/* gpgkeys_hkp.c - talk to an HKP keyserver
 * Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
 *               2009 Free Software Foundation, Inc.
 *
 * This file is part of GnuPG.
 *
 * GnuPG is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * GnuPG is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 * In addition, as a special exception, the Free Software Foundation
 * gives permission to link the code of the keyserver helper tools:
 * gpgkeys_ldap, gpgkeys_curl and gpgkeys_hkp with the OpenSSL
 * project's "OpenSSL" library (or with modified versions of it that
 * use the same license as the "OpenSSL" library), and distribute the
 * linked executables.  You must obey the GNU General Public License
 * in all respects for all of the code used other than "OpenSSL".  If
 * you modify this file, you may extend this exception to your version
 * of the file, but you are not obligated to do so.  If you do not
 * wish to do so, delete this exception statement from your version.
 */

#include <config.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif
#ifdef HAVE_LIBCURL
#include <curl/curl.h>
#else
#include "curl-shim.h"
#endif
#include "compat.h"
#include "keyserver.h"
#include "ksutil.h"

extern char *optarg;
extern int optind;

static FILE *input,*output,*console;
static CURL *curl;
static struct ks_options *opt;
static char errorbuffer[CURL_ERROR_SIZE];
static char *proto,*port;

static size_t
curl_mrindex_writer(const void *ptr,size_t size,size_t nmemb,void *stream)
{
  static int checked=0,swallow=0;

  if(!checked)
    {
      /* If the document begins with a '<', assume it's a HTML
	 response, which we don't support.  Discard the whole message
	 body.  GPG can handle it, but this is an optimization to deal
	 with it on this side of the pipe.  */
      const char *buf=ptr;
      if(buf[0]=='<')
	swallow=1;

      checked=1;
    }

  if(swallow || fwrite(ptr,size,nmemb,stream)==nmemb)
    return size*nmemb;
  else
    return 0;
}

/* Append but avoid creating a double slash // in the path. */
static char *
append_path(char *dest,const char *src)
{
  size_t n=strlen(dest);

  if(src[0]=='/' && n>0 && dest[n-1]=='/')
    dest[n-1]='\0';

  return strcat(dest,src);
}

int
send_key(int *eof)
{
  CURLcode res;
  char request[MAX_URL+15];
  int begin=0,end=0,ret=KEYSERVER_INTERNAL_ERROR;
  char keyid[17],state[6];
  char line[MAX_LINE];
  char *key=NULL,*encoded_key=NULL;
  size_t keysize=1;

  key=malloc(1);
  if(!key)
    {
      fprintf(console,"gpgkeys: unable to allocate memory for key\n");
      ret=KEYSERVER_NO_MEMORY;
      goto fail;
    }

  key[0]='\0';

  /* Read and throw away input until we see the BEGIN */

  while(fgets(line,MAX_LINE,input)!=NULL)
    if(sscanf(line,"KEY%*[ ]%16s%*[ ]%5s\n",keyid,state)==2
       && strcmp(state,"BEGIN")==0)
      {
	begin=1;
	break;
      }

  if(!begin)
    {
      /* i.e. eof before the KEY BEGIN was found.  This isn't an
	 error. */
      *eof=1;
      ret=KEYSERVER_OK;
      goto fail;
    }

  /* Now slurp up everything until we see the END */

  while(fgets(line,MAX_LINE,input))
    if(sscanf(line,"KEY%*[ ]%16s%*[ ]%3s\n",keyid,state)==2
       && strcmp(state,"END")==0)
      {
	end=1;
	break;
      }
    else
      {
	char *tempkey;
	keysize+=strlen(line);
	tempkey=realloc(key,keysize);
	if(tempkey==NULL)
	  {
	    fprintf(console,"gpgkeys: unable to reallocate for key\n");
	    ret=KEYSERVER_NO_MEMORY;
	    goto fail;
	  }
	else
	  key=tempkey;

	strcat(key,line);
      }

  if(!end)
    {
      fprintf(console,"gpgkeys: no KEY %s END found\n",keyid);
      *eof=1;
      ret=KEYSERVER_KEY_INCOMPLETE;
      goto fail;
    }

