sslgen.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2008, 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.
 *
 * $Id$
 ***************************************************************************/

/* This file is for "generic" SSL functions that all libcurl internals should
   use. It is responsible for calling the proper 'ossl' function in ssluse.c
   (OpenSSL based) or the 'gtls' function in gtls.c (GnuTLS based).

   SSL-functions in libcurl should call functions in this source file, and not
   to any specific SSL-layer.

   Curl_ssl_ - prefix for generic ones
   Curl_ossl_ - prefix for OpenSSL ones
   Curl_gtls_ - prefix for GnuTLS ones
   Curl_nss_ - prefix for NSS ones

   Note that this source code uses curlssl_* functions, and they are all
   defines/macros #defined by the lib-specific header files.

   "SSL/TLS Strong Encryption: An Introduction"
   http://httpd.apache.org/docs-2.0/ssl/ssl_intro.html
*/

#include "setup.h"

#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif

#include "urldata.h"
#define SSLGEN_C
#include "sslgen.h" /* generic SSL protos etc */
#include "ssluse.h" /* OpenSSL versions */
#include "gtls.h"   /* GnuTLS versions */
#include "nssg.h"   /* NSS versions */
#include "qssl.h"   /* QSOSSL versions */
#include "sendf.h"
#include "strequal.h"
#include "url.h"
#include "memory.h"
#include "progress.h"
/* The last #include file should be: */
#include "memdebug.h"

static bool safe_strequal(char* str1, char* str2);

static bool safe_strequal(char* str1, char* str2)
{
  if(str1 && str2)
    /* both pointers point to something then compare them */
    return (bool)(0 != strequal(str1, str2));
  else
    /* if both pointers are NULL then treat them as equal */
    return (bool)(!str1 && !str2);
}

bool
Curl_ssl_config_matches(struct ssl_config_data* data,
                        struct ssl_config_data* needle)
{
  if((data->version == needle->version) &&
     (data->verifypeer == needle->verifypeer) &&
     (data->verifyhost == needle->verifyhost) &&
     safe_strequal(data->CApath, needle->CApath) &&
     safe_strequal(data->CAfile, needle->CAfile) &&
     safe_strequal(data->random_file, needle->random_file) &&
     safe_strequal(data->egdsocket, needle->egdsocket) &&
     safe_strequal(data->cipher_list, needle->cipher_list))
    return TRUE;

  return FALSE;
}

bool
Curl_clone_ssl_config(struct ssl_config_data *source,
                      struct ssl_config_data *dest)
{
  dest->sessionid = source->sessionid;
  dest->verifyhost = source->verifyhost;
  dest->verifypeer = source->verifypeer;
  dest->version = source->version;

  if(source->CAfile) {
    dest->CAfile = strdup(source->CAfile);
    if(!dest->CAfile)
      return FALSE;
  }

  if(source->CApath) {
    dest->CApath = strdup(source->CApath);
    if(!dest->CApath)
      return FALSE;
  }

  if(source->cipher_list) {
    dest->cipher_list = strdup(source->cipher_list);
    if(!dest->cipher_list)
      return FALSE;
  }

  if(source->egdsocket) {
    dest->egdsocket = strdup(source->egdsocket);
    if(!dest->egdsocket)
      return FALSE;
  }

  if(source->random_file) {
    dest->random_file = strdup(source->random_file);
    if(!dest->random_file)
      return FALSE;
  }

  return TRUE;
}

void Curl_free_ssl_config(struct ssl_config_data* sslc)
{
  Curl_safefree(sslc->CAfile);
  Curl_safefree(sslc->CApath);
  Curl_safefree(sslc->cipher_list);
  Curl_safefree(sslc->egdsocket);
  Curl_safefree(sslc->random_file);
}

#ifdef USE_SSL

/* "global" init done? */
static bool init_ssl=FALSE;

/**
 * Global SSL init
 *
 * @retval 0 error initializing SSL
 * @retval 1 SSL initialized successfully
 */
int Curl_ssl_init(void)
{
  /* make sure this is only done once */
  if(init_ssl)
    return 1;
  init_ssl = TRUE; /* never again */

  return curlssl_init();
}


/* Global cleanup */
void Curl_ssl_cleanup(void)
{
  if(init_ssl) {
    /* only cleanup if we did a previous init */
    curlssl_cleanup();
    init_ssl = FALSE;
  }
}

