random.h (2752B)
1 /** 2 * \file random.h 3 * 4 * \brief This file contains the prototypes of helper functions to generate 5 * random numbers for the purpose of testing. 6 */ 7 8 /* 9 * Copyright The Mbed TLS Contributors 10 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later 11 */ 12 13 #ifndef TEST_RANDOM_H 14 #define TEST_RANDOM_H 15 16 #include "mbedtls/build_info.h" 17 18 #include <stddef.h> 19 #include <stdint.h> 20 21 typedef struct { 22 unsigned char *buf; /* Pointer to a buffer of length bytes. */ 23 size_t length; 24 /* If fallback_f_rng is NULL, fail after delivering length bytes. */ 25 int (*fallback_f_rng)(void *, unsigned char *, size_t); 26 void *fallback_p_rng; 27 } mbedtls_test_rnd_buf_info; 28 29 /** 30 * Info structure for the pseudo random function 31 * 32 * Key should be set at the start to a test-unique value. 33 * Do not forget endianness! 34 * State( v0, v1 ) should be set to zero. 35 */ 36 typedef struct { 37 uint32_t key[16]; 38 uint32_t v0, v1; 39 } mbedtls_test_rnd_pseudo_info; 40 41 /** 42 * This function just returns data from rand(). 43 * Although predictable and often similar on multiple 44 * runs, this does not result in identical random on 45 * each run. So do not use this if the results of a 46 * test depend on the random data that is generated. 47 * 48 * rng_state shall be NULL. 49 */ 50 int mbedtls_test_rnd_std_rand(void *rng_state, 51 unsigned char *output, 52 size_t len); 53 54 /** 55 * This function only returns zeros. 56 * 57 * \p rng_state shall be \c NULL. 58 */ 59 int mbedtls_test_rnd_zero_rand(void *rng_state, 60 unsigned char *output, 61 size_t len); 62 63 /** 64 * This function returns random data based on a buffer it receives. 65 * 66 * \p rng_state shall be a pointer to a #mbedtls_test_rnd_buf_info structure. 67 * 68 * The number of bytes released from the buffer on each call to 69 * the random function is specified by \p len. 70 * 71 * After the buffer is empty, this function will call the fallback RNG in the 72 * #mbedtls_test_rnd_buf_info structure if there is one, and 73 * will return #MBEDTLS_ERR_ENTROPY_SOURCE_FAILED otherwise. 74 */ 75 int mbedtls_test_rnd_buffer_rand(void *rng_state, 76 unsigned char *output, 77 size_t len); 78 79 /** 80 * This function returns random based on a pseudo random function. 81 * This means the results should be identical on all systems. 82 * Pseudo random is based on the XTEA encryption algorithm to 83 * generate pseudorandom. 84 * 85 * \p rng_state shall be a pointer to a #mbedtls_test_rnd_pseudo_info structure. 86 */ 87 int mbedtls_test_rnd_pseudo_rand(void *rng_state, 88 unsigned char *output, 89 size_t len); 90 91 #endif /* TEST_RANDOM_H */