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 /* #define DEBUG_GNUTLS */
  36
  37 /*
  38  * If GNUTLS is built against GCrypt then
  39  *
  40  *  - When GNUTLS >= 2.12, we must not initialize gcrypt threading
  41  *    because GNUTLS will do that itself
  42  *  - When GNUTLS < 2.12 we must always initialize gcrypt threading
  43  *  - When GNUTLS is disabled we must always initialize gcrypt threading
  44  *
  45  * But....
  46  *
  47  *    When gcrypt >= 1.6.0 we must not initialize gcrypt threading
  48  *    because gcrypt will do that itself.
  49  *
  50  * So we need to init gcrypt threading if
  51  *
  52  *   - gcrypt < 1.6.0
  53  * AND
  54  *      - gnutls < 2.12
  55  *   OR
  56  *      - gnutls is disabled
  57  *
  58  */
  59
  60 #if (defined(CONFIG_GCRYPT) &&                  \
  61      (!defined(CONFIG_GNUTLS) ||                \
  62      (LIBGNUTLS_VERSION_NUMBER < 0x020c00)) &&    \
  63      (!defined(GCRYPT_VERSION_NUMBER) ||        \
  64       (GCRYPT_VERSION_NUMBER < 0x010600)))
  65 #define QCRYPTO_INIT_GCRYPT_THREADS
  66 #else
  67 #undef QCRYPTO_INIT_GCRYPT_THREADS
  68 #endif
  69
  70 #ifdef DEBUG_GNUTLS
  71 static void qcrypto_gnutls_log(int level, const char *str)
  72 {
  73     fprintf(stderr, "%d: %s", level, str);
  74 }
  75 #endif
  76
  77 #ifdef QCRYPTO_INIT_GCRYPT_THREADS
  78 static int qcrypto_gcrypt_mutex_init(void **priv)
  79 {                                                                             \
  80     QemuMutex *lock = NULL;
  81     lock = g_new0(QemuMutex, 1);
  82     qemu_mutex_init(lock);
  83     *priv = lock;
  84     return 0;
  85 }
  86
  87 static int qcrypto_gcrypt_mutex_destroy(void **priv)
  88 {
  89     QemuMutex *lock = *priv;
  90     qemu_mutex_destroy(lock);
  91     g_free(lock);
  92     return 0;
  93 }
  94
  95 static int qcrypto_gcrypt_mutex_lock(void **priv)
  96 {
  97     QemuMutex *lock = *priv;
  98     qemu_mutex_lock(lock);
  99     return 0;
 100 }
 101
 102 static int qcrypto_gcrypt_mutex_unlock(void **priv)
 103 {
 104     QemuMutex *lock = *priv;
 105     qemu_mutex_unlock(lock);
 106     return 0;
 107 }
 108
 109 static struct gcry_thread_cbs qcrypto_gcrypt_thread_impl = {
 110     (GCRY_THREAD_OPTION_PTHREAD | (GCRY_THREAD_OPTION_VERSION << 8)),
 111     NULL,
 112     qcrypto_gcrypt_mutex_init,
 113     qcrypto_gcrypt_mutex_destroy,
 114     qcrypto_gcrypt_mutex_lock,
 115     qcrypto_gcrypt_mutex_unlock,
 116     NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
 117 };
 118 #endif /* QCRYPTO_INIT_GCRYPT */
 119
 120 int qcrypto_init(Error **errp)
 121 {
 122 #ifdef CONFIG_GNUTLS
 123     int ret;
 124     ret = gnutls_global_init();
 125     if (ret < 0) {
 126         error_setg(errp,
 127                    "Unable to initialize GNUTLS library: %s",
 128                    gnutls_strerror(ret));
 129         return -1;
 130     }
 131 #ifdef DEBUG_GNUTLS
 132     gnutls_global_set_log_level(10);
 133     gnutls_global_set_log_function(qcrypto_gnutls_log);
 134 #endif
 135 #endif
 136
 137 #ifdef CONFIG_GCRYPT
 138     if (!gcry_check_version(GCRYPT_VERSION)) {
 139         error_setg(errp, "Unable to initialize gcrypt");
 140         return -1;
 141     }
 142 #ifdef QCRYPTO_INIT_GCRYPT_THREADS
 143     gcry_control(GCRYCTL_SET_THREAD_CBS, &qcrypto_gcrypt_thread_impl);
 144 #endif /* QCRYPTO_INIT_GCRYPT_THREADS */
 145     gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
 146 #endif
 147
 148     return 0;
 149 }