cxx: more algorithm-agnostic API

The code (in the utilities in particular) is a mess though, so a
refactoring's coming up.

11 files changed, 995 insertions, 978 deletions

diff --git a/cxx/include/aesnixx/aes.hpp b/cxx/include/aesnixx/aes.hpp
index 5d293ca..b2febf5 100644
--- a/cxx/include/aesnixx/aes.hpp
+++ b/cxx/include/aesnixx/aes.hpp
@@ -9,581 +9,270 @@
 #pragma once
 
 #include "algorithm.hpp"
-#include "data.hpp"
+#include "api.hpp"
+#include "error.hpp"
 #include "mode.hpp"
 
 #include <aesni/all.h>
 
+#include <cstddef>
+
 #include <string>
 
 namespace aesni
 {
-    namespace aes
+    namespace aes128
+    {
+        typedef AesNI_AES128_Block Block;
+        typedef AesNI_AES128_RoundKeys RoundKeys;
+        typedef AesNI_AES128_Key Key;
+    }
+
+    template <>
+    struct Types<AESNI_AES128>
+    {
+        typedef aes128::Block Block;
+        typedef aes128::RoundKeys RoundKeys;
+        typedef aes128::Key Key;
+    };
+
+    template <>
+    std::size_t get_number_of_rounds<AESNI_AES128>()
+    {
+        return 11;
+    }
+
+    template <>
+    void from_string<AESNI_AES128>(aes128::Block& dest, const char* src)
+    {
+        aesni_AES128_parse_block(&dest, src, ErrorDetailsThrowsInDestructor());
+    }
+
+    template <>
+    std::string to_string<AESNI_AES128>(const aes128::Block& src)
+    {
+        AesNI_AES128_BlockString str;
+        aesni_AES128_format_block(&str, &src, ErrorDetailsThrowsInDestructor());
+        return { str.str };
+    }
+
+    template <>
+    std::string to_matrix_string<AESNI_AES128>(const aes128::Block& src)
+    {
+        AesNI_AES128_BlockMatrixString str;
+        aesni_AES128_format_block_as_matrix(&str, &src, ErrorDetailsThrowsInDestructor());
+        return { str.str };
+    }
+
+    template <>
+    void from_string<AESNI_AES128>(aes128::Key& dest, const char* src)
+    {
+        aesni_AES128_parse_key(&dest, src, ErrorDetailsThrowsInDestructor());
+    }
+
+    template <>
+    std::string to_string<AESNI_AES128>(const aes128::Key& src)
+    {
+        AesNI_AES128_KeyString str;
+        aesni_AES128_format_key(&str, &src, ErrorDetailsThrowsInDestructor());
+        return { str.str };
+    }
+
+    template <>
+    inline void expand_key<AESNI_AES128>(
+        const aes128::Key& key,
+        aes128::RoundKeys& encryption_keys)
+    {
+        aesni_AES128_expand_key(&key, &encryption_keys);
+    }
+
+    template <>
+    inline void derive_decryption_keys<AESNI_AES128>(
+        const aes128::RoundKeys& encryption_keys,
+        aes128::RoundKeys& decryption_keys)
+    {
+        aesni_AES128_derive_decryption_keys(
+            &encryption_keys, &decryption_keys);
+    }
+
+    AESNIXX_ENCRYPT_BLOCK_ECB(AES128);
+    AESNIXX_DECRYPT_BLOCK_ECB(AES128);
+    AESNIXX_ENCRYPT_BLOCK_CBC(AES128);
+    AESNIXX_DECRYPT_BLOCK_CBC(AES128);
+    AESNIXX_ENCRYPT_BLOCK_CFB(AES128);
+    AESNIXX_DECRYPT_BLOCK_CFB(AES128);
+    AESNIXX_ENCRYPT_BLOCK_OFB(AES128);
+    AESNIXX_DECRYPT_BLOCK_OFB(AES128);
+    AESNIXX_ENCRYPT_BLOCK_CTR(AES128);
+    AESNIXX_DECRYPT_BLOCK_CTR(AES128);
+
+    namespace aes192
+    {
+        typedef AesNI_AES192_Block Block;
+        typedef AesNI_AES192_RoundKeys RoundKeys;
+        typedef AesNI_AES192_Key Key;
+    }
+
+    template <>
+    struct Types<AESNI_AES192>
+    {
+        typedef aes192::Block Block;
+        typedef aes192::RoundKeys RoundKeys;
+        typedef aes192::Key Key;
+    };
+
+    template <>
+    std::size_t get_number_of_rounds<AESNI_AES192>()
+    {
+        return 13;
+    }
+
+    template <>
+    void from_string<AESNI_AES192>(aes192::Block& dest, const char* src)
+    {
+        aesni_AES192_parse_block(&dest, src, ErrorDetailsThrowsInDestructor());
+    }
+
+    template <>
+    std::string to_string<AESNI_AES192>(const aes192::Block& src)
+    {
+        AesNI_AES192_BlockString str;
+        aesni_AES192_format_block(&str, &src, ErrorDetailsThrowsInDestructor());
+        return { str.str };
+    }
+
+    template <>
+    std::string to_matrix_string<AESNI_AES192>(const aes192::Block& src)
+    {
+        AesNI_AES192_BlockMatrixString str;
+        aesni_AES192_format_block_as_matrix(&str, &src, ErrorDetailsThrowsInDestructor());
+        return { str.str };
+    }
+
+    template <>
+    void from_string<AESNI_AES192>(aes192::Key& dest, const char* src)
+    {
+        aesni_AES192_parse_key(&dest, src, ErrorDetailsThrowsInDestructor());
+    }
+
+    template <>
+    std::string to_string<AESNI_AES192>(const aes192::Key& src)
+    {
+        AesNI_AES192_KeyString str;
+        aesni_AES192_format_key(&str, &src, ErrorDetailsThrowsInDestructor());
+        return { str.str };
+    }
+
+    template <>
+    inline void expand_key<AESNI_AES192>(
+        const aes192::Key& key,
+        aes192::RoundKeys& encryption_keys)
+    {
+        aesni_AES192_expand_key(&key, &encryption_keys);
+    }
+
+    template <>
+    inline void derive_decryption_keys<AESNI_AES192>(
+        const aes192::RoundKeys& encryption_keys,
+        aes192::RoundKeys& decryption_keys)
+    {
+        aesni_AES192_derive_decryption_keys(
+            &encryption_keys, &decryption_keys);
+    }
+
+    AESNIXX_ENCRYPT_BLOCK_ECB(AES192);
+    AESNIXX_DECRYPT_BLOCK_ECB(AES192);
+    AESNIXX_ENCRYPT_BLOCK_CBC(AES192);
+    AESNIXX_DECRYPT_BLOCK_CBC(AES192);
+    AESNIXX_ENCRYPT_BLOCK_CFB(AES192);
+    AESNIXX_DECRYPT_BLOCK_CFB(AES192);
+    AESNIXX_ENCRYPT_BLOCK_OFB(AES192);
+    AESNIXX_DECRYPT_BLOCK_OFB(AES192);
+    AESNIXX_ENCRYPT_BLOCK_CTR(AES192);
+    AESNIXX_DECRYPT_BLOCK_CTR(AES192);
+
+    namespace aes256
     {
-        typedef AesNI_AES_Block Block;
-
-        typedef AesNI_AES128_Key Key128;
-        typedef AesNI_AES192_Key Key192;
-        typedef AesNI_AES256_Key Key256;
-
-        inline void make_block(Block& dest, int hi3, int hi2, int lo1, int lo0)
-        {
-            aesni_AES_make_block(&dest, hi3, hi2, lo1, lo0);
-        }
-
-        inline void make_key(Key128& dest, int hi3, int hi2, int lo1, int lo0)
-        {
-            aesni_AES128_make_key(&dest, hi3, hi2, lo1, lo0);
-        }
-
-        inline void make_key(Key192& dest, int hi5, int hi4, int hi3, int lo2, int lo1, int lo0)
-        {
-            aesni_AES192_make_key(&dest, hi5, hi4, hi3, lo2, lo1, lo0);
-        }
-
-        inline void make_key(Key256& dest, int hi7, int hi6, int hi5, int hi4, int lo3, int lo2, int lo1, int lo0)
-        {
-            aesni_AES256_make_key(&dest, hi7, hi6, hi5, hi4, lo3, lo2, lo1, lo0);
-        }
-
-        std::string to_string(const Block& block)
-        {
-            AesNI_AES_BlockString str;
-            aesni_AES_format_block(&str, &block, ErrorDetailsThrowsInDestructor());
-            return std::string(str.str);
-        }
-
-        std::string to_matrix_string(const Block& block)
-        {
-            AesNI_AES_BlockMatrixString str;
-            aesni_AES_format_block_as_matrix(&str, &block, ErrorDetailsThrowsInDestructor());
-            return std::string(str.str);
-        }
-
-        inline void from_string(Block& dest, const char* src)
-        {
-            aesni_AES_parse_block(&dest, src, ErrorDetailsThrowsInDestructor());
-        }
-
-        inline void from_string(Block& dest, const std::string& src)
-        {
-            from_string(dest, src.c_str());
-        }
-
-        std::string to_string(const Key128& block)
-        {
-            AesNI_AES128_KeyString str;
-            aesni_AES128_format_key(&str, &block, ErrorDetailsThrowsInDestructor());
-            return std::string(str.str);
-        }
-
-        std::string to_string(const Key192& block)
-        {
-            AesNI_AES192_KeyString str;
-            aesni_AES192_format_key(&str, &block, ErrorDetailsThrowsInDestructor());
-            return std::string(str.str);
-        }
-
-        std::string to_string(const Key256& block)
-        {
-            AesNI_AES256_KeyString str;
-            aesni_AES256_format_key(&str, &block, ErrorDetailsThrowsInDestructor());
-            return std::string(str.str);
-        }
-
-        inline void from_string(Key128& dest, const char* src)
-        {
-            aesni_AES128_parse_key(&dest, src, ErrorDetailsThrowsInDestructor());
-        }
-
-        inline void from_string(Key192& dest, const char* src)
-        {
-            aesni_AES192_parse_key(&dest, src, ErrorDetailsThrowsInDestructor());
-        }
-
-        inline void from_string(Key256& dest, const char* src)
-        {
-            aesni_AES256_parse_key(&dest, src, ErrorDetailsThrowsInDestructor());
-        }
-
-        inline void from_string(Key128& dest, const std::string& src)
