glib/gchecksum.c

   1 /* gchecksum.h - data hashing functions
   2  *
   3  * Copyright (C) 2007  Emmanuele Bassi  <ebassi@gnome.org>
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Library General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Library General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Library General Public
  16  * License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  */
  20
  21 #include "config.h"
  22
  23 #include <string.h>
  24
  25 #include "gchecksum.h"
  26
  27 #include "gslice.h"
  28 #include "gmem.h"
  29 #include "gstrfuncs.h"
  30 #include "gtestutils.h"
  31 #include "gtypes.h"
  32 #include "glibintl.h"
  33
  34
  35 /**
  36  * SECTION:checksum
  37  * @title: Data Checksums
  38  * @short_description: computes the checksum for data
  39  *
  40  * GLib provides a generic API for computing checksums (or "digests")
  41  * for a sequence of arbitrary bytes, using various hashing algorithms
  42  * like MD5, SHA-1 and SHA-256. Checksums are commonly used in various
  43  * environments and specifications.
  44  *
  45  * GLib supports incremental checksums using the GChecksum data
  46  * structure, by calling g_checksum_update() as long as there's data
  47  * available and then using g_checksum_get_string() or
  48  * g_checksum_get_digest() to compute the checksum and return it either
  49  * as a string in hexadecimal form, or as a raw sequence of bytes. To
  50  * compute the checksum for binary blobs and NUL-terminated strings in
  51  * one go, use the convenience functions g_compute_checksum_for_data()
  52  * and g_compute_checksum_for_string(), respectively.
  53  *
  54  * Support for checksums has been added in GLib 2.16
  55  **/
  56
  57 #define IS_VALID_TYPE(type)     ((type) >= G_CHECKSUM_MD5 && (type) <= G_CHECKSUM_SHA256)
  58
  59 /* The fact that these are lower case characters is part of the ABI */
  60 static const gchar hex_digits[] = "0123456789abcdef";
  61
  62 #define MD5_DATASIZE    64
  63 #define MD5_DIGEST_LEN  16
  64
  65 typedef struct
  66 {
  67   guint32 buf[4];
  68   guint32 bits[2];
  69
  70   union {
  71     guchar data[MD5_DATASIZE];
  72     guint32 data32[MD5_DATASIZE / 4];
  73   } u;
  74
  75   guchar digest[MD5_DIGEST_LEN];
  76 } Md5sum;
  77
  78 #define SHA1_DATASIZE   64
  79 #define SHA1_DIGEST_LEN 20
  80
  81 typedef struct
  82 {
  83   guint32 buf[5];
  84   guint32 bits[2];
  85
  86   /* we pack 64 unsigned chars into 16 32-bit unsigned integers */
  87   guint32 data[16];
  88
  89   guchar digest[SHA1_DIGEST_LEN];
  90 } Sha1sum;
  91
  92 #define SHA256_DATASIZE         64
  93 #define SHA256_DIGEST_LEN       32
  94
  95 typedef struct
  96 {
  97   guint32 buf[8];
  98   guint32 bits[2];
  99
 100   guint8 data[SHA256_DATASIZE];
 101
 102   guchar digest[SHA256_DIGEST_LEN];
 103 } Sha256sum;
 104
 105 struct _GChecksum
 106 {
 107   GChecksumType type;
 108
 109   gchar *digest_str;
 110
 111   union {
 112     Md5sum md5;
 113     Sha1sum sha1;
 114     Sha256sum sha256;
 115   } sum;
 116 };
 117
 118 /* we need different byte swapping functions because MD5 expects buffers
 119  * to be little-endian, while SHA1 and SHA256 expect them in big-endian
 120  * form.
 121  */
 122
 123 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
 124 #define md5_byte_reverse(buffer,length)
 125 #else
 126 /* assume that the passed buffer is integer aligned */
 127 static inline void
 128 md5_byte_reverse (guchar *buffer,
 129                   gulong  length)
 130 {
 131   guint32 bit;
 132
 133   do
 134     {
 135       bit = (guint32) ((unsigned) buffer[3] << 8 | buffer[2]) << 16 |
 136                       ((unsigned) buffer[1] << 8 | buffer[0]);
 137       * (guint32 *) buffer = bit;
 138       buffer += 4;
 139     }
 140   while (--length);
 141 }
 142 #endif /* G_BYTE_ORDER == G_LITTLE_ENDIAN */
 143
 144 #if G_BYTE_ORDER == G_BIG_ENDIAN
 145 #define sha_byte_reverse(buffer,length)
 146 #else
 147 static inline void
 148 sha_byte_reverse (guint32 *buffer,
 149                   gint     length)
 150 {
 151   length /= sizeof (guint32);
 152   while (length--)
 153     {
 154       *buffer = GUINT32_SWAP_LE_BE (*buffer);
 155       ++buffer;
 156     }
 157 }
 158 #endif /* G_BYTE_ORDER == G_BIG_ENDIAN */
 159
 160 static gchar *
 161 digest_to_string (guint8 *digest,
 162                   gsize   digest_len)
 163 {
 164   gint len = digest_len * 2;
 165   gint i;
 166   gchar *retval;
 167
 168   retval = g_new (gchar, len + 1);
 169
 170   for (i = 0; i < digest_len; i++)
 171     {
 172       guint8 byte = digest[i];
 173
 174       retval[2 * i] = hex_digits[byte >> 4];
 175       retval[2 * i + 1] = hex_digits[byte & 0xf];
 176     }
 177
 178   retval[len] = 0;
 179
 180   return retval;
 181 }
 182
 183 /*
 184  * MD5 Checksum
 185  */
 186
 187 /* This MD5 digest computation is based on the equivalent code
 188  * written by Colin Plumb. It came with this notice:
 189  *
 190  * This code implements the MD5 message-digest algorithm.
 191  * The algorithm is due to Ron Rivest.  This code was
 192  * written by Colin Plumb in 1993, no copyright is claimed.
 193  * This code is in the public domain; do with it what you wish.
 194  *
 195  * Equivalent code is available from RSA Data Security, Inc.
 196  * This code has been tested against that, and is equivalent,
 197  * except that you don't need to include two pages of legalese
 198  * with every copy.
 199  */
 200
 201 static void
 202 md5_sum_init (Md5sum *md5)
 203 {
 204   /* arbitrary constants */
 205   md5->buf[0] = 0x67452301;
 206   md5->buf[1] = 0xefcdab89;
 207   md5->buf[2] = 0x98badcfe;
 208   md5->buf[3] = 0x10325476;
 209
 210   md5->bits[0] = md5->bits[1] = 0;
 211 }
 212
 213 /*
 214  * The core of the MD5 algorithm, this alters an existing MD5 hash to
 215  * reflect the addition of 16 longwords of new data.  md5_sum_update()
 216  * blocks the data and converts bytes into longwords for this routine.