CURLcode
Curl_ssl_connect(struct connectdata *conn, int sockindex)
{
  CURLcode res;
  /* mark this is being ssl-enabled from here on. */
  conn->ssl[sockindex].use = TRUE;
  conn->ssl[sockindex].state = ssl_connection_negotiating;

  res = curlssl_connect(conn, sockindex);

  if(!res)
    Curl_pgrsTime(conn->data, TIMER_APPCONNECT); /* SSL is connected */

  return res;
}

CURLcode
Curl_ssl_connect_nonblocking(struct connectdata *conn, int sockindex,
                             bool *done)
{
#ifdef curlssl_connect_nonblocking
  /* mark this is being ssl requested from here on. */
  conn->ssl[sockindex].use = TRUE;
  return curlssl_connect_nonblocking(conn, sockindex, done);
#else
  *done = TRUE; /* fallback to BLOCKING */
  conn->ssl[sockindex].use = TRUE;
  return curlssl_connect(conn, sockindex);
#endif /* non-blocking connect support */
}

/*
 * Check if there's a session ID for the given connection in the cache, and if
 * there's one suitable, it is provided. Returns TRUE when no entry matched.
 */
int Curl_ssl_getsessionid(struct connectdata *conn,
                          void **ssl_sessionid,
                          size_t *idsize) /* set 0 if unknown */
{
  struct curl_ssl_session *check;
  struct SessionHandle *data = conn->data;
  long i;

  if(!conn->ssl_config.sessionid)
    /* session ID re-use is disabled */
    return TRUE;

  for(i=0; i< data->set.ssl.numsessions; i++) {
    check = &data->state.session[i];
    if(!check->sessionid)
      /* not session ID means blank entry */
      continue;
    if(curl_strequal(conn->host.name, check->name) &&
       (conn->remote_port == check->remote_port) &&
       Curl_ssl_config_matches(&conn->ssl_config, &check->ssl_config)) {
      /* yes, we have a session ID! */
      data->state.sessionage++;            /* increase general age */
      check->age = data->state.sessionage; /* set this as used in this age */
      *ssl_sessionid = check->sessionid;
      if(idsize)
        *idsize = check->idsize;
      return FALSE;
    }
  }
  *ssl_sessionid = NULL;
  return TRUE;
}

/*
 * Kill a single session ID entry in the cache.
 */
static int kill_session(struct curl_ssl_session *session)
{
  if(session->sessionid) {
    /* defensive check */

    /* free the ID the SSL-layer specific way */
    curlssl_session_free(session->sessionid);

    session->sessionid=NULL;
    session->age = 0; /* fresh */

    Curl_free_ssl_config(&session->ssl_config);

    Curl_safefree(session->name);
    session->name = NULL; /* no name */

    return 0; /* ok */
  }
  else
    return 1;
}

/*
 * Store session id in the session cache. The ID passed on to this function
 * must already have been extracted and allocated the proper way for the SSL
 * layer. Curl_XXXX_session_free() will be called to free/kill the session ID
 * later on.
 */
CURLcode Curl_ssl_addsessionid(struct connectdata *conn,
                               void *ssl_sessionid,
                               size_t idsize)
{
  long i;
  struct SessionHandle *data=conn->data; /* the mother of all structs */
  struct curl_ssl_session *store = &data->state.session[0];
  long oldest_age=data->state.session[0].age; /* zero if unused */
  char *clone_host;

  /* Even though session ID re-use might be disabled, that only disables USING
     IT. We still store it here in case the re-using is again enabled for an
     upcoming transfer */

  clone_host = strdup(conn->host.name);
  if(!clone_host)
    return CURLE_OUT_OF_MEMORY; /* bail out */

  /* Now we should add the session ID and the host name to the cache, (remove
     the oldest if necessary) */

  /* find an empty slot for us, or find the oldest */
  for(i=1; (i<data->set.ssl.numsessions) &&
        data->state.session[i].sessionid; i++) {
    if(data->state.session[i].age < oldest_age) {
      oldest_age = data->state.session[i].age;
      store = &data->state.session[i];
    }
  }
  if(i == data->set.ssl.numsessions)
    /* cache is full, we must "kill" the oldest entry! */
    kill_session(store);
  else
    store = &data->state.session[i]; /* use this slot */