-        {
-            return from_string(dest, src.c_str());
-        }
-
-        inline void from_string(Key192& dest, const std::string& src)
-        {
-            return from_string(dest, src.c_str());
-        }
-
-        inline void from_string(Key256& dest, const std::string& src)
-        {
-            return from_string(dest, src.c_str());
-        }
-
-        typedef AesNI_AES128_RoundKeys RoundKeys128;
-        typedef AesNI_AES192_RoundKeys RoundKeys192;
-        typedef AesNI_AES256_RoundKeys RoundKeys256;
-
-        template <typename RoundKeysT>
-        inline std::size_t get_number_of_rounds(const RoundKeysT& round_keys)
-        {
-            return sizeof(round_keys) / sizeof(Block128);
-        }
-
-        inline void expand_key(
-            const Key128& key,
-            RoundKeys128& encryption_keys)
-        {
-            aesni_AES128_expand_key(&key, &encryption_keys);
-        }
-
-        inline void expand_key(
-            const Key192& key,
-            RoundKeys192& encryption_keys)
-        {
-            aesni_AES192_expand_key(&key, &encryption_keys);
-        }
-
-        inline void expand_key(
-            const Key256& key,
-            RoundKeys256& encryption_keys)
-        {
-            aesni_AES256_expand_key(&key, &encryption_keys);
-        }
-
-        inline void derive_decryption_keys(
-            const RoundKeys128& encryption_keys,
-            RoundKeys128& decryption_keys)
-        {
-            aesni_AES128_derive_decryption_keys(
-                &encryption_keys, &decryption_keys);
-        }
-
-        inline void derive_decryption_keys(
-            const RoundKeys192& encryption_keys,
-            RoundKeys192& decryption_keys)
-        {
-            aesni_AES192_derive_decryption_keys(
-                &encryption_keys, &decryption_keys);
-        }
-
-        inline void derive_decryption_keys(
-            const RoundKeys256& encryption_keys,
-            RoundKeys256& decryption_keys)
-        {
-            aesni_AES256_derive_decryption_keys(
-                &encryption_keys, &decryption_keys);
-        }
-
-        inline Block encrypt_ecb(
-            const Block& plaintext,
-            const RoundKeys128& encryption_keys)
-        {
-            return aesni_AES128_encrypt_block_ECB(plaintext, &encryption_keys);
-        }
-
-        inline Block decrypt_ecb(
-            const Block& ciphertext,
-            const RoundKeys128& decryption_keys)
-        {
-            return aesni_AES128_decrypt_block_ECB(ciphertext, &decryption_keys);
-        }
-
-        inline Block encrypt_cbc(
-            const Block& plaintext,
-            const RoundKeys128& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES128_encrypt_block_CBC(plaintext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block decrypt_cbc(
-            const Block& ciphertext,
-            const RoundKeys128& decryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES128_decrypt_block_CBC(ciphertext, &decryption_keys, iv, &next_iv);
-        }
-
-        inline Block encrypt_cfb(
-            const Block& plaintext,
-            const RoundKeys128& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES128_encrypt_block_CFB(plaintext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block decrypt_cfb(
-            const Block& ciphertext,
-            const RoundKeys128& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES128_decrypt_block_CFB(ciphertext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block encrypt_ofb(
-            const Block& plaintext,
-            const RoundKeys128& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES128_encrypt_block_OFB(plaintext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block decrypt_ofb(
-            const Block& ciphertext,
-            const RoundKeys128& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES128_decrypt_block_OFB(ciphertext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block encrypt_ctr(
-            const Block& plaintext,
-            const RoundKeys128& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES128_encrypt_block_CTR(plaintext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block decrypt_ctr(
-            const Block& ciphertext,
-            const RoundKeys128& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES128_decrypt_block_CTR(ciphertext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block encrypt_ecb(
-            const Block& plaintext,
-            const RoundKeys192& encryption_keys)
-        {
-            return aesni_AES192_encrypt_block_ECB(plaintext, &encryption_keys);
-        }
-
-        inline Block decrypt_ecb(
-            const Block& ciphertext,
-            const RoundKeys192& decryption_keys)
-        {
-            return aesni_AES192_decrypt_block_ECB(ciphertext, &decryption_keys);
-        }
-
-        inline Block encrypt_cbc(
-            const Block& plaintext,
-            const RoundKeys192& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES192_encrypt_block_CBC(plaintext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block decrypt_cbc(
-            const Block& ciphertext,
-            const RoundKeys192& decryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES192_decrypt_block_CBC(ciphertext, &decryption_keys, iv, &next_iv);
-        }
-
-        inline Block encrypt_cfb(
-            const Block& plaintext,
-            const RoundKeys192& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES192_encrypt_block_CFB(plaintext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block decrypt_cfb(
-            const Block& ciphertext,
-            const RoundKeys192& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES192_decrypt_block_CFB(ciphertext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block encrypt_ofb(
-            const Block& plaintext,
-            const RoundKeys192& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES192_encrypt_block_OFB(plaintext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block decrypt_ofb(
-            const Block& ciphertext,
-            const RoundKeys192& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES192_decrypt_block_OFB(ciphertext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block encrypt_ctr(
-            const Block& plaintext,
-            const RoundKeys192& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES192_encrypt_block_CTR(plaintext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block decrypt_ctr(
-            const Block& ciphertext,
-            const RoundKeys192& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES192_decrypt_block_CTR(ciphertext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block encrypt_ecb(
-            const Block& plaintext,
-            const RoundKeys256& encryption_keys)
-        {
-            return aesni_AES256_encrypt_block_ECB(plaintext, &encryption_keys);
-        }
-
-        inline Block decrypt_ecb(
-            const Block& ciphertext,
-            const RoundKeys256& decryption_keys)
-        {
-            return aesni_AES256_decrypt_block_ECB(ciphertext, &decryption_keys);
-        }
-
-        inline Block encrypt_cbc(
-            const Block& plaintext,
-            const RoundKeys256& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES256_encrypt_block_CBC(plaintext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block decrypt_cbc(
-            const Block& ciphertext,
-            const RoundKeys256& decryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES256_decrypt_block_CBC(ciphertext, &decryption_keys, iv, &next_iv);
-        }
-
-        inline Block encrypt_cfb(
-            const Block& plaintext,
-            const RoundKeys256& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES256_encrypt_block_CFB(plaintext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block decrypt_cfb(
-            const Block& ciphertext,
-            const RoundKeys256& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES256_decrypt_block_CFB(ciphertext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block encrypt_ofb(
-            const Block& plaintext,
-            const RoundKeys256& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES256_encrypt_block_OFB(plaintext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block decrypt_ofb(
-            const Block& ciphertext,
-            const RoundKeys256& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES256_decrypt_block_OFB(ciphertext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block encrypt_ctr(
-            const Block& plaintext,