 217  */
 218 static void
 219 md5_transform (guint32       buf[4],
 220                guint32 const in[16])
 221 {
 222   register guint32 a, b, c, d;
 223
 224 /* The four core functions - F1 is optimized somewhat */
 225 #define F1(x, y, z)     (z ^ (x & (y ^ z)))
 226 #define F2(x, y, z)     F1 (z, x, y)
 227 #define F3(x, y, z)     (x ^ y ^ z)
 228 #define F4(x, y, z)     (y ^ (x | ~z))
 229
 230 /* This is the central step in the MD5 algorithm. */
 231 #define md5_step(f, w, x, y, z, data, s) \
 232         ( w += f (x, y, z) + data,  w = w << s | w >> (32 - s),  w += x )
 233
 234   a = buf[0];
 235   b = buf[1];
 236   c = buf[2];
 237   d = buf[3];
 238
 239   md5_step (F1, a, b, c, d, in[0]  + 0xd76aa478,  7);
 240   md5_step (F1, d, a, b, c, in[1]  + 0xe8c7b756, 12);
 241   md5_step (F1, c, d, a, b, in[2]  + 0x242070db, 17);
 242   md5_step (F1, b, c, d, a, in[3]  + 0xc1bdceee, 22);
 243   md5_step (F1, a, b, c, d, in[4]  + 0xf57c0faf,  7);
 244   md5_step (F1, d, a, b, c, in[5]  + 0x4787c62a, 12);
 245   md5_step (F1, c, d, a, b, in[6]  + 0xa8304613, 17);
 246   md5_step (F1, b, c, d, a, in[7]  + 0xfd469501, 22);
 247   md5_step (F1, a, b, c, d, in[8]  + 0x698098d8,  7);
 248   md5_step (F1, d, a, b, c, in[9]  + 0x8b44f7af, 12);
 249   md5_step (F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 250   md5_step (F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 251   md5_step (F1, a, b, c, d, in[12] + 0x6b901122,  7);
 252   md5_step (F1, d, a, b, c, in[13] + 0xfd987193, 12);
 253   md5_step (F1, c, d, a, b, in[14] + 0xa679438e, 17);
 254   md5_step (F1, b, c, d, a, in[15] + 0x49b40821, 22);
 255
 256   md5_step (F2, a, b, c, d, in[1]  + 0xf61e2562,  5);
 257   md5_step (F2, d, a, b, c, in[6]  + 0xc040b340,  9);
 258   md5_step (F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 259   md5_step (F2, b, c, d, a, in[0]  + 0xe9b6c7aa, 20);
 260   md5_step (F2, a, b, c, d, in[5]  + 0xd62f105d,  5);
 261   md5_step (F2, d, a, b, c, in[10] + 0x02441453,  9);
 262   md5_step (F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 263   md5_step (F2, b, c, d, a, in[4]  + 0xe7d3fbc8, 20);
 264   md5_step (F2, a, b, c, d, in[9]  + 0x21e1cde6,  5);
 265   md5_step (F2, d, a, b, c, in[14] + 0xc33707d6,  9);
 266   md5_step (F2, c, d, a, b, in[3]  + 0xf4d50d87, 14);
 267   md5_step (F2, b, c, d, a, in[8]  + 0x455a14ed, 20);
 268   md5_step (F2, a, b, c, d, in[13] + 0xa9e3e905,  5);
 269   md5_step (F2, d, a, b, c, in[2]  + 0xfcefa3f8,  9);
 270   md5_step (F2, c, d, a, b, in[7]  + 0x676f02d9, 14);
 271   md5_step (F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 272
 273   md5_step (F3, a, b, c, d, in[5]  + 0xfffa3942,  4);
 274   md5_step (F3, d, a, b, c, in[8]  + 0x8771f681, 11);
 275   md5_step (F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 276   md5_step (F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 277   md5_step (F3, a, b, c, d, in[1]  + 0xa4beea44,  4);
 278   md5_step (F3, d, a, b, c, in[4]  + 0x4bdecfa9, 11);
 279   md5_step (F3, c, d, a, b, in[7]  + 0xf6bb4b60, 16);
 280   md5_step (F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 281   md5_step (F3, a, b, c, d, in[13] + 0x289b7ec6,  4);
 282   md5_step (F3, d, a, b, c, in[0]  + 0xeaa127fa, 11);
 283   md5_step (F3, c, d, a, b, in[3]  + 0xd4ef3085, 16);
 284   md5_step (F3, b, c, d, a, in[6]  + 0x04881d05, 23);
 285   md5_step (F3, a, b, c, d, in[9]  + 0xd9d4d039,  4);
 286   md5_step (F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 287   md5_step (F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 288   md5_step (F3, b, c, d, a, in[2]  + 0xc4ac5665, 23);
 289
 290   md5_step (F4, a, b, c, d, in[0]  + 0xf4292244,  6);
 291   md5_step (F4, d, a, b, c, in[7]  + 0x432aff97, 10);
 292   md5_step (F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 293   md5_step (F4, b, c, d, a, in[5]  + 0xfc93a039, 21);
 294   md5_step (F4, a, b, c, d, in[12] + 0x655b59c3,  6);
 295   md5_step (F4, d, a, b, c, in[3]  + 0x8f0ccc92, 10);
 296   md5_step (F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 297   md5_step (F4, b, c, d, a, in[1]  + 0x85845dd1, 21);
 298   md5_step (F4, a, b, c, d, in[8]  + 0x6fa87e4f,  6);
 299   md5_step (F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 300   md5_step (F4, c, d, a, b, in[6]  + 0xa3014314, 15);
 301   md5_step (F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 302   md5_step (F4, a, b, c, d, in[4]  + 0xf7537e82,  6);
 303   md5_step (F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 304   md5_step (F4, c, d, a, b, in[2]  + 0x2ad7d2bb, 15);
 305   md5_step (F4, b, c, d, a, in[9]  + 0xeb86d391, 21);
 306
 307   buf[0] += a;
 308   buf[1] += b;
 309   buf[2] += c;
 310   buf[3] += d;
 311
 312 #undef F1
 313 #undef F2
 314 #undef F3
 315 #undef F4
 316 #undef md5_step
 317 }
 318
 319 static void
 320 md5_sum_update (Md5sum       *md5,
 321                 const guchar *data,
 322                 gsize         length)
 323 {
 324   guint32 bit;
 325
 326   bit = md5->bits[0];
 327   md5->bits[0] = bit + ((guint32) length << 3);
 328
 329   /* carry from low to high */
 330   if (md5->bits[0] < bit)
 331     md5->bits[1] += 1;
 332
 333   md5->bits[1] += length >> 29;
 334
 335   /* bytes already in Md5sum->u.data */
 336   bit = (bit >> 3) & 0x3f;
 337
 338   /* handle any leading odd-sized chunks */
 339   if (bit)
 340     {
 341       guchar *p = md5->u.data + bit;
 342
 343       bit = MD5_DATASIZE - bit;
 344       if (length < bit)
 345         {
 346           memcpy (p, data, length);
 347           return;
 348         }
 349
 350       memcpy (p, data, bit);
 351
 352       md5_byte_reverse (md5->u.data, 16);
 353       md5_transform (md5->buf, md5->u.data32);
 354
 355       data += bit;
 356       length -= bit;
 357     }
 358
 359   /* process data in 64-byte chunks */
 360   while (length >= MD5_DATASIZE)
 361     {
 362       memcpy (md5->u.data, data, MD5_DATASIZE);
 363
 364       md5_byte_reverse (md5->u.data, 16);
 365       md5_transform (md5->buf, md5->u.data32);
 366
 367       data += MD5_DATASIZE;
 368       length -= MD5_DATASIZE;
 369     }
 370
 371   /* handle any remaining bytes of data */
 372   memcpy (md5->u.data, data, length);
 373 }
 374
 375 /* closes a checksum */
 376 static void
 377 md5_sum_close (Md5sum *md5)
 378 {
 379   guint count;
 380   guchar *p;
 381
 382   /* Compute number of bytes mod 64 */
 383   count = (md5->bits[0] >> 3) & 0x3F;
 384
 385   /* Set the first char of padding to 0x80.
