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Diffstat (limited to 'src/engine/def_engine/def_mode.cpp')
| -rw-r--r-- | src/engine/def_engine/def_mode.cpp | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/src/engine/def_engine/def_mode.cpp b/src/engine/def_engine/def_mode.cpp new file mode 100644 index 000000000..7933fbb84 --- /dev/null +++ b/src/engine/def_engine/def_mode.cpp @@ -0,0 +1,194 @@ +/************************************************* +* Default Engine Source File * +* (C) 1999-2007 Jack Lloyd * +*************************************************/ + +#include <botan/def_eng.h> +#include <botan/parsing.h> +#include <botan/filters.h> +#include <botan/libstate.h> +#include <botan/mode_pad.h> +#include <memory> + +#if defined(BOTAN_HAS_ECB) + #include <botan/ecb.h> +#endif + +#if defined(BOTAN_HAS_CBC) + #include <botan/cbc.h> +#endif + +#if defined(BOTAN_HAS_CTS) + #include <botan/cts.h> +#endif + +#if defined(BOTAN_HAS_CFB) + #include <botan/cfb.h> +#endif + +#if defined(BOTAN_HAS_OFB) + #include <botan/ofb.h> +#endif + +#if defined(BOTAN_HAS_CTR) + #include <botan/ctr.h> +#endif + +#if defined(BOTAN_HAS_EAX) + #include <botan/eax.h> +#endif + +namespace Botan { + +namespace { + +/** +* Get a block cipher padding method by name +*/ +BlockCipherModePaddingMethod* get_bc_pad(const std::string& algo_spec) + { + SCAN_Name request(algo_spec); + +#if defined(BOTAN_HAS_CIPHER_MODE_PADDING) + if(request.algo_name() == "PKCS7") + return new PKCS7_Padding; + + if(request.algo_name() == "OneAndZeros") + return new OneAndZeros_Padding; + + if(request.algo_name() == "X9.23") + return new ANSI_X923_Padding; + + if(request.algo_name() == "NoPadding") + return new Null_Padding; +#endif + + throw Algorithm_Not_Found(algo_spec); + } + +} + +/************************************************* +* Get a cipher object * +*************************************************/ +Keyed_Filter* Default_Engine::get_cipher(const std::string& algo_spec, + Cipher_Dir direction) + { + std::vector<std::string> algo_parts = split_on(algo_spec, '/'); + if(algo_parts.empty()) + throw Invalid_Algorithm_Name(algo_spec); + + const std::string cipher_name = algo_parts[0]; + + Algorithm_Factory& af = global_state().algo_factory(); + + // check if it is a stream cipher first (easy case) + const StreamCipher* stream_cipher = af.prototype_stream_cipher(cipher_name); + if(stream_cipher) + return new StreamCipher_Filter(stream_cipher->clone()); + + const BlockCipher* block_cipher = af.prototype_block_cipher(cipher_name); + if(!block_cipher) + return 0; + + if(algo_parts.size() != 2 && algo_parts.size() != 3) + return 0; + + std::string mode = algo_parts[1]; + u32bit bits = 0; + + if(mode.find("CFB") != std::string::npos || + mode.find("EAX") != std::string::npos) + { + std::vector<std::string> algo_info = parse_algorithm_name(mode); + mode = algo_info[0]; + if(algo_info.size() == 1) + bits = 8*block_cipher->BLOCK_SIZE; + else if(algo_info.size() == 2) + bits = to_u32bit(algo_info[1]); + else + throw Invalid_Algorithm_Name(algo_spec); + } + + std::string padding; + if(algo_parts.size() == 3) + padding = algo_parts[2]; + else + padding = (mode == "CBC") ? "PKCS7" : "NoPadding"; + + if(mode == "ECB" && padding == "CTS") + return 0; + else if((mode != "CBC" && mode != "ECB") && padding != "NoPadding") + throw Invalid_Algorithm_Name(algo_spec); + +#if defined(BOTAN_HAS_OFB) + if(mode == "OFB") + return new OFB(block_cipher->clone()); +#endif + +#if defined(BOTAN_HAS_CTR) + if(mode == "CTR-BE") + return new CTR_BE(block_cipher->clone()); +#endif + +#if defined(BOTAN_HAS_ECB) + if(mode == "ECB") + { + if(direction == ENCRYPTION) + return new ECB_Encryption(block_cipher->clone(), get_bc_pad(padding)); + else + return new ECB_Decryption(block_cipher->clone(), get_bc_pad(padding)); + } +#endif + +#if defined(BOTAN_HAS_CFB) + if(mode == "CFB") + { + if(direction == ENCRYPTION) + return new CFB_Encryption(block_cipher->clone(), bits); + else + return new CFB_Decryption(block_cipher->clone(), bits); + } +#endif + + if(mode == "CBC") + { + if(padding == "CTS") + { +#if defined(BOTAN_HAS_CTS) + if(direction == ENCRYPTION) + return new CTS_Encryption(block_cipher->clone()); + else + return new CTS_Decryption(block_cipher->clone()); +#else + return 0; +#endif + } + +#if defined(BOTAN_HAS_CBC) + if(direction == ENCRYPTION) + return new CBC_Encryption(block_cipher->clone(), + get_bc_pad(padding)); + else + return new CBC_Decryption(block_cipher->clone(), + get_bc_pad(padding)); +#else + return 0; +#endif + } + +#if defined(BOTAN_HAS_EAX) + if(mode == "EAX") + { + if(direction == ENCRYPTION) + return new EAX_Encryption(block_cipher->clone(), bits); + else + return new EAX_Decryption(block_cipher->clone(), bits); + } +#endif + + throw Algorithm_Not_Found("get_mode: " + cipher_name + "/" + + mode + "/" + padding); + } + +} |