keyserver/curl-shim.c

   1 /* curl-shim.c - Implement a small subset of the curl API in terms of
   2  * the iobuf HTTP API
   3  *
   4  * Copyright (C) 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
   5  *
   6  * This file is part of GnuPG.
   7  *
   8  * GnuPG is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 3 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * GnuPG is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <config.h>
  23 #include <stdarg.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27 #include <errno.h>
  28
  29 #include "http.h"
  30 #include "util.h"
  31 #include "ksutil.h"
  32 #include "curl-shim.h"
  33
  34 static CURLcode
  35 handle_error(CURL *curl,CURLcode err,const char *str)
  36 {
  37   if(curl->errorbuffer)
  38     {
  39       /* Make sure you never exceed CURL_ERROR_SIZE, currently set to
  40          256 in curl-shim.h */
  41       switch(err)
  42         {
  43         case CURLE_OK:
  44           strcpy(curl->errorbuffer,"okay");
  45           break;
  46
  47         case CURLE_UNSUPPORTED_PROTOCOL:
  48           strcpy(curl->errorbuffer,"unsupported protocol");
  49           break;
  50
  51         case CURLE_COULDNT_CONNECT:
  52           strcpy(curl->errorbuffer,"couldn't connect");
  53           break;
  54
  55         case CURLE_WRITE_ERROR:
  56           strcpy(curl->errorbuffer,"write error");
  57           break;
  58
  59         case CURLE_HTTP_RETURNED_ERROR:
  60           sprintf(curl->errorbuffer,"url returned error %u",curl->status);
  61           break;
  62
  63         default:
  64           strcpy(curl->errorbuffer,"generic error");
  65           break;
  66         }
  67
  68       if(str && (strlen(curl->errorbuffer)+2+strlen(str)+1)<=CURL_ERROR_SIZE)
  69         {
  70           strcat(curl->errorbuffer,": ");
  71           strcat(curl->errorbuffer,str);
  72         }
  73     }
  74
  75   return err;
  76 }
  77
  78 CURLcode
  79 curl_global_init(long flags)
  80 {
  81   (void)flags;
  82   return CURLE_OK;
  83 }
  84
  85 void
  86 curl_global_cleanup(void) {}
  87
  88 CURL *
  89 curl_easy_init(void)
  90 {
  91   CURL *handle;
  92
  93 #ifdef HAVE_W32_SYSTEM
  94   w32_init_sockets ();
  95 #endif
  96
  97   handle=calloc(1,sizeof(CURL));
  98   if(handle)
  99     handle->errors=stderr;
 100
 101   return handle;
 102 }
 103
 104 void
 105 curl_easy_cleanup(CURL *curl)
 106 {
 107   if (curl)
 108     {
 109       http_close (curl->hd, 0);
 110       free(curl);
 111     }
 112 }
 113
 114 CURLcode
 115 curl_easy_setopt(CURL *curl,CURLoption option,...)
 116 {
 117   va_list ap;
 118
 119   va_start(ap,option);
 120
 121   switch(option)
 122     {
 123     case CURLOPT_URL:
 124       curl->url=va_arg(ap,char *);
 125       break;
 126     case CURLOPT_USERPWD:
 127       curl->auth=va_arg(ap,char *);
 128       break;
 129     case CURLOPT_WRITEFUNCTION:
 130       curl->writer=va_arg(ap,write_func);
 131       break;
 132     case CURLOPT_FILE:
 133       curl->file=va_arg(ap,void *);
 134       break;
 135     case CURLOPT_ERRORBUFFER:
 136       curl->errorbuffer=va_arg(ap,char *);
 137       break;
 138     case CURLOPT_PROXY:
 139       curl->proxy=va_arg(ap,char *);
 140       break;
 141     case CURLOPT_POST:
 142       curl->flags.post=va_arg(ap,long)?1:0;
 143       break;
 144     case CURLOPT_POSTFIELDS:
 145       curl->postfields=va_arg(ap,char *);
 146       break;
 147     case CURLOPT_SRVTAG_GPG_HACK:
 148       curl->srvtag=va_arg(ap,char *);
 149       break;
 150     case CURLOPT_FAILONERROR:
 151       curl->flags.failonerror=va_arg(ap,long)?1:0;
 152       break;
 153     case CURLOPT_VERBOSE:
 154       curl->flags.verbose=va_arg(ap,long)?1:0;
 155       break;
 156     case CURLOPT_STDERR:
 157       curl->errors=va_arg(ap,FILE *);
 158       break;
 159     default:
 160       /* We ignore the huge majority of curl options */
 161       break;
 162     }
 163
 164   return handle_error(curl,CURLE_OK,NULL);
 165 }
 166
 167 CURLcode
 168 curl_easy_perform(CURL *curl)
 169 {
 170   int rc;
 171   CURLcode err=CURLE_OK;
 172   const char *errstr=NULL;
 173   char *proxy=NULL;
 174
 175   /* Emulate the libcurl proxy behavior.  If the calling program set a
 176      proxy, use it.  If it didn't set a proxy or set it to NULL, check
 177      for one in the environment.  If the calling program explicitly
 178      set a null-string proxy the http code doesn't use a proxy at
 179      all. */
 180
 181   if(curl->proxy)
 182     proxy=curl->proxy;
 183   else
 184     proxy=getenv(HTTP_PROXY_ENV);
 185
 186   if(curl->flags.verbose)
 187     {
 188       fprintf(curl->errors,"* HTTP proxy is \"%s\"\n",proxy?proxy:"null");
 189       fprintf(curl->errors,"* HTTP URL is \"%s\"\n",curl->url);
