GnuTLS support added. There's now a "generic" SSL layer that we use all over

internally, with code provided by sslgen.c. All SSL-layer-specific code is
then written in ssluse.c (for OpenSSL) and gtls.c (for GnuTLS).

As far as possible, internals should not need to know what SSL layer that is
in use. Building with GnuTLS currently makes two test cases fail.

TODO.gnutls contains a few known outstanding issues for the GnuTLS support.

GnuTLS support is enabled with configure --with-gnutls

1 files changed, 464 insertions, 0 deletions

diff --git a/lib/gtls.c b/lib/gtls.c
new file mode 100644
index 000000000..f3ab78c3c
--- /dev/null
+++ b/lib/gtls.c
@@ -0,0 +1,464 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2005, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * $Id$
+ ***************************************************************************/
+
+/*
+ * Source file for all GnuTLS-specific code for the TLS/SSL layer. No code
+ * but sslgen.c should ever call or use these functions.
+ *
+ * Note: don't use the GnuTLS' *_t variable type names in this source code,
+ * since they were not present in 1.0.X.
+ */
+
+#include "setup.h"
+#ifdef USE_GNUTLS
+#include <gnutls/gnutls.h>
+#include <gnutls/x509.h>
+
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+
+#include "urldata.h"
+#include "sendf.h"
+#include "gtls.h"
+#include "sslgen.h"
+#include "parsedate.h"
+#include "connect.h" /* for the connect timeout */
+#include "select.h"
+#define _MPRINTF_REPLACE /* use our functions only */
+#include <curl/mprintf.h>
+#include "memory.h"
+/* The last #include file should be: */
+#include "memdebug.h"
+
+/* Global GnuTLS init, called from Curl_ssl_init() */
+int Curl_gtls_init(void)
+{
+  gnutls_global_init();
+  return 1;
+}
+
+int Curl_gtls_cleanup(void)
+{
+  gnutls_global_deinit();
+  return 1;
+}
+
+static void showtime(struct SessionHandle *data,
+                     const char *text,
+                     time_t stamp)
+{
+  struct tm *tm;
+#ifdef HAVE_GMTIME_R
+  struct tm buffer;
+  tm = (struct tm *)gmtime_r(&stamp, &buffer);
+#else
+  tm = gmtime(&stamp);
+#endif
+  snprintf(data->state.buffer,
+           BUFSIZE,
+           "\t %s: %s, %02d %s %4d %02d:%02d:%02d GMT\n",
+           text,
+           Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
+           tm->tm_mday,
+           Curl_month[tm->tm_mon],
+           tm->tm_year + 1900,
+           tm->tm_hour,
+           tm->tm_min,
+           tm->tm_sec);
+  infof(data, "%s", data->state.buffer);
+}
+
+
+/*
+ * This function is called after the TCP connect has completed. Setup the TLS
+ * layer and do all necessary magic.
