geniv.c 3.8 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * geniv: Shared IV generator code
  4. *
  5. * This file provides common code to IV generators such as seqiv.
  6. *
  7. * Copyright (c) 2007-2019 Herbert Xu <herbert@gondor.apana.org.au>
  8. */
  9. #include <crypto/internal/geniv.h>
  10. #include <crypto/internal/rng.h>
  11. #include <crypto/null.h>
  12. #include <linux/err.h>
  13. #include <linux/kernel.h>
  14. #include <linux/module.h>
  15. #include <linux/rtnetlink.h>
  16. #include <linux/slab.h>
  17. static int aead_geniv_setkey(struct crypto_aead *tfm,
  18. const u8 *key, unsigned int keylen)
  19. {
  20. struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
  21. return crypto_aead_setkey(ctx->child, key, keylen);
  22. }
  23. static int aead_geniv_setauthsize(struct crypto_aead *tfm,
  24. unsigned int authsize)
  25. {
  26. struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
  27. return crypto_aead_setauthsize(ctx->child, authsize);
  28. }
  29. static void aead_geniv_free(struct aead_instance *inst)
  30. {
  31. crypto_drop_aead(aead_instance_ctx(inst));
  32. kfree(inst);
  33. }
  34. struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,
  35. struct rtattr **tb)
  36. {
  37. struct crypto_aead_spawn *spawn;
  38. struct aead_instance *inst;
  39. struct aead_alg *alg;
  40. unsigned int ivsize;
  41. unsigned int maxauthsize;
  42. u32 mask;
  43. int err;
  44. err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
  45. if (err)
  46. return ERR_PTR(err);
  47. inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
  48. if (!inst)
  49. return ERR_PTR(-ENOMEM);
  50. spawn = aead_instance_ctx(inst);
  51. err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
  52. crypto_attr_alg_name(tb[1]), 0, mask);
  53. if (err)
  54. goto err_free_inst;
  55. alg = crypto_spawn_aead_alg(spawn);
  56. ivsize = crypto_aead_alg_ivsize(alg);
  57. maxauthsize = crypto_aead_alg_maxauthsize(alg);
  58. err = -EINVAL;
  59. if (ivsize < sizeof(u64))
  60. goto err_free_inst;
  61. err = -ENAMETOOLONG;
  62. if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
  63. "%s(%s)", tmpl->name, alg->base.cra_name) >=
  64. CRYPTO_MAX_ALG_NAME)
  65. goto err_free_inst;
  66. if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
  67. "%s(%s)", tmpl->name, alg->base.cra_driver_name) >=
  68. CRYPTO_MAX_ALG_NAME)
  69. goto err_free_inst;
  70. inst->alg.base.cra_priority = alg->base.cra_priority;
  71. inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
  72. inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
  73. inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
  74. inst->alg.setkey = aead_geniv_setkey;
  75. inst->alg.setauthsize = aead_geniv_setauthsize;
  76. inst->alg.ivsize = ivsize;
  77. inst->alg.maxauthsize = maxauthsize;
  78. inst->free = aead_geniv_free;
  79. out:
  80. return inst;
  81. err_free_inst:
  82. aead_geniv_free(inst);
  83. inst = ERR_PTR(err);
  84. goto out;
  85. }
  86. EXPORT_SYMBOL_GPL(aead_geniv_alloc);
  87. int aead_init_geniv(struct crypto_aead *aead)
  88. {
  89. struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
  90. struct aead_instance *inst = aead_alg_instance(aead);
  91. struct crypto_aead *child;
  92. int err;
  93. spin_lock_init(&ctx->lock);
  94. err = crypto_get_default_rng();
  95. if (err)
  96. goto out;
  97. err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
  98. crypto_aead_ivsize(aead));
  99. crypto_put_default_rng();
  100. if (err)
  101. goto out;
  102. ctx->sknull = crypto_get_default_null_skcipher();
  103. err = PTR_ERR(ctx->sknull);
  104. if (IS_ERR(ctx->sknull))
  105. goto out;
  106. child = crypto_spawn_aead(aead_instance_ctx(inst));
  107. err = PTR_ERR(child);
  108. if (IS_ERR(child))
  109. goto drop_null;
  110. ctx->child = child;
  111. crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
  112. sizeof(struct aead_request));
  113. err = 0;
  114. out:
  115. return err;
  116. drop_null:
  117. crypto_put_default_null_skcipher();
  118. goto out;
  119. }
  120. EXPORT_SYMBOL_GPL(aead_init_geniv);
  121. void aead_exit_geniv(struct crypto_aead *tfm)
  122. {
  123. struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
  124. crypto_free_aead(ctx->child);
  125. crypto_put_default_null_skcipher();
  126. }
  127. EXPORT_SYMBOL_GPL(aead_exit_geniv);
  128. MODULE_LICENSE("GPL");
  129. MODULE_DESCRIPTION("Shared IV generator code");