1 /* 2 * Copyright (c) 2001-2007, Tom St Denis 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 11 * 2. Redistributions in binary form must reproduce the above copyright notice, 12 * this list of conditions and the following disclaimer in the documentation 13 * and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25 * POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 /* LibTomCrypt, modular cryptographic library -- Tom St Denis 29 * 30 * LibTomCrypt is a library that provides various cryptographic 31 * algorithms in a highly modular and flexible manner. 32 * 33 * The library is free for all purposes without any express 34 * guarantee it works. 35 * 36 * Tom St Denis, tomstdenis@gmail.com, http://libtom.org 37 */ 38 #include "tomcrypt.h" 39 40 /** 41 @file sprng.c 42 Secure PRNG, Tom St Denis 43 */ 44 45 /* A secure PRNG using the RNG functions. Basically this is a 46 * wrapper that allows you to use a secure RNG as a PRNG 47 * in the various other functions. 48 */ 49 50 #ifdef LTC_SPRNG 51 52 const struct ltc_prng_descriptor sprng_desc = 53 { 54 "sprng", 0, 55 &sprng_start, 56 &sprng_add_entropy, 57 &sprng_ready, 58 &sprng_read, 59 &sprng_done, 60 &sprng_export, 61 &sprng_import, 62 &sprng_test 63 }; 64 65 /** 66 Start the PRNG 67 @param prng [out] The PRNG state to initialize 68 @return CRYPT_OK if successful 69 */ 70 int sprng_start(prng_state *prng) 71 { 72 LTC_UNUSED_PARAM(prng); 73 return CRYPT_OK; 74 } 75 76 /** 77 Add entropy to the PRNG state 78 @param in The data to add 79 @param inlen Length of the data to add 80 @param prng PRNG state to update 81 @return CRYPT_OK if successful 82 */ 83 int sprng_add_entropy(const unsigned char *in, unsigned long inlen, prng_state *prng) 84 { 85 LTC_UNUSED_PARAM(in); 86 LTC_UNUSED_PARAM(inlen); 87 LTC_UNUSED_PARAM(prng); 88 return CRYPT_OK; 89 } 90 91 /** 92 Make the PRNG ready to read from 93 @param prng The PRNG to make active 94 @return CRYPT_OK if successful 95 */ 96 int sprng_ready(prng_state *prng) 97 { 98 LTC_UNUSED_PARAM(prng); 99 return CRYPT_OK; 100 } 101 102 /** 103 Read from the PRNG 104 @param out Destination 105 @param outlen Length of output 106 @param prng The active PRNG to read from 107 @return Number of octets read 108 */ 109 unsigned long sprng_read(unsigned char *out, unsigned long outlen, prng_state *prng) 110 { 111 LTC_ARGCHK(out != NULL); 112 LTC_UNUSED_PARAM(prng); 113 return rng_get_bytes(out, outlen, NULL); 114 } 115 116 /** 117 Terminate the PRNG 118 @param prng The PRNG to terminate 119 @return CRYPT_OK if successful 120 */ 121 int sprng_done(prng_state *prng) 122 { 123 LTC_UNUSED_PARAM(prng); 124 return CRYPT_OK; 125 } 126 127 /** 128 Export the PRNG state 129 @param out [out] Destination 130 @param outlen [in/out] Max size and resulting size of the state 131 @param prng The PRNG to export 132 @return CRYPT_OK if successful 133 */ 134 int sprng_export(unsigned char *out, unsigned long *outlen, prng_state *prng) 135 { 136 LTC_ARGCHK(outlen != NULL); 137 LTC_UNUSED_PARAM(out); 138 LTC_UNUSED_PARAM(prng); 139 140 *outlen = 0; 141 return CRYPT_OK; 142 } 143 144 /** 145 Import a PRNG state 146 @param in The PRNG state 147 @param inlen Size of the state 148 @param prng The PRNG to import 149 @return CRYPT_OK if successful 150 */ 151 int sprng_import(const unsigned char *in, unsigned long inlen, prng_state *prng) 152 { 153 LTC_UNUSED_PARAM(in); 154 LTC_UNUSED_PARAM(inlen); 155 LTC_UNUSED_PARAM(prng); 156 return CRYPT_OK; 157 } 158 159 /** 160 PRNG self-test 161 @return CRYPT_OK if successful, CRYPT_NOP if self-testing has been disabled 162 */ 163 int sprng_test(void) 164 { 165 return CRYPT_OK; 166 } 167 168 #endif 169 170 171 172 173 /* $Source: /cvs/libtom/libtomcrypt/src/prngs/sprng.c,v $ */ 174 /* $Revision: 1.6 $ */ 175 /* $Date: 2007/05/12 14:32:35 $ */ 176