Provisional AES XTS support.

[thirdparty/openssl.git] / crypto / evp / e_aes.c

diff --git a/crypto/evp/e_aes.c b/crypto/evp/e_aes.c
index b1a701b65d6221e0933fb8766a8d1fe40f594725..a6d1b5da9f0cc468ec384dd015708adf6439e88c 100644 (file)
--- a/crypto/evp/e_aes.c
+++ b/crypto/evp/e_aes.c
@@ -458,5 +458,104 @@ static const EVP_CIPHER aes_256_gcm_cipher=
 
 const EVP_CIPHER *EVP_aes_256_gcm (void)
 {      return &aes_256_gcm_cipher;     }
+
+typedef struct
+       {
+       /* AES key schedules to use */
+       AES_KEY ks1, ks2;
+       XTS128_CONTEXT xts;
+       } EVP_AES_XTS_CTX;
+
+static int aes_xts_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
+       {
+       EVP_AES_XTS_CTX *xctx = c->cipher_data;
+       if (type != EVP_CTRL_INIT)
+               return -1;
+       /* key1 and key2 are used as an indicator both key and IV are set */
+       xctx->xts.key1 = NULL;
+       xctx->xts.key2 = NULL;
+       xctx->xts.block1 = (block128_f)AES_encrypt;
+       xctx->xts.block2 = (block128_f)AES_encrypt;
+       return 1;
+       }
+
+static int aes_xts_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
+                        const unsigned char *iv, int enc)
+       {
+       EVP_AES_XTS_CTX *xctx = ctx->cipher_data;
+       if (!iv && !key)
+               return 1;
+
+       if (key)
+               {
+               AES_set_encrypt_key(key, ctx->key_len * 8, &xctx->ks1);
+               AES_set_encrypt_key(key + ctx->key_len, ctx->key_len * 8,
+                                                               &xctx->ks2);
+
+               xctx->xts.key1 = &xctx->ks1;
+               xctx->xts.block1 = (block128_f)AES_encrypt;
+               xctx->xts.block2 = (block128_f)AES_encrypt;
+               }
+
+       if (iv)
+               {
+               xctx->xts.key2 = &xctx->ks2;
+               memcpy(ctx->iv, iv, 16);
+               }
+
+       return 1;
+       }
+
+static int aes_xts(EVP_CIPHER_CTX *ctx, unsigned char *out,
+               const unsigned char *in, size_t len)
+       {
+       EVP_AES_XTS_CTX *xctx = ctx->cipher_data;
+       if (!xctx->xts.key1 || !xctx->xts.key2)
+               return -1;
+       if (!out || !in)
+               return -1;
+       if (CRYPTO_xts128_encrypt(&xctx->xts, ctx->iv, in, out, len,
+                                                               ctx->encrypt))
+               return -1;
+       return len;
+       }
+
+static const EVP_CIPHER aes_128_xts_cipher=
+       {
+       NID_aes_128_xts,16,32,16,
+       EVP_CIPH_XTS_MODE|EVP_CIPH_FLAG_FIPS|EVP_CIPH_FLAG_DEFAULT_ASN1
+               | EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER
+               | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT,
+       aes_xts_init_key,
+       aes_xts,
+       0,
+       sizeof(EVP_AES_XTS_CTX),
+       NULL,
+       NULL,
+       aes_xts_ctrl,
+       NULL
+       };
+
+const EVP_CIPHER *EVP_aes_128_xts (void)
+{      return &aes_128_xts_cipher;     }
+       
+static const EVP_CIPHER aes_256_xts_cipher=
+       {
+       NID_aes_256_xts,16,64,16,
+       EVP_CIPH_XTS_MODE|EVP_CIPH_FLAG_FIPS|EVP_CIPH_FLAG_DEFAULT_ASN1
+               | EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER
+               | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT,
+       aes_xts_init_key,
+       aes_xts,
+       0,
+       sizeof(EVP_AES_XTS_CTX),
+       NULL,
+       NULL,
+       aes_xts_ctrl,
+       NULL
+       };
+
+const EVP_CIPHER *EVP_aes_256_xts (void)
+{      return &aes_256_xts_cipher;     }
                
 #endif