 386    * This is safe since there is always at least one byte free
 387    */
 388   p = md5->u.data + count;
 389   *p++ = 0x80;
 390
 391   /* Bytes of padding needed to make 64 bytes */
 392   count = MD5_DATASIZE - 1 - count;
 393
 394   /* Pad out to 56 mod 64 */
 395   if (count < 8)
 396     {
 397       /* Two lots of padding:  Pad the first block to 64 bytes */
 398       memset (p, 0, count);
 399
 400       md5_byte_reverse (md5->u.data, 16);
 401       md5_transform (md5->buf, md5->u.data32);
 402
 403       /* Now fill the next block with 56 bytes */
 404       memset (md5->u.data, 0, MD5_DATASIZE - 8);
 405     }
 406   else
 407     {
 408       /* Pad block to 56 bytes */
 409       memset (p, 0, count - 8);
 410     }
 411
 412   md5_byte_reverse (md5->u.data, 14);
 413
 414   /* Append length in bits and transform */
 415   md5->u.data32[14] = md5->bits[0];
 416   md5->u.data32[15] = md5->bits[1];
 417
 418   md5_transform (md5->buf, md5->u.data32);
 419   md5_byte_reverse ((guchar *) md5->buf, 4);
 420
 421   memcpy (md5->digest, md5->buf, 16);
 422
 423   /* Reset buffers in case they contain sensitive data */
 424   memset (md5->buf, 0, sizeof (md5->buf));
 425   memset (md5->u.data, 0, sizeof (md5->u.data));
 426 }
 427
 428 static gchar *
 429 md5_sum_to_string (Md5sum *md5)
 430 {
 431   return digest_to_string (md5->digest, MD5_DIGEST_LEN);
 432 }
 433
 434 static void
 435 md5_sum_digest (Md5sum *md5,
 436                 guint8 *digest)
 437 {
 438   gint i;
 439
 440   for (i = 0; i < MD5_DIGEST_LEN; i++)
 441     digest[i] = md5->digest[i];
 442 }
 443
 444 /*
 445  * SHA-1 Checksum
 446  */
 447
 448 /* The following implementation comes from D-Bus dbus-sha.c. I've changed
 449  * it to use GLib types and to work more like the MD5 implementation above.
 450  * I left the comments to have an history of this code.
 451  *      -- Emmanuele Bassi, ebassi@gnome.org
 452  */
 453
 454 /* The following comments have the history of where this code
 455  * comes from. I actually copied it from GNet in GNOME CVS.
 456  * - hp@redhat.com
 457  */
 458
 459 /*
 460  *  sha.h : Implementation of the Secure Hash Algorithm
 461  *
 462  * Part of the Python Cryptography Toolkit, version 1.0.0
 463  *
 464  * Copyright (C) 1995, A.M. Kuchling
 465  *
 466  * Distribute and use freely; there are no restrictions on further
 467  * dissemination and usage except those imposed by the laws of your
 468  * country of residence.
 469  *
 470  */
 471
 472 /* SHA: NIST's Secure Hash Algorithm */
 473
 474 /* Based on SHA code originally posted to sci.crypt by Peter Gutmann
 475    in message <30ajo5$oe8@ccu2.auckland.ac.nz>.
 476    Modified to test for endianness on creation of SHA objects by AMK.
 477    Also, the original specification of SHA was found to have a weakness
 478    by NSA/NIST.  This code implements the fixed version of SHA.
 479 */
 480
 481 /* Here's the first paragraph of Peter Gutmann's posting:
 482
 483 The following is my SHA (FIPS 180) code updated to allow use of the "fixed"
 484 SHA, thanks to Jim Gillogly and an anonymous contributor for the information on
 485 what's changed in the new version.  The fix is a simple change which involves
 486 adding a single rotate in the initial expansion function.  It is unknown
 487 whether this is an optimal solution to the problem which was discovered in the
 488 SHA or whether it's simply a bandaid which fixes the problem with a minimum of
 489 effort (for example the reengineering of a great many Capstone chips).
 490 */
 491
 492 static void
 493 sha1_sum_init (Sha1sum *sha1)
 494 {
 495   /* initialize constants */
 496   sha1->buf[0] = 0x67452301L;
 497   sha1->buf[1] = 0xEFCDAB89L;
 498   sha1->buf[2] = 0x98BADCFEL;
 499   sha1->buf[3] = 0x10325476L;
 500   sha1->buf[4] = 0xC3D2E1F0L;
 501
 502   /* initialize bits */
 503   sha1->bits[0] = sha1->bits[1] = 0;
 504 }
 505
 506 /* The SHA f()-functions. */
 507
 508 #define f1(x,y,z)       (z ^ (x & (y ^ z)))             /* Rounds  0-19 */
 509 #define f2(x,y,z)       (x ^ y ^ z)                     /* Rounds 20-39 */
 510 #define f3(x,y,z)       (( x & y) | (z & (x | y)))      /* Rounds 40-59 */
 511 #define f4(x,y,z)       (x ^ y ^ z)                     /* Rounds 60-79 */
 512
 513 /* The SHA Mysterious Constants */
 514 #define K1  0x5A827999L                                 /* Rounds  0-19 */
 515 #define K2  0x6ED9EBA1L                                 /* Rounds 20-39 */
 516 #define K3  0x8F1BBCDCL                                 /* Rounds 40-59 */
 517 #define K4  0xCA62C1D6L                                 /* Rounds 60-79 */
 518
 519 /* 32-bit rotate left - kludged with shifts */
 520 #define ROTL(n,X) (((X) << n ) | ((X) >> (32 - n)))
 521
 522 /* The initial expanding function.  The hash function is defined over an
 523    80-word expanded input array W, where the first 16 are copies of the input
 524    data, and the remaining 64 are defined by
 525
 526         W[ i ] = W[ i - 16 ] ^ W[ i - 14 ] ^ W[ i - 8 ] ^ W[ i - 3 ]
 527
 528    This implementation generates these values on the fly in a circular
 529    buffer - thanks to Colin Plumb, colin@nyx10.cs.du.edu for this
 530    optimization.
 531
 532    The updated SHA changes the expanding function by adding a rotate of 1
 533    bit.  Thanks to Jim Gillogly, jim@rand.org, and an anonymous contributor
 534    for this information */
 535
 536 #define expand(W,i) (W[ i & 15 ] = ROTL (1, (W[ i       & 15] ^ \
 537                                              W[(i - 14) & 15] ^ \
 538                                              W[(i -  8) & 15] ^ \
 539                                              W[(i -  3) & 15])))
 540
 541
 542 /* The prototype SHA sub-round.  The fundamental sub-round is:
 543
 544         a' = e + ROTL( 5, a ) + f( b, c, d ) + k + data;
 545         b' = a;
 546         c' = ROTL( 30, b );
 547         d' = c;
 548         e' = d;
 549
 550    but this is implemented by unrolling the loop 5 times and renaming the
 551    variables ( e, a, b, c, d ) = ( a', b', c', d', e' ) each iteration.