-            const RoundKeys256& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES256_encrypt_block_CTR(plaintext, &encryption_keys, iv, &next_iv);
-        }
-
-        inline Block decrypt_ctr(
-            const Block& ciphertext,
-            const RoundKeys256& encryption_keys,
-            const Block& iv,
-            Block& next_iv)
-        {
-            return aesni_AES256_decrypt_block_CTR(ciphertext, &encryption_keys, iv, &next_iv);
-        }
-
-        template <Algorithm>
-        struct Types;
-
-        template <>
-        struct Types<AESNI_AES128>
-        {
-            typedef aesni::aes::Block BlockT;
-            typedef aesni::aes::Key128 KeyT;
-            typedef aesni::aes::RoundKeys128 RoundKeysT;
-        };
-
-        template <>
-        struct Types<AESNI_AES192>
-        {
-            typedef aesni::aes::Block BlockT;
-            typedef aesni::aes::Key192 KeyT;
-            typedef aesni::aes::RoundKeys192 RoundKeysT;
-        };
-
-        template <>
-        struct Types<AESNI_AES256>
-        {
-            typedef aesni::aes::Block BlockT;
-            typedef aesni::aes::Key256 KeyT;
-            typedef aesni::aes::RoundKeys256 RoundKeysT;
-        };
-
-        template <Algorithm algorithm, Mode mode>
-        struct Encrypt;
-
-        template <Algorithm algorithm>
-        struct Encrypt<algorithm, AESNI_ECB>
-        {
-            Encrypt(const typename Types<algorithm>::KeyT& key,
-                    const typename Types<algorithm>::BlockT& iv)
-            {
-                expand_key(key, encryption_keys);
-                derive_decryption_keys(encryption_keys, decryption_keys);
-            }
-
-            inline typename Types<algorithm>::BlockT encrypt(const typename Types<algorithm>::BlockT& plaintext)
-            {
-                return encrypt_ecb(plaintext, encryption_keys);
-            }
-
-            inline typename Types<algorithm>::BlockT decrypt(const typename Types<algorithm>::BlockT& ciphertext)
-            {
-                return decrypt_ecb(ciphertext, decryption_keys);
-            }
-
-            typename Types<algorithm>::RoundKeysT encryption_keys;
-            typename Types<algorithm>::RoundKeysT decryption_keys;
-        };
-
-        template <Algorithm algorithm>
-        struct Encrypt<algorithm, AESNI_CBC>
-        {
-            Encrypt(const typename Types<algorithm>::KeyT& key,
-                    const typename Types<algorithm>::BlockT& iv)
-                : iv(iv)
-            {
-                expand_key(key, encryption_keys);
-                derive_decryption_keys(encryption_keys, decryption_keys);
-            }
-
-            inline typename Types<algorithm>::BlockT encrypt(const typename Types<algorithm>::BlockT& plaintext)
-            {
-                return encrypt_cbc(plaintext, encryption_keys, iv, iv);
-            }
-
-            inline typename Types<algorithm>::BlockT decrypt(const typename Types<algorithm>::BlockT& ciphertext)
-            {
-                return decrypt_cbc(ciphertext, decryption_keys, iv, iv);
-            }
-
-            typename Types<algorithm>::BlockT iv;
-            typename Types<algorithm>::RoundKeysT encryption_keys;
-            typename Types<algorithm>::RoundKeysT decryption_keys;
-        };
-
-        template <Algorithm algorithm>
-        struct Encrypt<algorithm, AESNI_CFB>
-        {
-            Encrypt(const typename Types<algorithm>::KeyT& key,
-                    const typename Types<algorithm>::BlockT& iv)
-                : iv(iv)
-            {
-                expand_key(key, encryption_keys);
-            }
-
-            inline typename Types<algorithm>::BlockT encrypt(const typename Types<algorithm>::BlockT& plaintext)
-            {
-                return encrypt_cfb(plaintext, encryption_keys, iv, iv);
-            }
-
-            inline typename Types<algorithm>::BlockT decrypt(const typename Types<algorithm>::BlockT& ciphertext)
-            {
-                return decrypt_cfb(ciphertext, encryption_keys, iv, iv);
-            }
-
-            typename Types<algorithm>::BlockT iv;
-            typename Types<algorithm>::RoundKeysT encryption_keys;
-        };
-
-        template <Algorithm algorithm>
-        struct Encrypt<algorithm, AESNI_OFB>
-        {
-            Encrypt(const typename Types<algorithm>::KeyT& key,
-                    const typename Types<algorithm>::BlockT& iv)
-                : iv(iv)
-            {
-                expand_key(key, encryption_keys);
-            }
-
-            inline typename Types<algorithm>::BlockT encrypt(const typename Types<algorithm>::BlockT& plaintext)
-            {
-                return encrypt_ofb(plaintext, encryption_keys, iv, iv);
-            }
-
-            inline typename Types<algorithm>::BlockT decrypt(const typename Types<algorithm>::BlockT& ciphertext)
-            {
-                return decrypt_ofb(ciphertext, encryption_keys, iv, iv);
-            }
-
-            typename Types<algorithm>::BlockT iv;
-            typename Types<algorithm>::RoundKeysT encryption_keys;
-        };
-
-        template <Algorithm algorithm>
-        struct Encrypt<algorithm, AESNI_CTR>
-        {
-            Encrypt(const typename Types<algorithm>::KeyT& key,
-                    const typename Types<algorithm>::BlockT& iv)
-                : iv(iv)
-            {
-                expand_key(key, encryption_keys);
-            }
-
-            inline typename Types<algorithm>::BlockT encrypt(const typename Types<algorithm>::BlockT& plaintext)
-            {
-                return encrypt_ctr(plaintext, encryption_keys, iv, iv);
-            }
-
-            inline typename Types<algorithm>::BlockT decrypt(const typename Types<algorithm>::BlockT& ciphertext)
-            {
-                return decrypt_ctr(ciphertext, encryption_keys, iv, iv);
-            }
-
-            typename Types<algorithm>::RoundKeysT encryption_keys;
-            typename Types<algorithm>::BlockT iv;
-        };
+        typedef AesNI_AES256_Block Block;
+        typedef AesNI_AES256_RoundKeys RoundKeys;
+        typedef AesNI_AES256_Key Key;
     }
+
+    template <>
+    struct Types<AESNI_AES256>
+    {
+        typedef aes256::Block Block;
+        typedef aes256::RoundKeys RoundKeys;
+        typedef aes256::Key Key;
+    };
+
+    template <>
+    std::size_t get_number_of_rounds<AESNI_AES256>()
+    {
+        return 15;
+    }
+
+    template <>
+    void from_string<AESNI_AES256>(aes256::Block& dest, const char* src)
+    {
+        aesni_AES256_parse_block(&dest, src, ErrorDetailsThrowsInDestructor());
+    }
+
+    template <>
+    std::string to_string<AESNI_AES256>(const aes256::Block& src)
+    {
+        AesNI_AES256_BlockString str;
+        aesni_AES256_format_block(&str, &src, ErrorDetailsThrowsInDestructor());
+        return { str.str };
+    }
+
+    template <>
+    std::string to_matrix_string<AESNI_AES256>(const aes256::Block& src)
+    {
+        AesNI_AES256_BlockMatrixString str;
+        aesni_AES256_format_block_as_matrix(&str, &src, ErrorDetailsThrowsInDestructor());
+        return { str.str };
+    }
+
+    template <>
+    void from_string<AESNI_AES256>(aes256::Key& dest, const char* src)
+    {
+        aesni_AES256_parse_key(&dest, src, ErrorDetailsThrowsInDestructor());
+    }
+
+    template <>
+    std::string to_string<AESNI_AES256>(const aes256::Key& src)
+    {
+        AesNI_AES256_KeyString str;
+        aesni_AES256_format_key(&str, &src, ErrorDetailsThrowsInDestructor());
+        return { str.str };
+    }
+
+    template <>
+    inline void expand_key<AESNI_AES256>(
+        const aes256::Key& key,
+        aes256::RoundKeys& encryption_keys)
+    {
+        aesni_AES256_expand_key(&key, &encryption_keys);
+    }
+
+    template <>
+    inline void derive_decryption_keys<AESNI_AES256>(
+        const aes256::RoundKeys& encryption_keys,
+        aes256::RoundKeys& decryption_keys)
+    {
+        aesni_AES256_derive_decryption_keys(
+            &encryption_keys, &decryption_keys);
+    }
+
+    AESNIXX_ENCRYPT_BLOCK_ECB(AES256);
+    AESNIXX_DECRYPT_BLOCK_ECB(AES256);
+    AESNIXX_ENCRYPT_BLOCK_CBC(AES256);
+    AESNIXX_DECRYPT_BLOCK_CBC(AES256);
+    AESNIXX_ENCRYPT_BLOCK_CFB(AES256);
+    AESNIXX_DECRYPT_BLOCK_CFB(AES256);
+    AESNIXX_ENCRYPT_BLOCK_OFB(AES256);
+    AESNIXX_DECRYPT_BLOCK_OFB(AES256);
+    AESNIXX_ENCRYPT_BLOCK_CTR(AES256);
+    AESNIXX_DECRYPT_BLOCK_CTR(AES256);
 }
diff --git a/cxx/include/aesnixx/all.hpp b/cxx/include/aesnixx/all.hpp
index 2bdf301..417d9ea 100644
--- a/cxx/include/aesnixx/all.hpp
+++ b/cxx/include/aesnixx/all.hpp
@@ -10,6 +10,7 @@
 
