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 "crypto/init.h"
  22 #include "qemu/thread.h"
  23
  24 #ifdef CONFIG_GNUTLS
  25 #include <gnutls/gnutls.h>
  26 #include <gnutls/crypto.h>
  27 #endif
  28
  29 #ifdef CONFIG_GCRYPT
  30 #include <gcrypt.h>
  31 #endif
  32
  33 /* #define DEBUG_GNUTLS */
  34
  35 /*
  36  * If GNUTLS is built against GCrypt then
  37  *
  38  *  - When GNUTLS >= 2.12, we must not initialize gcrypt threading
  39  *    because GNUTLS will do that itself
  40  *  - When GNUTLS < 2.12 we must always initialize gcrypt threading
  41  *  - When GNUTLS is disabled we must always initialize gcrypt threading
  42  *
  43  * But....
  44  *
  45  *    When gcrypt >= 1.6.0 we must not initialize gcrypt threading
  46  *    because gcrypt will do that itself.
  47  *
  48  * So we need to init gcrypt threading if
  49  *
  50  *   - gcrypt < 1.6.0
  51  * AND
  52  *      - gnutls < 2.12
  53  *   OR
  54  *      - gnutls is disabled
  55  *
  56  */
  57
  58 #if (defined(CONFIG_GCRYPT) &&                  \
  59      (!defined(CONFIG_GNUTLS) ||                \
  60       !defined(GNUTLS_VERSION_NUMBER) ||       \
  61       (GNUTLS_VERSION_NUMBER < 0x020c00)) &&    \
  62      (!defined(GCRYPT_VERSION_NUMBER) ||        \
  63       (GCRYPT_VERSION_NUMBER < 0x010600)))
  64 #define QCRYPTO_INIT_GCRYPT_THREADS
  65 #else
  66 #undef QCRYPTO_INIT_GCRYPT_THREADS
  67 #endif
  68
  69 #ifdef DEBUG_GNUTLS
  70 static void qcrypto_gnutls_log(int level, const char *str)
  71 {
  72     fprintf(stderr, "%d: %s", level, str);
  73 }
  74 #endif
  75
  76 #ifdef QCRYPTO_INIT_GCRYPT_THREADS
  77 static int qcrypto_gcrypt_mutex_init(void **priv)
  78 {                                                                             \
  79     QemuMutex *lock = NULL;
  80     lock = g_new0(QemuMutex, 1);
  81     qemu_mutex_init(lock);
  82     *priv = lock;
  83     return 0;
  84 }
  85
  86 static int qcrypto_gcrypt_mutex_destroy(void **priv)
  87 {
  88     QemuMutex *lock = *priv;
  89     qemu_mutex_destroy(lock);
  90     g_free(lock);
  91     return 0;
  92 }
  93
  94 static int qcrypto_gcrypt_mutex_lock(void **priv)
  95 {
  96     QemuMutex *lock = *priv;
  97     qemu_mutex_lock(lock);
  98     return 0;
  99 }
 100
 101 static int qcrypto_gcrypt_mutex_unlock(void **priv)
 102 {
 103     QemuMutex *lock = *priv;
 104     qemu_mutex_unlock(lock);
 105     return 0;
 106 }
 107
 108 static struct gcry_thread_cbs qcrypto_gcrypt_thread_impl = {
 109     (GCRY_THREAD_OPTION_PTHREAD | (GCRY_THREAD_OPTION_VERSION << 8)),
 110     NULL,
 111     qcrypto_gcrypt_mutex_init,
 112     qcrypto_gcrypt_mutex_destroy,
 113     qcrypto_gcrypt_mutex_lock,
 114     qcrypto_gcrypt_mutex_unlock,
 115     NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
 116 };
 117 #endif /* QCRYPTO_INIT_GCRYPT */
 118
 119 int qcrypto_init(Error **errp)
 120 {
 121 #ifdef CONFIG_GNUTLS
 122     int ret;
 123     ret = gnutls_global_init();
 124     if (ret < 0) {
 125         error_setg(errp,
 126                    "Unable to initialize GNUTLS library: %s",
 127                    gnutls_strerror(ret));
 128         return -1;
 129     }
 130 #ifdef DEBUG_GNUTLS
 131     gnutls_global_set_log_level(10);
 132     gnutls_global_set_log_function(qcrypto_gnutls_log);
 133 #endif
 134 #endif
 135
 136 #ifdef CONFIG_GCRYPT
 137     if (!gcry_check_version(GCRYPT_VERSION)) {
 138         error_setg(errp, "Unable to initialize gcrypt");
 139         return -1;
 140     }
 141 #ifdef QCRYPTO_INIT_GCRYPT_THREADS
 142     gcry_control(GCRYCTL_SET_THREAD_CBS, &qcrypto_gcrypt_thread_impl);
 143 #endif /* QCRYPTO_INIT_GCRYPT_THREADS */
 144     gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
 145 #endif
 146
 147     return 0;
 148 }