 190       fprintf(curl->errors,"* HTTP auth is \"%s\"\n",
 191               curl->auth?curl->auth:"null");
 192       fprintf(curl->errors,"* HTTP method is %s\n",
 193               curl->flags.post?"POST":"GET");
 194     }
 195
 196   if(curl->flags.post)
 197     {
 198       rc = http_open (&curl->hd, HTTP_REQ_POST, curl->url, curl->auth,
 199                       0, proxy, NULL, curl->srvtag);
 200       if (!rc)
 201         {
 202           unsigned int post_len = strlen(curl->postfields);
 203
 204           es_fprintf (http_get_write_ptr (curl->hd),
 205                       "Content-Type: application/x-www-form-urlencoded\r\n"
 206                       "Content-Length: %u\r\n", post_len);
 207           http_start_data (curl->hd);
 208           es_write (http_get_write_ptr (curl->hd),
 209                     curl->postfields, post_len, NULL);
 210
 211           rc = http_wait_response (curl->hd);
 212           curl->status = http_get_status_code (curl->hd);
 213           if (!rc && curl->flags.failonerror && curl->status>=300)
 214             err = CURLE_HTTP_RETURNED_ERROR;
 215           http_close (curl->hd, 0);
 216           curl->hd = NULL;
 217         }
 218     }
 219   else
 220     {
 221       rc = http_open (&curl->hd, HTTP_REQ_GET, curl->url, curl->auth,
 222                       0, proxy, NULL, curl->srvtag);
 223       if (!rc)
 224         {
 225           rc = http_wait_response (curl->hd);
 226           curl->status = http_get_status_code (curl->hd);
 227           if (!rc)
 228             {
 229               if (curl->flags.failonerror && curl->status>=300)
 230                 err = CURLE_HTTP_RETURNED_ERROR;
 231               else
 232                 {
 233                   size_t maxlen = 1024;
 234                   size_t buflen;
 235                   unsigned int len;
 236                   char *line = NULL;
 237
 238                   while ((len = es_read_line (http_get_read_ptr (curl->hd),
 239                                               &line, &buflen, &maxlen)))
 240                     {
 241                       size_t ret;
 242
 243                       maxlen=1024;
 244
 245                       ret=(curl->writer)(line,len,1,curl->file);
 246                       if(ret!=len)
 247                         {
 248                           err=CURLE_WRITE_ERROR;
 249                           break;
 250                         }
 251                     }
 252
 253                   es_free (line);
 254                   http_close(curl->hd, 0);
 255                   curl->hd = NULL;
 256                 }
 257             }
 258           else
 259             {
 260               http_close (curl->hd, 0);
 261               curl->hd = NULL;
 262             }
 263         }
 264     }
 265
 266   switch(gpg_err_code (rc))
 267     {
 268     case 0:
 269       break;
 270
 271     case GPG_ERR_INV_URI:
 272       err=CURLE_UNSUPPORTED_PROTOCOL;
 273       break;
 274
 275     default:
 276       errstr=gpg_strerror (rc);
 277       err=CURLE_COULDNT_CONNECT;
 278       break;
 279     }
 280
 281   return handle_error(curl,err,errstr);
 282 }
 283
 284 /* This is not the same exact set that is allowed according to
 285    RFC-2396, but it is what the real curl uses. */
 286 #define VALID_URI_CHARS "abcdefghijklmnopqrstuvwxyz" \
 287                         "ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
 288                         "0123456789"
 289
 290 char *
 291 curl_escape(char *str,int length)
 292 {
 293   int len,max,idx,enc_idx=0;
 294   char *enc;
 295
 296   if(length)
 297     len=length;
 298   else
 299     len=strlen(str);
 300
 301   enc=malloc(len+1);
 302   if(!enc)
 303     return enc;
 304
 305   max=len;
 306
 307   for(idx=0;idx<len;idx++)
 308     {
 309       if(enc_idx+3>max)
 310         {
 311           char *tmp;
 312
 313           max+=100;
 314
 315           tmp=realloc(enc,max+1);
 316           if(!tmp)
 317             {
 318               free(enc);
 319               return NULL;
 320             }
 321
 322           enc=tmp;
 323         }
 324
 325       if(strchr(VALID_URI_CHARS,str[idx]))
 326         enc[enc_idx++]=str[idx];
 327       else
 328         {
 329           char numbuf[5];
 330           sprintf(numbuf,"%%%02X",str[idx]);
 331           strcpy(&enc[enc_idx],numbuf);
 332           enc_idx+=3;
 333         }
 334     }
 335
 336   enc[enc_idx]='\0';
 337
 338   return enc;
 339 }
 340
 341 curl_version_info_data *
 342 curl_version_info(int type)
 343 {
 344   static curl_version_info_data data;
 345   static const char *protocols[]={"http",NULL};
 346
 347   (void)type;
 348
 349   data.protocols=protocols;
 350
 351   return &data;
 352 }