 #include "aes.hpp"
 #include "algorithm.hpp"
+#include "api.hpp"
 #include "data.hpp"
 #include "debug.hpp"
 #include "error.hpp"
diff --git a/cxx/include/aesnixx/api.hpp b/cxx/include/aesnixx/api.hpp
new file mode 100644
index 0000000..6995ae2
--- /dev/null
+++ b/cxx/include/aesnixx/api.hpp
@@ -0,0 +1,171 @@
+/**
+ * \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 "algorithm.hpp"
+#include "mode.hpp"
+
+#include <cstddef>
+
+#include <string>
+#include <type_traits>
+
+namespace aesni
+{
+    template <Algorithm algorithm>
+    struct Types;
+
+    template <Algorithm algorithm>
+    std::size_t get_number_of_rounds();
+
+    template <Algorithm algorithm>
+    void from_string(
+        typename Types<algorithm>::Block&,
+        const char*);
+
+    template <Algorithm algorithm>
+    inline void from_string(
+        typename Types<algorithm>::Block& dest,
+        const std::string& src)
+    {
+        from_string<algorithm>(dest, src.c_str());
+    }
+
+    template <Algorithm algorithm>
+    std::string to_string(const typename Types<algorithm>::Block&);
+
+    template <Algorithm algorithm>
+    std::string to_matrix_string(const typename Types<algorithm>::Block&);
+
+    template <Algorithm algorithm>
+    void from_string(
+        typename Types<algorithm>::Key&,
+        const char*);
+
+    template <Algorithm algorithm>
+    inline void from_string(
+        typename Types<algorithm>::Key& dest,
+        const std::string& src)
+    {
+        from_string<algorithm>(dest, src.c_str());
+    }
+
+    template <Algorithm algorithm>
+    std::string to_string(const typename Types<algorithm>::Key&);
+
+    template <Algorithm algorithm>
+    inline void expand_key(
+        const typename Types<algorithm>::Key& key,
+        typename Types<algorithm>::RoundKeys& encryption_keys);
+
+    template <Algorithm algorithm>
+    inline void derive_decryption_keys(
+        const typename Types<algorithm>::RoundKeys& encryption_keys,
+        typename Types<algorithm>::RoundKeys& decryption_keys);
+
+    template <Algorithm algorithm, Mode mode, typename std::enable_if<ModeRequiresInitializationVector<mode>::value>::type* = 0>
+    inline void encrypt_block(
+        const typename Types<algorithm>::Block& plaintext,
+        const typename Types<algorithm>::RoundKeys& round_keys,
+        typename Types<algorithm>::Block& iv,
+        typename Types<algorithm>::Block& ciphertext);
+
+    template <Algorithm algorithm, Mode mode, typename std::enable_if<!ModeRequiresInitializationVector<mode>::value>::type* = 0>
+    inline void encrypt_block(
+        const typename Types<algorithm>::Block& plaintext,
+        const typename Types<algorithm>::RoundKeys& round_keys,
+        typename Types<algorithm>::Block& ciphertext);
+
+    template <Algorithm algorithm, Mode mode, typename std::enable_if<!ModeRequiresInitializationVector<mode>::value>::type* = 0>
+    inline void encrypt_block(
+        const typename Types<algorithm>::Block& plaintext,
+        const typename Types<algorithm>::RoundKeys& round_keys,
+        typename Types<algorithm>::Block&,
+        typename Types<algorithm>::Block& ciphertext)
+    {
+        encrypt_block<algorithm, mode>(plaintext, round_keys, ciphertext);
+    }
+
+    template <Algorithm algorithm, Mode mode, typename std::enable_if<ModeRequiresInitializationVector<mode>::value>::type* = 0>
+    inline void decrypt_block(
+        const typename Types<algorithm>::Block& ciphertext,
+        const typename Types<algorithm>::RoundKeys& round_keys,
+        typename Types<algorithm>::Block& iv,
+        typename Types<algorithm>::Block& plaintext);
+
+    template <Algorithm algorithm, Mode mode, typename std::enable_if<!ModeRequiresInitializationVector<mode>::value>::type* = 0>
+    inline void decrypt_block(
+        const typename Types<algorithm>::Block& ciphertext,
+        const typename Types<algorithm>::RoundKeys& round_keys,
+        typename Types<algorithm>::Block& plaintext);
+
+    template <Algorithm algorithm, Mode mode, typename std::enable_if<!ModeRequiresInitializationVector<mode>::value>::type* = 0>
+    inline void decrypt_block(
+        const typename Types<algorithm>::Block& ciphertext,
+        const typename Types<algorithm>::RoundKeys& round_keys,
+        typename Types<algorithm>::Block&,
+        typename Types<algorithm>::Block& plaintext)
+    {
+        decrypt_block<algorithm, mode>(ciphertext, round_keys, plaintext);
+    }
+
+    template <Algorithm algorithm, Mode mode>
+    struct EncryptWrapper
+    {
+        EncryptWrapper(
+            const typename Types<algorithm>::Key& key,
+            const typename Types<algorithm>::Block& iv) : iv(iv)
+        {
+            expand_key<algorithm>(key, encryption_keys);
+        }
+
+        inline void encrypt_block(
+            const typename Types<algorithm>::Block& plaintext,
+            typename Types<algorithm>::Block& ciphertext)
+        {
+            aesni::encrypt_block<algorithm, mode>(
+                plaintext, encryption_keys, iv, ciphertext);
+        }
+
+        typename Types<algorithm>::Block iv;
+        typename Types<algorithm>::RoundKeys encryption_keys;
+    };
+
+    template <Algorithm algorithm, Mode mode>
+    struct DecryptWrapper
+    {
+        DecryptWrapper(
+            const typename Types<algorithm>::Key& key,
+            const typename Types<algorithm>::Block& iv) : iv(iv)
+        {
+            typename Types<algorithm>::RoundKeys encryption_keys;
+            expand_key<algorithm>(key, encryption_keys);
+
+            if (ModeUsesEncryptionKeysOnly<mode>::value)
+            {
+                decryption_keys = encryption_keys;
+            }
+            else
+            {
+                derive_decryption_keys<algorithm>(encryption_keys, decryption_keys);
+            }
+        }
+
+        inline void decrypt_block(
+            const typename Types<algorithm>::Block& ciphertext,
+            typename Types<algorithm>::Block& plaintext)
+        {
+            aesni::decrypt_block<algorithm, mode>(
+                ciphertext, decryption_keys, iv, plaintext);
+        }
+
+        typename Types<algorithm>::Block iv;
+        typename Types<algorithm>::RoundKeys decryption_keys;
+    };
+}
diff --git a/cxx/include/aesnixx/mode.hpp b/cxx/include/aesnixx/mode.hpp
index a0af051..e19dbbd 100644
--- a/cxx/include/aesnixx/mode.hpp
+++ b/cxx/include/aesnixx/mode.hpp
@@ -45,4 +45,112 @@ namespace aesni
     {
         return mode != AESNI_ECB && mode != AESNI_CBC;
     }
+
+#define AESNIXX_ENCRYPT_BLOCK_ECB(prefix) \
+    template <> \
+    inline void encrypt_block<AESNI_## prefix, AESNI_ECB>( \
+        const typename Types<AESNI_## prefix>::Block& plaintext, \
+        const typename Types<AESNI_## prefix>::RoundKeys& encryption_keys, \
+        typename Types<AESNI_## prefix>::Block& ciphertext) \
+    { \
+        ciphertext = aesni_## prefix ##_encrypt_block_ECB(plaintext, &encryption_keys); \
+    }
+
+#define AESNIXX_DECRYPT_BLOCK_ECB(prefix) \
+    template <> \
+    inline void decrypt_block<AESNI_## prefix, AESNI_ECB>( \
+        const typename Types<AESNI_## prefix>::Block& ciphertext, \
+        const typename Types<AESNI_## prefix>::RoundKeys& decryption_keys, \
+        typename Types<AESNI_## prefix>::Block& plaintext) \
+    { \
+        plaintext = aesni_## prefix ##_decrypt_block_ECB(ciphertext, &decryption_keys); \
+    }
+
+#define AESNIXX_ENCRYPT_BLOCK_CBC(prefix) \
+    template <> \
+    inline void encrypt_block<AESNI_## prefix, AESNI_CBC>( \
+        const typename Types<AESNI_## prefix>::Block& plaintext, \
+        const typename Types<AESNI_## prefix>::RoundKeys& encryption_keys, \
+        typename Types<AESNI_## prefix>::Block& iv, \
+        typename Types<AESNI_## prefix>::Block& ciphertext) \
+    { \
+        ciphertext = aesni_## prefix ##_encrypt_block_CBC(plaintext, &encryption_keys, iv, &iv); \
+    }
+
+#define AESNIXX_DECRYPT_BLOCK_CBC(prefix) \
+    template <> \
+    inline void decrypt_block<AESNI_## prefix, AESNI_CBC>( \
+        const typename Types<AESNI_## prefix>::Block& ciphertext, \
+        const typename Types<AESNI_## prefix>::RoundKeys& decryption_keys, \
+        typename Types<AESNI_## prefix>::Block& iv, \
+        typename Types<AESNI_## prefix>::Block& plaintext) \
+    { \
+        plaintext = aesni_## prefix ##_decrypt_block_CBC(ciphertext, &decryption_keys, iv, &iv); \
+    }
+
+#define AESNIXX_ENCRYPT_BLOCK_CFB(prefix) \
+    template <> \
+    inline void encrypt_block<AESNI_## prefix, AESNI_CFB>( \
+        const typename Types<AESNI_## prefix>::Block& plaintext, \
+        const typename Types<AESNI_## prefix>::RoundKeys& encryption_keys, \
+        typename Types<AESNI_## prefix>::Block& iv, \
+        typename Types<AESNI_## prefix>::Block& ciphertext) \
+    { \
+        ciphertext = aesni_## prefix ##_encrypt_block_CFB(plaintext, &encryption_keys, iv, &iv); \
+    }
+
+#define AESNIXX_DECRYPT_BLOCK_CFB(prefix) \
+    template <> \
+    inline void decrypt_block<AESNI_## prefix, AESNI_CFB>( \
+        const typename Types<AESNI_## prefix>::Block& ciphertext, \
+        const typename Types<AESNI_## prefix>::RoundKeys& encryption_keys, \
+        typename Types<AESNI_## prefix>::Block& iv, \
+        typename Types<AESNI_## prefix>::Block& plaintext) \
+    { \
+        plaintext = aesni_## prefix ##_decrypt_block_CFB(ciphertext, &encryption_keys, iv, &iv); \
+    }
+
+#define AESNIXX_ENCRYPT_BLOCK_OFB(prefix) \
+    template <> \
+    inline void encrypt_block<AESNI_## prefix, AESNI_OFB>( \
+        const typename Types<AESNI_## prefix>::Block& plaintext, \
+        const typename Types<AESNI_## prefix>::RoundKeys& encryption_keys, \
+        typename Types<AESNI_## prefix>::Block& iv, \
+        typename Types<AESNI_## prefix>::Block& ciphertext) \
+    { \
+        ciphertext = aesni_## prefix ##_encrypt_block_OFB(plaintext, &encryption_keys, iv, &iv); \
+    }
+
+#define AESNIXX_DECRYPT_BLOCK_OFB(prefix) \
+    template <> \
+    inline void decrypt_block<AESNI_## prefix, AESNI_OFB>( \
+        const typename Types<AESNI_## prefix>::Block& ciphertext, \
+        const typename Types<AESNI_## prefix>::RoundKeys& encryption_keys, \
+        typename Types<AESNI_## prefix>::Block& iv, \
+        typename Types<AESNI_## prefix>::Block& plaintext) \
+    { \
+        plaintext = aesni_## prefix ##_decrypt_block_OFB(ciphertext, &encryption_keys, iv, &iv); \
+    }
+
+#define AESNIXX_ENCRYPT_BLOCK_CTR(prefix) \
+    template <> \
+    inline void encrypt_block<AESNI_## prefix, AESNI_CTR>( \
+        const typename Types<AESNI_## prefix>::Block& plaintext, \
+        const typename Types<AESNI_## prefix>::RoundKeys& encryption_keys, \
+        typename Types<AESNI_## prefix>::Block& iv, \
+        typename Types<AESNI_## prefix>::Block& ciphertext) \
+    { \
+        ciphertext = aesni_## prefix ##_encrypt_block_CTR(plaintext, &encryption_keys, iv, &iv); \
+    }
+
+#define AESNIXX_DECRYPT_BLOCK_CTR(prefix) \
+    template <> \
+    inline void decrypt_block<AESNI_## prefix, AESNI_CTR>( \
+        const typename Types<AESNI_## prefix>::Block& ciphertext, \
+        const typename Types<AESNI_## prefix>::RoundKeys& encryption_keys, \
+        typename Types<AESNI_## prefix>::Block& iv, \
+        typename Types<AESNI_## prefix>::Block& plaintext) \
+    { \
+        plaintext = aesni_## prefix ##_decrypt_block_CTR(ciphertext, &encryption_keys, iv, &iv); \
+    }
 }
diff --git a/utils/aes_block_common.hpp b/utils/aes_block_common.hpp
index bdb6ac6..52b9ce3 100644
--- a/utils/aes_block_common.hpp
+++ b/utils/aes_block_common.hpp
@@ -151,126 +151,92 @@ namespace
 
