factoring out AES-specific stuff

10 files changed, 372 insertions, 316 deletions

diff --git a/include/aesni/algorithm.h b/include/aesni/algorithm.h
deleted file mode 100644
index 8aacfdc..0000000
--- a/include/aesni/algorithm.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/**
- * \file
- * \author Egor Tensin <Egor.Tensin@gmail.com>
- * \date 2015
- * \copyright This file is licensed under the terms of the MIT License.
- *            See LICENSE.txt for details.
- */
-
-#pragma once
-
-typedef enum
-{
-    AESNI_AES128,
-    AESNI_AES192,
-    AESNI_AES256,
-}
-AesNI_Algorithm;
diff --git a/include/aesni/all.h b/include/aesni/all.h
index 26f7a41..dfe9494 100644
--- a/include/aesni/all.h
+++ b/include/aesni/all.h
@@ -16,9 +16,9 @@
  */
 
 #include "aes.h"
-#include "algorithm.h"
 #include "box.h"
+#include "box_aes.h"
+#include "box_data.h"
 #include "buffer.h"
 #include "data.h"
 #include "error.h"
-#include "mode.h"
diff --git a/include/aesni/box.h b/include/aesni/box.h
index 70b2787..fd28cf1 100644
--- a/include/aesni/box.h
+++ b/include/aesni/box.h
@@ -8,74 +8,32 @@
 
 #pragma once
 
-#include "algorithm.h"
-#include "data.h"
+#include "box_data.h"
 #include "error.h"
-#include "mode.h"
 
 #ifdef __cplusplus
 extern "C"
 {
 #endif
 
-typedef union
-{
-    AesNI_Aes128_RoundKeys aes128_key_schedule;
-    AesNI_Aes192_RoundKeys aes192_key_schedule;
-    AesNI_Aes256_RoundKeys aes256_key_schedule;
-}
-AesNI_EncryptionParams;
-
-typedef union
-{
-    AesNI_Aes128_RoundKeys aes128_key_schedule;
-    AesNI_Aes192_RoundKeys aes192_key_schedule;
-    AesNI_Aes256_RoundKeys aes256_key_schedule;
-}
-AesNI_DecryptionParams;
-
-typedef union
-{
-    AesNI_Block128 aes_block;
-}
-AesNI_State;
-
-typedef union
-{
-    AesNI_Block128 aes128_key;
-    AesNI_Block192 aes192_key;
-    AesNI_Block256 aes256_key;
-}
-AesNI_AlgorithmParams;
-
-typedef struct
-{
-    AesNI_Algorithm algorithm;
-    AesNI_EncryptionParams encrypt_params;
-    AesNI_DecryptionParams decrypt_params;
-    AesNI_Mode mode;
-    AesNI_State iv;
-}
-AesNI_Box;
-
 AesNI_StatusCode aesni_box_init(
     AesNI_Box*,
-    AesNI_Algorithm,
-    const AesNI_AlgorithmParams*,
-    AesNI_Mode,
-    const AesNI_State* iv,
+    AesNI_BoxAlgorithm,
+    const AesNI_BoxAlgorithmParams*,
+    AesNI_BoxMode,
+    const AesNI_BoxBlock* iv,
     AesNI_ErrorDetails*);
 
 AesNI_StatusCode aesni_box_encrypt(
     AesNI_Box*,
-    const AesNI_State*,
-    AesNI_State*,
+    const AesNI_BoxBlock*,
+    AesNI_BoxBlock*,
     AesNI_ErrorDetails*);
 
 AesNI_StatusCode aesni_box_decrypt(
     AesNI_Box*,
-    const AesNI_State*,
-    AesNI_State*,
+    const AesNI_BoxBlock*,
+    AesNI_BoxBlock*,
     AesNI_ErrorDetails*);
 
