digest.c 3.7 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159
  1. /*
  2. * Cryptographic API.
  3. *
  4. * Digest operations.
  5. *
  6. * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  7. *
  8. * This program is free software; you can redistribute it and/or modify it
  9. * under the terms of the GNU General Public License as published by the Free
  10. * Software Foundation; either version 2 of the License, or (at your option)
  11. * any later version.
  12. *
  13. */
  14. #include <linux/mm.h>
  15. #include <linux/errno.h>
  16. #include <linux/hardirq.h>
  17. #include <linux/highmem.h>
  18. #include <linux/kernel.h>
  19. #include <linux/module.h>
  20. #include <linux/scatterlist.h>
  21. #include "internal.h"
  22. #include "scatterwalk.h"
  23. static int init(struct hash_desc *desc)
  24. {
  25. struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
  26. tfm->__crt_alg->cra_digest.dia_init(tfm);
  27. return 0;
  28. }
  29. static int update2(struct hash_desc *desc,
  30. struct scatterlist *sg, unsigned int nbytes)
  31. {
  32. struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
  33. unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
  34. if (!nbytes)
  35. return 0;
  36. for (;;) {
  37. struct page *pg = sg->page;
  38. unsigned int offset = sg->offset;
  39. unsigned int l = sg->length;
  40. if (unlikely(l > nbytes))
  41. l = nbytes;
  42. nbytes -= l;
  43. do {
  44. unsigned int bytes_from_page = min(l, ((unsigned int)
  45. (PAGE_SIZE)) -
  46. offset);
  47. char *src = crypto_kmap(pg, 0);
  48. char *p = src + offset;
  49. if (unlikely(offset & alignmask)) {
  50. unsigned int bytes =
  51. alignmask + 1 - (offset & alignmask);
  52. bytes = min(bytes, bytes_from_page);
  53. tfm->__crt_alg->cra_digest.dia_update(tfm, p,
  54. bytes);
  55. p += bytes;
  56. bytes_from_page -= bytes;
  57. l -= bytes;
  58. }
  59. tfm->__crt_alg->cra_digest.dia_update(tfm, p,
  60. bytes_from_page);
  61. crypto_kunmap(src, 0);
  62. crypto_yield(desc->flags);
  63. offset = 0;
  64. pg++;
  65. l -= bytes_from_page;
  66. } while (l > 0);
  67. if (!nbytes)
  68. break;
  69. sg = sg_next(sg);
  70. }
  71. return 0;
  72. }
  73. static int update(struct hash_desc *desc,
  74. struct scatterlist *sg, unsigned int nbytes)
  75. {
  76. if (WARN_ON_ONCE(in_irq()))
  77. return -EDEADLK;
  78. return update2(desc, sg, nbytes);
  79. }
  80. static int final(struct hash_desc *desc, u8 *out)
  81. {
  82. struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
  83. unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
  84. struct digest_alg *digest = &tfm->__crt_alg->cra_digest;
  85. if (unlikely((unsigned long)out & alignmask)) {
  86. unsigned long align = alignmask + 1;
  87. unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm);
  88. u8 *dst = (u8 *)ALIGN(addr, align) +
  89. ALIGN(tfm->__crt_alg->cra_ctxsize, align);
  90. digest->dia_final(tfm, dst);
  91. memcpy(out, dst, digest->dia_digestsize);
  92. } else
  93. digest->dia_final(tfm, out);
  94. return 0;
  95. }
  96. static int nosetkey(struct crypto_hash *tfm, const u8 *key, unsigned int keylen)
  97. {
  98. crypto_hash_clear_flags(tfm, CRYPTO_TFM_RES_MASK);
  99. return -ENOSYS;
  100. }
  101. static int setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen)
  102. {
  103. struct crypto_tfm *tfm = crypto_hash_tfm(hash);
  104. crypto_hash_clear_flags(hash, CRYPTO_TFM_RES_MASK);
  105. return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen);
  106. }
  107. static int digest(struct hash_desc *desc,
  108. struct scatterlist *sg, unsigned int nbytes, u8 *out)
  109. {
  110. if (WARN_ON_ONCE(in_irq()))
  111. return -EDEADLK;
  112. init(desc);
  113. update2(desc, sg, nbytes);
  114. return final(desc, out);
  115. }
  116. int crypto_init_digest_ops(struct crypto_tfm *tfm)
  117. {
  118. struct hash_tfm *ops = &tfm->crt_hash;
  119. struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;
  120. if (dalg->dia_digestsize > crypto_tfm_alg_blocksize(tfm))
  121. return -EINVAL;
  122. ops->init = init;
  123. ops->update = update;
  124. ops->final = final;
  125. ops->digest = digest;
  126. ops->setkey = dalg->dia_setkey ? setkey : nosetkey;
  127. ops->digestsize = dalg->dia_digestsize;
  128. return 0;
  129. }
  130. void crypto_exit_digest_ops(struct crypto_tfm *tfm)
  131. {
  132. }