 namespace
 {
-    void dump_block(const char* name, const aesni::aes::Block& block)
+    template <aesni::Algorithm algorithm>
+    void dump_block(const char* name, const typename aesni::Types<algorithm>::Block& block)
     {
-        std::cout << name << ": " << aesni::aes::to_string(block) << "\n" << aesni::aes::to_matrix_string(block) << "\n";
+        std::cout << name << ": " << aesni::to_string<algorithm>(block) << "\n" << aesni::to_matrix_string<algorithm>(block) << "\n";
     }
 
-    void dump_plaintext(const aesni::aes::Block& block)
+    template <aesni::Algorithm algorithm>
+    void dump_plaintext(const typename aesni::Types<algorithm>::Block& block)
     {
-        dump_block("Plaintext", block);
+        dump_block<algorithm>("Plaintext", block);
     }
 
-    template <typename KeyT>
-    void dump_key(const KeyT& key)
+    template <aesni::Algorithm algorithm>
+    void dump_key(const typename aesni::Types<algorithm>::Key& key)
     {
-        std::cout << "Key: " << aesni::aes::to_string(key) << "\n\n";
+        std::cout << "Key: " << aesni::to_string<algorithm>(key) << "\n\n";
     }
 
-    void dump_ciphertext(const aesni::aes::Block& ciphertext)
+    template <aesni::Algorithm algorithm>
+    void dump_ciphertext(const typename aesni::Types<algorithm>::Block& ciphertext)
     {
-        dump_block("Ciphertext", ciphertext);
+        dump_block<algorithm>("Ciphertext", ciphertext);
     }
 
-    void dump_iv(const aesni::aes::Block& iv)
+    template <aesni::Algorithm algorithm>
+    void dump_iv(const typename aesni::Types<algorithm>::Block& iv)
     {
-        dump_block("Initialization vector", iv);
+        dump_block<algorithm>("Initialization vector", iv);
     }
 
-    void dump_next_iv(const aesni::aes::Block& next_iv)
-    {
-        dump_block("Next initialization vector", next_iv);
-    }
-
-    template <typename RoundKeysT>
-    void dump_round_keys(const char* name, const RoundKeysT& round_keys)
+    template <aesni::Algorithm algorithm>
+    void dump_round_keys(const char* name, const typename aesni::Types<algorithm>::RoundKeys& round_keys)
     {
         std::cout << name << ":\n";
-        for (std::size_t i = 0; i < aesni::aes::get_number_of_rounds(round_keys); ++i)
-            std::cout << "\t[" << i << "]: " << aesni::aes::to_string(round_keys.keys[i]) << "\n";
+        for (std::size_t i = 0; i < aesni::get_number_of_rounds<algorithm>(); ++i)
+            std::cout << "\t[" << i << "]: " << aesni::to_string<algorithm>(round_keys.keys[i]) << "\n";
         std::cout << "\n";
     }
 
-    template <typename RoundKeysT>
-    void dump_encryption_keys(const RoundKeysT& round_keys)
+    template <aesni::Algorithm algorithm>
+    void dump_encryption_keys(const typename aesni::Types<algorithm>::RoundKeys& round_keys)
     {
-        dump_round_keys("Encryption round keys", round_keys);
+        dump_round_keys<algorithm>("Encryption round keys", round_keys);
     }
 
-    template <typename RoundKeysT>
-    void dump_decryption_keys(const RoundKeysT& round_keys)
+    template <aesni::Algorithm algorithm>
+    void dump_decryption_keys(const typename aesni::Types<algorithm>::RoundKeys& round_keys)
     {
-        dump_round_keys("Decryption round keys", round_keys);
+        dump_round_keys<algorithm>("Decryption round keys", round_keys);
     }
 
-    template <aesni::Algorithm algo, aesni::Mode mode>
-    struct Dumper;
-
-    template <aesni::Algorithm algo>
-    struct Dumper<algo, AESNI_ECB>
-    {
-        static void dump_round_keys(const aesni::aes::Encrypt<algo, AESNI_ECB>& encrypt)
-        {
-            dump_encryption_keys(encrypt.encryption_keys);
-            dump_decryption_keys(encrypt.decryption_keys);
-        }
-
-        static void dump_next_iv(const aesni::aes::Encrypt<algo, AESNI_ECB>&)
-        { }
-    };
-
-    template <aesni::Algorithm algo>
-    struct Dumper<algo, AESNI_CBC>
+    template <aesni::Algorithm algorithm, aesni::Mode mode>
+    void dump_wrapper(
+        const aesni::EncryptWrapper<algorithm, mode>& wrapper)
     {
-        static void dump_round_keys(const aesni::aes::Encrypt<algo, AESNI_CBC>& encrypt)
-        {
-            dump_encryption_keys(encrypt.encryption_keys);
-            dump_decryption_keys(encrypt.decryption_keys);
-        }
-
-        static void dump_next_iv(const aesni::aes::Encrypt<algo, AESNI_CBC>&)
-        { }
-    };
+        dump_encryption_keys<algorithm>(wrapper.encryption_keys);
+    }
 
-    template <aesni::Algorithm algo>
-    struct Dumper<algo, AESNI_CFB>
+    template <aesni::Algorithm algorithm, aesni::Mode mode>
+    void dump_wrapper(
+        const aesni::DecryptWrapper<algorithm, mode>& wrapper)
     {
-        static void dump_round_keys(const aesni::aes::Encrypt<algo, AESNI_CFB>& encrypt)
-        {
-            dump_encryption_keys(encrypt.encryption_keys);
-        }
-
-        static void dump_next_iv(const aesni::aes::Encrypt<algo, AESNI_CFB>& encrypt)
-        {
-            ::dump_next_iv(encrypt.iv);
-        }
-    };
+        dump_decryption_keys<algorithm>(wrapper.decryption_keys);
+    }
 
-    template <aesni::Algorithm algo>
-    struct Dumper<algo, AESNI_OFB>
+    template <aesni::Algorithm algorithm, aesni::Mode mode, typename std::enable_if<aesni::ModeRequiresInitializationVector<mode>::value>::type* = 0>
+    void dump_next_iv(
+        const aesni::EncryptWrapper<algorithm, mode>& wrapper)
     {
-        static void dump_round_keys(const aesni::aes::Encrypt<algo, AESNI_OFB>& encrypt)
-        {
-            dump_encryption_keys(encrypt.encryption_keys);
-        }
+        dump_block<algorithm>("Next initialization vector", wrapper.iv);
+    }
 
-        static void dump_next_iv(const aesni::aes::Encrypt<algo, AESNI_OFB>& encrypt)
-        {
-            ::dump_next_iv(encrypt.iv);
-        }
-    };
+    template <aesni::Algorithm algorithm, aesni::Mode mode, typename std::enable_if<!aesni::ModeRequiresInitializationVector<mode>::value>::type* = 0>
+    void dump_next_iv(
+        const aesni::EncryptWrapper<algorithm, mode>&)
+    { }
 
-    template <aesni::Algorithm algo>
-    struct Dumper<algo, AESNI_CTR>
+    template <aesni::Algorithm algorithm, aesni::Mode mode, typename std::enable_if<aesni::ModeRequiresInitializationVector<mode>::value>::type* = 0>
+    void dump_next_iv(
+        const aesni::DecryptWrapper<algorithm, mode>& wrapper)
     {
-        static void dump_round_keys(const aesni::aes::Encrypt<algo, AESNI_CTR>& encrypt)
-        {
-            dump_encryption_keys(encrypt.encryption_keys);
-        }
+        dump_block<algorithm>("Next initialization vector", wrapper.iv);
+    }
 
-        static void dump_next_iv(const aesni::aes::Encrypt<algo, AESNI_CTR>& encrypt)
-        {
-            ::dump_next_iv(encrypt.iv);
-        }
-    };
+    template <aesni::Algorithm algorithm, aesni::Mode mode, typename std::enable_if<!aesni::ModeRequiresInitializationVector<mode>::value>::type* = 0>
+    void dump_next_iv(
+        const aesni::DecryptWrapper<algorithm, mode>&)
+    { }
 }
diff --git a/utils/aes_decrypt_block.cpp b/utils/aes_decrypt_block.cpp
index bab5f50..0f41b47 100644
--- a/utils/aes_decrypt_block.cpp
+++ b/utils/aes_decrypt_block.cpp
@@ -25,48 +25,48 @@ namespace
         std::deque<std::string>& ciphertexts,
         bool verbose = false)
     {
-        typename aesni::aes::Types<algorithm>::BlockT iv;
+        typename aesni::Types<algorithm>::Block iv;
 
         if (aesni::ModeRequiresInitializationVector<mode>())
         {
             if (ciphertexts.empty())
                 return false;
 
-            aesni::aes::from_string(iv, ciphertexts.front());
+            aesni::from_string<algorithm>(iv, ciphertexts.front());
             ciphertexts.pop_front();
 
             if (verbose)
-                dump_iv(iv);
+                dump_iv<algorithm>(iv);
         }
 
-        typename aesni::aes::Types<algorithm>::KeyT key;
-        aesni::aes::from_string(key, key_str);
+        typename aesni::Types<algorithm>::Key key;
+        aesni::from_string<algorithm>(key, key_str);
 
         if (verbose)
-            dump_key(key);
+            dump_key<algorithm>(key);
 
-        aesni::aes::Encrypt<algorithm, mode> encrypt(key, iv);
+        aesni::DecryptWrapper<algorithm, mode> decrypt(key, iv);
 
         if (verbose)
-            Dumper<algorithm, mode>::dump_round_keys(encrypt);
+            dump_wrapper<algorithm, mode>(decrypt);
 
         while (!ciphertexts.empty())
         {
-            typename aesni::aes::Types<algorithm>::BlockT ciphertext;
-            aesni::aes::from_string(ciphertext, ciphertexts.front());
+            typename aesni::Types<algorithm>::Block ciphertext, plaintext;
+            aesni::from_string<algorithm>(ciphertext, ciphertexts.front());
             ciphertexts.pop_front();
 
-            const auto plaintext = encrypt.decrypt(ciphertext);
+            decrypt.decrypt_block(ciphertext, plaintext);
 
             if (verbose)
             {
-                dump_ciphertext(ciphertext);
-                dump_plaintext(plaintext);
-                Dumper<algorithm, mode>::dump_next_iv(encrypt);
+                dump_ciphertext<algorithm>(ciphertext);
+                dump_plaintext<algorithm>(plaintext);
+                dump_next_iv<algorithm, mode>(decrypt);
             }
             else
             {
-                std::cout << aesni::aes::to_string(plaintext) << "\n";
+                std::cout << aesni::to_string<algorithm>(plaintext) << "\n";
             }
         }
 
@@ -102,7 +102,7 @@ namespace
         }
     }
 
-    bool decrypt(
+    bool decrypt_using_cxx_api(
         aesni::Algorithm algorithm,
         aesni::Mode mode,
         const std::string& key_str,
@@ -125,32 +125,13 @@ namespace
         }
     }
 