+ */
+CURLcode
+Curl_gtls_connect(struct connectdata *conn,
+                  int sockindex)
+
+{
+  const int cert_type_priority[3] = { GNUTLS_CRT_X509, 0 };
+  struct SessionHandle *data = conn->data;
+  gnutls_session session;
+  int rc;
+  unsigned int cert_list_size;
+  const gnutls_datum *chainp;
+  unsigned int verify_status;
+  gnutls_x509_crt x509_cert;
+  char certbuf[256]; /* big enough? */
+  size_t size;
+  unsigned int algo;
+  unsigned int bits;
+  time_t clock;
+  const char *ptr;
+  void *ssl_sessionid;
+  size_t ssl_idsize;
+
+  /* GnuTLS only supports TLSv1 (and SSLv3?) */
+  if(data->set.ssl.version == CURL_SSLVERSION_SSLv2) {
+    failf(data, "GnuTLS does not support SSLv2");
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+  /* allocate a cred struct */
+  rc = gnutls_certificate_allocate_credentials(&conn->ssl[sockindex].cred);
+  if(rc < 0) {
+    failf(data, "gnutls_cert_all_cred() failed: %d", rc);
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+  /* set the trusted CA cert bundle file */
+  rc = gnutls_certificate_set_x509_trust_file(conn->ssl[sockindex].cred,
+                                              data->set.ssl.CAfile,
+                                              GNUTLS_X509_FMT_PEM);
+
+  /* Initialize TLS session as a client */
+  rc = gnutls_init(&conn->ssl[sockindex].session, GNUTLS_CLIENT);
+  if(rc) {
+    failf(data, "gnutls_init() failed: %d", rc);
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+  /* convenient assign */
+  session = conn->ssl[sockindex].session;
+
+  /* Use default priorities */
+  rc = gnutls_set_default_priority(session);
+  if(rc < 0)
+    return CURLE_SSL_CONNECT_ERROR;
+
+  /* Sets the priority on the certificate types supported by gnutls. Priority
+     is higher for types specified before others. After specifying the types
+     you want, you must append a 0. */
+  rc = gnutls_certificate_type_set_priority(session, cert_type_priority);
+  if(rc < 0)
+    return CURLE_SSL_CONNECT_ERROR;
+
+  /* put the anonymous credentials to the current session */
+  rc = gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE,
+                              conn->ssl[sockindex].cred);
+
+  /* set the connection handle (file descriptor for the socket) */
+  gnutls_transport_set_ptr(session,
+                           (gnutls_transport_ptr)conn->sock[sockindex]);
+
+  /* This might be a reconnect, so we check for a session ID in the cache
+     to speed up things */
+
+  if(!Curl_ssl_getsessionid(conn, &ssl_sessionid, &ssl_idsize)) {
+    /* we got a session id, use it! */
+    gnutls_session_set_data(session, ssl_sessionid, ssl_idsize);
+
+    /* Informational message */
+    infof (data, "SSL re-using session ID\n");
+  }
+
+  do {
+    rc = gnutls_handshake(session);
+
+    if((rc == GNUTLS_E_AGAIN) || (rc == GNUTLS_E_INTERRUPTED)) {
+      long timeout_ms;
+      long has_passed;
+
+      if(data->set.timeout || data->set.connecttimeout) {
+        /* get the most strict timeout of the ones converted to milliseconds */
+        if(data->set.timeout &&
+           (data->set.timeout>data->set.connecttimeout))
+          timeout_ms = data->set.timeout*1000;
+        else
+          timeout_ms = data->set.connecttimeout*1000;
+      }
+      else
+        timeout_ms = DEFAULT_CONNECT_TIMEOUT;
+
+      /* Evaluate in milliseconds how much time that has passed */
+      has_passed = Curl_tvdiff(Curl_tvnow(), data->progress.t_startsingle);
+
+      /* subtract the passed time */
+      timeout_ms -= has_passed;
+
+      if(timeout_ms < 0) {
+        /* a precaution, no need to continue if time already is up */
+        failf(data, "SSL connection timeout");
+        return CURLE_OPERATION_TIMEOUTED;
+      }
+
+      rc = Curl_select(conn->sock[sockindex],
+                         conn->sock[sockindex], (int)timeout_ms);
+      if(rc > 0)
+        /* reabable or writable, go loop*/
+        continue;