  encoded_key=curl_easy_escape(curl,key,keysize);
  if(!encoded_key)
    {
      fprintf(console,"gpgkeys: out of memory\n");
      ret=KEYSERVER_NO_MEMORY;
      goto fail;
    }

  free(key);

  key=malloc(8+strlen(encoded_key)+1);
  if(!key)
    {
      fprintf(console,"gpgkeys: out of memory\n");
      ret=KEYSERVER_NO_MEMORY;
      goto fail;
    }

  strcpy(key,"keytext=");
  strcat(key,encoded_key);

  strcpy(request,proto);
  strcat(request,opt->host);
  strcat(request,":");
  strcat(request,port);
  strcat(request,opt->path);
  /* request is MAX_URL+15 bytes long - MAX_URL covers the whole URL,
     including any supplied path.  The 15 covers /pks/add. */
  append_path(request,"/pks/add");

  if(opt->verbose>2)
    fprintf(console,"gpgkeys: HTTP URL is `%s'\n",request);

  curl_easy_setopt(curl,CURLOPT_URL,request);
  curl_easy_setopt(curl,CURLOPT_POST,1L);
  curl_easy_setopt(curl,CURLOPT_POSTFIELDS,key);
  curl_easy_setopt(curl,CURLOPT_FAILONERROR,1L);

  res=curl_easy_perform(curl);
  if(res!=0)
    {
      fprintf(console,"gpgkeys: HTTP post error %d: %s\n",res,errorbuffer);
      ret=curl_err_to_gpg_err(res);
      goto fail;
    }
  else
    fprintf(output,"\nKEY %s SENT\n",keyid);

  ret=KEYSERVER_OK;

 fail:
  free(key);
  curl_free(encoded_key);

  if(ret!=0 && begin)
    fprintf(output,"KEY %s FAILED %d\n",keyid,ret);

  return ret;
}

static int
get_key(char *getkey)
{
  CURLcode res;
  char request[MAX_URL+60];
  char *offset;
  struct curl_writer_ctx ctx;

  memset(&ctx,0,sizeof(ctx));

  /* Build the search string.  HKP only uses the short key IDs. */

  if(strncmp(getkey,"0x",2)==0)
    getkey+=2;

  fprintf(output,"KEY 0x%s BEGIN\n",getkey);

  if(strlen(getkey)==32)
    {
      fprintf(console,
	      "gpgkeys: HKP keyservers do not support v3 fingerprints\n");
      fprintf(output,"KEY 0x%s FAILED %d\n",getkey,KEYSERVER_NOT_SUPPORTED);
      return KEYSERVER_NOT_SUPPORTED;
    }

  strcpy(request,proto);
  strcat(request,opt->host);
  strcat(request,":");
  strcat(request,port);
  strcat(request,opt->path);
  /* request is MAX_URL+55 bytes long - MAX_URL covers the whole URL,
     including any supplied path.  The 60 overcovers this /pks/... etc
     string plus the 8 bytes of key id */
  append_path(request,"/pks/lookup?op=get&options=mr&search=0x");

  /* fingerprint or long key id.  Take the last 8 characters and treat
     it like a short key id */
  if(strlen(getkey)>8)
    offset=&getkey[strlen(getkey)-8];
  else
    offset=getkey;

  strcat(request,offset);

  if(opt->verbose>2)
    fprintf(console,"gpgkeys: HTTP URL is `%s'\n",request);

  curl_easy_setopt(curl,CURLOPT_URL,request);
  curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,curl_writer);
  ctx.stream=output;
  curl_easy_setopt(curl,CURLOPT_FILE,&ctx);

  res=curl_easy_perform(curl);
  if(res!=CURLE_OK)
    {
      fprintf(console,"gpgkeys: HTTP fetch error %d: %s\n",res,errorbuffer);
      fprintf(output,"\nKEY 0x%s FAILED %d\n",getkey,curl_err_to_gpg_err(res));
    }
  else
    {
      curl_writer_finalize(&ctx);
      if(!ctx.flags.done)
	{
	  fprintf(console,"gpgkeys: key %s not found on keyserver\n",getkey);
	  fprintf(output,"\nKEY 0x%s FAILED %d\n",
		  getkey,KEYSERVER_KEY_NOT_FOUND);
	}
      else
	fprintf(output,"\nKEY 0x%s END\n",getkey);
    }