-    bool decrypt_using_boxes(
-        aesni::Algorithm algorithm,
+    template <aesni::Algorithm algorithm>
+    bool decrypt_using_boxes_with_algorithm(
+        const AesNI_BoxAlgorithmParams& algorithm_params,
         aesni::Mode mode,
         const std::string& key,
         std::deque<std::string> ciphertexts)
     {
-        AesNI_BoxAlgorithmParams algorithm_params;
-
-        switch (algorithm)
-        {
-            case AESNI_AES128:
-                aesni::aes::from_string(algorithm_params.aes128_key, key);
-                break;
-
-            case AESNI_AES192:
-                aesni::aes::from_string(algorithm_params.aes192_key, key);
-                break;
-
-            case AESNI_AES256:
-                aesni::aes::from_string(algorithm_params.aes256_key, key);
-                break;
-
-            default:
-                return false;
-        }
-
         AesNI_BoxBlock iv;
         AesNI_BoxBlock* iv_ptr = nullptr;
 
@@ -159,7 +140,7 @@ namespace
             if (ciphertexts.empty())
                 return false;
 
-            aesni::aes::from_string(iv.aes_block, ciphertexts.front());
+            aesni::from_string<algorithm>(iv.aes_block, ciphertexts.front());
             iv_ptr = &iv;
             ciphertexts.pop_front();
         }
@@ -176,7 +157,7 @@ namespace
         while (!ciphertexts.empty())
         {
             AesNI_BoxBlock ciphertext;
-            aesni::aes::from_string(ciphertext.aes_block, ciphertexts.front());
+            aesni::from_string<algorithm>(ciphertext.aes_block, ciphertexts.front());
             ciphertexts.pop_front();
 
             AesNI_BoxBlock plaintext;
@@ -186,11 +167,44 @@ namespace
                 &plaintext,
                 aesni::ErrorDetailsThrowsInDestructor());
 
-            std::cout << aesni::aes::to_string(plaintext.aes_block) << "\n";
+            std::cout << aesni::to_string<algorithm>(plaintext.aes_block) << "\n";
         }
 
         return true;
     }
+
+    bool decrypt_using_boxes(
+        aesni::Algorithm algorithm,
+        aesni::Mode mode,
+        const std::string& key,
+        std::deque<std::string> ciphertexts)
+    {
+        AesNI_BoxAlgorithmParams algorithm_params;
+
+        switch (algorithm)
+        {
+            case AESNI_AES128:
+                aesni::from_string<AESNI_AES128>(
+                    algorithm_params.aes128_key, key);
+                return decrypt_using_boxes_with_algorithm<AESNI_AES128>(
+                    algorithm_params, mode, key, ciphertexts);
+
+            case AESNI_AES192:
+                aesni::from_string<AESNI_AES192>(
+                    algorithm_params.aes192_key, key);
+                return decrypt_using_boxes_with_algorithm<AESNI_AES192>(
+                    algorithm_params, mode, key, ciphertexts);
+
+            case AESNI_AES256:
+                aesni::from_string<AESNI_AES256>(
+                    algorithm_params.aes256_key, key);
+                return decrypt_using_boxes_with_algorithm<AESNI_AES256>(
+                    algorithm_params, mode, key, ciphertexts);
+
+            default:
+                return false;
+        }
+    }
 }
 
 int main(int argc, char** argv)
@@ -228,7 +242,7 @@ int main(int argc, char** argv)
 
             const auto success = cmd_parser.use_boxes()
                 ? decrypt_using_boxes(algorithm, mode, key, ciphertexts)
-                : decrypt(algorithm, mode, key, ciphertexts, cmd_parser.verbose());
+                : decrypt_using_cxx_api(algorithm, mode, key, ciphertexts, cmd_parser.verbose());
 
             if (!success)
             {
diff --git a/utils/aes_decrypt_bmp.cpp b/utils/aes_decrypt_bmp.cpp
index b9f669e..cf96847 100644
--- a/utils/aes_decrypt_bmp.cpp
+++ b/utils/aes_decrypt_bmp.cpp
@@ -17,6 +17,7 @@
 #include <cstdlib>
 #include <cstring>
 
+#include <deque>
 #include <exception>
 #include <fstream>
 #include <iostream>
@@ -58,72 +59,28 @@ namespace
         ofs.open(path, std::ofstream::binary);
         ofs.write(src.data(), src.size());
     }
-}
 
-int main(int argc, char** argv)
-{
-    try
+    template <aesni::Algorithm algorithm>
+    bool decrypt_bmp_with_algorithm(
+        const AesNI_BoxAlgorithmParams& algorithm_params,
+        aesni::Mode mode,
+        std::deque<std::string>& args)
     {
-        CommandLineParser cmd_parser("aes_decrypt_bmp.exe");
-
-        if (!cmd_parser.parse_options(argc, argv))
-            return 0;
-
-        auto args = cmd_parser.get_args();
-
-        if (args.empty())
-        {
-            cmd_parser.print_usage();
-            return 1;
-        }
-
-        AesNI_BoxAlgorithmParams algorithm_params;
-
-        switch (cmd_parser.get_algorithm())
-        {
-            case AESNI_AES128:
-                aesni::aes::from_string(algorithm_params.aes128_key, args.front());
-                break;
-
-            case AESNI_AES192:
-                aesni::aes::from_string(algorithm_params.aes192_key, args.front());
-                break;
-
-            case AESNI_AES256:
-                aesni::aes::from_string(algorithm_params.aes256_key, args.front());
-                break;
-        }
-
-        args.pop_front();
-
         AesNI_BoxBlock iv;
         AesNI_BoxBlock* iv_ptr = nullptr;
 
-        switch (cmd_parser.get_mode())
+        if (aesni::mode_requires_initialization_vector(mode))
         {
-            case AESNI_ECB:
-                break;
-
-            case AESNI_CBC:
-            case AESNI_CFB:
-            case AESNI_OFB:
-            case AESNI_CTR:
-                if (args.empty())
-                {
-                    cmd_parser.print_usage();
-                    return 1;
-                }
-                aesni::aes::from_string(iv.aes_block, args.front());
-                iv_ptr = &iv;
-                args.pop_front();
-                break;
+            if (args.empty())
+                return false;
+
+            aesni::from_string<algorithm>(iv.aes_block, args.front());
+            iv_ptr = &iv;
+            args.pop_front();
         }
 
         if (args.size() != 2)
-        {
-            cmd_parser.print_usage();
-            return 1;
-        }
+            return false;
 
         const auto src_path = args[0];
         const auto dest_path = args[1];
@@ -140,9 +97,9 @@ int main(int argc, char** argv)
 
         aesni_box_init(
             &box,
-            cmd_parser.get_algorithm(),
+            algorithm,
             &algorithm_params,
-            cmd_parser.get_mode(),
+            mode,
             iv_ptr,
             aesni::ErrorDetailsThrowsInDestructor());
 
@@ -171,6 +128,63 @@ int main(int argc, char** argv)
         dest_buf.resize(header_size + pixels_size);
         write_file(dest_path, dest_buf);
 
+        return true;
+    }
+
+    bool decrypt_bmp(
+        aesni::Algorithm algorithm,
+        aesni::Mode mode,
+        std::deque<std::string>& args)
+    {
+        if (args.empty())
+            return false;
+
+        AesNI_BoxAlgorithmParams algorithm_params;
+
+        switch (algorithm)
+        {
+            case AESNI_AES128:
+                aesni::from_string<AESNI_AES128>(
+                    algorithm_params.aes128_key, args.front());
+                args.pop_front();
+                return decrypt_bmp_with_algorithm<AESNI_AES128>(
+                    algorithm_params, mode, args);
+
+            case AESNI_AES192:
+                aesni::from_string<AESNI_AES192>(
+                    algorithm_params.aes192_key, args.front());
+                args.pop_front();
+                return decrypt_bmp_with_algorithm<AESNI_AES192>(
+                    algorithm_params, mode, args);
+
+            case AESNI_AES256:
+                aesni::from_string<AESNI_AES256>(
+                    algorithm_params.aes256_key, args.front());
+                args.pop_front();
+                return decrypt_bmp_with_algorithm<AESNI_AES256>(
+                    algorithm_params, mode, args);
+
+            default:
+                return false;
+        }
+    }
+}
+
+int main(int argc, char** argv)
+{
+    try
+    {
+        CommandLineParser cmd_parser("aes_decrypt_bmp.exe");
+
+        if (!cmd_parser.parse_options(argc, argv))
+            return 0;
+
+        if (!decrypt_bmp(cmd_parser.get_algorithm(), cmd_parser.get_mode(), cmd_parser.get_args()))
+        {
+            cmd_parser.print_usage();
+            return 1;
+        }
+
         return 0;
     }
     catch (const boost::program_options::error& e)
diff --git a/utils/aes_decrypt_file.cpp b/utils/aes_decrypt_file.cpp
index 650ca5e..d456b67 100644
--- a/utils/aes_decrypt_file.cpp
+++ b/utils/aes_decrypt_file.cpp
@@ -16,6 +16,7 @@
 
 #include <cstdlib>
 
+#include <deque>
 #include <exception>
 #include <fstream>
 #include <iostream>
@@ -55,72 +56,28 @@ namespace
         ofs.open(path, std::ofstream::binary);
         ofs.write(src.data(), src.size());
     }
-}
 
-int main(int argc, char** argv)
-{
-    try
+    template <aesni::Algorithm algorithm>
+    bool decrypt_file_with_algorithm(
+        const AesNI_BoxAlgorithmParams& algorithm_params,
+        aesni::Mode mode,
+        std::deque<std::string>& args)
     {
-        CommandLineParser cmd_parser("aes_encrypt_file.exe");
-
-        if (!cmd_parser.parse_options(argc, argv))
-            return 0;
-
-        auto args = cmd_parser.get_args();
-
-        if (args.empty())
-        {
-            cmd_parser.print_usage();
-            return 1;
-        }
-
-        AesNI_BoxAlgorithmParams algorithm_params;
-
-        switch (cmd_parser.get_algorithm())
-        {
-            case AESNI_AES128:
-                aesni::aes::from_string(algorithm_params.aes128_key, args.front());
-                break;
-
-            case AESNI_AES192:
-                aesni::aes::from_string(algorithm_params.aes192_key, args.front());
-                break;
-
-            case AESNI_AES256:
-                aesni::aes::from_string(algorithm_params.aes256_key, args.front());
-                break;
-        }
-
-        args.pop_front();
-
         AesNI_BoxBlock iv;
         AesNI_BoxBlock* iv_ptr = nullptr;
 