 552    This code is then replicated 20 times for each of the 4 functions, using
 553    the next 20 values from the W[] array each time */
 554
 555 #define subRound(a, b, c, d, e, f, k, data) \
 556    (e += ROTL (5, a) + f(b, c, d) + k + data, b = ROTL (30, b))
 557
 558 static void
 559 sha1_transform (guint32  buf[5],
 560                 guint32  in[16])
 561 {
 562   guint32 A, B, C, D, E;
 563
 564   A = buf[0];
 565   B = buf[1];
 566   C = buf[2];
 567   D = buf[3];
 568   E = buf[4];
 569
 570   /* Heavy mangling, in 4 sub-rounds of 20 iterations each. */
 571   subRound (A, B, C, D, E, f1, K1, in[0]);
 572   subRound (E, A, B, C, D, f1, K1, in[1]);
 573   subRound (D, E, A, B, C, f1, K1, in[2]);
 574   subRound (C, D, E, A, B, f1, K1, in[3]);
 575   subRound (B, C, D, E, A, f1, K1, in[4]);
 576   subRound (A, B, C, D, E, f1, K1, in[5]);
 577   subRound (E, A, B, C, D, f1, K1, in[6]);
 578   subRound (D, E, A, B, C, f1, K1, in[7]);
 579   subRound (C, D, E, A, B, f1, K1, in[8]);
 580   subRound (B, C, D, E, A, f1, K1, in[9]);
 581   subRound (A, B, C, D, E, f1, K1, in[10]);
 582   subRound (E, A, B, C, D, f1, K1, in[11]);
 583   subRound (D, E, A, B, C, f1, K1, in[12]);
 584   subRound (C, D, E, A, B, f1, K1, in[13]);
 585   subRound (B, C, D, E, A, f1, K1, in[14]);
 586   subRound (A, B, C, D, E, f1, K1, in[15]);
 587   subRound (E, A, B, C, D, f1, K1, expand (in, 16));
 588   subRound (D, E, A, B, C, f1, K1, expand (in, 17));
 589   subRound (C, D, E, A, B, f1, K1, expand (in, 18));
 590   subRound (B, C, D, E, A, f1, K1, expand (in, 19));
 591
 592   subRound (A, B, C, D, E, f2, K2, expand (in, 20));
 593   subRound (E, A, B, C, D, f2, K2, expand (in, 21));
 594   subRound (D, E, A, B, C, f2, K2, expand (in, 22));
 595   subRound (C, D, E, A, B, f2, K2, expand (in, 23));
 596   subRound (B, C, D, E, A, f2, K2, expand (in, 24));
 597   subRound (A, B, C, D, E, f2, K2, expand (in, 25));
 598   subRound (E, A, B, C, D, f2, K2, expand (in, 26));
 599   subRound (D, E, A, B, C, f2, K2, expand (in, 27));
 600   subRound (C, D, E, A, B, f2, K2, expand (in, 28));
 601   subRound (B, C, D, E, A, f2, K2, expand (in, 29));
 602   subRound (A, B, C, D, E, f2, K2, expand (in, 30));
 603   subRound (E, A, B, C, D, f2, K2, expand (in, 31));
 604   subRound (D, E, A, B, C, f2, K2, expand (in, 32));
 605   subRound (C, D, E, A, B, f2, K2, expand (in, 33));
 606   subRound (B, C, D, E, A, f2, K2, expand (in, 34));
 607   subRound (A, B, C, D, E, f2, K2, expand (in, 35));
 608   subRound (E, A, B, C, D, f2, K2, expand (in, 36));
 609   subRound (D, E, A, B, C, f2, K2, expand (in, 37));
 610   subRound (C, D, E, A, B, f2, K2, expand (in, 38));
 611   subRound (B, C, D, E, A, f2, K2, expand (in, 39));
 612
 613   subRound (A, B, C, D, E, f3, K3, expand (in, 40));
 614   subRound (E, A, B, C, D, f3, K3, expand (in, 41));
 615   subRound (D, E, A, B, C, f3, K3, expand (in, 42));
 616   subRound (C, D, E, A, B, f3, K3, expand (in, 43));
 617   subRound (B, C, D, E, A, f3, K3, expand (in, 44));
 618   subRound (A, B, C, D, E, f3, K3, expand (in, 45));
 619   subRound (E, A, B, C, D, f3, K3, expand (in, 46));
 620   subRound (D, E, A, B, C, f3, K3, expand (in, 47));
 621   subRound (C, D, E, A, B, f3, K3, expand (in, 48));
 622   subRound (B, C, D, E, A, f3, K3, expand (in, 49));
 623   subRound (A, B, C, D, E, f3, K3, expand (in, 50));
 624   subRound (E, A, B, C, D, f3, K3, expand (in, 51));
 625   subRound (D, E, A, B, C, f3, K3, expand (in, 52));
 626   subRound (C, D, E, A, B, f3, K3, expand (in, 53));
 627   subRound (B, C, D, E, A, f3, K3, expand (in, 54));
 628   subRound (A, B, C, D, E, f3, K3, expand (in, 55));
 629   subRound (E, A, B, C, D, f3, K3, expand (in, 56));
 630   subRound (D, E, A, B, C, f3, K3, expand (in, 57));
 631   subRound (C, D, E, A, B, f3, K3, expand (in, 58));
 632   subRound (B, C, D, E, A, f3, K3, expand (in, 59));
 633
 634   subRound (A, B, C, D, E, f4, K4, expand (in, 60));
 635   subRound (E, A, B, C, D, f4, K4, expand (in, 61));
 636   subRound (D, E, A, B, C, f4, K4, expand (in, 62));
 637   subRound (C, D, E, A, B, f4, K4, expand (in, 63));
 638   subRound (B, C, D, E, A, f4, K4, expand (in, 64));
 639   subRound (A, B, C, D, E, f4, K4, expand (in, 65));
 640   subRound (E, A, B, C, D, f4, K4, expand (in, 66));
 641   subRound (D, E, A, B, C, f4, K4, expand (in, 67));
 642   subRound (C, D, E, A, B, f4, K4, expand (in, 68));
 643   subRound (B, C, D, E, A, f4, K4, expand (in, 69));
 644   subRound (A, B, C, D, E, f4, K4, expand (in, 70));
 645   subRound (E, A, B, C, D, f4, K4, expand (in, 71));
 646   subRound (D, E, A, B, C, f4, K4, expand (in, 72));
 647   subRound (C, D, E, A, B, f4, K4, expand (in, 73));
 648   subRound (B, C, D, E, A, f4, K4, expand (in, 74));
 649   subRound (A, B, C, D, E, f4, K4, expand (in, 75));
 650   subRound (E, A, B, C, D, f4, K4, expand (in, 76));
 651   subRound (D, E, A, B, C, f4, K4, expand (in, 77));
 652   subRound (C, D, E, A, B, f4, K4, expand (in, 78));
 653   subRound (B, C, D, E, A, f4, K4, expand (in, 79));
 654
 655   /* Build message digest */
 656   buf[0] += A;
 657   buf[1] += B;
 658   buf[2] += C;
 659   buf[3] += D;
 660   buf[4] += E;
 661 }
 662
 663 #undef K1
 664 #undef K2
 665 #undef K3
 666 #undef K4
 667 #undef f1
 668 #undef f2
 669 #undef f3
 670 #undef f4
 671 #undef ROTL
 672 #undef expand
 673 #undef subRound
 674
 675 static void
 676 sha1_sum_update (Sha1sum      *sha1,
 677                  const guchar *buffer,
 678                  gsize         count)
 679 {
 680   guint32 tmp;
 681   guint dataCount;
 682
 683   /* Update bitcount */
 684   tmp = sha1->bits[0];
 685   if ((sha1->bits[0] = tmp + ((guint32) count << 3) ) < tmp)
 686     sha1->bits[1] += 1;             /* Carry from low to high */
 687   sha1->bits[1] += count >> 29;