+      else if(0 == rc) {
+        /* timeout */
+        failf(data, "SSL connection timeout");
+        return CURLE_OPERATION_TIMEDOUT;
+      }
+      else {
+        /* anything that gets here is fatally bad */
+        failf(data, "select on SSL socket, errno: %d", Curl_ourerrno());
+        return CURLE_SSL_CONNECT_ERROR;
+      }
+    }
+    else
+      break;
+  } while(1);
+
+  if (rc < 0) {
+    failf(data, "gnutls_handshake() failed: %d", rc);
+    /* gnutls_perror(ret); */
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+  /* This function will return the peer's raw certificate (chain) as sent by
+     the peer. These certificates are in raw format (DER encoded for
+     X.509). In case of a X.509 then a certificate list may be present. The
+     first certificate in the list is the peer's certificate, following the
+     issuer's certificate, then the issuer's issuer etc. */
+
+  chainp = gnutls_certificate_get_peers(session, &cert_list_size);
+  if(!chainp) {
+    if(data->set.ssl.verifyhost) {
+      failf(data, "failed to get server cert");
+      return CURLE_SSL_PEER_CERTIFICATE;
+    }
+    infof(data, "\t common name: WARNING couldn't obtain\n");
+  }
+
+  /* This function will try to verify the peer's certificate and return its
+     status (trusted, invalid etc.). The value of status should be one or more
+     of the gnutls_certificate_status_t enumerated elements bitwise or'd. To
+     avoid denial of service attacks some default upper limits regarding the
+     certificate key size and chain size are set. To override them use
+     gnutls_certificate_set_verify_limits(). */
+
+  rc = gnutls_certificate_verify_peers2(session, &verify_status);
+  if (rc < 0) {
+    failf(data, "server cert verify failed: %d", rc);
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+  /* verify_status is a bitmask of gnutls_certificate_status bits */
+  if(verify_status & GNUTLS_CERT_INVALID) {
+    if (data->set.ssl.verifypeer) {
+      failf(data, "server certificate verification failed. CAfile: %s",
+            data->set.ssl.CAfile?data->set.ssl.CAfile:"none");
+      return CURLE_SSL_CACERT;
+    }
+    else
+      infof(data, "\t server certificate verification FAILED\n");
+  }
+  else
+      infof(data, "\t server certificate verification OK\n");
+
+  /* initialize an X.509 certificate structure. */
+  gnutls_x509_crt_init(&x509_cert);
+
+  /* convert the given DER or PEM encoded Certificate to the native
+     gnutls_x509_crt_t format */
+  gnutls_x509_crt_import(x509_cert, chainp, GNUTLS_X509_FMT_DER);
+
+  size=sizeof(certbuf);
+  rc = gnutls_x509_crt_get_dn_by_oid(x509_cert, GNUTLS_OID_X520_COMMON_NAME,
+                                     0, /* the first and only one */
+                                     TRUE, /* give to me raw please */
+                                     certbuf,
+                                     &size);
+
+  /* This function will check if the given certificate's subject matches the
+     given hostname. This is a basic implementation of the matching described
+     in RFC2818 (HTTPS), which takes into account wildcards, and the subject
+     alternative name PKIX extension. Returns non zero on success, and zero on
+     failure. */
+  rc = gnutls_x509_crt_check_hostname(x509_cert, conn->host.name);
+
+  if(!rc) {
+    if (data->set.ssl.verifyhost > 1) {
+      failf(data, "SSL: certificate subject name (%s) does not match "
+            "target host name '%s'", certbuf, conn->host.dispname);
+      gnutls_x509_crt_deinit(x509_cert);
+      return CURLE_SSL_PEER_CERTIFICATE;
+    }
+    else
+      infof(data, "\t common name: %s (does not match '%s')\n",
+            certbuf, conn->host.dispname);
+  }
+  else
+    infof(data, "\t common name: %s (matched)\n", certbuf);
+
+  /* Show:
+
+  - ciphers used
+  - subject
+  - start date
+  - expire date
+  - common name
+  - issuer
+
+  */
+
+  /* public key algorithm's parameters */
