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Annotation of embedaddon/strongswan/src/libstrongswan/crypto/rngs/rng.h, revision 1.1.1.1

1.1       misho       1: /*
                      2:  * Copyright (C) 2012 Tobias Brunner
                      3:  * Copyright (C) 2008 Martin Willi
                      4:  * HSR Hochschule fuer Technik Rapperswil
                      5:  *
                      6:  * This program is free software; you can redistribute it and/or modify it
                      7:  * under the terms of the GNU General Public License as published by the
                      8:  * Free Software Foundation; either version 2 of the License, or (at your
                      9:  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
                     10:  *
                     11:  * This program is distributed in the hope that it will be useful, but
                     12:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
                     13:  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
                     14:  * for more details.
                     15:  */
                     16: 
                     17: /**
                     18:  * @defgroup rng rng
                     19:  * @{ @ingroup crypto
                     20:  */
                     21: 
                     22: #ifndef RNG_H_
                     23: #define RNG_H_
                     24: 
                     25: typedef enum rng_quality_t rng_quality_t;
                     26: typedef struct rng_t rng_t;
                     27: 
                     28: #include <library.h>
                     29: 
                     30: /**
                     31:  * Quality of generated random bytes.
                     32:  */
                     33: enum rng_quality_t {
                     34:        /** weak randomness, usable for nonces, IVs */
                     35:        RNG_WEAK,
                     36:        /** stronger randomness, usable for session keys */
                     37:        RNG_STRONG,
                     38:        /** true random key material */
                     39:        RNG_TRUE,
                     40: };
                     41: 
                     42: /**
                     43:  * enum name for rng_quality_t.
                     44:  */
                     45: extern enum_name_t *rng_quality_names;
                     46: 
                     47: /**
                     48:  * Generic interface for random number generators.
                     49:  */
                     50: struct rng_t {
                     51: 
                     52:        /**
                     53:         * Generates random bytes and writes them in the buffer.
                     54:         *
                     55:         * @param len           number of bytes to get
                     56:         * @param buffer        pointer where the generated bytes will be written
                     57:         * @return                      TRUE if bytes successfully written
                     58:         */
                     59:        bool (*get_bytes)(rng_t *this, size_t len,
                     60:                                          uint8_t *buffer) __attribute__((warn_unused_result));
                     61: 
                     62:        /**
                     63:         * Generates random bytes and allocate space for them.
                     64:         *
                     65:         * @param len           number of bytes to get
                     66:         * @param chunk         chunk which will hold generated bytes
                     67:         * @return                      TRUE if allocation succeeded
                     68:         */
                     69:        bool (*allocate_bytes)(rng_t *this, size_t len,
                     70:                                                   chunk_t *chunk) __attribute__((warn_unused_result));
                     71: 
                     72:        /**
                     73:         * Destroys a rng object.
                     74:         */
                     75:        void (*destroy)(rng_t *this);
                     76: };
                     77: 
                     78: /**
                     79:  * Wrapper around rng_t.get_bytes() ensuring that either all bytes or at least
                     80:  * the first byte is not zero.
                     81:  *
                     82:  * @param rng                  rng_t object
                     83:  * @param len                  number of bytes to get
                     84:  * @param buffer               pointer where the generated bytes will be written
                     85:  * @param all                  TRUE if all bytes have to be non-zero, FALSE for first
                     86:  * @return                             TRUE if bytes successfully written
                     87:  */
                     88: bool rng_get_bytes_not_zero(rng_t *rng, size_t len, uint8_t *buffer,
                     89:                                                        bool all) __attribute__((warn_unused_result));
                     90: 
                     91: /**
                     92:  * Wrapper around rng_t.allocate_bytes() ensuring that either all bytes or at
                     93:  * least the first byte is not zero.
                     94:  *
                     95:  * @param rng                  rng_t object
                     96:  * @param len                  number of bytes to get
                     97:  * @param chunk                        chunk that stores the generated bytes (allocated)
                     98:  * @param all                  TRUE if all bytes have to be non-zero, FALSE for first
                     99:  * @return                             TRUE if bytes successfully written
                    100:  */
                    101: bool rng_allocate_bytes_not_zero(rng_t *rng, size_t len, chunk_t *chunk,
                    102:                                                                 bool all) __attribute__((warn_unused_result));
                    103: 
                    104: 
                    105: 
                    106: #endif /** RNG_H_ @}*/