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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 17:20:00 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 17:20:00 +0000
commit8daa83a594a2e98f39d764422bfbdbc62c9efd44 (patch)
tree4099e8021376c7d8c05bdf8503093d80e9c7bad0 /third_party/heimdal/lib/krb5/crypto-rand.c
parentInitial commit. (diff)
downloadsamba-8daa83a594a2e98f39d764422bfbdbc62c9efd44.tar.xz
samba-8daa83a594a2e98f39d764422bfbdbc62c9efd44.zip
Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg
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.c152
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
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+/*
+ * 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");
+}