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Diffstat (limited to 'comm/third_party/botan/src/lib/modes/cipher_mode.h')
| -rw-r--r-- | comm/third_party/botan/src/lib/modes/cipher_mode.h | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/modes/cipher_mode.h b/comm/third_party/botan/src/lib/modes/cipher_mode.h new file mode 100644 index 0000000000..9bf0b6811e --- /dev/null +++ b/comm/third_party/botan/src/lib/modes/cipher_mode.h @@ -0,0 +1,198 @@ +/* +* Cipher Modes +* (C) 2013,2016 Jack Lloyd +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#ifndef BOTAN_CIPHER_MODE_H_ +#define BOTAN_CIPHER_MODE_H_ + +#include <botan/secmem.h> +#include <botan/sym_algo.h> +#include <botan/exceptn.h> +#include <string> +#include <vector> + +namespace Botan { + +/** +* The two possible directions for cipher filters, determining whether they +* actually perform encryption or decryption. +*/ +enum Cipher_Dir : int { ENCRYPTION, DECRYPTION }; + +/** +* Interface for cipher modes +*/ +class BOTAN_PUBLIC_API(2,0) Cipher_Mode : public SymmetricAlgorithm + { + public: + /** + * @return list of available providers for this algorithm, empty if not available + * @param algo_spec algorithm name + */ + static std::vector<std::string> providers(const std::string& algo_spec); + + /** + * Create an AEAD mode + * @param algo the algorithm to create + * @param direction specify if this should be an encryption or decryption AEAD + * @param provider optional specification for provider to use + * @return an AEAD mode or a null pointer if not available + */ + static std::unique_ptr<Cipher_Mode> create(const std::string& algo, + Cipher_Dir direction, + const std::string& provider = ""); + + /** + * Create an AEAD mode, or throw + * @param algo the algorithm to create + * @param direction specify if this should be an encryption or decryption AEAD + * @param provider optional specification for provider to use + * @return an AEAD mode, or throw an exception + */ + static std::unique_ptr<Cipher_Mode> create_or_throw(const std::string& algo, + Cipher_Dir direction, + const std::string& provider = ""); + + /* + * Prepare for processing a message under the specified nonce + */ + virtual void start_msg(const uint8_t nonce[], size_t nonce_len) = 0; + + /** + * Begin processing a message. + * @param nonce the per message nonce + */ + template<typename Alloc> + void start(const std::vector<uint8_t, Alloc>& nonce) + { + start_msg(nonce.data(), nonce.size()); + } + + /** + * Begin processing a message. + * @param nonce the per message nonce + * @param nonce_len length of nonce + */ + void start(const uint8_t nonce[], size_t nonce_len) + { + start_msg(nonce, nonce_len); + } + + /** + * Begin processing a message. + */ + void start() + { + return start_msg(nullptr, 0); + } + + /** + * Process message blocks + * + * Input must be a multiple of update_granularity + * + * Processes msg in place and returns bytes written. Normally + * this will be either msg_len (indicating the entire message was + * processed) or for certain AEAD modes zero (indicating that the + * mode requires the entire message be processed in one pass). + * + * @param msg the message to be processed + * @param msg_len length of the message in bytes + */ + virtual size_t process(uint8_t msg[], size_t msg_len) = 0; + + /** + * Process some data. Input must be in size update_granularity() uint8_t blocks. + * @param buffer in/out parameter which will possibly be resized + * @param offset an offset into blocks to begin processing + */ + void update(secure_vector<uint8_t>& buffer, size_t offset = 0) + { + BOTAN_ASSERT(buffer.size() >= offset, "Offset ok"); + uint8_t* buf = buffer.data() + offset; + const size_t buf_size = buffer.size() - offset; + + const size_t written = process(buf, buf_size); + buffer.resize(offset + written); + } + + /** + * Complete processing of a message. + * + * @param final_block in/out parameter which must be at least + * minimum_final_size() bytes, and will be set to any final output + * @param offset an offset into final_block to begin processing + */ + virtual void finish(secure_vector<uint8_t>& final_block, size_t offset = 0) = 0; + + /** + * Returns the size of the output if this transform is used to process a + * message with input_length bytes. In most cases the answer is precise. + * If it is not possible to precise (namely for CBC decryption) instead a + * lower bound is returned. + */ + virtual size_t output_length(size_t input_length) const = 0; + + /** + * @return size of required blocks to update + */ + virtual size_t update_granularity() const = 0; + + /** + * @return required minimium size to finalize() - may be any + * length larger than this. + */ + virtual size_t minimum_final_size() const = 0; + + /** + * @return the default size for a nonce + */ + virtual size_t default_nonce_length() const = 0; + + /** + * @return true iff nonce_len is a valid length for the nonce + */ + virtual bool valid_nonce_length(size_t nonce_len) const = 0; + + /** + * Resets just the message specific state and allows encrypting again under the existing key + */ + virtual void reset() = 0; + + /** + * @return true iff this mode provides authentication as well as + * confidentiality. + */ + virtual bool authenticated() const { return false; } + + /** + * @return the size of the authentication tag used (in bytes) + */ + virtual size_t tag_size() const { return 0; } + + /** + * @return provider information about this implementation. Default is "base", + * might also return "sse2", "avx2", "openssl", or some other arbitrary string. + */ + virtual std::string provider() const { return "base"; } + }; + +/** +* Get a cipher mode by name (eg "AES-128/CBC" or "Serpent/XTS") +* @param algo_spec cipher name +* @param direction ENCRYPTION or DECRYPTION +* @param provider provider implementation to choose +*/ +inline Cipher_Mode* get_cipher_mode(const std::string& algo_spec, + Cipher_Dir direction, + const std::string& provider = "") + { + return Cipher_Mode::create(algo_spec, direction, provider).release(); + } + +} + +#endif |