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author | Andrew Bartlett <abartlet@samba.org> | 2010-11-12 15:27:43 +1100 |
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committer | Andrew Bartlett <abartlet@samba.org> | 2010-11-15 01:25:06 +0000 |
commit | 6a27fbbfc4c51ae1635b8a5fa51c470ebc9f01e2 (patch) | |
tree | 67429e7173cb2e524bcb340e233008b33241dc77 /source4/heimdal/lib/krb5/crypto-rand.c | |
parent | 192a555c9ab425fa8e18ee5bed84a8c2fd527200 (diff) | |
download | samba-6a27fbbfc4c51ae1635b8a5fa51c470ebc9f01e2.tar.gz samba-6a27fbbfc4c51ae1635b8a5fa51c470ebc9f01e2.tar.bz2 samba-6a27fbbfc4c51ae1635b8a5fa51c470ebc9f01e2.zip |
heimdal Extra files required for merge up to current heimdal
Diffstat (limited to 'source4/heimdal/lib/krb5/crypto-rand.c')
-rw-r--r-- | source4/heimdal/lib/krb5/crypto-rand.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/source4/heimdal/lib/krb5/crypto-rand.c b/source4/heimdal/lib/krb5/crypto-rand.c new file mode 100644 index 0000000000..49bd679362 --- /dev/null +++ b/source4/heimdal/lib/krb5/crypto-rand.c @@ -0,0 +1,109 @@ +/* + * 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" + +#define ENTROPY_NEEDED 128 + +static HEIMDAL_MUTEX crypto_mutex = HEIMDAL_MUTEX_INITIALIZER; + +static int +seed_something(void) +{ + 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'; + + /* 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) { +#ifndef _WIN32 + krb5_context context; + const char *p; + + /* Try using egd */ + if (!krb5_init_context(&context)) { + p = krb5_config_get_string(context, NULL, "libdefaults", + "egd_socket", NULL); + if (p != NULL) + RAND_egd_bytes(p, ENTROPY_NEEDED); + krb5_free_context(context); + } +#else + /* TODO: Once a Windows CryptoAPI RAND method is defined, we + can use that and failover to another method. */ +#endif + } + + if (RAND_status() == 1) { + /* Update the seed file */ + if (seedfile[0]) + RAND_write_file(seedfile); + + return 0; + } else + return -1; +} + +KRB5_LIB_FUNCTION void KRB5_LIB_CALL +krb5_generate_random_block(void *buf, size_t len) +{ + static int rng_initialized = 0; + + HEIMDAL_MUTEX_lock(&crypto_mutex); + if (!rng_initialized) { + if (seed_something()) + krb5_abortx(NULL, "Fatal: could not seed the " + "random number generator"); + + rng_initialized = 1; + } + HEIMDAL_MUTEX_unlock(&crypto_mutex); + if (RAND_bytes(buf, len) <= 0) + krb5_abortx(NULL, "Failed to generate random block"); +} |