 #ifdef __cplusplus
diff --git a/include/aesni/box_aes.h b/include/aesni/box_aes.h
new file mode 100644
index 0000000..391f13e
--- /dev/null
+++ b/include/aesni/box_aes.h
@@ -0,0 +1,155 @@
+/**
+ * \file
+ * \author Egor Tensin <Egor.Tensin@gmail.com>
+ * \date 2015
+ * \copyright This file is licensed under the terms of the MIT License.
+ *            See LICENSE.txt for details.
+ */
+
+#pragma once
+
+#include "aes.h"
+#include "box_aes.h"
+#include "box_data.h"
+#include "data.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+static __inline AesNI_StatusCode aesni_box_derive_params_aes128(
+    const AesNI_BoxAlgorithmParams* algorithm_params,
+    AesNI_BoxEncryptionParams* encrypt_params,
+    AesNI_BoxDecryptionParams* decrypt_params,
+    AesNI_ErrorDetails* err_details)
+{
+    aesni_aes128_expand_key_(
+        algorithm_params->aes128_key,
+        &encrypt_params->aes128_encryption_keys);
+    aesni_aes128_derive_decryption_keys_(
+        &encrypt_params->aes128_encryption_keys,
+        &decrypt_params->aes128_decryption_keys);
+    return AESNI_SUCCESS;
+}
+
+static __inline AesNI_StatusCode aesni_box_derive_params_aes192(
+    const AesNI_BoxAlgorithmParams* algorithm_params,
+    AesNI_BoxEncryptionParams* encrypt_params,
+    AesNI_BoxDecryptionParams* decrypt_params,
+    AesNI_ErrorDetails* err_details)
+{
+    aesni_aes192_expand_key_(
+        algorithm_params->aes192_key.lo,
+        algorithm_params->aes192_key.hi,
+        &encrypt_params->aes192_encryption_keys);
+    aesni_aes192_derive_decryption_keys_(
+        &encrypt_params->aes192_encryption_keys,
+        &decrypt_params->aes192_decryption_keys);
+    return AESNI_SUCCESS;
+}
+
+static __inline AesNI_StatusCode aesni_box_derive_params_aes256(
+    const AesNI_BoxAlgorithmParams* algorithm_params,
+    AesNI_BoxEncryptionParams* encrypt_params,
+    AesNI_BoxDecryptionParams* decrypt_params,
+    AesNI_ErrorDetails* err_details)
+{
+    aesni_aes256_expand_key_(
+        algorithm_params->aes256_key.lo,
+        algorithm_params->aes256_key.hi,
+        &encrypt_params->aes256_encryption_keys);
+    aesni_aes256_derive_decryption_keys_(
+        &encrypt_params->aes256_encryption_keys,
+        &decrypt_params->aes256_decryption_keys);
+    return AESNI_SUCCESS;
+}
+
+static __inline AesNI_StatusCode aesni_box_xor_block_aes(
+    AesNI_BoxBlock* dest,
+    const AesNI_BoxBlock* src,
+    AesNI_ErrorDetails* err_details)
+{
+    dest->aes_block = aesni_xor_block128(dest->aes_block, src->aes_block);
+    return AESNI_SUCCESS;
+}
+
+static __inline AesNI_StatusCode aesni_box_encrypt_aes128(
+    const AesNI_BoxBlock* input,
+    const AesNI_BoxEncryptionParams* params,
+    AesNI_BoxBlock* output,
+    AesNI_ErrorDetails* err_details)
+{
+    output->aes_block = aesni_aes128_encrypt_block_(
+        input->aes_block,
+        &params->aes128_encryption_keys);
+    return AESNI_SUCCESS;
+}
+
+static __inline AesNI_StatusCode aesni_box_decrypt_aes128(
+    const AesNI_BoxBlock* input,
+    const AesNI_BoxDecryptionParams* params,
+    AesNI_BoxBlock* output,
+    AesNI_ErrorDetails* err_details)
+{
+    output->aes_block = aesni_aes128_decrypt_block_(
+        input->aes_block,
+        &params->aes128_decryption_keys);
+    return AESNI_SUCCESS;
+}
+
+static __inline AesNI_StatusCode aesni_box_encrypt_aes192(
+    const AesNI_BoxBlock* input,
+    const AesNI_BoxEncryptionParams* params,
+    AesNI_BoxBlock* output,
+    AesNI_ErrorDetails* err_details)
+{
+    output->aes_block = aesni_aes192_encrypt_block_(
+        input->aes_block,
+        &params->aes192_encryption_keys);
+    return AESNI_SUCCESS;
+}
+
+static __inline AesNI_StatusCode aesni_box_decrypt_aes192(
+    const AesNI_BoxBlock* input,
+    const AesNI_BoxDecryptionParams* params,
+    AesNI_BoxBlock* output,
+    AesNI_ErrorDetails* err_details)
+{
+    output->aes_block = aesni_aes192_decrypt_block_(
+        input->aes_block,
+        &params->aes192_decryption_keys);
+    return AESNI_SUCCESS;
+}
+
