_End(SHA256_CTX* context, char buffer[SHA256_DIGEST_STRING_LENGTH]) {
500        sha2_byte       digest[SHA256_DIGEST_LENGTH], *d = digest;
501        int             i;
502
503        /* Sanity check: */
504        assert(context != (SHA256_CTX*)0);
505
506        if (buffer != (char*)0) {
507                apr__SHA256_Final(digest, context);
508
509                for (i = 0; i < SHA256_DIGEST_LENGTH; i++) {
510                        *buffer++ = sha2_hex_digits[(*d & 0xf0) >> 4];
511                        *buffer++ = sha2_hex_digits[*d & 0x0f];
512                        d++;
513                }
514                *buffer = (char)0;
515        } else {
516                MEMSET_BZERO(context, sizeof(*context));
517        }
518        MEMSET_BZERO(digest, SHA256_DIGEST_LENGTH);
519        return buffer;
520}
521
522char* apr__SHA256_Data(const sha2_byte* data, size_t len, char digest[SHA256_DIGEST_STRING_LENGTH]) {
523        SHA256_CTX      context;
524
525        apr__SHA256_Init(&context);
526        apr__SHA256_Update(&context, data, len);
527        return apr__SHA256_End(&context, digest);
528}
529