-        switch (cmd_parser.get_mode())
+        if (aesni::mode_requires_initialization_vector(mode))
         {
-            case AESNI_ECB:
-                break;
-
-            case AESNI_CBC:
-            case AESNI_CFB:
-            case AESNI_OFB:
-            case AESNI_CTR:
-                if (args.empty())
-                {
-                    cmd_parser.print_usage();
-                    return 1;
-                }
-                aesni::aes::from_string(iv.aes_block, args.front());
-                iv_ptr = &iv;
-                args.pop_front();
-                break;
+            if (args.empty())
+                return false;
+
+            aesni::from_string<algorithm>(iv.aes_block, args.front());
+            iv_ptr = &iv;
+            args.pop_front();
         }
 
         if (args.size() != 2)
-        {
-            cmd_parser.print_usage();
-            return 1;
-        }
+            return false;
 
         const auto src_path = args[0];
         const auto dest_path = args[1];
@@ -131,9 +88,9 @@ int main(int argc, char** argv)
 
         aesni_box_init(
             &box,
-            cmd_parser.get_algorithm(),
+            algorithm,
             &algorithm_params,
-            cmd_parser.get_mode(),
+            mode,
             iv_ptr,
             aesni::ErrorDetailsThrowsInDestructor());
 
@@ -159,9 +116,65 @@ int main(int argc, char** argv)
             aesni::ErrorDetailsThrowsInDestructor());
 
         dest_buf.resize(dest_size);
-
         write_file(dest_path, dest_buf);
 
+        return true;
+    }
+
+    bool decrypt_file(
+        aesni::Algorithm algorithm,
+        aesni::Mode mode,
+        std::deque<std::string>& args)
+    {
+        if (args.empty())
+            return false;
+
+        AesNI_BoxAlgorithmParams algorithm_params;
+
+        switch (algorithm)
+        {
+            case AESNI_AES128:
+                aesni::from_string<AESNI_AES128>(
+                    algorithm_params.aes128_key, args.front());
+                args.pop_front();
+                return decrypt_file_with_algorithm<AESNI_AES128>(
+                    algorithm_params, mode, args);
+
+            case AESNI_AES192:
+                aesni::from_string<AESNI_AES192>(
+                    algorithm_params.aes192_key, args.front());
+                args.pop_front();
+                return decrypt_file_with_algorithm<AESNI_AES192>(
+                    algorithm_params, mode, args);
+
+            case AESNI_AES256:
+                aesni::from_string<AESNI_AES256>(
+                    algorithm_params.aes256_key, args.front());
+                args.pop_front();
+                return decrypt_file_with_algorithm<AESNI_AES256>(
+                    algorithm_params, mode, args);
+
+            default:
+                return false;
+        }
+    }
+}
+
+int main(int argc, char** argv)
+{
+    try
+    {
+        CommandLineParser cmd_parser("aes_encrypt_file.exe");
+
+        if (!cmd_parser.parse_options(argc, argv))
+            return 0;
+
+        if (!decrypt_file(cmd_parser.get_algorithm(), cmd_parser.get_mode(), cmd_parser.get_args()))
+        {
+            cmd_parser.print_usage();
+            return 1;
+        }
+
         return 0;
     }
     catch (const boost::program_options::error& e)
diff --git a/utils/aes_encrypt_block.cpp b/utils/aes_encrypt_block.cpp
index b814e99..1b6b788 100644
--- a/utils/aes_encrypt_block.cpp
+++ b/utils/aes_encrypt_block.cpp
@@ -25,47 +25,47 @@ namespace
         std::deque<std::string>& plaintexts,
         bool verbose = false)
     {
-        typename aesni::aes::Types<algorithm>::BlockT iv;
+        typename aesni::Types<algorithm>::Block iv;
 
-        if (aesni::ModeRequiresInitializationVector<mode>())
+        if (aesni::ModeRequiresInitializationVector<mode>::value)
         {
             if (plaintexts.empty())
                 return false;
 
-            aesni::aes::from_string(iv, plaintexts.front());
+            aesni::from_string<algorithm>(iv, plaintexts.front());
             plaintexts.pop_front();
 
             if (verbose)
-                dump_iv(iv);
+                dump_iv<algorithm>(iv);
         }
 
-        typename aesni::aes::Types<algorithm>::KeyT key;
-        aesni::aes::from_string(key, key_str);
+        typename aesni::Types<algorithm>::Key key;
+        aesni::from_string<algorithm>(key, key_str);
 
         if (verbose)
-            dump_key(key);
+            dump_key<algorithm>(key);
 
-        aesni::aes::Encrypt<algorithm, mode> encrypt(key, iv);
+        aesni::EncryptWrapper<algorithm, mode> encrypt(key, iv);
 
         if (verbose)
-            Dumper<algorithm, mode>::dump_round_keys(encrypt);
+            dump_wrapper<algorithm, mode>(encrypt);
 
         while (!plaintexts.empty())
         {
-            typename aesni::aes::Types<algorithm>::BlockT plaintext;
-            aesni::aes::from_string(plaintext, plaintexts.front());
+            typename aesni::Types<algorithm>::Block plaintext, ciphertext;
+            aesni::from_string<algorithm>(plaintext, plaintexts.front());
             plaintexts.pop_front();
-            const auto ciphertext = encrypt.encrypt(plaintext);
+            encrypt.encrypt_block(plaintext, ciphertext);
 
             if (verbose)
             {
-                dump_plaintext(plaintext);
-                dump_ciphertext(ciphertext);
-                Dumper<algorithm, mode>::dump_next_iv(encrypt);
+                dump_plaintext<algorithm>(plaintext);
+                dump_ciphertext<algorithm>(ciphertext);
+                dump_next_iv<algorithm, mode>(encrypt);
             }
             else
             {
-                std::cout << aesni::aes::to_string(ciphertext) << "\n";
+                std::cout << aesni::to_string<algorithm>(ciphertext) << "\n";
             }
         }
 
@@ -101,11 +101,11 @@ namespace
         }
     }
 
-    bool encrypt(
+    bool encrypt_using_cxx_api(
         aesni::Algorithm algorithm,
         aesni::Mode mode,
         const std::string& key_str,
-        std::deque<std::string> plaintexts,
+        std::deque<std::string>& plaintexts,
         bool verbose = false)
     {
         switch (algorithm)
@@ -124,32 +124,13 @@ namespace
         }
     }
 
-    bool encrypt_using_boxes(
-        aesni::Algorithm algorithm,
+    template <aesni::Algorithm algorithm>
+    bool encrypt_using_boxes_with_algorithm(
+        const AesNI_BoxAlgorithmParams& algorithm_params,
         aesni::Mode mode,
         const std::string& key,
         std::deque<std::string> plaintexts)
     {
-        AesNI_BoxAlgorithmParams algorithm_params;
-
-        switch (algorithm)
-        {
-            case AESNI_AES128:
-                aesni::aes::from_string(algorithm_params.aes128_key, key);
-                break;
-
-            case AESNI_AES192:
-                aesni::aes::from_string(algorithm_params.aes192_key, key);
-                break;
-
-            case AESNI_AES256:
-                aesni::aes::from_string(algorithm_params.aes256_key, key);
-                break;
-
-            default:
-                return false;
-        }
-
         AesNI_BoxBlock iv;
         AesNI_BoxBlock* iv_ptr = nullptr;
 
@@ -158,7 +139,7 @@ namespace
             if (plaintexts.empty())
                 return false;
 
-            aesni::aes::from_string(iv.aes_block, plaintexts.front());
+            aesni::from_string<AESNI_AES128>(iv.aes_block, plaintexts.front());
             iv_ptr = &iv;
             plaintexts.pop_front();
         }
@@ -175,7 +156,7 @@ namespace
         while (!plaintexts.empty())
         {
             AesNI_BoxBlock plaintext;
-            aesni::aes::from_string(plaintext.aes_block, plaintexts.front());
+            aesni::from_string<algorithm>(plaintext.aes_block, plaintexts.front());
             plaintexts.pop_front();
 
             AesNI_BoxBlock ciphertext;
@@ -185,11 +166,44 @@ namespace
                 &ciphertext,
                 aesni::ErrorDetailsThrowsInDestructor());
 
-            std::cout << aesni::aes::to_string(ciphertext.aes_block) << "\n";
+            std::cout << aesni::to_string<algorithm>(ciphertext.aes_block) << "\n";
         }
 
         return true;
     }
+
+    bool encrypt_using_boxes(
+        aesni::Algorithm algorithm,
+        aesni::Mode mode,
+        const std::string& key,
+        std::deque<std::string> plaintexts)
+    {
+        AesNI_BoxAlgorithmParams algorithm_params;
+
+        switch (algorithm)
+        {
+            case AESNI_AES128:
+                aesni::from_string<AESNI_AES128>(
+                    algorithm_params.aes128_key, key);
+                return encrypt_using_boxes_with_algorithm<AESNI_AES128>(
+                    algorithm_params, mode, key, plaintexts);
+
+            case AESNI_AES192:
+                aesni::from_string<AESNI_AES192>(
+                    algorithm_params.aes192_key, key);
+                return encrypt_using_boxes_with_algorithm<AESNI_AES192>(
+                    algorithm_params, mode, key, plaintexts);
+
+            case AESNI_AES256:
+                aesni::from_string<AESNI_AES256>(
+                    algorithm_params.aes256_key, key);
+                return encrypt_using_boxes_with_algorithm<AESNI_AES256>(
+                    algorithm_params, mode, key, plaintexts);
+
+            default:
+                return false;
+        }
+    }
 }
 
 int main(int argc, char** argv)
@@ -227,7 +241,7 @@ int main(int argc, char** argv)
 
             const auto success = cmd_parser.use_boxes()
                 ? encrypt_using_boxes(algorithm, mode, key, plaintexts)
-                : encrypt(algorithm, mode, key, plaintexts, cmd_parser.verbose());
+                : encrypt_using_cxx_api(algorithm, mode, key, plaintexts, cmd_parser.verbose());
 
             if (!success)
             {
diff --git a/utils/aes_encrypt_bmp.cpp b/utils/aes_encrypt_bmp.cpp
index f36cfb0..2615889 100644
--- a/utils/aes_encrypt_bmp.cpp
+++ b/utils/aes_encrypt_bmp.cpp
@@ -17,6 +17,7 @@
 #include <cstdlib>
 #include <cstring>
 