  return KEYSERVER_OK;
}

static int
get_name(const char *getkey)
{
  CURLcode res;
  char *request=NULL;
  char *searchkey_encoded;
  int ret=KEYSERVER_INTERNAL_ERROR;
  struct curl_writer_ctx ctx;

  memset(&ctx,0,sizeof(ctx));

  searchkey_encoded=curl_easy_escape(curl,(char *)getkey,0);
  if(!searchkey_encoded)
    {
      fprintf(console,"gpgkeys: out of memory\n");
      ret=KEYSERVER_NO_MEMORY;
      goto fail;
    }

  request=malloc(MAX_URL+60+strlen(searchkey_encoded));
  if(!request)
    {
      fprintf(console,"gpgkeys: out of memory\n");
      ret=KEYSERVER_NO_MEMORY;
      goto fail;
    }

  fprintf(output,"NAME %s BEGIN\n",getkey);

  strcpy(request,proto);
  strcat(request,opt->host);
  strcat(request,":");
  strcat(request,port);
  strcat(request,opt->path);
  append_path(request,"/pks/lookup?op=get&options=mr&search=");
  strcat(request,searchkey_encoded);

  if(opt->action==KS_GETNAME)
    strcat(request,"&exact=on");

  if(opt->verbose>2)
    fprintf(console,"gpgkeys: HTTP URL is `%s'\n",request);

  curl_easy_setopt(curl,CURLOPT_URL,request);
  curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,curl_writer);
  ctx.stream=output;
  curl_easy_setopt(curl,CURLOPT_FILE,&ctx);

  res=curl_easy_perform(curl);
  if(res!=CURLE_OK)
    {
      fprintf(console,"gpgkeys: HTTP fetch error %d: %s\n",res,errorbuffer);
      ret=curl_err_to_gpg_err(res);
    }
  else
    {
      curl_writer_finalize(&ctx);
      if(!ctx.flags.done)
	{
	  fprintf(console,"gpgkeys: key %s not found on keyserver\n",getkey);
	  ret=KEYSERVER_KEY_NOT_FOUND;
	}
      else
	{
	  fprintf(output,"\nNAME %s END\n",getkey);
	  ret=KEYSERVER_OK;
	}
    }

 fail:
  curl_free(searchkey_encoded);
  free(request);

  if(ret!=KEYSERVER_OK)
    fprintf(output,"\nNAME %s FAILED %d\n",getkey,ret);

  return ret;
}

static int
search_key(const char *searchkey)
{
  CURLcode res;
  char *request=NULL;
  char *searchkey_encoded;
  int ret=KEYSERVER_INTERNAL_ERROR;
  enum ks_search_type search_type;

  search_type=classify_ks_search(&searchkey);

  if(opt->debug)
    fprintf(console,"gpgkeys: search type is %d, and key is \"%s\"\n",
	    search_type,searchkey);

  searchkey_encoded=curl_easy_escape(curl,(char *)searchkey,0);
  if(!searchkey_encoded)
    {
      fprintf(console,"gpgkeys: out of memory\n");
      ret=KEYSERVER_NO_MEMORY;
      goto fail;
    }

  request=malloc(MAX_URL+60+strlen(searchkey_encoded));
  if(!request)
    {
      fprintf(console,"gpgkeys: out of memory\n");
      ret=KEYSERVER_NO_MEMORY;
      goto fail;
    }

  fprintf(output,"SEARCH %s BEGIN\n",searchkey);

  strcpy(request,proto);
  strcat(request,opt->host);
  strcat(request,":");
  strcat(request,port);
  strcat(request,opt->path);
  append_path(request,"/pks/lookup?op=index&options=mr&search=");

  /* HKP keyservers like the 0x to be present when searching by
     keyid */
  if(search_type==KS_SEARCH_KEYID_SHORT || search_type==KS_SEARCH_KEYID_LONG)
    strcat(request,"0x");

  strcat(request,searchkey_encoded);

  if(search_type!=KS_SEARCH_SUBSTR)
    strcat(request,"&exact=on");

  if(opt->verbose>2)
    fprintf(console,"gpgkeys: HTTP URL is `%s'\n",request);

  curl_easy_setopt(curl,CURLOPT_URL,request);
  curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,curl_mrindex_writer);
  curl_easy_setopt(curl,CURLOPT_FILE,output);

