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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-05 17:47:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-05 17:47:29 +0000 |
commit | 4f5791ebd03eaec1c7da0865a383175b05102712 (patch) | |
tree | 8ce7b00f7a76baa386372422adebbe64510812d4 /third_party/heimdal/lib/krb5/crypto-rand.c | |
parent | Initial commit. (diff) | |
download | samba-4f5791ebd03eaec1c7da0865a383175b05102712.tar.xz samba-4f5791ebd03eaec1c7da0865a383175b05102712.zip |
Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/heimdal/lib/krb5/crypto-rand.c')
-rw-r--r-- | third_party/heimdal/lib/krb5/crypto-rand.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/krb5/crypto-rand.c b/third_party/heimdal/lib/krb5/crypto-rand.c new file mode 100644 index 0000000..7b126c6 --- /dev/null +++ b/third_party/heimdal/lib/krb5/crypto-rand.c @@ -0,0 +1,152 @@ +/* + * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "krb5_locl.h" + +#undef HEIMDAL_WARN_UNUSED_RESULT_ATTRIBUTE +#define HEIMDAL_WARN_UNUSED_RESULT_ATTRIBUTE + +#define ENTROPY_NEEDED 128 + +static HEIMDAL_MUTEX crypto_mutex = HEIMDAL_MUTEX_INITIALIZER; + +static int +seed_something(void) +{ +#ifndef NO_RANDFILE + char buf[1024], seedfile[256]; + + /* If there is a seed file, load it. But such a file cannot be trusted, + so use 0 for the entropy estimate */ + if (RAND_file_name(seedfile, sizeof(seedfile))) { + int fd; + fd = open(seedfile, O_RDONLY | O_BINARY | O_CLOEXEC); + if (fd >= 0) { + ssize_t ret; + rk_cloexec(fd); + ret = read(fd, buf, sizeof(buf)); + if (ret > 0) + RAND_add(buf, ret, 0.0); + close(fd); + } else + seedfile[0] = '\0'; + } else + seedfile[0] = '\0'; +#endif + + /* Calling RAND_status() will try to use /dev/urandom if it exists so + we do not have to deal with it. */ + if (RAND_status() != 1) { + /* TODO: Once a Windows CryptoAPI RAND method is defined, we + can use that and failover to another method. */ + } + + if (RAND_status() == 1) { +#ifndef NO_RANDFILE + /* Update the seed file */ + if (seedfile[0]) + RAND_write_file(seedfile); +#endif + + return 0; + } else + return -1; +} + +/** + * Fill buffer buf with len bytes of PRNG randomness that is ok to use + * for key generation, padding and public diclosing the randomness w/o + * disclosing the randomness source. + * + * This function can fail, and callers must check the return value. + * + * @param buf a buffer to fill with randomness + * @param len length of memory that buf points to. + * + * @return return 0 on success or HEIM_ERR_RANDOM_OFFLINE if the + * funcation failed to initialize the randomness source. + * + * @ingroup krb5_crypto + */ + +HEIMDAL_WARN_UNUSED_RESULT_ATTRIBUTE +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_generate_random(void *buf, size_t len) +{ + static int rng_initialized = 0; + int ret; + + HEIMDAL_MUTEX_lock(&crypto_mutex); + if (!rng_initialized) { + if (seed_something()) { + HEIMDAL_MUTEX_unlock(&crypto_mutex); + return HEIM_ERR_RANDOM_OFFLINE; + } + rng_initialized = 1; + } + if (RAND_bytes(buf, len) <= 0) + ret = HEIM_ERR_RANDOM_OFFLINE; + else + ret = 0; + HEIMDAL_MUTEX_unlock(&crypto_mutex); + + return ret; +} + +/** + * Fill buffer buf with len bytes of PRNG randomness that is ok to use + * for key generation, padding and public diclosing the randomness w/o + * disclosing the randomness source. + * + * This function can NOT fail, instead it will abort() and program will crash. + * + * If this function is called after a successful krb5_init_context(), + * the chance of it failing is low due to that krb5_init_context() + * pulls out some random, and quite commonly the randomness sources + * will not fail once it have started to produce good output, + * /dev/urandom behavies that way. + * + * @param buf a buffer to fill with randomness + * @param len length of memory that buf points to. + * + * @ingroup krb5_crypto + */ + + +KRB5_LIB_FUNCTION void KRB5_LIB_CALL +krb5_generate_random_block(void *buf, size_t len) +{ + int ret = krb5_generate_random(buf, len); + if (ret) + krb5_abortx(NULL, "Failed to generate random block"); +} |