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git.proxmox.com Git - mirror_ovs.git/blob - lib/entropy.c
1 /* Copyright (c) 2008, 2009, 2010, 2011, 2013 Nicira, Inc.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
27 #include "socket-util.h"
28 #include "openvswitch/vlog.h"
30 VLOG_DEFINE_THIS_MODULE(entropy
);
32 static const char urandom
[] = "/dev/urandom";
34 /* Initializes 'buffer' with 'n' bytes of high-quality random numbers. Returns
35 * 0 if successful, otherwise a positive errno value or EOF on error. */
37 get_entropy(void *buffer
, size_t n
)
44 fd
= open(urandom
, O_RDONLY
);
46 VLOG_ERR("%s: open failed (%s)", urandom
, ovs_strerror(errno
));
47 return errno
? errno
: EINVAL
;
50 error
= read_fully(fd
, buffer
, n
, &bytes_read
);
54 VLOG_ERR("%s: read error (%s)", urandom
, ovs_retval_to_string(error
));
58 HCRYPTPROV crypt_prov
= 0;
60 CryptAcquireContext(&crypt_prov
, NULL
, NULL
,
61 PROV_RSA_FULL
, CRYPT_VERIFYCONTEXT
);
62 if (!CryptGenRandom(crypt_prov
, n
, buffer
)) {
63 VLOG_ERR("CryptGenRandom: read error (%s)", ovs_lasterror_to_string());
67 CryptReleaseContext(crypt_prov
, 0);
72 /* Initializes 'buffer' with 'n' bytes of high-quality random numbers. Exits
73 * if an error occurs. */
75 get_entropy_or_die(void *buffer
, size_t n
)
77 int error
= get_entropy(buffer
, n
);
79 VLOG_FATAL("%s: read error (%s)",
80 urandom
, ovs_retval_to_string(error
));