 688
 689   /* Get count of bytes already in data */
 690   dataCount = (guint) (tmp >> 3) & 0x3F;
 691
 692   /* Handle any leading odd-sized chunks */
 693   if (dataCount)
 694     {
 695       guchar *p = (guchar *) sha1->data + dataCount;
 696
 697       dataCount = SHA1_DATASIZE - dataCount;
 698       if (count < dataCount)
 699         {
 700           memcpy (p, buffer, count);
 701           return;
 702         }
 703
 704       memcpy (p, buffer, dataCount);
 705
 706       sha_byte_reverse (sha1->data, SHA1_DATASIZE);
 707       sha1_transform (sha1->buf, sha1->data);
 708
 709       buffer += dataCount;
 710       count -= dataCount;
 711     }
 712
 713   /* Process data in SHA1_DATASIZE chunks */
 714   while (count >= SHA1_DATASIZE)
 715     {
 716       memcpy (sha1->data, buffer, SHA1_DATASIZE);
 717
 718       sha_byte_reverse (sha1->data, SHA1_DATASIZE);
 719       sha1_transform (sha1->buf, sha1->data);
 720
 721       buffer += SHA1_DATASIZE;
 722       count -= SHA1_DATASIZE;
 723     }
 724
 725   /* Handle any remaining bytes of data. */
 726   memcpy (sha1->data, buffer, count);
 727 }
 728
 729 /* Final wrapup - pad to SHA_DATASIZE-byte boundary with the bit pattern
 730    1 0* (64-bit count of bits processed, MSB-first) */
 731 static void
 732 sha1_sum_close (Sha1sum *sha1)
 733 {
 734   gint count;
 735   guchar *data_p;
 736
 737   /* Compute number of bytes mod 64 */
 738   count = (gint) ((sha1->bits[0] >> 3) & 0x3f);
 739
 740   /* Set the first char of padding to 0x80.  This is safe since there is
 741      always at least one byte free */
 742   data_p = (guchar *) sha1->data + count;
 743   *data_p++ = 0x80;
 744
 745   /* Bytes of padding needed to make 64 bytes */
 746   count = SHA1_DATASIZE - 1 - count;
 747
 748   /* Pad out to 56 mod 64 */
 749   if (count < 8)
 750     {
 751       /* Two lots of padding:  Pad the first block to 64 bytes */
 752       memset (data_p, 0, count);
 753
 754       sha_byte_reverse (sha1->data, SHA1_DATASIZE);
 755       sha1_transform (sha1->buf, sha1->data);
 756
 757       /* Now fill the next block with 56 bytes */
 758       memset (sha1->data, 0, SHA1_DATASIZE - 8);
 759     }
 760   else
 761     {
 762       /* Pad block to 56 bytes */
 763       memset (data_p, 0, count - 8);
 764     }
 765
 766   /* Append length in bits and transform */
 767   sha1->data[14] = sha1->bits[1];
 768   sha1->data[15] = sha1->bits[0];
 769
 770   sha_byte_reverse (sha1->data, SHA1_DATASIZE - 8);
 771   sha1_transform (sha1->buf, sha1->data);
 772   sha_byte_reverse (sha1->buf, SHA1_DIGEST_LEN);
 773
 774   memcpy (sha1->digest, sha1->buf, SHA1_DIGEST_LEN);
 775
 776   /* Reset buffers in case they contain sensitive data */
 777   memset (sha1->buf, 0, sizeof (sha1->buf));
 778   memset (sha1->data, 0, sizeof (sha1->data));
 779 }
 780
 781 static gchar *
 782 sha1_sum_to_string (Sha1sum *sha1)
 783 {
 784   return digest_to_string (sha1->digest, SHA1_DIGEST_LEN);
 785 }
 786
 787 static void
 788 sha1_sum_digest (Sha1sum *sha1,
 789                  guint8  *digest)
 790 {
 791   gint i;
 792
 793   for (i = 0; i < SHA1_DIGEST_LEN; i++)
 794     digest[i] = sha1->digest[i];
 795 }
 796
 797 /*
 798  * SHA-256 Checksum
 799  */
 800
 801 /* adapted from the SHA256 implementation in gsk/src/hash/gskhash.c.
 802  *
 803  * Copyright (C) 2006 Dave Benson
 804  * Released under the terms of the GNU Lesser General Public License
 805  */
 806
 807 static void
 808 sha256_sum_init (Sha256sum *sha256)
 809 {
 810   sha256->buf[0] = 0x6a09e667;
 811   sha256->buf[1] = 0xbb67ae85;
 812   sha256->buf[2] = 0x3c6ef372;
 813   sha256->buf[3] = 0xa54ff53a;
 814   sha256->buf[4] = 0x510e527f;
 815   sha256->buf[5] = 0x9b05688c;
 816   sha256->buf[6] = 0x1f83d9ab;
 817   sha256->buf[7] = 0x5be0cd19;
 818
 819   sha256->bits[0] = sha256->bits[1] = 0;
 820 }
 821
 822 #define GET_UINT32(n,b,i)               G_STMT_START{   \
 823     (n) = ((guint32) (b)[(i)    ] << 24)                \
 824         | ((guint32) (b)[(i) + 1] << 16)                \
 825         | ((guint32) (b)[(i) + 2] <<  8)                \
 826         | ((guint32) (b)[(i) + 3]      ); } G_STMT_END
 827
 828 #define PUT_UINT32(n,b,i)               G_STMT_START{   \
 829     (b)[(i)    ] = (guint8) ((n) >> 24);                \
 830     (b)[(i) + 1] = (guint8) ((n) >> 16);                \
 831     (b)[(i) + 2] = (guint8) ((n) >>  8);                \
 832     (b)[(i) + 3] = (guint8) ((n)      ); } G_STMT_END
 833
 834 static void
 835 sha256_transform (guint32      buf[8],
 836                   guint8 const data[64])
 837 {
 838   guint32 temp1, temp2, W[64];
 839   guint32 A, B, C, D, E, F, G, H;
 840
 841   GET_UINT32 (W[0],  data,  0);
 842   GET_UINT32 (W[1],  data,  4);
 843   GET_UINT32 (W[2],  data,  8);
 844   GET_UINT32 (W[3],  data, 12);
 845   GET_UINT32 (W[4],  data, 16);
 846   GET_UINT32 (W[5],  data, 20);
 847   GET_UINT32 (W[6],  data, 24);
 848   GET_UINT32 (W[7],  data, 28);
 849   GET_UINT32 (W[8],  data, 32);
 850   GET_UINT32 (W[9],  data, 36);
 851   GET_UINT32 (W[10], data, 40);
 852   GET_UINT32 (W[11], data, 44);
 853   GET_UINT32 (W[12], data, 48);
 854   GET_UINT32 (W[13], data, 52);
 855   GET_UINT32 (W[14], data, 56);
 856   GET_UINT32 (W[15], data, 60);
 857
 858 #define SHR(x,n)        ((x & 0xFFFFFFFF) >> n)
 859 #define ROTR(x,n)       (SHR (x,n) | (x << (32 - n)))
 860
 861 #define S0(x) (ROTR (x, 7) ^ ROTR (x,18) ^  SHR (x, 3))
 862 #define S1(x) (ROTR (x,17) ^ ROTR (x,19) ^  SHR (x,10))
 863 #define S2(x) (ROTR (x, 2) ^ ROTR (x,13) ^ ROTR (x,22))
 864 #define S3(x) (ROTR (x, 6) ^ ROTR (x,11) ^ ROTR (x,25))
 865
 866 #define F0(x,y,z) ((x & y) | (z & (x | y)))
 867 #define F1(x,y,z) (z ^ (x & (y ^ z)))
 868
 869 #define R(t)    (W[t] = S1(W[t -  2]) + W[t -  7] + \
