1 /*

     2  * This is an OpenSSL-compatible implementation of the RSA Data Security, Inc.

     3  * MD5 Message-Digest Algorithm (RFC 1321).

     4  *

     5  * Homepage:

     6  * http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5

     7  *

     8  * Author:

     9  * Alexander Peslyak, better known as Solar Designer <solar at openwall.com>

    10  *

    11  * This software was written by Alexander Peslyak in 2001.  No copyright is

    12  * claimed, and the software is hereby placed in the public domain.

    13  * In case this attempt to disclaim copyright and place the software in the

    14  * public domain is deemed null and void, then the software is

    15  * Copyright (c) 2001 Alexander Peslyak and it is hereby released to the

    16  * general public under the following terms:

    17  *

    18  * Redistribution and use in source and binary forms, with or without

    19  * modification, are permitted.

    20  *

    21  * There's ABSOLUTELY NO WARRANTY, express or implied.

    22  *

    23  * (This is a heavily cut-down "BSD license".)

    24  *

    25  * This differs from Colin Plumb's older public domain implementation in that

    26  * no exactly 32-bit integer data type is required (any 32-bit or wider

    27  * unsigned integer data type will do), there's no compile-time endianness

    28  * configuration, and the function prototypes match OpenSSL's.  No code from

    29  * Colin Plumb's implementation has been reused; this comment merely compares

    30  * the properties of the two independent implementations.

    31  *

    32  * The primary goals of this implementation are portability and ease of use.

    33  * It is meant to be fast, but not as fast as possible.  Some known

    34  * optimizations are not included to reduce source code size and avoid

    35  * compile-time configuration.

    36  */

    37 

    38 #ifndef HAVE_OPENSSL

    39 

    40 #include <string.h>

    41 

    42 #include "md5.h"

    43 

    44 /*

    45  * The basic MD5 functions.

    46  *

    47  * F and G are optimized compared to their RFC 1321 definitions for

    48  * architectures that lack an AND-NOT instruction, just like in Colin Plumb's

    49  * implementation.

    50  */

    51 #define F(x, y, z)                      ((z) ^ ((x) & ((y) ^ (z))))

    52 #define G(x, y, z)                      ((y) ^ ((z) & ((x) ^ (y))))

    53 #define H(x, y, z)                      (((x) ^ (y)) ^ (z))

    54 #define H2(x, y, z)                     ((x) ^ ((y) ^ (z)))

    55 #define I(x, y, z)                      ((y) ^ ((x) | ~(z)))

    56 

    57 /*

    58  * The MD5 transformation for all four rounds.

    59  */

    60 #define STEP(f, a, b, c, d, x, t, s) \

    61         (a) += f((b), (c), (d)) + (x) + (t); \

    62         (a) = (((a) << (s)) | (((a) & 0xffffffff) >> (32 - (s)))); \

    63         (a) += (b);

    64 

    65 /*

    66  * SET reads 4 input bytes in little-endian byte order and stores them in a

    67  * properly aligned word in host byte order.

    68  *

    69  * The check for little-endian architectures that tolerate unaligned memory

    70  * accesses is just an optimization.  Nothing will break if it fails to detect

    71  * a suitable architecture.

    72  *

    73  * Unfortunately, this optimization may be a C strict aliasing rules violation

    74  * if the caller's data buffer has effective type that cannot be aliased by

    75  * MD5_u32plus.  In practice, this problem may occur if these MD5 routines are

    76  * inlined into a calling function, or with future and dangerously advanced

    77  * link-time optimizations.  For the time being, keeping these MD5 routines in

    78  * their own translation unit avoids the problem.

    79  */

    80 #if defined(__i386__) || defined(__x86_64__) || defined(__vax__)

    81 #define SET(n) \

    82         (*(MD5_u32plus *)&ptr[(n) * 4])

    83 #define GET(n) \

    84         SET(n)

    85 #else

    86 #define SET(n) \

    87         (ctx->block[(n)] = \

    88         (MD5_u32plus)ptr[(n) * 4] | \

    89         ((MD5_u32plus)ptr[(n) * 4 + 1] << 8) | \

    90         ((MD5_u32plus)ptr[(n) * 4 + 2] << 16) | \

    91         ((MD5_u32plus)ptr[(n) * 4 + 3] << 24))

    92 #define GET(n) \

    93         (ctx->block[(n)])

    94 #endif

    95 

    96 /*

    97  * This processes one or more 64-byte data blocks, but does NOT update the bit

    98  * counters.  There are no alignment requirements.

