LXR linux/arch/arm/crypto/aes

   1/*
   2 * Glue Code for the asm optimized version of the AES Cipher Algorithm
   3 */
   4
   5#include <linux/module.h>
   6#include <linux/crypto.h>
   7#include <crypto/aes.h>
   8
   9#define AES_MAXNR 14
  10
  11typedef struct {
  12        unsigned int rd_key[4 *(AES_MAXNR + 1)];
  13        int rounds;
  14} AES_KEY;
  15
  16struct AES_CTX {
  17        AES_KEY enc_key;
  18        AES_KEY dec_key;
  19};
  20
  21asmlinkage void AES_encrypt(const u8 *in, u8 *out, AES_KEY *ctx);
  22asmlinkage void AES_decrypt(const u8 *in, u8 *out, AES_KEY *ctx);
  23asmlinkage int private_AES_set_decrypt_key(const unsigned char *userKey, const int bits, AES_KEY *key);
  24asmlinkage int private_AES_set_encrypt_key(const unsigned char *userKey, const int bits, AES_KEY *key);
  25
  26static void aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
  27{
  28        struct AES_CTX *ctx = crypto_tfm_ctx(tfm);
  29        AES_encrypt(src, dst, &ctx->enc_key);
  30}
  31
  32static void aes_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
  33{
  34        struct AES_CTX *ctx = crypto_tfm_ctx(tfm);
  35        AES_decrypt(src, dst, &ctx->dec_key);
  36}
  37
  38static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
  39                unsigned int key_len)
  40{
  41        struct AES_CTX *ctx = crypto_tfm_ctx(tfm);
  42
  43        switch (key_len) {
  44        case AES_KEYSIZE_128:
  45                key_len = 128;
  46                break;
  47        case AES_KEYSIZE_192:
  48                key_len = 192;
  49                break;
  50        case AES_KEYSIZE_256:
  51                key_len = 256;
  52                break;
  53        default:
  54                tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
  55                return -EINVAL;
  56        }
  57
  58        if (private_AES_set_encrypt_key(in_key, key_len, &ctx->enc_key) == -1) {
  59                tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
  60                return -EINVAL;
  61        }
  62        /* private_AES_set_decrypt_key expects an encryption key as input */
  63        ctx->dec_key = ctx->enc_key;
  64        if (private_AES_set_decrypt_key(in_key, key_len, &ctx->dec_key) == -1) {
  65                tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
  66                return -EINVAL;
  67        }
  68        return 0;
  69}
  70
  71static struct crypto_alg aes_alg = {
  72        .cra_name               = "aes",
  73        .cra_driver_name        = "aes-asm",
  74        .cra_priority           = 200,
  75        .cra_flags              = CRYPTO_ALG_TYPE_CIPHER,
  76        .cra_blocksize          = AES_BLOCK_SIZE,
  77        .cra_ctxsize            = sizeof(struct AES_CTX),
  78        .cra_module             = THIS_MODULE,
  79        .cra_list               = LIST_HEAD_INIT(aes_alg.cra_list),
  80        .cra_u  = {
  81                .cipher = {
  82                        .cia_min_keysize        = AES_MIN_KEY_SIZE,
  83                        .cia_max_keysize        = AES_MAX_KEY_SIZE,
  84                        .cia_setkey                     = aes_set_key,
  85                        .cia_encrypt            = aes_encrypt,
  86                        .cia_decrypt            = aes_decrypt
  87                }
  88        }
  89};
  90
  91static int __init aes_init(void)
  92{
  93        return crypto_register_alg(&aes_alg);
  94}
  95
  96static void __exit aes_fini(void)
  97{
  98        crypto_unregister_alg(&aes_alg);
  99}
 100
 101module_init(aes_init);
 102module_exit(aes_fini);
 103
 104MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm (ASM)");
 105MODULE_LICENSE("GPL");
 106MODULE_ALIAS("aes");
 107MODULE_ALIAS("aes-asm");
 108MODULE_AUTHOR("David McCullough <ucdevel@gmail.com>");
 109