 870                         S0(W[t - 15]) + W[t - 16])
 871
 872 #define P(a,b,c,d,e,f,g,h,x,K)          G_STMT_START {  \
 873         temp1 = h + S3(e) + F1(e,f,g) + K + x;          \
 874         temp2 = S2(a) + F0(a,b,c);                      \
 875         d += temp1; h = temp1 + temp2; } G_STMT_END
 876
 877   A = buf[0];
 878   B = buf[1];
 879   C = buf[2];
 880   D = buf[3];
 881   E = buf[4];
 882   F = buf[5];
 883   G = buf[6];
 884   H = buf[7];
 885
 886   P (A, B, C, D, E, F, G, H, W[ 0], 0x428A2F98);
 887   P (H, A, B, C, D, E, F, G, W[ 1], 0x71374491);
 888   P (G, H, A, B, C, D, E, F, W[ 2], 0xB5C0FBCF);
 889   P (F, G, H, A, B, C, D, E, W[ 3], 0xE9B5DBA5);
 890   P (E, F, G, H, A, B, C, D, W[ 4], 0x3956C25B);
 891   P (D, E, F, G, H, A, B, C, W[ 5], 0x59F111F1);
 892   P (C, D, E, F, G, H, A, B, W[ 6], 0x923F82A4);
 893   P (B, C, D, E, F, G, H, A, W[ 7], 0xAB1C5ED5);
 894   P (A, B, C, D, E, F, G, H, W[ 8], 0xD807AA98);
 895   P (H, A, B, C, D, E, F, G, W[ 9], 0x12835B01);
 896   P (G, H, A, B, C, D, E, F, W[10], 0x243185BE);
 897   P (F, G, H, A, B, C, D, E, W[11], 0x550C7DC3);
 898   P (E, F, G, H, A, B, C, D, W[12], 0x72BE5D74);
 899   P (D, E, F, G, H, A, B, C, W[13], 0x80DEB1FE);
 900   P (C, D, E, F, G, H, A, B, W[14], 0x9BDC06A7);
 901   P (B, C, D, E, F, G, H, A, W[15], 0xC19BF174);
 902   P (A, B, C, D, E, F, G, H, R(16), 0xE49B69C1);
 903   P (H, A, B, C, D, E, F, G, R(17), 0xEFBE4786);
 904   P (G, H, A, B, C, D, E, F, R(18), 0x0FC19DC6);
 905   P (F, G, H, A, B, C, D, E, R(19), 0x240CA1CC);
 906   P (E, F, G, H, A, B, C, D, R(20), 0x2DE92C6F);
 907   P (D, E, F, G, H, A, B, C, R(21), 0x4A7484AA);
 908   P (C, D, E, F, G, H, A, B, R(22), 0x5CB0A9DC);
 909   P (B, C, D, E, F, G, H, A, R(23), 0x76F988DA);
 910   P (A, B, C, D, E, F, G, H, R(24), 0x983E5152);
 911   P (H, A, B, C, D, E, F, G, R(25), 0xA831C66D);
 912   P (G, H, A, B, C, D, E, F, R(26), 0xB00327C8);
 913   P (F, G, H, A, B, C, D, E, R(27), 0xBF597FC7);
 914   P (E, F, G, H, A, B, C, D, R(28), 0xC6E00BF3);
 915   P (D, E, F, G, H, A, B, C, R(29), 0xD5A79147);
 916   P (C, D, E, F, G, H, A, B, R(30), 0x06CA6351);
 917   P (B, C, D, E, F, G, H, A, R(31), 0x14292967);
 918   P (A, B, C, D, E, F, G, H, R(32), 0x27B70A85);
 919   P (H, A, B, C, D, E, F, G, R(33), 0x2E1B2138);
 920   P (G, H, A, B, C, D, E, F, R(34), 0x4D2C6DFC);
 921   P (F, G, H, A, B, C, D, E, R(35), 0x53380D13);
 922   P (E, F, G, H, A, B, C, D, R(36), 0x650A7354);
 923   P (D, E, F, G, H, A, B, C, R(37), 0x766A0ABB);
 924   P (C, D, E, F, G, H, A, B, R(38), 0x81C2C92E);
 925   P (B, C, D, E, F, G, H, A, R(39), 0x92722C85);
 926   P (A, B, C, D, E, F, G, H, R(40), 0xA2BFE8A1);
 927   P (H, A, B, C, D, E, F, G, R(41), 0xA81A664B);
 928   P (G, H, A, B, C, D, E, F, R(42), 0xC24B8B70);
 929   P (F, G, H, A, B, C, D, E, R(43), 0xC76C51A3);
 930   P (E, F, G, H, A, B, C, D, R(44), 0xD192E819);
 931   P (D, E, F, G, H, A, B, C, R(45), 0xD6990624);
 932   P (C, D, E, F, G, H, A, B, R(46), 0xF40E3585);
 933   P (B, C, D, E, F, G, H, A, R(47), 0x106AA070);
 934   P (A, B, C, D, E, F, G, H, R(48), 0x19A4C116);
 935   P (H, A, B, C, D, E, F, G, R(49), 0x1E376C08);
 936   P (G, H, A, B, C, D, E, F, R(50), 0x2748774C);
 937   P (F, G, H, A, B, C, D, E, R(51), 0x34B0BCB5);
 938   P (E, F, G, H, A, B, C, D, R(52), 0x391C0CB3);
 939   P (D, E, F, G, H, A, B, C, R(53), 0x4ED8AA4A);
 940   P (C, D, E, F, G, H, A, B, R(54), 0x5B9CCA4F);
 941   P (B, C, D, E, F, G, H, A, R(55), 0x682E6FF3);
 942   P (A, B, C, D, E, F, G, H, R(56), 0x748F82EE);
 943   P (H, A, B, C, D, E, F, G, R(57), 0x78A5636F);
 944   P (G, H, A, B, C, D, E, F, R(58), 0x84C87814);
 945   P (F, G, H, A, B, C, D, E, R(59), 0x8CC70208);
 946   P (E, F, G, H, A, B, C, D, R(60), 0x90BEFFFA);
 947   P (D, E, F, G, H, A, B, C, R(61), 0xA4506CEB);
 948   P (C, D, E, F, G, H, A, B, R(62), 0xBEF9A3F7);
 949   P (B, C, D, E, F, G, H, A, R(63), 0xC67178F2);
 950
 951 #undef SHR
 952 #undef ROTR
 953 #undef S0
 954 #undef S1
 955 #undef S2
 956 #undef S3
 957 #undef F0
 958 #undef F1
 959 #undef R
 960 #undef P
 961
 962   buf[0] += A;
 963   buf[1] += B;
 964   buf[2] += C;
 965   buf[3] += D;
 966   buf[4] += E;
 967   buf[5] += F;
 968   buf[6] += G;
 969   buf[7] += H;
 970 }
 971
 972 static void
 973 sha256_sum_update (Sha256sum    *sha256,
 974                    const guchar *buffer,
 975                    gsize         length)
 976 {
 977   guint32 left, fill;
 978   const guint8 *input = buffer;
 979
 980   if (length == 0)
 981     return;
 982
 983   left = sha256->bits[0] & 0x3F;
 984   fill = 64 - left;
 985
 986   sha256->bits[0] += length;
 987   sha256->bits[0] &= 0xFFFFFFFF;
 988
 989   if (sha256->bits[0] < length)
 990       sha256->bits[1]++;
 991
 992   if (left > 0 && length >= fill)
 993     {
 994       memcpy ((sha256->data + left), input, fill);
 995
 996       sha256_transform (sha256->buf, sha256->data);
 997       length -= fill;
 998       input += fill;
 999
1000       left = 0;
1001     }
1002
1003   while (length >= SHA256_DATASIZE)
1004     {
1005       sha256_transform (sha256->buf, input);
1006
1007       length -= 64;
1008       input += 64;
1009     }
1010
1011   if (length)
1012     memcpy (sha256->data + left, input, length);
1013 }
1014
1015 static guint8 sha256_padding[64] =
1016 {
1017  0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1018     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1019     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1020     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1021 };
1022
1023 static void
1024 sha256_sum_close (Sha256sum *sha256)
1025 {
1026   guint32 last, padn;
1027   guint32 high, low;
1028   guint8 msglen[8];
1029
1030   high = (sha256->bits[0] >> 29)
1031        | (sha256->bits[1] <<  3);
1032   low  = (sha256->bits[0] <<  3);
1033