+static __inline AesNI_StatusCode aesni_box_encrypt_aes256(
+    const AesNI_BoxBlock* input,
+    const AesNI_BoxEncryptionParams* params,
+    AesNI_BoxBlock* output,
+    AesNI_ErrorDetails* err_details)
+{
+    output->aes_block = aesni_aes256_encrypt_block_(
+        input->aes_block,
+        &params->aes256_encryption_keys);
+    return AESNI_SUCCESS;
+}
+
+static __inline AesNI_StatusCode aesni_box_decrypt_aes256(
+    const AesNI_BoxBlock* input,
+    const AesNI_BoxDecryptionParams* params,
+    AesNI_BoxBlock* output,
+    AesNI_ErrorDetails* err_details)
+{
+    output->aes_block = aesni_aes256_decrypt_block_(
+        input->aes_block,
+        &params->aes256_decryption_keys);
+    return AESNI_SUCCESS;
+}
+
+extern AesNI_BoxAlgorithmInterface aesni_box_aes128_iface;
+extern AesNI_BoxAlgorithmInterface aesni_box_aes192_iface;
+extern AesNI_BoxAlgorithmInterface aesni_box_aes256_iface;
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/include/aesni/box_data.h b/include/aesni/box_data.h
new file mode 100644
index 0000000..160cf34
--- /dev/null
+++ b/include/aesni/box_data.h
@@ -0,0 +1,110 @@
+/**
+ * \file
+ * \author Egor Tensin <Egor.Tensin@gmail.com>
+ * \date 2015
+ * \copyright This file is licensed under the terms of the MIT License.
+ *            See LICENSE.txt for details.
+ */
+
+#pragma once
+
+#include "error.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+typedef union
+{
+    AesNI_Block128 aes128_key;
+    AesNI_Block192 aes192_key;
+    AesNI_Block256 aes256_key;
+}
+AesNI_BoxAlgorithmParams;
+
+typedef enum
+{
+    AESNI_AES128,
+    AESNI_AES192,
+    AESNI_AES256,
+}
+AesNI_BoxAlgorithm;
+
+typedef enum
+{
+    AESNI_ECB,
+    AESNI_CBC,
+    AESNI_CFB,
+    AESNI_OFB,
+    AESNI_CTR,
+}
+AesNI_BoxMode;
+
+typedef union
+{
+    AesNI_Aes128_RoundKeys aes128_encryption_keys;
+    AesNI_Aes192_RoundKeys aes192_encryption_keys;
+    AesNI_Aes256_RoundKeys aes256_encryption_keys;
+}
+AesNI_BoxEncryptionParams;
+
+typedef union
+{
+    AesNI_Aes128_RoundKeys aes128_decryption_keys;
+    AesNI_Aes192_RoundKeys aes192_decryption_keys;
+    AesNI_Aes256_RoundKeys aes256_decryption_keys;
+}
+AesNI_BoxDecryptionParams;
+
+typedef union
+{
+    AesNI_Block128 aes_block;
+}
+AesNI_BoxBlock;
+
+typedef AesNI_StatusCode (*AesNI_BoxDeriveParams)(
+    const AesNI_BoxAlgorithmParams* params,
+    AesNI_BoxEncryptionParams*,
+    AesNI_BoxDecryptionParams*,
+    AesNI_ErrorDetails* err_details);
+
+typedef AesNI_StatusCode (*AesNI_BoxEncrypt)(
+    const AesNI_BoxBlock* plaintext,
+    const AesNI_BoxEncryptionParams* params,
+    AesNI_BoxBlock* ciphertext,
+    AesNI_ErrorDetails* err_details);
+
+typedef AesNI_StatusCode (*AesNI_BoxDecrypt)(
+    const AesNI_BoxBlock* ciphertext,
+    const AesNI_BoxDecryptionParams* params,
+    AesNI_BoxBlock* plaintext,
+    AesNI_ErrorDetails* err_details);
+
+typedef AesNI_StatusCode (*AesNI_BoxXorBlock)(
+    AesNI_BoxBlock*,
+    const AesNI_BoxBlock*,
+    AesNI_ErrorDetails*);
+
+typedef struct
+{
+    AesNI_BoxDeriveParams derive_params;
+    AesNI_BoxEncrypt encrypt;
+    AesNI_BoxDecrypt decrypt;
+    AesNI_BoxXorBlock xor_block;
+}
+AesNI_BoxAlgorithmInterface;
+
+typedef struct
+{
+    const AesNI_BoxAlgorithmInterface* algorithm_iface;
+    AesNI_BoxEncryptionParams encrypt_params;
+    AesNI_BoxDecryptionParams decrypt_params;
+    AesNI_BoxMode mode;
+    AesNI_BoxBlock iv;
+}
+AesNI_Box;
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/include/aesni/mode.h b/include/aesni/mode.h
deleted file mode 100644
index fc00e9c..0000000
--- a/include/aesni/mode.h
+++ /dev/null
@@ -1,19 +0,0 @@
-/**
- * \file
- * \author Egor Tensin <Egor.Tensin@gmail.com>
- * \date 2015
- * \copyright This file is licensed under the terms of the MIT License.
- *            See LICENSE.txt for details.
- */
-
-#pragma once
-
-typedef enum
-{
-    AESNI_ECB,
-    AESNI_CBC,
-    AESNI_CFB,
-    AESNI_OFB,
-    AESNI_CTR,
-}
-AesNI_Mode;
diff --git a/src/box.c b/src/box.c
index 4484390..0fa7297 100644
--- a/src/box.c
+++ b/src/box.c
@@ -8,193 +8,29 @@
 