    99  */

   100 static const void *body(MD5_CTX *ctx, const void *data, unsigned long size)

   101 {

   102         const unsigned char *ptr;

   103         MD5_u32plus a, b, c, d;

   104         MD5_u32plus saved_a, saved_b, saved_c, saved_d;

   105 

   106         ptr = (const unsigned char *)data;

   107 

   108         a = ctx->a;

   109         b = ctx->b;

   110         c = ctx->c;

   111         d = ctx->d;

   112 

   113         do {

   114                 saved_a = a;

   115                 saved_b = b;

   116                 saved_c = c;

   117                 saved_d = d;

   118 

   119 /* Round 1 */

   120                 STEP(F, a, b, c, d, SET(0), 0xd76aa478, 7)

   121                 STEP(F, d, a, b, c, SET(1), 0xe8c7b756, 12)

   122                 STEP(F, c, d, a, b, SET(2), 0x242070db, 17)

   123                 STEP(F, b, c, d, a, SET(3), 0xc1bdceee, 22)

   124                 STEP(F, a, b, c, d, SET(4), 0xf57c0faf, 7)

   125                 STEP(F, d, a, b, c, SET(5), 0x4787c62a, 12)

   126                 STEP(F, c, d, a, b, SET(6), 0xa8304613, 17)

   127                 STEP(F, b, c, d, a, SET(7), 0xfd469501, 22)

   128                 STEP(F, a, b, c, d, SET(8), 0x698098d8, 7)

   129                 STEP(F, d, a, b, c, SET(9), 0x8b44f7af, 12)

   130                 STEP(F, c, d, a, b, SET(10), 0xffff5bb1, 17)

   131                 STEP(F, b, c, d, a, SET(11), 0x895cd7be, 22)

   132                 STEP(F, a, b, c, d, SET(12), 0x6b901122, 7)

   133                 STEP(F, d, a, b, c, SET(13), 0xfd987193, 12)

   134                 STEP(F, c, d, a, b, SET(14), 0xa679438e, 17)

   135                 STEP(F, b, c, d, a, SET(15), 0x49b40821, 22)

   136 

   137 /* Round 2 */

   138                 STEP(G, a, b, c, d, GET(1), 0xf61e2562, 5)

   139                 STEP(G, d, a, b, c, GET(6), 0xc040b340, 9)

   140                 STEP(G, c, d, a, b, GET(11), 0x265e5a51, 14)

   141                 STEP(G, b, c, d, a, GET(0), 0xe9b6c7aa, 20)

   142                 STEP(G, a, b, c, d, GET(5), 0xd62f105d, 5)

   143                 STEP(G, d, a, b, c, GET(10), 0x02441453, 9)

   144                 STEP(G, c, d, a, b, GET(15), 0xd8a1e681, 14)

   145                 STEP(G, b, c, d, a, GET(4), 0xe7d3fbc8, 20)

   146                 STEP(G, a, b, c, d, GET(9), 0x21e1cde6, 5)

   147                 STEP(G, d, a, b, c, GET(14), 0xc33707d6, 9)

   148                 STEP(G, c, d, a, b, GET(3), 0xf4d50d87, 14)

   149                 STEP(G, b, c, d, a, GET(8), 0x455a14ed, 20)

   150                 STEP(G, a, b, c, d, GET(13), 0xa9e3e905, 5)

   151                 STEP(G, d, a, b, c, GET(2), 0xfcefa3f8, 9)

   152                 STEP(G, c, d, a, b, GET(7), 0x676f02d9, 14)

   153                 STEP(G, b, c, d, a, GET(12), 0x8d2a4c8a, 20)

   154 

   155 /* Round 3 */

   156                 STEP(H, a, b, c, d, GET(5), 0xfffa3942, 4)

   157                 STEP(H2, d, a, b, c, GET(8), 0x8771f681, 11)

   158                 STEP(H, c, d, a, b, GET(11), 0x6d9d6122, 16)

   159                 STEP(H2, b, c, d, a, GET(14), 0xfde5380c, 23)

   160                 STEP(H, a, b, c, d, GET(1), 0xa4beea44, 4)

   161                 STEP(H2, d, a, b, c, GET(4), 0x4bdecfa9, 11)

   162                 STEP(H, c, d, a, b, GET(7), 0xf6bb4b60, 16)

   163                 STEP(H2, b, c, d, a, GET(10), 0xbebfbc70, 23)

   164                 STEP(H, a, b, c, d, GET(13), 0x289b7ec6, 4)

   165                 STEP(H2, d, a, b, c, GET(0), 0xeaa127fa, 11)

   166                 STEP(H, c, d, a, b, GET(3), 0xd4ef3085, 16)

   167                 STEP(H2, b, c, d, a, GET(6), 0x04881d05, 23)

   168                 STEP(H, a, b, c, d, GET(9), 0xd9d4d039, 4)

   169                 STEP(H2, d, a, b, c, GET(12), 0xe6db99e5, 11)

   170                 STEP(H, c, d, a, b, GET(15), 0x1fa27cf8, 16)

   171                 STEP(H2, b, c, d, a, GET(2), 0xc4ac5665, 23)

   172 

   173 /* Round 4 */

   174                 STEP(I, a, b, c, d, GET(0), 0xf4292244, 6)

   175                 STEP(I, d, a, b, c, GET(7), 0x432aff97, 10)