  /* now init the session struct wisely */
  store->sessionid = ssl_sessionid;
  store->idsize = idsize;
  store->age = data->state.sessionage;    /* set current age */
  if (store->name)
    /* free it if there's one already present */
    free(store->name);
  store->name = clone_host;               /* clone host name */
  store->remote_port = conn->remote_port; /* port number */

  if(!Curl_clone_ssl_config(&conn->ssl_config, &store->ssl_config))
    return CURLE_OUT_OF_MEMORY;

  return CURLE_OK;
}


void Curl_ssl_close_all(struct SessionHandle *data)
{
  long i;
  /* kill the session ID cache */
  if(data->state.session) {
    for(i=0; i< data->set.ssl.numsessions; i++)
      /* the single-killer function handles empty table slots */
      kill_session(&data->state.session[i]);

    /* free the cache data */
    free(data->state.session);
    data->state.session = NULL;
  }

  curlssl_close_all(data);
}

void Curl_ssl_close(struct connectdata *conn, int sockindex)
{
  DEBUGASSERT((sockindex <= 1) && (sockindex >= -1));
  curlssl_close(conn, sockindex);
}

CURLcode Curl_ssl_shutdown(struct connectdata *conn, int sockindex)
{
  if(curlssl_shutdown(conn, sockindex))
    return CURLE_SSL_SHUTDOWN_FAILED;

  conn->ssl[sockindex].use = FALSE; /* get back to ordinary socket usage */
  conn->ssl[sockindex].state = ssl_connection_none;

  return CURLE_OK;
}

/* Selects an SSL crypto engine
 */
CURLcode Curl_ssl_set_engine(struct SessionHandle *data, const char *engine)
{
  return curlssl_set_engine(data, engine);
}

/* Selects the default SSL crypto engine
 */
CURLcode Curl_ssl_set_engine_default(struct SessionHandle *data)
{
  return curlssl_set_engine_default(data);
}

/* Return list of OpenSSL crypto engine names. */
struct curl_slist *Curl_ssl_engines_list(struct SessionHandle *data)
{
  return curlssl_engines_list(data);
}

/* return number of sent (non-SSL) bytes */
ssize_t Curl_ssl_send(struct connectdata *conn,
                      int sockindex,
                      const void *mem,
                      size_t len)
{
  return curlssl_send(conn, sockindex, mem, len);
}

/* return number of received (decrypted) bytes */

/*
 * If the read would block (EWOULDBLOCK) we return -1. Otherwise we return
 * a regular CURLcode value.
 */
ssize_t Curl_ssl_recv(struct connectdata *conn, /* connection data */
                      int sockindex,            /* socketindex */
                      char *mem,                /* store read data here */
                      size_t len)               /* max amount to read */
{
  ssize_t nread;
  bool block = FALSE;

  nread = curlssl_recv(conn, sockindex, mem, len, &block);
  if(nread == -1) {
    if(!block)
      return 0; /* this is a true error, not EWOULDBLOCK */
    else
      return -1;
  }

  return nread;
}


/*
 * This sets up a session ID cache to the specified size. Make sure this code
 * is agnostic to what underlying SSL technology we use.
 */
CURLcode Curl_ssl_initsessions(struct SessionHandle *data, long amount)
{
  struct curl_ssl_session *session;

  if(data->state.session)
    /* this is just a precaution to prevent multiple inits */
    return CURLE_OK;

  session = calloc(sizeof(struct curl_ssl_session), amount);
  if(!session)
    return CURLE_OUT_OF_MEMORY;

  /* store the info in the SSL section */
  data->set.ssl.numsessions = amount;
  data->state.session = session;
  data->state.sessionage = 1; /* this is brand new */
  return CURLE_OK;
}

size_t Curl_ssl_version(char *buffer, size_t size)
{
  return curlssl_version(buffer, size);
}

/*
 * This function tries to determine connection status.
 *
 * Return codes:
 *     1 means the connection is still in place
 *     0 means the connection has been closed
 *    -1 means the connection status is unknown
 */
int Curl_ssl_check_cxn(struct connectdata *conn)
{
  return curlssl_check_cxn(conn);
}

bool Curl_ssl_data_pending(const struct connectdata *conn,
                           int connindex)
{
  return curlssl_data_pending(conn, connindex);
}

void Curl_ssl_free_certinfo(struct SessionHandle *data)
{
  int i;
  struct curl_certinfo *ci = &data->info.certs;
  if(ci->num_of_certs) {
    /* free all individual lists used */
    for(i=0; i<ci->num_of_certs; i++)
      curl_slist_free_all(ci->certinfo[i]);
    free(ci->certinfo); /* free the actual array too */
    ci->num_of_certs = 0;
  }
}
#endif /* USE_SSL */