 #include <aesni/all.h>
 
-static AesNI_StatusCode aesni_box_xor_state_aes(
-    AesNI_State* dest,
-    const AesNI_State* src,
-    AesNI_ErrorDetails* err_details)
-{
-    dest->aes_block = aesni_xor_block128(dest->aes_block, src->aes_block);
-    return AESNI_SUCCESS;
-}
-
-static AesNI_StatusCode aesni_box_encrypt_aes128(
-    const AesNI_State* input,
-    const AesNI_EncryptionParams* params,
-    AesNI_State* output,
-    AesNI_ErrorDetails* err_details)
-{
-    output->aes_block = aesni_aes128_encrypt_block_(
-        input->aes_block,
-        &params->aes128_key_schedule);
-    return AESNI_SUCCESS;
-}
-
-static AesNI_StatusCode aesni_box_decrypt_aes128(
-    const AesNI_State* input,
-    const AesNI_DecryptionParams* params,
-    AesNI_State* output,
-    AesNI_ErrorDetails* err_details)
-{
-    output->aes_block = aesni_aes128_decrypt_block_(
-        input->aes_block,
-        &params->aes128_key_schedule);
-    return AESNI_SUCCESS;
-}
-
-static AesNI_StatusCode aesni_box_encrypt_aes192(
-    const AesNI_State* input,
-    const AesNI_EncryptionParams* params,
-    AesNI_State* output,
-    AesNI_ErrorDetails* err_details)
-{
-    output->aes_block = aesni_aes192_encrypt_block_(
-        input->aes_block,
-        &params->aes192_key_schedule);
-    return AESNI_SUCCESS;
-}
-
-static AesNI_StatusCode aesni_box_decrypt_aes192(
-    const AesNI_State* input,
-    const AesNI_DecryptionParams* params,
-    AesNI_State* output,
-    AesNI_ErrorDetails* err_details)
-{
-    output->aes_block = aesni_aes192_decrypt_block_(
-        input->aes_block,
-        &params->aes192_key_schedule);
-    return AESNI_SUCCESS;
-}
-
-static AesNI_StatusCode aesni_box_encrypt_aes256(
-    const AesNI_State* input,
-    const AesNI_EncryptionParams* params,
-    AesNI_State* output,
-    AesNI_ErrorDetails* err_details)
-{
-    output->aes_block = aesni_aes256_encrypt_block_(
-        input->aes_block,
-        &params->aes256_key_schedule);
-    return AESNI_SUCCESS;
-}
-
-static AesNI_StatusCode aesni_box_decrypt_aes256(
-    const AesNI_State* input,
-    const AesNI_DecryptionParams* params,
-    AesNI_State* output,
-    AesNI_ErrorDetails* err_details)
-{
-    output->aes_block = aesni_aes256_decrypt_block_(
-        input->aes_block,
-        &params->aes256_key_schedule);
-    return AESNI_SUCCESS;
-}
-
-typedef AesNI_StatusCode (*AesNI_BoxEncrypt)(
-    const AesNI_State*,
-    const AesNI_EncryptionParams* params,
-    AesNI_State* output,
-    AesNI_ErrorDetails* err_details);
-
-static AesNI_BoxEncrypt aesni_box_encrypt_algorithm[] =
-{
-    &aesni_box_encrypt_aes128,
-    &aesni_box_encrypt_aes192,
-    &aesni_box_encrypt_aes256,
-};
-
-typedef AesNI_StatusCode (*AesNI_BoxDecrypt)(
-    const AesNI_State*,
-    const AesNI_DecryptionParams* params,
-    AesNI_State* output,
