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
  28 #ifdef CONFIG_GNUTLS_GCRYPT
  29 #include <gcrypt.h>
  30 #endif
  31
  32 /* #define DEBUG_GNUTLS */
  33
  34 /*
  35  * If GNUTLS is built against GCrypt then
  36  *
  37  *  - When GNUTLS >= 2.12, we must not initialize gcrypt threading
  38  *    because GNUTLS will do that itself
  39  *  - When GNUTLS < 2.12 we must always initialize gcrypt threading
  40  *
  41  * But....
  42  *
  43  *    When gcrypt >= 1.6.0 we must not initialize gcrypt threading
  44  *    because gcrypt will do that itself.
  45  *
  46  * So we need to init gcrypt threading if
  47  *
  48  *   - gcrypt < 1.6.0
  49  * AND
  50  *   - gnutls < 2.12
  51  *
  52  */
  53
  54 #if (defined(CONFIG_GNUTLS_GCRYPT) &&           \
  55      (!defined(GNUTLS_VERSION_NUMBER) ||        \
  56       (GNUTLS_VERSION_NUMBER < 0x020c00)) &&    \
  57      (!defined(GCRYPT_VERSION_NUMBER) ||        \
  58       (GCRYPT_VERSION_NUMBER < 0x010600)))
  59 #define QCRYPTO_INIT_GCRYPT_THREADS
  60 #else
  61 #undef QCRYPTO_INIT_GCRYPT_THREADS
  62 #endif
  63
  64 #ifdef DEBUG_GNUTLS
  65 static void qcrypto_gnutls_log(int level, const char *str)
  66 {
  67     fprintf(stderr, "%d: %s", level, str);
  68 }
  69 #endif
  70
  71 #ifdef QCRYPTO_INIT_GCRYPT_THREADS
  72 static int qcrypto_gcrypt_mutex_init(void **priv)
  73 {                                                                             \
  74     QemuMutex *lock = NULL;
  75     lock = g_new0(QemuMutex, 1);
  76     qemu_mutex_init(lock);
  77     *priv = lock;
  78     return 0;
  79 }
  80
  81 static int qcrypto_gcrypt_mutex_destroy(void **priv)
  82 {
  83     QemuMutex *lock = *priv;
  84     qemu_mutex_destroy(lock);
  85     g_free(lock);
  86     return 0;
  87 }
  88
  89 static int qcrypto_gcrypt_mutex_lock(void **priv)
  90 {
  91     QemuMutex *lock = *priv;
  92     qemu_mutex_lock(lock);
  93     return 0;
  94 }
  95
  96 static int qcrypto_gcrypt_mutex_unlock(void **priv)
  97 {
  98     QemuMutex *lock = *priv;
  99     qemu_mutex_unlock(lock);
 100     return 0;
 101 }
 102
 103 static struct gcry_thread_cbs qcrypto_gcrypt_thread_impl = {
 104     (GCRY_THREAD_OPTION_PTHREAD | (GCRY_THREAD_OPTION_VERSION << 8)),
 105     NULL,
 106     qcrypto_gcrypt_mutex_init,
 107     qcrypto_gcrypt_mutex_destroy,
 108     qcrypto_gcrypt_mutex_lock,
 109     qcrypto_gcrypt_mutex_unlock,
 110     NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
 111 };
 112 #endif /* QCRYPTO_INIT_GCRYPT */
 113
 114 int qcrypto_init(Error **errp)
 115 {
 116     int ret;
 117     ret = gnutls_global_init();
 118     if (ret < 0) {
 119         error_setg(errp,
 120                    "Unable to initialize GNUTLS library: %s",
 121                    gnutls_strerror(ret));
 122         return -1;
 123     }
 124 #ifdef DEBUG_GNUTLS
 125     gnutls_global_set_log_level(10);
 126     gnutls_global_set_log_function(qcrypto_gnutls_log);
 127 #endif
 128
 129 #ifdef CONFIG_GNUTLS_GCRYPT
 130     if (!gcry_check_version(GCRYPT_VERSION)) {
 131         error_setg(errp, "Unable to initialize gcrypt");
 132         return -1;
 133     }
 134 #ifdef QCRYPTO_INIT_GCRYPT_THREADS
 135     gcry_control(GCRYCTL_SET_THREAD_CBS, &qcrypto_gcrypt_thread_impl);
 136 #endif /* QCRYPTO_INIT_GCRYPT_THREADS */
 137     gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
 138 #endif
 139
 140     return 0;
 141 }
 142
 143 #else /* ! CONFIG_GNUTLS */
 144
 145 int qcrypto_init(Error **errp G_GNUC_UNUSED)
 146 {
 147     return 0;
 148 }
 149
 150 #endif /* ! CONFIG_GNUTLS */