crypto/init.c

   1 /*
   2  * QEMU Crypto initialization
   3  *
   4  * Copyright (c) 2015 Red Hat, Inc.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include "qemu/osdep.h"
  22 #include "crypto/init.h"
  23 #include "qapi/error.h"
  24 #include "qemu/thread.h"
  25
  26 #ifdef CONFIG_GNUTLS
  27 #include <gnutls/gnutls.h>
  28 #include <gnutls/crypto.h>
  29 #endif
  30
  31 #ifdef CONFIG_GCRYPT
  32 #include <gcrypt.h>
  33 #endif
  34
  35 #include "crypto/random.h"
  36
  37 /* #define DEBUG_GNUTLS */
  38
  39 /*
  40  * If GNUTLS is built against GCrypt then
  41  *
  42  *  - When GNUTLS >= 2.12, we must not initialize gcrypt threading
  43  *    because GNUTLS will do that itself
  44  *  - When GNUTLS < 2.12 we must always initialize gcrypt threading
  45  *  - When GNUTLS is disabled we must always initialize gcrypt threading
  46  *
  47  * But....
  48  *
  49  *    When gcrypt >= 1.6.0 we must not initialize gcrypt threading
  50  *    because gcrypt will do that itself.
  51  *
  52  * So we need to init gcrypt threading if
  53  *
  54  *   - gcrypt < 1.6.0
  55  * AND
  56  *      - gnutls < 2.12
  57  *   OR
  58  *      - gnutls is disabled
  59  *
  60  */
  61
  62 #if (defined(CONFIG_GCRYPT) &&                  \
  63      (!defined(CONFIG_GNUTLS) ||                \
  64      (LIBGNUTLS_VERSION_NUMBER < 0x020c00)) &&    \
  65      (!defined(GCRYPT_VERSION_NUMBER) ||        \
  66       (GCRYPT_VERSION_NUMBER < 0x010600)))
  67 #define QCRYPTO_INIT_GCRYPT_THREADS
  68 #else
  69 #undef QCRYPTO_INIT_GCRYPT_THREADS
  70 #endif
  71
  72 #ifdef DEBUG_GNUTLS
  73 static void qcrypto_gnutls_log(int level, const char *str)
  74 {
  75     fprintf(stderr, "%d: %s", level, str);
  76 }
  77 #endif
  78
  79 #ifdef QCRYPTO_INIT_GCRYPT_THREADS
  80 static int qcrypto_gcrypt_mutex_init(void **priv)
  81 {                                                                             \
  82     QemuMutex *lock = NULL;
  83     lock = g_new0(QemuMutex, 1);
  84     qemu_mutex_init(lock);
  85     *priv = lock;
  86     return 0;
  87 }
  88
  89 static int qcrypto_gcrypt_mutex_destroy(void **priv)
  90 {
  91     QemuMutex *lock = *priv;
  92     qemu_mutex_destroy(lock);
  93     g_free(lock);
  94     return 0;
  95 }
  96
  97 static int qcrypto_gcrypt_mutex_lock(void **priv)
  98 {
  99     QemuMutex *lock = *priv;
 100     qemu_mutex_lock(lock);
 101     return 0;
 102 }
 103
 104 static int qcrypto_gcrypt_mutex_unlock(void **priv)
 105 {
 106     QemuMutex *lock = *priv;
 107     qemu_mutex_unlock(lock);
 108     return 0;
 109 }
 110
 111 static struct gcry_thread_cbs qcrypto_gcrypt_thread_impl = {
 112     (GCRY_THREAD_OPTION_PTHREAD | (GCRY_THREAD_OPTION_VERSION << 8)),
 113     NULL,
 114     qcrypto_gcrypt_mutex_init,
 115     qcrypto_gcrypt_mutex_destroy,
 116     qcrypto_gcrypt_mutex_lock,
 117     qcrypto_gcrypt_mutex_unlock,
 118     NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
 119 };
 120 #endif /* QCRYPTO_INIT_GCRYPT */
 121
 122 int qcrypto_init(Error **errp)
 123 {
 124 #ifdef QCRYPTO_INIT_GCRYPT_THREADS
 125     gcry_control(GCRYCTL_SET_THREAD_CBS, &qcrypto_gcrypt_thread_impl);
 126 #endif /* QCRYPTO_INIT_GCRYPT_THREADS */
 127
 128 #ifdef CONFIG_GNUTLS
 129     int ret;
 130     ret = gnutls_global_init();
 131     if (ret < 0) {
 132         error_setg(errp,
 133                    "Unable to initialize GNUTLS library: %s",
 134                    gnutls_strerror(ret));
 135         return -1;
 136     }
 137 #ifdef DEBUG_GNUTLS
 138     gnutls_global_set_log_level(10);
 139     gnutls_global_set_log_function(qcrypto_gnutls_log);
 140 #endif
 141 #endif
 142
 143 #ifdef CONFIG_GCRYPT
 144     if (!gcry_check_version(GCRYPT_VERSION)) {
 145         error_setg(errp, "Unable to initialize gcrypt");
 146         return -1;
 147     }
 148     gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
 149 #endif
 150
 151     if (qcrypto_random_init(errp) < 0) {
 152         return -1;
 153     }
 154
 155     return 0;
 156 }