-    AesNI_ErrorDetails* err_details);
-
-static AesNI_BoxDecrypt aesni_box_decrypt_algorithm[] =
-{
-    &aesni_box_decrypt_aes128,
-    &aesni_box_decrypt_aes192,
-    &aesni_box_decrypt_aes256,
-};
-
-typedef AesNI_StatusCode (*AesNI_BoxXorState)(
-    AesNI_State*,
-    const AesNI_State*,
-    AesNI_ErrorDetails*);
-
-static AesNI_BoxXorState aesni_box_xor_state[] =
-{
-    &aesni_box_xor_state_aes,
-    &aesni_box_xor_state_aes,
-    &aesni_box_xor_state_aes,
-};
-
-static AesNI_StatusCode aesni_box_init_aes128(
-    AesNI_Box* box,
-    const AesNI_AlgorithmParams* algorithm_params,
-    AesNI_ErrorDetails* err_details)
-{
-    aesni_aes128_expand_key_(
-        algorithm_params->aes128_key,
-        &box->encrypt_params.aes128_key_schedule);
-    aesni_aes128_derive_decryption_keys_(
-        &box->encrypt_params.aes128_key_schedule,
-        &box->decrypt_params.aes128_key_schedule);
-    return AESNI_SUCCESS;
-}
-
-static AesNI_StatusCode aesni_box_init_aes192(
-    AesNI_Box* box,
-    const AesNI_AlgorithmParams* algorithm_params,
-    AesNI_ErrorDetails* err_details)
-{
-    aesni_aes192_expand_key_(
-        algorithm_params->aes192_key.lo,
-        algorithm_params->aes192_key.hi,
-        &box->encrypt_params.aes192_key_schedule);
-    aesni_aes192_derive_decryption_keys_(
-        &box->encrypt_params.aes192_key_schedule,
-        &box->decrypt_params.aes192_key_schedule);
-    return AESNI_SUCCESS;
-}
-
-static AesNI_StatusCode aesni_box_init_aes256(
-    AesNI_Box* box,
-    const AesNI_AlgorithmParams* algorithm_params,
-    AesNI_ErrorDetails* err_details)
-{
-    aesni_aes256_expand_key_(
-        algorithm_params->aes256_key.lo,
-        algorithm_params->aes256_key.hi,
-        &box->encrypt_params.aes256_key_schedule);
-    aesni_aes256_derive_decryption_keys_(
-        &box->encrypt_params.aes256_key_schedule,
-        &box->decrypt_params.aes256_key_schedule);
-    return AESNI_SUCCESS;
-}
-
-typedef AesNI_StatusCode (*AesNI_BoxInitializeAlgorithm)(
-    AesNI_Box*,
-    const AesNI_AlgorithmParams*,
-    AesNI_ErrorDetails*);
-
-static AesNI_BoxInitializeAlgorithm aesni_box_init_algorithm[] =
+static const AesNI_BoxAlgorithmInterface* aesni_box_algorithm_ifaces[] =
 {
-    &aesni_box_init_aes128,
-    &aesni_box_init_aes192,
-    &aesni_box_init_aes256,
+    &aesni_box_aes128_iface,
+    &aesni_box_aes192_iface,
+    &aesni_box_aes256_iface,
 };
 
 AesNI_StatusCode aesni_box_init(
     AesNI_Box* box,
-    AesNI_Algorithm algorithm,
-    const AesNI_AlgorithmParams* algorithm_params,
-    AesNI_Mode mode,
-    const AesNI_State* iv,
+    AesNI_BoxAlgorithm algorithm,
+    const AesNI_BoxAlgorithmParams* algorithm_params,
+    AesNI_BoxMode mode,
+    const AesNI_BoxBlock* iv,
     AesNI_ErrorDetails* err_details)
 {
     AesNI_StatusCode status = AESNI_SUCCESS;
 
