| // SPDX-License-Identifier: BSD-2-Clause |
| /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
| * |
| * LibTomCrypt is a library that provides various cryptographic |
| * algorithms in a highly modular and flexible manner. |
| * |
| * The library is free for all purposes without any express |
| * guarantee it works. |
| */ |
| #include "tomcrypt_private.h" |
| |
| /** |
| @file sprng.c |
| Secure PRNG, Tom St Denis |
| */ |
| |
| /* A secure PRNG using the RNG functions. Basically this is a |
| * wrapper that allows you to use a secure RNG as a PRNG |
| * in the various other functions. |
| */ |
| |
| #ifdef LTC_SPRNG |
| |
| const struct ltc_prng_descriptor sprng_desc = |
| { |
| "sprng", 0, |
| &sprng_start, |
| &sprng_add_entropy, |
| &sprng_ready, |
| &sprng_read, |
| &sprng_done, |
| &sprng_export, |
| &sprng_import, |
| &sprng_test |
| }; |
| |
| /** |
| Start the PRNG |
| @param prng [out] The PRNG state to initialize |
| @return CRYPT_OK if successful |
| */ |
| int sprng_start(prng_state *prng) |
| { |
| LTC_UNUSED_PARAM(prng); |
| return CRYPT_OK; |
| } |
| |
| /** |
| Add entropy to the PRNG state |
| @param in The data to add |
| @param inlen Length of the data to add |
| @param prng PRNG state to update |
| @return CRYPT_OK if successful |
| */ |
| int sprng_add_entropy(const unsigned char *in, unsigned long inlen, prng_state *prng) |
| { |
| LTC_UNUSED_PARAM(in); |
| LTC_UNUSED_PARAM(inlen); |
| LTC_UNUSED_PARAM(prng); |
| return CRYPT_OK; |
| } |
| |
| /** |
| Make the PRNG ready to read from |
| @param prng The PRNG to make active |
| @return CRYPT_OK if successful |
| */ |
| int sprng_ready(prng_state *prng) |
| { |
| LTC_UNUSED_PARAM(prng); |
| return CRYPT_OK; |
| } |
| |
| /** |
| Read from the PRNG |
| @param out Destination |
| @param outlen Length of output |
| @param prng The active PRNG to read from |
| @return Number of octets read |
| */ |
| unsigned long sprng_read(unsigned char *out, unsigned long outlen, prng_state *prng) |
| { |
| LTC_ARGCHK(out != NULL); |
| LTC_UNUSED_PARAM(prng); |
| return rng_get_bytes(out, outlen, NULL); |
| } |
| |
| /** |
| Terminate the PRNG |
| @param prng The PRNG to terminate |
| @return CRYPT_OK if successful |
| */ |
| int sprng_done(prng_state *prng) |
| { |
| LTC_UNUSED_PARAM(prng); |
| return CRYPT_OK; |
| } |
| |
| /** |
| Export the PRNG state |
| @param out [out] Destination |
| @param outlen [in/out] Max size and resulting size of the state |
| @param prng The PRNG to export |
| @return CRYPT_OK if successful |
| */ |
| /* NOLINTNEXTLINE(readability-non-const-parameter) - silence clang-tidy warning */ |
| int sprng_export(unsigned char *out, unsigned long *outlen, prng_state *prng) |
| { |
| LTC_ARGCHK(outlen != NULL); |
| LTC_UNUSED_PARAM(out); |
| LTC_UNUSED_PARAM(prng); |
| |
| *outlen = 0; |
| return CRYPT_OK; |
| } |
| |
| /** |
| Import a PRNG state |
| @param in The PRNG state |
| @param inlen Size of the state |
| @param prng The PRNG to import |
| @return CRYPT_OK if successful |
| */ |
| int sprng_import(const unsigned char *in, unsigned long inlen, prng_state *prng) |
| { |
| LTC_UNUSED_PARAM(in); |
| LTC_UNUSED_PARAM(inlen); |
| LTC_UNUSED_PARAM(prng); |
| return CRYPT_OK; |
| } |
| |
| /** |
| PRNG self-test |
| @return CRYPT_OK if successful, CRYPT_NOP if self-testing has been disabled |
| */ |
| int sprng_test(void) |
| { |
| #ifndef LTC_TEST |
| return CRYPT_NOP; |
| #else |
| prng_state st; |
| unsigned char en[] = { 0x01, 0x02, 0x03, 0x04 }; |
| unsigned char out[1000]; |
| int err; |
| |
| if ((err = sprng_start(&st)) != CRYPT_OK) return err; |
| if ((err = sprng_add_entropy(en, sizeof(en), &st)) != CRYPT_OK) return err; |
| if ((err = sprng_ready(&st)) != CRYPT_OK) return err; |
| if (sprng_read(out, 500, &st) != 500) return CRYPT_ERROR_READPRNG; /* skip 500 bytes */ |
| if ((err = sprng_done(&st)) != CRYPT_OK) return err; |
| |
| return CRYPT_OK; |
| #endif |
| } |
| |
| #endif |
| |
| |
| |
| |
| /* ref: $Format:%D$ */ |
| /* git commit: $Format:%H$ */ |
| /* commit time: $Format:%ai$ */ |