1034   PUT_UINT32 (high, msglen, 0);
1035   PUT_UINT32 (low, msglen, 4);
1036
1037   last = sha256->bits[0] & 0x3F;
1038   padn = (last < 56) ? (56 - last) : (120 - last);
1039
1040   sha256_sum_update (sha256, sha256_padding, padn);
1041   sha256_sum_update (sha256, msglen, 8);
1042
1043   PUT_UINT32 (sha256->buf[0], sha256->digest,  0);
1044   PUT_UINT32 (sha256->buf[1], sha256->digest,  4);
1045   PUT_UINT32 (sha256->buf[2], sha256->digest,  8);
1046   PUT_UINT32 (sha256->buf[3], sha256->digest, 12);
1047   PUT_UINT32 (sha256->buf[4], sha256->digest, 16);
1048   PUT_UINT32 (sha256->buf[5], sha256->digest, 20);
1049   PUT_UINT32 (sha256->buf[6], sha256->digest, 24);
1050   PUT_UINT32 (sha256->buf[7], sha256->digest, 28);
1051 }
1052
1053 #undef PUT_UINT32
1054 #undef GET_UINT32
1055
1056 static gchar *
1057 sha256_sum_to_string (Sha256sum *sha256)
1058 {
1059   return digest_to_string (sha256->digest, SHA256_DIGEST_LEN);
1060 }
1061
1062 static void
1063 sha256_sum_digest (Sha256sum *sha256,
1064                    guint8    *digest)
1065 {
1066   gint i;
1067
1068   for (i = 0; i < SHA256_DIGEST_LEN; i++)
1069     digest[i] = sha256->digest[i];
1070 }
1071
1072
1073 /*
1074  * Public API
1075  */
1076
1077 /**
1078  * g_checksum_type_get_length:
1079  * @checksum_type: a #GChecksumType
1080  *
1081  * Gets the length in bytes of digests of type @checksum_type
1082  *
1083  * Return value: the checksum length, or -1 if @checksum_type is
1084  * not supported.
1085  *
1086  * Since: 2.16
1087  */
1088 gssize
1089 g_checksum_type_get_length (GChecksumType checksum_type)
1090 {
1091   gssize len = -1;
1092
1093   switch (checksum_type)
1094     {
1095     case G_CHECKSUM_MD5:
1096       len = MD5_DIGEST_LEN;
1097       break;
1098     case G_CHECKSUM_SHA1:
1099       len = SHA1_DIGEST_LEN;
1100       break;
1101     case G_CHECKSUM_SHA256:
1102       len = SHA256_DIGEST_LEN;
1103       break;
1104     default:
1105       len = -1;
1106       break;
1107     }
1108
1109   return len;
1110 }
1111
1112 /**
1113  * g_checksum_new:
1114  * @checksum_type: the desired type of checksum
1115  *
1116  * Creates a new #GChecksum, using the checksum algorithm @checksum_type.
1117  * If the @checksum_type is not known, %NULL is returned.
1118  * A #GChecksum can be used to compute the checksum, or digest, of an
1119  * arbitrary binary blob, using different hashing algorithms.
1120  *
1121  * A #GChecksum works by feeding a binary blob through g_checksum_update()
1122  * until there is data to be checked; the digest can then be extracted
1123  * using g_checksum_get_string(), which will return the checksum as a
1124  * hexadecimal string; or g_checksum_get_digest(), which will return a
1125  * vector of raw bytes. Once either g_checksum_get_string() or
1126  * g_checksum_get_digest() have been called on a #GChecksum, the checksum
1127  * will be closed and it won't be possible to call g_checksum_update()
1128  * on it anymore.
1129  *
1130  * Return value: the newly created #GChecksum, or %NULL.
1131  *   Use g_checksum_free() to free the memory allocated by it.
1132  *
1133  * Since: 2.16
1134  */
1135 GChecksum *
1136 g_checksum_new (GChecksumType checksum_type)
1137 {
1138   GChecksum *checksum;
1139
1140   if (! IS_VALID_TYPE (checksum_type))
1141     return NULL;
1142
1143   checksum = g_slice_new0 (GChecksum);
1144   checksum->type = checksum_type;
1145
1146   g_checksum_reset (checksum);
1147
1148   return checksum;
1149 }
1150
1151 /**
1152  * g_checksum_reset:
1153  * @checksum: the #GChecksum to reset
1154  *
1155  * Resets the state of the @checksum back to its initial state.
1156  *
1157  * Since: 2.18
1158  **/
1159 void
1160 g_checksum_reset (GChecksum *checksum)
1161 {
1162   g_return_if_fail (checksum != NULL);
1163
1164   g_free (checksum->digest_str);
1165   checksum->digest_str = NULL;
1166
1167   switch (checksum->type)
1168     {
1169     case G_CHECKSUM_MD5:
1170       md5_sum_init (&(checksum->sum.md5));
1171       break;
1172     case G_CHECKSUM_SHA1:
1173       sha1_sum_init (&(checksum->sum.sha1));
1174       break;
1175     case G_CHECKSUM_SHA256:
1176       sha256_sum_init (&(checksum->sum.sha256));
1177       break;
1178     default:
1179       g_assert_not_reached ();
1180       break;
1181     }
1182 }
1183
1184 /**
1185  * g_checksum_copy:
1186  * @checksum: the #GChecksum to copy
1187  *
1188  * Copies a #GChecksum. If @checksum has been closed, by calling
1189  * g_checksum_get_string() or g_checksum_get_digest(), the copied
1190  * checksum will be closed as well.
1191  *
1192  * Return value: the copy of the passed #GChecksum. Use g_checksum_free()
1193  *   when finished using it.
1194  *
1195  * Since: 2.16
1196  */
1197 GChecksum *
1198 g_checksum_copy (const GChecksum *checksum)
1199 {
1200   GChecksum *copy;
1201
1202   g_return_val_if_fail (checksum != NULL, NULL);
1203
1204   copy = g_slice_new (GChecksum);
1205   *copy = *checksum;
1206
1207   copy->digest_str = g_strdup (checksum->digest_str);
1208
1209   return copy;
1210 }
1211
1212 /**
1213  * g_checksum_free:
1214  * @checksum: a #GChecksum
1215  *
1216  * Frees the memory allocated for @checksum.
1217  *
1218  * Since: 2.16
1219  */
1220 void
1221 g_checksum_free (GChecksum *checksum)
1222 {
1223   if (G_LIKELY (checksum))
1224     {
1225       g_free (checksum->digest_str);
1226
1227       g_slice_free (GChecksum, checksum);
1228     }
1229 }
1230
1231 /**
1232  * g_checksum_update:
1233  * @checksum: a #GChecksum
1234  * @data: buffer used to compute the checksum
1235  * @length: size of the buffer, or -1 if it is a null-terminated string.
1236  *
1237  * Feeds @data into an existing #GChecksum. The checksum must still be
1238  * open, that is g_checksum_get_string() or g_checksum_get_digest() must
1239  * not have been called on @checksum.