-    box->algorithm = algorithm;
-    if (aesni_is_error(status = aesni_box_init_algorithm[algorithm](box, algorithm_params, err_details)))
+    box->algorithm_iface = aesni_box_algorithm_ifaces[algorithm];
+    if (aesni_is_error(status = box->algorithm_iface->derive_params(
+            algorithm_params,
+            &box->encrypt_params,
+            &box->decrypt_params,
+            err_details)))
         return status;
     box->mode = mode;
     if (iv != NULL)
@@ -205,11 +41,11 @@ AesNI_StatusCode aesni_box_init(
 
 static AesNI_StatusCode aesni_box_encrypt_ecb(
     AesNI_Box* box,
-    const AesNI_State* input,
-    AesNI_State* output,
+    const AesNI_BoxBlock* input,
+    AesNI_BoxBlock* output,
     AesNI_ErrorDetails* err_details)
 {
-    return aesni_box_encrypt_algorithm[box->algorithm](
+    return box->algorithm_iface->encrypt(
         input,
         &box->encrypt_params,
         output,
@@ -218,21 +54,21 @@ static AesNI_StatusCode aesni_box_encrypt_ecb(
 
 static AesNI_StatusCode aesni_box_encrypt_cbc(
     AesNI_Box* box,
-    const AesNI_State* input,
-    AesNI_State* output,
+    const AesNI_BoxBlock* input,
+    AesNI_BoxBlock* output,
     AesNI_ErrorDetails* err_details)
 {
     AesNI_StatusCode status = AESNI_SUCCESS;
 
-    AesNI_State xored_input = *input;
-    status = aesni_box_xor_state[box->algorithm](
+    AesNI_BoxBlock xored_input = *input;
+    status = box->algorithm_iface->xor_block(
         &xored_input,
         &box->iv,
         err_details);
     if (aesni_is_error(status))
         return status;
 
-    status = aesni_box_encrypt_algorithm[box->algorithm](
+    status = box->algorithm_iface->encrypt(
         &xored_input,
         &box->encrypt_params,
         output,
@@ -246,11 +82,11 @@ static AesNI_StatusCode aesni_box_encrypt_cbc(
 
 static AesNI_StatusCode aesni_box_encrypt_cfb(
     AesNI_Box* box,
-    const AesNI_State* input,
-    AesNI_State* output,
+    const AesNI_BoxBlock* input,
+    AesNI_BoxBlock* output,
     AesNI_ErrorDetails* err_details)
 {
-    AesNI_StatusCode status = aesni_box_encrypt_algorithm[box->algorithm](
+    AesNI_StatusCode status = box->algorithm_iface->encrypt(
         &box->iv,
         &box->encrypt_params,
         output,
@@ -258,7 +94,7 @@ static AesNI_StatusCode aesni_box_encrypt_cfb(
     if (aesni_is_error(status))
         return status;
 
-    status = aesni_box_xor_state[box->algorithm](output, input, err_details);
+    status = box->algorithm_iface->xor_block(output, input, err_details);
     if (aesni_is_error(status))
         return status;
 
@@ -268,11 +104,11 @@ static AesNI_StatusCode aesni_box_encrypt_cfb(
 
 static AesNI_StatusCode aesni_box_encrypt_ofb(
     AesNI_Box* box,
-    const AesNI_State* input,
-    AesNI_State* output,
+    const AesNI_BoxBlock* input,
+    AesNI_BoxBlock* output,
     AesNI_ErrorDetails* err_details)
 {
-    AesNI_StatusCode status = aesni_box_encrypt_algorithm[box->algorithm](
+    AesNI_StatusCode status = box->algorithm_iface->encrypt(
         &box->iv,
         &box->encrypt_params,
         &box->iv,
@@ -282,7 +118,7 @@ static AesNI_StatusCode aesni_box_encrypt_ofb(
 
     *output = box->iv;
 
-    status = aesni_box_xor_state[box->algorithm](output, input, err_details);
+    status = box->algorithm_iface->xor_block(output, input, err_details);
     if (aesni_is_error(status))
         return status;
 
@@ -291,8 +127,8 @@ static AesNI_StatusCode aesni_box_encrypt_ofb(
 
 static AesNI_StatusCode aesni_box_encrypt_ctr(
     AesNI_Box* box,
-    const AesNI_State* input,
-    AesNI_State* output,
+    const AesNI_BoxBlock* input,
+    AesNI_BoxBlock* output,
     AesNI_ErrorDetails* err_details)
 {
     return aesni_error_not_implemented(err_details);
@@ -300,8 +136,8 @@ static AesNI_StatusCode aesni_box_encrypt_ctr(
 
 typedef AesNI_StatusCode (*AesNI_BoxEncryptMode)(
     AesNI_Box*,
-    const AesNI_State*,
-    AesNI_State*,
+    const AesNI_BoxBlock*,
+    AesNI_BoxBlock*,
     AesNI_ErrorDetails*);
 
 static AesNI_BoxEncryptMode aesni_box_encrypt_mode[] =
@@ -315,8 +151,8 @@ static AesNI_BoxEncryptMode aesni_box_encrypt_mode[] =
 
