diff options
| -rw-r--r-- | src/aead/aead.h | 62 | ||||
| -rw-r--r-- | src/algo_base/transform.h | 86 |
2 files changed, 91 insertions, 57 deletions
diff --git a/src/aead/aead.h b/src/aead/aead.h index 0aa50f348..97f156d60 100644 --- a/src/aead/aead.h +++ b/src/aead/aead.h @@ -8,7 +8,7 @@ #ifndef BOTAN_AEAD_MODE_H__ #define BOTAN_AEAD_MODE_H__ -#include <botan/sym_algo.h> +#include <botan/transform.h> namespace Botan { @@ -19,33 +19,10 @@ namespace Botan { * which is not included in the ciphertext (for instance a sequence * number). */ -class AEAD_Mode : public SymmetricAlgorithm +class AEAD_Mode : public Transformation { public: /** - * Returns the size of the output if this mode is used to process - * a message with input_length bytes. Typically this will be - * input_length plus or minus the length of the tag. - */ - 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 Random nonce appropriate for passing to start - */ - //virtual secure_vector<byte> nonce(RandomNumberGenerator& rng) const = 0; - - /** * Set associated data that is not included in the ciphertext but * that should be authenticated. Must be called after set_key * and before finish. @@ -65,40 +42,11 @@ class AEAD_Mode : public SymmetricAlgorithm set_associated_data(&ad[0], ad.size()); } - virtual bool valid_nonce_length(size_t) const = 0; - - /** - * Begin processing a message. - * - * @param nonce the per message nonce - * @param nonce_len length of nonce - */ - virtual secure_vector<byte> start(const byte nonce[], size_t nonce_len) = 0; - - template<typename Alloc> - secure_vector<byte> start_vec(const std::vector<byte, Alloc>& nonce) - { - return start(&nonce[0], nonce.size()); - } - - /** - * Update (encrypt or decrypt) some data. Input must be in size - * update_granularity() byte blocks. - * @param blocks in/out paramter which will possibly be resized - */ - virtual void update(secure_vector<byte>& blocks, size_t offset = 0) = 0; - /** - * Complete processing of a message. For decryption, may throw an exception - * due to authentication failure. - * - * @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 + * Default AEAD nonce size (a commonly supported value among AEAD + * modes, and, large enough that random collisions are unlikely). */ - virtual void finish(secure_vector<byte>& final_block, size_t offset = 0) = 0; - - virtual ~AEAD_Mode() {} + size_t default_nonce_size() const override { return 12; } }; /** diff --git a/src/algo_base/transform.h b/src/algo_base/transform.h new file mode 100644 index 000000000..672b39ed0 --- /dev/null +++ b/src/algo_base/transform.h @@ -0,0 +1,86 @@ +/* +* Transformations of data +* (C) 2013 Jack Lloyd +* +* Distributed under the terms of the Botan license +*/ + +#ifndef BOTAN_TRANSFORM_H__ +#define BOTAN_TRANSFORM_H__ + +#include <botan/sym_algo.h> + +namespace Botan { + +/** +* Interface for general transformations on data +*/ +class Transformation : public SymmetricAlgorithm + { + public: + /** + * Begin processing a message. + * @param nonce the per message nonce + */ + template<typename Alloc> + secure_vector<byte> start_vec(const std::vector<byte, Alloc>& nonce) + { + return start(&nonce[0], nonce.size()); + } + + /** + * Begin processing a message. + * @param nonce the per message nonce + * @param nonce_len length of nonce + */ + virtual secure_vector<byte> start(const byte nonce[], size_t nonce_len) = 0; + + /** + * Process some data. Input must be in size update_granularity() byte blocks. + * @param blocks in/out paramter which will possibly be resized + */ + virtual void update(secure_vector<byte>& blocks, size_t offset = 0) = 0; + + /** + * 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<byte>& 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. Will throw if unable to give a precise + * answer. + */ + 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_size() 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; + + virtual ~Transformation() {} + }; + +} + +#endif |