   176                 STEP(I, c, d, a, b, GET(14), 0xab9423a7, 15)

   177                 STEP(I, b, c, d, a, GET(5), 0xfc93a039, 21)

   178                 STEP(I, a, b, c, d, GET(12), 0x655b59c3, 6)

   179                 STEP(I, d, a, b, c, GET(3), 0x8f0ccc92, 10)

   180                 STEP(I, c, d, a, b, GET(10), 0xffeff47d, 15)

   181                 STEP(I, b, c, d, a, GET(1), 0x85845dd1, 21)

   182                 STEP(I, a, b, c, d, GET(8), 0x6fa87e4f, 6)

   183                 STEP(I, d, a, b, c, GET(15), 0xfe2ce6e0, 10)

   184                 STEP(I, c, d, a, b, GET(6), 0xa3014314, 15)

   185                 STEP(I, b, c, d, a, GET(13), 0x4e0811a1, 21)

   186                 STEP(I, a, b, c, d, GET(4), 0xf7537e82, 6)

   187                 STEP(I, d, a, b, c, GET(11), 0xbd3af235, 10)

   188                 STEP(I, c, d, a, b, GET(2), 0x2ad7d2bb, 15)

   189                 STEP(I, b, c, d, a, GET(9), 0xeb86d391, 21)

   190 

   191                 a += saved_a;

   192                 b += saved_b;

   193                 c += saved_c;

   194                 d += saved_d;

   195 

   196                 ptr += 64;

   197         } while (size -= 64);

   198 

   199         ctx->a = a;

   200         ctx->b = b;

   201         ctx->c = c;

   202         ctx->d = d;

   203 

   204         return ptr;

   205 }

   206 

   207 void MD5_Init(MD5_CTX *ctx)

   208 {

   209         ctx->a = 0x67452301;

   210         ctx->b = 0xefcdab89;

   211         ctx->c = 0x98badcfe;

   212         ctx->d = 0x10325476;

   213 

   214         ctx->lo = 0;

   215         ctx->hi = 0;

   216 }

   217 

   218 void MD5_Update(MD5_CTX *ctx, const void *data, unsigned long size)

   219 {

   220         MD5_u32plus saved_lo;

   221         unsigned long used, available;

   222 

   223         saved_lo = ctx->lo;

   224         if ((ctx->lo = (saved_lo + size) & 0x1fffffff) < saved_lo)

   225                 ctx->hi++;

   226         ctx->hi += size >> 29;

   227 

   228         used = saved_lo & 0x3f;

   229 

   230         if (used) {

   231                 available = 64 - used;

   232 

   233                 if (size < available) {

   234                         memcpy(&ctx->buffer[used], data, size);

   235                         return;

   236                 }

   237 

   238                 memcpy(&ctx->buffer[used], data, available);

   239                 data = (const unsigned char *)data + available;

   240                 size -= available;

   241                 body(ctx, ctx->buffer, 64);

   242         }

   243 

   244         if (size >= 64) {

   245                 data = body(ctx, data, size & ~(unsigned long)0x3f);

   246                 size &= 0x3f;

   247         }

   248 

   249         memcpy(ctx->buffer, data, size);

   250 }

   251 

   252 #define OUT(dst, src) \

   253         (dst)[0] = (unsigned char)(src); \

   254         (dst)[1] = (unsigned char)((src) >> 8); \

   255         (dst)[2] = (unsigned char)((src) >> 16); \

   256         (dst)[3] = (unsigned char)((src) >> 24);

   257 

   258 void MD5_Final(unsigned char *result, MD5_CTX *ctx)

   259 {

   260         unsigned long used, available;

   261 

   262         used = ctx->lo & 0x3f;

   263 

   264         ctx->buffer[used++] = 0x80;

   265 

   266         available = 64 - used;

   267 

   268         if (available < 8) {

   269                 memset(&ctx->buffer[used], 0, available);

   270                 body(ctx, ctx->buffer, 64);

   271                 used = 0;

   272                 available = 64;

   273         }

   274 

   275         memset(&ctx->buffer[used], 0, available - 8);

   276 

   277         ctx->lo <<= 3;

   278         OUT(&ctx->buffer[56], ctx->lo)

   279         OUT(&ctx->buffer[60], ctx->hi)

   280 

   281         body(ctx, ctx->buffer, 64);

   282 

   283         OUT(&result[0], ctx->a)

   284         OUT(&result[4], ctx->b)

   285         OUT(&result[8], ctx->c)

   286         OUT(&result[12], ctx->d)

   287 

   288         memset(ctx, 0, sizeof(*ctx));

   289 }

   290 

   291 #endif