 AesNI_StatusCode aesni_box_encrypt(
     AesNI_Box* box,
-    const AesNI_State* input,
-    AesNI_State* output,
+    const AesNI_BoxBlock* input,
+    AesNI_BoxBlock* output,
     AesNI_ErrorDetails* err_details)
 {
     return aesni_box_encrypt_mode[box->mode](box, input, output, err_details);
@@ -324,11 +160,11 @@ AesNI_StatusCode aesni_box_encrypt(
 
 static AesNI_StatusCode aesni_box_decrypt_ecb(
     AesNI_Box* box,
-    const AesNI_State* input,
-    AesNI_State* output,
+    const AesNI_BoxBlock* input,
+    AesNI_BoxBlock* output,
     AesNI_ErrorDetails* err_details)
 {
-    return aesni_box_decrypt_algorithm[box->algorithm](
+    return box->algorithm_iface->decrypt(
         input,
         &box->decrypt_params,
         output,
@@ -337,11 +173,11 @@ static AesNI_StatusCode aesni_box_decrypt_ecb(
 
 static AesNI_StatusCode aesni_box_decrypt_cbc(
     AesNI_Box* box,
-    const AesNI_State* input,
-    AesNI_State* output,
+    const AesNI_BoxBlock* input,
+    AesNI_BoxBlock* output,
     AesNI_ErrorDetails* err_details)
 {
-    AesNI_StatusCode status = aesni_box_decrypt_algorithm[box->algorithm](
+    AesNI_StatusCode status = box->algorithm_iface->decrypt(
         input,
         &box->decrypt_params,
         output,
@@ -349,7 +185,7 @@ static AesNI_StatusCode aesni_box_decrypt_cbc(
     if (aesni_is_error(status))
         return status;
 
-    status = aesni_box_xor_state[box->algorithm](
+    status = box->algorithm_iface->xor_block(
         output,
         &box->iv,
         err_details);
@@ -362,11 +198,11 @@ static AesNI_StatusCode aesni_box_decrypt_cbc(
 
 static AesNI_StatusCode aesni_box_decrypt_cfb(
     AesNI_Box* box,
-    const AesNI_State* input,
-    AesNI_State* output,
+    const AesNI_BoxBlock* input,
+    AesNI_BoxBlock* output,
     AesNI_ErrorDetails* err_details)
 {
-    AesNI_StatusCode status = aesni_box_encrypt_algorithm[box->algorithm](
+    AesNI_StatusCode status = box->algorithm_iface->encrypt(
         &box->iv,
         &box->encrypt_params,
         output,
@@ -374,7 +210,7 @@ static AesNI_StatusCode aesni_box_decrypt_cfb(
     if (aesni_is_error(status))
         return status;
 
-    status = aesni_box_xor_state[box->algorithm](
+    status = box->algorithm_iface->xor_block(
         output,
         input,
         err_details);
@@ -388,11 +224,11 @@ static AesNI_StatusCode aesni_box_decrypt_cfb(
 
 static AesNI_StatusCode aesni_box_decrypt_ofb(
     AesNI_Box* box,
-    const AesNI_State* input,
-    AesNI_State* output,
+    const AesNI_BoxBlock* input,
+    AesNI_BoxBlock* output,
     AesNI_ErrorDetails* err_details)
 {
-    AesNI_StatusCode status = aesni_box_encrypt_algorithm[box->algorithm](
+    AesNI_StatusCode status = box->algorithm_iface->encrypt(
         &box->iv,
         &box->encrypt_params,
         output,
@@ -402,7 +238,7 @@ static AesNI_StatusCode aesni_box_decrypt_ofb(
 
     box->iv = *output;
 
-    status = aesni_box_xor_state[box->algorithm](
+    status = box->algorithm_iface->xor_block(
         output,
         input,
         err_details);
@@ -414,8 +250,8 @@ static AesNI_StatusCode aesni_box_decrypt_ofb(
 
 static AesNI_StatusCode aesni_box_decrypt_ctr(
     AesNI_Box* box,
-    const AesNI_State* input,
-    AesNI_State* output,
+    const AesNI_BoxBlock* input,
+    AesNI_BoxBlock* output,
     AesNI_ErrorDetails* err_details)
 {
     return aesni_error_not_implemented(err_details);
@@ -434,8 +270,8 @@ static AesNI_BoxDecryptMode aesni_box_decrypt_mode[] =
 
