arch/arm/crypto/aes_glue.c

   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
  11 typedef struct {
  12         unsigned int rd_key[4 *(AES_MAXNR + 1)];
  13         int rounds;
  14 } AES_KEY;
  15
  16 struct AES_CTX {
  17         AES_KEY enc_key;
  18         AES_KEY dec_key;
  19 };
  20
  21 asmlinkage void AES_encrypt(const u8 *in, u8 *out, AES_KEY *ctx);
  22 asmlinkage void AES_decrypt(const u8 *in, u8 *out, AES_KEY *ctx);
  23 asmlinkage int private_AES_set_decrypt_key(const unsigned char *userKey, const int bits, AES_KEY *key);
  24 asmlinkage int private_AES_set_encrypt_key(const unsigned char *userKey, const int bits, AES_KEY *key);
  25
  26 static 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
  32 static 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
  38 static 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
  71 static 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
  91 static int __init aes_init(void)
  92 {
  93         return crypto_register_alg(&aes_alg);
  94 }
  95
  96 static void __exit aes_fini(void)
  97 {
  98         crypto_unregister_alg(&aes_alg);
  99 }
 100
 101 module_init(aes_init);
 102 module_exit(aes_fini);
 103
 104 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm (ASM)");
 105 MODULE_LICENSE("GPL");
 106 MODULE_ALIAS("aes");
 107 MODULE_ALIAS("aes-asm");
 108 MODULE_AUTHOR("David McCullough <ucdevel@gmail.com>");