+#include <deque>
 #include <exception>
 #include <fstream>
 #include <iostream>
@@ -58,72 +59,28 @@ namespace
         ofs.open(path, std::ofstream::binary);
         ofs.write(src.data(), src.size());
     }
-}
 
-int main(int argc, char** argv)
-{
-    try
+    template <aesni::Algorithm algorithm>
+    bool encrypt_bmp_with_algorithm(
+        const AesNI_BoxAlgorithmParams& algorithm_params,
+        aesni::Mode mode,
+        std::deque<std::string>& args)
     {
-        CommandLineParser cmd_parser("aes_encrypt_bmp.exe");
-
-        if (!cmd_parser.parse_options(argc, argv))
-            return 0;
-
-        auto args = cmd_parser.get_args();
-
-        if (args.empty())
-        {
-            cmd_parser.print_usage();
-            return 1;
-        }
-
-        AesNI_BoxAlgorithmParams algorithm_params;
-
-        switch (cmd_parser.get_algorithm())
-        {
-            case AESNI_AES128:
-                aesni::aes::from_string(algorithm_params.aes128_key, args.front());
-                break;
-
-            case AESNI_AES192:
-                aesni::aes::from_string(algorithm_params.aes192_key, args.front());
-                break;
-
-            case AESNI_AES256:
-                aesni::aes::from_string(algorithm_params.aes256_key, args.front());
-                break;
-        }
-
-        args.pop_front();
-
         AesNI_BoxBlock iv;
         AesNI_BoxBlock* iv_ptr = nullptr;
 
-        switch (cmd_parser.get_mode())
+        if (aesni::mode_requires_initialization_vector(mode))
         {
-            case AESNI_ECB:
-                break;
-
-            case AESNI_CBC:
-            case AESNI_CFB:
-            case AESNI_OFB:
-            case AESNI_CTR:
-                if (args.empty())
-                {
-                    cmd_parser.print_usage();
-                    return 1;
-                }
-                aesni::aes::from_string(iv.aes_block, args.front());
-                iv_ptr = &iv;
-                args.pop_front();
-                break;
+            if (args.empty())
+                return false;
+
+            aesni::from_string<algorithm>(iv.aes_block, args.front());
+            iv_ptr = &iv;
+            args.pop_front();
         }
 
         if (args.size() != 2)
-        {
-            cmd_parser.print_usage();
-            return 1;
-        }
+            return false;
 
         const auto src_path = args[0];
         const auto dest_path = args[1];
@@ -140,9 +97,9 @@ int main(int argc, char** argv)
 
         aesni_box_init(
             &box,
-            cmd_parser.get_algorithm(),
+            algorithm,
             &algorithm_params,
-            cmd_parser.get_mode(),
+            mode,
             iv_ptr,
             aesni::ErrorDetailsThrowsInDestructor());
 
@@ -170,6 +127,63 @@ int main(int argc, char** argv)
 
         write_file(dest_path, dest_buf);
 
+        return true;
+    }
+
+    bool encrypt_bmp(
+        aesni::Algorithm algorithm,
+        aesni::Mode mode,
+        std::deque<std::string>& args)
+    {
+        if (args.empty())
+            return false;
+
+        AesNI_BoxAlgorithmParams algorithm_params;
+
+        switch (algorithm)
+        {
+            case AESNI_AES128:
+                aesni::from_string<AESNI_AES128>(
+                    algorithm_params.aes128_key, args.front());
+                args.pop_front();
+                return encrypt_bmp_with_algorithm<AESNI_AES128>(
+                    algorithm_params, mode, args);
+
+            case AESNI_AES192:
+                aesni::from_string<AESNI_AES192>(
+                    algorithm_params.aes192_key, args.front());
+                args.pop_front();
+                return encrypt_bmp_with_algorithm<AESNI_AES192>(
+                    algorithm_params, mode, args);
+
+            case AESNI_AES256:
+                aesni::from_string<AESNI_AES256>(
+                    algorithm_params.aes256_key, args.front());
+                args.pop_front();
+                return encrypt_bmp_with_algorithm<AESNI_AES256>(
+                    algorithm_params, mode, args);
+
+            default:
+                return false;
+        }
+    }
+}
+
+int main(int argc, char** argv)
+{
+    try
+    {
+        CommandLineParser cmd_parser("aes_encrypt_bmp.exe");
+
+        if (!cmd_parser.parse_options(argc, argv))
+            return 0;
+
+        if (!encrypt_bmp(cmd_parser.get_algorithm(), cmd_parser.get_mode(), cmd_parser.get_args()))
+        {
+            cmd_parser.print_usage();
+            return 1;
+        }
+
         return 0;
     }
     catch (const boost::program_options::error& e)
diff --git a/utils/aes_encrypt_file.cpp b/utils/aes_encrypt_file.cpp
index 93b7cbd..61b9ba1 100644
--- a/utils/aes_encrypt_file.cpp
+++ b/utils/aes_encrypt_file.cpp
@@ -16,6 +16,7 @@
 
 #include <cstdlib>
 
+#include <deque>
 #include <exception>
 #include <fstream>
 #include <iostream>
@@ -55,72 +56,28 @@ namespace
         ofs.open(path, std::ofstream::binary);
         ofs.write(src.data(), src.size());
     }
-}
 
-int main(int argc, char** argv)
-{
-    try
+    template <aesni::Algorithm algorithm>
+    bool encrypt_file_with_algorithm(
+        const AesNI_BoxAlgorithmParams& algorithm_params,
+        aesni::Mode mode,
+        std::deque<std::string>& args)
     {
-        CommandLineParser cmd_parser("aes_encrypt_file.exe");
-
-        if (!cmd_parser.parse_options(argc, argv))
-            return 0;
-
-        auto args = cmd_parser.get_args();
-
-        if (args.empty())
-        {
-            cmd_parser.print_usage();
-            return 1;
-        }
-
-        AesNI_BoxAlgorithmParams algorithm_params;
-
-        switch (cmd_parser.get_algorithm())
-        {
-            case AESNI_AES128:
-                aesni::aes::from_string(algorithm_params.aes128_key, args.front());
-                break;
-
-            case AESNI_AES192:
-                aesni::aes::from_string(algorithm_params.aes192_key, args.front());
-                break;
-
-            case AESNI_AES256:
-                aesni::aes::from_string(algorithm_params.aes256_key, args.front());
-                break;
-        }
-
-        args.pop_front();
-
         AesNI_BoxBlock iv;
         AesNI_BoxBlock* iv_ptr = nullptr;
 
-        switch (cmd_parser.get_mode())
+        if (aesni::mode_requires_initialization_vector(mode))
         {
-            case AESNI_ECB:
-                break;
-
-            case AESNI_CBC:
-            case AESNI_CFB:
-            case AESNI_OFB:
-            case AESNI_CTR:
-                if (args.empty())
-                {
-                    cmd_parser.print_usage();
-                    return 1;
-                }
-                aesni::aes::from_string(iv.aes_block, args.front());
-                iv_ptr = &iv;
-                args.pop_front();
-                break;
+            if (args.empty())
+                return false;
+
+            aesni::from_string<algorithm>(iv.aes_block, args.front());
+            iv_ptr = &iv;
+            args.pop_front();
         }
 
         if (args.size() != 2)
-        {
-            cmd_parser.print_usage();
-            return 1;
-        }
+            return true;
 
         const auto src_path = args[0];
         const auto dest_path = args[1];
@@ -131,9 +88,9 @@ int main(int argc, char** argv)
 
         aesni_box_init(
             &box,
-            cmd_parser.get_algorithm(),
+            algorithm,
             &algorithm_params,
-            cmd_parser.get_mode(),
+            mode,
             iv_ptr,
             aesni::ErrorDetailsThrowsInDestructor());
 
@@ -159,9 +116,65 @@ int main(int argc, char** argv)
             aesni::ErrorDetailsThrowsInDestructor());
 
         dest_buf.resize(dest_size);
-
         write_file(dest_path, dest_buf);
 
+        return true;
+    }
+
+    bool encrypt_file(
+        aesni::Algorithm algorithm,
+        aesni::Mode mode,
+        std::deque<std::string>& args)
+    {
+        if (args.empty())
+            return false;
+
+        AesNI_BoxAlgorithmParams algorithm_params;
+
+        switch (algorithm)
+        {
+            case AESNI_AES128:
+                aesni::from_string<AESNI_AES128>(
+                    algorithm_params.aes128_key, args.front());
+                args.pop_front();
+                return encrypt_file_with_algorithm<AESNI_AES128>(
+                    algorithm_params, mode, args);
+
+            case AESNI_AES192:
+                aesni::from_string<AESNI_AES192>(
+                    algorithm_params.aes192_key, args.front());
+                args.pop_front();
+                return encrypt_file_with_algorithm<AESNI_AES192>(
+                    algorithm_params, mode, args);
+
+            case AESNI_AES256:
+                aesni::from_string<AESNI_AES256>(
+                    algorithm_params.aes256_key, args.front());
+                args.pop_front();
+                return encrypt_file_with_algorithm<AESNI_AES256>(
+                    algorithm_params, mode, args);
+
+            default:
+                return false;
+        }
+    }
+}
+
+int main(int argc, char** argv)
+{
+    try
+    {
+        CommandLineParser cmd_parser("aes_encrypt_file.exe");
+
+        if (!cmd_parser.parse_options(argc, argv))
+            return 0;
+
+        if (!encrypt_file(cmd_parser.get_algorithm(), cmd_parser.get_mode(), cmd_parser.get_args()))
+        {
+            cmd_parser.print_usage();
+            return 1;
+        }
+
         return 0;
     }
     catch (const boost::program_options::error& e)