1240  *
1241  * Since: 2.16
1242  */
1243 void
1244 g_checksum_update (GChecksum    *checksum,
1245                    const guchar *data,
1246                    gssize        length)
1247 {
1248   g_return_if_fail (checksum != NULL);
1249   g_return_if_fail (length == 0 || data != NULL);
1250
1251   if (length < 0)
1252     length = strlen ((const gchar *) data);
1253
1254   if (checksum->digest_str)
1255     {
1256       g_warning ("The checksum `%s' has been closed and cannot be updated "
1257                  "anymore.",
1258                  checksum->digest_str);
1259       return;
1260     }
1261
1262   switch (checksum->type)
1263     {
1264     case G_CHECKSUM_MD5:
1265       md5_sum_update (&(checksum->sum.md5), data, length);
1266       break;
1267     case G_CHECKSUM_SHA1:
1268       sha1_sum_update (&(checksum->sum.sha1), data, length);
1269       break;
1270     case G_CHECKSUM_SHA256:
1271       sha256_sum_update (&(checksum->sum.sha256), data, length);
1272       break;
1273     default:
1274       g_assert_not_reached ();
1275       break;
1276     }
1277 }
1278
1279 /**
1280  * g_checksum_get_string:
1281  * @checksum: a #GChecksum
1282  *
1283  * Gets the digest as an hexadecimal string.
1284  *
1285  * Once this function has been called the #GChecksum can no longer be
1286  * updated with g_checksum_update().
1287  *
1288  * The hexadecimal characters will be lower case.
1289  *
1290  * Return value: the hexadecimal representation of the checksum. The
1291  *   returned string is owned by the checksum and should not be modified
1292  *   or freed.
1293  *
1294  * Since: 2.16
1295  */
1296 const gchar *
1297 g_checksum_get_string (GChecksum *checksum)
1298 {
1299   gchar *str = NULL;
1300
1301   g_return_val_if_fail (checksum != NULL, NULL);
1302
1303   if (checksum->digest_str)
1304     return checksum->digest_str;
1305
1306   switch (checksum->type)
1307     {
1308     case G_CHECKSUM_MD5:
1309       md5_sum_close (&(checksum->sum.md5));
1310       str = md5_sum_to_string (&(checksum->sum.md5));
1311       break;
1312     case G_CHECKSUM_SHA1:
1313       sha1_sum_close (&(checksum->sum.sha1));
1314       str = sha1_sum_to_string (&(checksum->sum.sha1));
1315       break;
1316     case G_CHECKSUM_SHA256:
1317       sha256_sum_close (&(checksum->sum.sha256));
1318       str = sha256_sum_to_string (&(checksum->sum.sha256));
1319       break;
1320     default:
1321       g_assert_not_reached ();
1322       break;
1323     }
1324
1325   checksum->digest_str = str;
1326
1327   return checksum->digest_str;
1328 }
1329
1330 /**
1331  * g_checksum_get_digest:
1332  * @checksum: a #GChecksum
1333  * @buffer: output buffer
1334  * @digest_len: an inout parameter. The caller initializes it to the size of @buffer.
1335  *   After the call it contains the length of the digest.
1336  *
1337  * Gets the digest from @checksum as a raw binary vector and places it
1338  * into @buffer. The size of the digest depends on the type of checksum.
1339  *
1340  * Once this function has been called, the #GChecksum is closed and can
1341  * no longer be updated with g_checksum_update().
1342  *
1343  * Since: 2.16
1344  */
1345 void
1346 g_checksum_get_digest (GChecksum  *checksum,
1347                        guint8     *buffer,
1348                        gsize      *digest_len)
1349 {
1350   gboolean checksum_open = FALSE;
1351   gchar *str = NULL;
1352   gsize len;
1353
1354   g_return_if_fail (checksum != NULL);
1355
1356   len = g_checksum_type_get_length (checksum->type);
1357   g_return_if_fail (*digest_len >= len);
1358
1359   checksum_open = !!(checksum->digest_str == NULL);
1360
1361   switch (checksum->type)
1362     {
1363     case G_CHECKSUM_MD5:
1364       if (checksum_open)
1365         {
1366           md5_sum_close (&(checksum->sum.md5));
1367           str = md5_sum_to_string (&(checksum->sum.md5));
1368         }
1369       md5_sum_digest (&(checksum->sum.md5), buffer);
1370       break;
1371     case G_CHECKSUM_SHA1:
1372       if (checksum_open)
1373         {
1374           sha1_sum_close (&(checksum->sum.sha1));
1375           str = sha1_sum_to_string (&(checksum->sum.sha1));
1376         }
1377       sha1_sum_digest (&(checksum->sum.sha1), buffer);
1378       break;
1379     case G_CHECKSUM_SHA256:
1380       if (checksum_open)
1381         {
1382           sha256_sum_close (&(checksum->sum.sha256));
1383           str = sha256_sum_to_string (&(checksum->sum.sha256));
1384         }
1385       sha256_sum_digest (&(checksum->sum.sha256), buffer);
1386       break;
1387     default:
1388       g_assert_not_reached ();
1389       break;
1390     }
1391
1392   if (str)
1393     checksum->digest_str = str;
1394
1395   *digest_len = len;
1396 }
1397
1398 /**
1399  * g_compute_checksum_for_data:
1400  * @checksum_type: a #GChecksumType
1401  * @data: binary blob to compute the digest of
1402  * @length: length of @data
1403  *
1404  * Computes the checksum for a binary @data of @length. This is a
1405  * convenience wrapper for g_checksum_new(), g_checksum_get_string()
1406  * and g_checksum_free().
1407  *
1408  * The hexadecimal string returned will be in lower case.
1409  *
1410  * Return value: the digest of the binary data as a string in hexadecimal.
1411  *   The returned string should be freed with g_free() when done using it.
1412  *
1413  * Since: 2.16
1414  */
1415 gchar *
1416 g_compute_checksum_for_data (GChecksumType  checksum_type,
1417                              const guchar  *data,
1418                              gsize          length)
1419 {
1420   GChecksum *checksum;
1421   gchar *retval;
1422
1423   g_return_val_if_fail (IS_VALID_TYPE (checksum_type), NULL);
1424   g_return_val_if_fail (length == 0 || data != NULL, NULL);
1425
1426   checksum = g_checksum_new (checksum_type);
1427   if (!checksum)
1428     return NULL;
1429
1430   g_checksum_update (checksum, data, length);
1431   retval = g_strdup (g_checksum_get_string (checksum));
1432   g_checksum_free (checksum);
1433
1434   return retval;
1435 }
1436
1437 /**
1438  * g_compute_checksum_for_string:
1439  * @checksum_type: a #GChecksumType
1440  * @str: the string to compute the checksum of
1441  * @length: the length of the string, or -1 if the string is null-terminated.
1442  *
1443  * Computes the checksum of a string.
1444  *
1445  * The hexadecimal string returned will be in lower case.
1446  *
1447  * Return value: the checksum as a hexadecimal string. The returned string
1448  *   should be freed with g_free() when done using it.
1449  *
1450  * Since: 2.16
1451  */
1452 gchar *
1453 g_compute_checksum_for_string (GChecksumType  checksum_type,
1454                                const gchar   *str,
1455                                gssize         length)
1456 {
1457   g_return_val_if_fail (IS_VALID_TYPE (checksum_type), NULL);
1458   g_return_val_if_fail (length == 0 || str != NULL, NULL);
1459
1460   if (length < 0)
1461     length = strlen (str);
1462
1463   return g_compute_checksum_for_data (checksum_type, (const guchar *) str, length);
1464 }