+  algo = gnutls_x509_crt_get_pk_algorithm(x509_cert, &bits);
+  infof(data, "\t certificate public key: %s\n",
+        gnutls_pk_algorithm_get_name(algo));
+
+  /* version of the X.509 certificate. */
+  infof(data, "\t certificate version: #%d\n",
+        gnutls_x509_crt_get_version(x509_cert));
+
+
+  size = sizeof(certbuf);
+  gnutls_x509_crt_get_dn(x509_cert, certbuf, &size);
+  infof(data, "\t subject: %s\n", certbuf);
+
+  clock = gnutls_x509_crt_get_activation_time(x509_cert);
+  showtime(data, "start date", clock);
+
+  clock = gnutls_x509_crt_get_expiration_time(x509_cert);
+  showtime(data, "expire date", clock);
+
+  size = sizeof(certbuf);
+  gnutls_x509_crt_get_issuer_dn(x509_cert, certbuf, &size);
+  infof(data, "\t issuer: %s\n", certbuf);
+
+  gnutls_x509_crt_deinit(x509_cert);
+
+  /* compression algorithm (if any) */
+  ptr = gnutls_compression_get_name(gnutls_compression_get(session));
+  /* the *_get_name() says "NULL" if GNUTLS_COMP_NULL is returned */
+  infof(data, "\t compression: %s\n", ptr);
+
+  /* the name of the cipher used. ie 3DES. */
+  ptr = gnutls_cipher_get_name(gnutls_cipher_get(session));
+  infof(data, "\t cipher: %s\n", ptr);
+
+  /* the MAC algorithms name. ie SHA1 */
+  ptr = gnutls_mac_get_name(gnutls_mac_get(session));
+  infof(data, "\t MAC: %s\n", ptr);
+
+  if(!ssl_sessionid) {
+    /* this session was not previously in the cache, add it now */
+
+    /* get the session ID data size */
+    gnutls_session_get_data(session, NULL, &ssl_idsize);
+    ssl_sessionid = malloc(ssl_idsize); /* get a buffer for it */
+
+    if(ssl_sessionid) {
+      /* extract session ID to the allocated buffer */
+      gnutls_session_get_data(session, ssl_sessionid, &ssl_idsize);
+
+      /* store this session id */
+      return Curl_ssl_addsessionid(conn, ssl_sessionid, ssl_idsize);
+    }
+  }
+
+  return CURLE_OK;
+}
+
+
+/* return number of sent (non-SSL) bytes */
+int Curl_gtls_send(struct connectdata *conn,
+                   int sockindex,
+                   void *mem,
+                   size_t len)
+{
+  int rc;
+  rc = gnutls_record_send(conn->ssl[sockindex].session, mem, len);
+
+  return rc;
+}
+
+void Curl_gtls_close_all(struct SessionHandle *data)
+{
+  /* FIX: make the OpenSSL code more generic and use parts of it here */
+  (void)data;
+}
+
+static void close_one(struct connectdata *conn,
+                      int index)
+{
+  gnutls_bye(conn->ssl[index].session, GNUTLS_SHUT_RDWR);
+  gnutls_deinit(conn->ssl[index].session);
+  gnutls_certificate_free_credentials(conn->ssl[index].cred);
+}
+
+void Curl_gtls_close(struct connectdata *conn)
+{
+  if(conn->ssl[0].use)
+    close_one(conn, 0);
+  if(conn->ssl[1].use)
+    close_one(conn, 1);
+}
+
+/*
+ * If the read would block we return -1 and set 'wouldblock' to TRUE.
+ * Otherwise we return the amount of data read. Other errors should return -1
+ * and set 'wouldblock' to FALSE.
+ */
+ssize_t Curl_gtls_recv(struct connectdata *conn, /* connection data */
+                       int num,                  /* socketindex */
+                       char *buf,                /* store read data here */
+                       size_t buffersize,        /* max amount to read */
+                       bool *wouldblock)
+{
+  ssize_t ret;
+
+  ret = gnutls_record_recv(conn->ssl[num].session, buf, buffersize);
+  if((ret == GNUTLS_E_AGAIN) || (ret == GNUTLS_E_INTERRUPTED)) {
+    *wouldblock = TRUE;
+    return -1;
+  }
+
+  *wouldblock = FALSE;
+  if (!ret) {
+    failf(conn->data, "Peer closed the TLS connection");
+    return -1;
+  }
+
+  if (ret < 0) {
+    failf(conn->data, "GnuTLS recv error (%d): %s",
+          (int)ret, gnutls_strerror(ret));
+    return -1;
+  }
+
+  return ret;
+}
+
+void Curl_gtls_session_free(void *ptr)
+{
+  free(ptr);
+}
+
+size_t Curl_gtls_version(char *buffer, size_t size)
+{
+  return snprintf(buffer, size, " GnuTLS/%s", gnutls_check_version(NULL));
+}
+
+#endif /* USE_GNUTLS */