 AesNI_StatusCode aesni_box_decrypt(
     AesNI_Box* box,
-    const AesNI_State* input,
-    AesNI_State* output,
+    const AesNI_BoxBlock* input,
+    AesNI_BoxBlock* output,
     AesNI_ErrorDetails* err_details)
 {
     return aesni_box_decrypt_mode[box->mode](box, input, output, err_details);
diff --git a/src/box_aes.c b/src/box_aes.c
new file mode 100644
index 0000000..5253415
--- /dev/null
+++ b/src/box_aes.c
@@ -0,0 +1,33 @@
+/**
+ * \file
+ * \author Egor Tensin <Egor.Tensin@gmail.com>
+ * \date 2015
+ * \copyright This file is licensed under the terms of the MIT License.
+ *            See LICENSE.txt for details.
+ */
+
+#include <aesni/all.h>
+
+AesNI_BoxAlgorithmInterface aesni_box_aes128_iface =
+{
+    &aesni_box_derive_params_aes128,
+    &aesni_box_encrypt_aes128,
+    &aesni_box_decrypt_aes128,
+    &aesni_box_xor_block_aes,
+};
+
+AesNI_BoxAlgorithmInterface aesni_box_aes192_iface =
+{
+    &aesni_box_derive_params_aes192,
+    &aesni_box_encrypt_aes192,
+    &aesni_box_decrypt_aes192,
+    &aesni_box_xor_block_aes,
+};
+
+AesNI_BoxAlgorithmInterface aesni_box_aes256_iface =
+{
+    &aesni_box_derive_params_aes256,
+    &aesni_box_encrypt_aes256,
+    &aesni_box_decrypt_aes256,
+    &aesni_box_xor_block_aes,
+};
diff --git a/test/decrypt_block_aes.cpp b/test/decrypt_block_aes.cpp
index acc9c6b..6cb9ce7 100644
--- a/test/decrypt_block_aes.cpp
+++ b/test/decrypt_block_aes.cpp
@@ -34,10 +34,10 @@ int main(int argc, char** argv)
             if (argc < 2)
                 exit_with_usage();
 
-            AesNI_AlgorithmParams algorithm_params;
+            AesNI_BoxAlgorithmParams algorithm_params;
             aesni::from_string(algorithm_params.aes128_key, argv[0]);
 
-            AesNI_State iv;
+            AesNI_BoxBlock iv;
             aesni::from_string(iv.aes_block, argv[1]);
 
             AesNI_Box box;
@@ -54,10 +54,10 @@ int main(int argc, char** argv)
                 if (std::strcmp("--", argv[0]) == 0)
                     break;
 
-                AesNI_State ciphertext;
+                AesNI_BoxBlock ciphertext;
                 aesni::from_string(ciphertext.aes_block, argv[0]);
 
-                AesNI_State plaintext;
+                AesNI_BoxBlock plaintext;
                 aesni_box_decrypt(
                     &box,
                     &ciphertext,
diff --git a/test/encrypt_block_aes.cpp b/test/encrypt_block_aes.cpp
index 9db6e32..f15ddda 100644
--- a/test/encrypt_block_aes.cpp
+++ b/test/encrypt_block_aes.cpp
@@ -34,10 +34,10 @@ int main(int argc, char** argv)
             if (argc < 2)
                 exit_with_usage();
 
-            AesNI_AlgorithmParams algorithm_params;
+            AesNI_BoxAlgorithmParams algorithm_params;
             aesni::from_string(algorithm_params.aes128_key, argv[0]);
 
-            AesNI_State iv;
+            AesNI_BoxBlock iv;
             aesni::from_string(iv.aes_block, argv[1]);
 
             AesNI_Box box;
@@ -54,10 +54,10 @@ int main(int argc, char** argv)
                 if (std::strcmp("--", argv[0]) == 0)
                     break;
 
-                AesNI_State plaintext;
+                AesNI_BoxBlock plaintext;
                 aesni::from_string(plaintext.aes_block, argv[0]);
 
-                AesNI_State ciphertext;
+                AesNI_BoxBlock ciphertext;
                 aesni_box_encrypt(
                     &box,
                     &plaintext,