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 11 * 12 * Licensed under the Apache License, Version 2.0 (the "License"); you may 13 * not use this file except in compliance with the License. 14 * You may obtain a copy of the License at 15 * 16 * http://www.apache.org/licenses/LICENSE-2.0 17 * 18 * Unless required by applicable law or agreed to in writing, software 19 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 20 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 21 * See the License for the specific language governing permissions and 22 * limitations under the License. 23 */ 24 25 #ifndef TEST_RANDOM_H 26 #define TEST_RANDOM_H 27 28 #if !defined(MBEDTLS_CONFIG_FILE) 29 #include "mbedtls/config.h" 30 #else 31 #include MBEDTLS_CONFIG_FILE 32 #endif 33 34 #include <stddef.h> 35 #include <stdint.h> 36 37 typedef struct 38 { 39 unsigned char *buf; /* Pointer to a buffer of length bytes. */ 40 size_t length; 41 /* If fallback_f_rng is NULL, fail after delivering length bytes. */ 42 int ( *fallback_f_rng )( void*, unsigned char *, size_t ); 43 void *fallback_p_rng; 44 } mbedtls_test_rnd_buf_info; 45 46 /** 47 * Info structure for the pseudo random function 48 * 49 * Key should be set at the start to a test-unique value. 50 * Do not forget endianness! 51 * State( v0, v1 ) should be set to zero. 52 */ 53 typedef struct 54 { 55 uint32_t key[16]; 56 uint32_t v0, v1; 57 } mbedtls_test_rnd_pseudo_info; 58 59 /** 60 * This function just returns data from rand(). 61 * Although predictable and often similar on multiple 62 * runs, this does not result in identical random on 63 * each run. So do not use this if the results of a 64 * test depend on the random data that is generated. 65 * 66 * rng_state shall be NULL. 67 */ 68 int mbedtls_test_rnd_std_rand( void *rng_state, 69 unsigned char *output, 70 size_t len ); 71 72 /** 73 * This function only returns zeros. 74 * 75 * \p rng_state shall be \c NULL. 76 */ 77 int mbedtls_test_rnd_zero_rand( void *rng_state, 78 unsigned char *output, 79 size_t len ); 80 81 /** 82 * This function returns random data based on a buffer it receives. 83 * 84 * \p rng_state shall be a pointer to a #mbedtls_test_rnd_buf_info structure. 85 * 86 * The number of bytes released from the buffer on each call to 87 * the random function is specified by \p len. 88 * 89 * After the buffer is empty, this function will call the fallback RNG in the 90 * #mbedtls_test_rnd_buf_info structure if there is one, and 91 * will return #MBEDTLS_ERR_ENTROPY_SOURCE_FAILED otherwise. 92 */ 93 int mbedtls_test_rnd_buffer_rand( void *rng_state, 94 unsigned char *output, 95 size_t len ); 96 97 /** 98 * This function returns random based on a pseudo random function. 99 * This means the results should be identical on all systems. 100 * Pseudo random is based on the XTEA encryption algorithm to 101 * generate pseudorandom. 102 * 103 * \p rng_state shall be a pointer to a #mbedtls_test_rnd_pseudo_info structure. 104 */ 105 int mbedtls_test_rnd_pseudo_rand( void *rng_state, 106 unsigned char *output, 107 size_t len ); 108 109 #endif /* TEST_RANDOM_H */ 110
