boxes: a number of improvements

* Algorithm interfaces are no longer required to load partial blocks,
the space for which is allocated dynamically.
* Padding schemes are now also separated, perhaps in the future to
become a "box" parameter.
Consequently, algorithm interfaces are no longer required to implement
padding either.

7 files changed, 82 insertions, 44 deletions

diff --git a/include/aesni/algorithm.h b/include/aesni/algorithm.h
new file mode 100644
index 0000000..8aacfdc
--- /dev/null
+++ b/include/aesni/algorithm.h
@@ -0,0 +1,17 @@
+/**
+ * \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 dfe9494..144a695 100644
--- a/include/aesni/all.h
+++ b/include/aesni/all.h
@@ -16,9 +16,12 @@
  */
 
 #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"
+#include "padding.h"
diff --git a/include/aesni/box.h b/include/aesni/box.h
index 12daa2e..1ff7941 100644
--- a/include/aesni/box.h
+++ b/include/aesni/box.h
@@ -8,6 +8,7 @@
 
 #pragma once
 
+#include "algorithm.h"
 #include "box_data.h"
 #include "error.h"
 
@@ -20,9 +21,9 @@ extern "C"
 
 AesNI_StatusCode aesni_box_init(
     AesNI_Box* box,
-    AesNI_BoxAlgorithm algorithm,
+    AesNI_Algorithm algorithm,
     const AesNI_BoxAlgorithmParams* algorithm_params,
-    AesNI_BoxMode mode,
+    AesNI_Mode mode,
     const AesNI_BoxBlock* iv,
     AesNI_ErrorDetails* err_details);
 
diff --git a/include/aesni/box_data.h b/include/aesni/box_data.h
index 9789f0f..8a1e357 100644
--- a/include/aesni/box_data.h
+++ b/include/aesni/box_data.h
@@ -10,6 +10,7 @@
 
 #include "aes.h"
 #include "error.h"
+#include "mode.h"
 
 #include <stdlib.h>
 
@@ -26,24 +27,6 @@ typedef union
 }
 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;
@@ -102,29 +85,11 @@ typedef AesNI_StatusCode (*AesNI_BoxStoreBlock)(
     const AesNI_BoxBlock*,
     AesNI_ErrorDetails*);
 
-typedef AesNI_StatusCode (*AesNI_BoxStorePartialBlock)(
-    void*,
-    const AesNI_BoxBlock*,
-    size_t,
-    AesNI_ErrorDetails*);
-
 typedef AesNI_StatusCode (*AesNI_BoxLoadBlock)(
     AesNI_BoxBlock*,
     const void*,
     AesNI_ErrorDetails*);
 
-typedef AesNI_StatusCode (*AesNI_BoxLoadPartialBlock)(
-    AesNI_BoxBlock*,
-    const void*,
-    size_t,
-    AesNI_ErrorDetails*);
-
-typedef AesNI_StatusCode (*AesNI_BoxLoadBlockWithPadding)(
-    AesNI_BoxBlock*,
-    const void*,
-    size_t,
-    AesNI_ErrorDetails*);
-
 typedef struct
 {
     AesNI_BoxDeriveParams derive_params;
@@ -134,10 +99,7 @@ typedef struct
     AesNI_BoxNextCounter next_counter;
     AesNI_BoxGetBlockSize get_block_size;
     AesNI_BoxStoreBlock store_block;
-    AesNI_BoxStorePartialBlock store_partial_block;
     AesNI_BoxLoadBlock load_block;
-    AesNI_BoxLoadPartialBlock load_partial_block;
-    AesNI_BoxLoadBlockWithPadding load_block_with_padding;
 }
 AesNI_BoxAlgorithmInterface;
 
@@ -146,7 +108,7 @@ typedef struct
     const AesNI_BoxAlgorithmInterface* algorithm;
     AesNI_BoxEncryptionParams encrypt_params;
     AesNI_BoxDecryptionParams decrypt_params;
-    AesNI_BoxMode mode;
+    AesNI_Mode mode;
     AesNI_BoxBlock iv;
 }
 AesNI_Box;
diff --git a/include/aesni/error.h b/include/aesni/error.h
index e78406a..a51284f 100644
--- a/include/aesni/error.h
+++ b/include/aesni/error.h
@@ -47,7 +47,8 @@ typedef enum
     AESNI_PARSE_ERROR,                 ///< Couldn't parse
     AESNI_INVALID_PKCS7_PADDING_ERROR, ///< Invalid PKCS7 padding while decrypting
     AESNI_NOT_IMPLEMENTED_ERROR,       ///< Not implemented
-    AESNI_INVALID_PLAINTEXT_LENGTH_ERROR,
+    AESNI_MISSING_PADDING_ERROR,
+    AESNI_MEMORY_ALLOCATION_ERROR,
 }
 AesNI_StatusCode;
 
@@ -168,7 +169,10 @@ AesNI_StatusCode aesni_error_not_implemented(
     AesNI_ErrorDetails* err_details,
     const char* what);
 
-AesNI_StatusCode aesni_error_invalid_plaintext_length(
+AesNI_StatusCode aesni_error_missing_padding(
+    AesNI_ErrorDetails* err_details);
+
+AesNI_StatusCode aesni_error_memory_allocation(
     AesNI_ErrorDetails* err_details);
 
 #ifdef __cplusplus
diff --git a/include/aesni/mode.h b/include/aesni/mode.h
new file mode 100644
index 0000000..fc00e9c
--- /dev/null
+++ b/include/aesni/mode.h
@@ -0,0 +1,19 @@
+/**
+ * \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/include/aesni/padding.h b/include/aesni/padding.h
new file mode 100644
index 0000000..f76df16
--- /dev/null
+++ b/include/aesni/padding.h
@@ -0,0 +1,32 @@
+/**
+ * \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"
+
+#include <stdlib.h>
+
+typedef enum
+{
+    AESNI_PADDING_PKCS7,
+}
+AesNI_PaddingMethod;
+
+AesNI_StatusCode aesni_extract_padding_size(
+    AesNI_PaddingMethod,
+    const void* src,
+    size_t src_size,
+    size_t* padding_size,
+    AesNI_ErrorDetails*);
+
+AesNI_StatusCode aesni_fill_with_padding(
+    AesNI_PaddingMethod,
+    void* dest,
+    size_t padding_size,
+    AesNI_ErrorDetails*);