sha1.c 3.2 KB

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  1. /*
  2. * Cryptographic API.
  3. *
  4. * SHA1 Secure Hash Algorithm.
  5. *
  6. * Derived from cryptoapi implementation, adapted for in-place
  7. * scatterlist interface.
  8. *
  9. * Copyright (c) Alan Smithee.
  10. * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
  11. * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
  12. *
  13. * This program is free software; you can redistribute it and/or modify it
  14. * under the terms of the GNU General Public License as published by the Free
  15. * Software Foundation; either version 2 of the License, or (at your option)
  16. * any later version.
  17. *
  18. */
  19. #include <linux/init.h>
  20. #include <linux/module.h>
  21. #include <linux/mm.h>
  22. #include <linux/crypto.h>
  23. #include <linux/cryptohash.h>
  24. #include <linux/types.h>
  25. #include <asm/scatterlist.h>
  26. #include <asm/byteorder.h>
  27. #define SHA1_DIGEST_SIZE 20
  28. #define SHA1_HMAC_BLOCK_SIZE 64
  29. struct sha1_ctx {
  30. u64 count;
  31. u32 state[5];
  32. u8 buffer[64];
  33. };
  34. static void sha1_init(struct crypto_tfm *tfm)
  35. {
  36. struct sha1_ctx *sctx = crypto_tfm_ctx(tfm);
  37. static const struct sha1_ctx initstate = {
  38. 0,
  39. { 0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0 },
  40. { 0, }
  41. };
  42. *sctx = initstate;
  43. }
  44. static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
  45. unsigned int len)
  46. {
  47. struct sha1_ctx *sctx = crypto_tfm_ctx(tfm);
  48. unsigned int partial, done;
  49. const u8 *src;
  50. partial = sctx->count & 0x3f;
  51. sctx->count += len;
  52. done = 0;
  53. src = data;
  54. if ((partial + len) > 63) {
  55. u32 temp[SHA_WORKSPACE_WORDS];
  56. if (partial) {
  57. done = -partial;
  58. memcpy(sctx->buffer + partial, data, done + 64);
  59. src = sctx->buffer;
  60. }
  61. do {
  62. sha_transform(sctx->state, src, temp);
  63. done += 64;
  64. src = data + done;
  65. } while (done + 63 < len);
  66. memset(temp, 0, sizeof(temp));
  67. partial = 0;
  68. }
  69. memcpy(sctx->buffer + partial, src, len - done);
  70. }
  71. /* Add padding and return the message digest. */
  72. static void sha1_final(struct crypto_tfm *tfm, u8 *out)
  73. {
  74. struct sha1_ctx *sctx = crypto_tfm_ctx(tfm);
  75. __be32 *dst = (__be32 *)out;
  76. u32 i, index, padlen;
  77. __be64 bits;
  78. static const u8 padding[64] = { 0x80, };
  79. bits = cpu_to_be64(sctx->count << 3);
  80. /* Pad out to 56 mod 64 */
  81. index = sctx->count & 0x3f;
  82. padlen = (index < 56) ? (56 - index) : ((64+56) - index);
  83. sha1_update(tfm, padding, padlen);
  84. /* Append length */
  85. sha1_update(tfm, (const u8 *)&bits, sizeof(bits));
  86. /* Store state in digest */
  87. for (i = 0; i < 5; i++)
  88. dst[i] = cpu_to_be32(sctx->state[i]);
  89. /* Wipe context */
  90. memset(sctx, 0, sizeof *sctx);
  91. }
  92. static struct crypto_alg alg = {
  93. .cra_name = "sha1",
  94. .cra_driver_name= "sha1-generic",
  95. .cra_flags = CRYPTO_ALG_TYPE_DIGEST,
  96. .cra_blocksize = SHA1_HMAC_BLOCK_SIZE,
  97. .cra_ctxsize = sizeof(struct sha1_ctx),
  98. .cra_module = THIS_MODULE,
  99. .cra_alignmask = 3,
  100. .cra_list = LIST_HEAD_INIT(alg.cra_list),
  101. .cra_u = { .digest = {
  102. .dia_digestsize = SHA1_DIGEST_SIZE,
  103. .dia_init = sha1_init,
  104. .dia_update = sha1_update,
  105. .dia_final = sha1_final } }
  106. };
  107. static int __init init(void)
  108. {
  109. return crypto_register_alg(&alg);
  110. }
  111. static void __exit fini(void)
  112. {
  113. crypto_unregister_alg(&alg);
  114. }
  115. module_init(init);
  116. module_exit(fini);
  117. MODULE_LICENSE("GPL");
  118. MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
  119. MODULE_ALIAS("sha1-generic");