  res=curl_easy_perform(curl);
  if(res!=0)
    {
      fprintf(console,"gpgkeys: HTTP search error %d: %s\n",res,errorbuffer);
      ret=curl_err_to_gpg_err(res);
    }
  else
    {
      fprintf(output,"\nSEARCH %s END\n",searchkey);
      ret=KEYSERVER_OK;
    }

 fail:

  curl_free(searchkey_encoded);
  free(request);

  if(ret!=KEYSERVER_OK)
    fprintf(output,"\nSEARCH %s FAILED %d\n",searchkey,ret);

  return ret;
}

void
fail_all(struct keylist *keylist,int err)
{
  if(!keylist)
    return;

  if(opt->action==KS_SEARCH)
    {
      fprintf(output,"SEARCH ");
      while(keylist)
	{
	  fprintf(output,"%s ",keylist->str);
	  keylist=keylist->next;
	}
      fprintf(output,"FAILED %d\n",err);
    }
  else
    while(keylist)
      {
	fprintf(output,"KEY %s FAILED %d\n",keylist->str,err);
	keylist=keylist->next;
      }
}

static void 
show_help (FILE *fp)
{
  fprintf (fp,"-h, --help\thelp\n");
  fprintf (fp,"-V\t\tmachine readable version\n");
  fprintf (fp,"--version\thuman readable version\n");
  fprintf (fp,"-o\t\toutput to this file\n");
}

int
main(int argc,char *argv[])
{
  int arg,ret=KEYSERVER_INTERNAL_ERROR;
  char line[MAX_LINE];
  int failed=0;
  struct keylist *keylist=NULL,*keyptr=NULL;
  char *proxy=NULL;

  console=stderr;

  /* Kludge to implement standard GNU options.  */
  if (argc > 1 && !strcmp (argv[1], "--version"))
    {
      printf ("gpgkeys_hkp (GnuPG) %s\n", VERSION);
      printf ("Uses: %s\n", curl_version());
      return 0;
    }
  else if (argc > 1 && !strcmp (argv[1], "--help"))
    {
      show_help (stdout);
      return 0;
    }

  while((arg=getopt(argc,argv,"hVo:"))!=-1)
    switch(arg)
      {
      default:
      case 'h':
        show_help (console);
	return KEYSERVER_OK;

      case 'V':
	fprintf(stdout,"%d\n%s\n",KEYSERVER_PROTO_VERSION,VERSION);
	return KEYSERVER_OK;

      case 'o':
	output=fopen(optarg,"w");
	if(output==NULL)
	  {
	    fprintf(console,"gpgkeys: Cannot open output file `%s': %s\n",
		    optarg,strerror(errno));
	    return KEYSERVER_INTERNAL_ERROR;
	  }

	break;
      }

  if(argc>optind)
    {
      input=fopen(argv[optind],"r");
      if(input==NULL)
	{
	  fprintf(console,"gpgkeys: Cannot open input file `%s': %s\n",
		  argv[optind],strerror(errno));
	  return KEYSERVER_INTERNAL_ERROR;
	}
    }

  if(input==NULL)
    input=stdin;

  if(output==NULL)
    output=stdout;

  opt=init_ks_options();
  if(!opt)
    return KEYSERVER_NO_MEMORY;

  /* Get the command and info block */

  while(fgets(line,MAX_LINE,input)!=NULL)
    {
      int err;
      char option[MAX_OPTION+1];

      if(line[0]=='\n')
	break;

      err=parse_ks_options(line,opt);
      if(err>0)
	{
	  ret=err;
	  goto fail;
	}
      else if(err==0)
	continue;

      if(sscanf(line,"OPTION %" MKSTRING(MAX_OPTION) "s\n",option)==1)
	{
	  int no=0;
	  char *start=&option[0];

	  option[MAX_OPTION]='\0';

	  if(ascii_strncasecmp(option,"no-",3)==0)
	    {
	      no=1;
	      start=&option[3];
	    }

	  if(ascii_strncasecmp(start,"http-proxy",10)==0)
	    {
	      if(no)
		{
		  free(proxy);
		  proxy=strdup("");
		}
	      else if(start[10]=='=')
		{
		  if(strlen(&start[11])<MAX_PROXY)
		    {
		      free(proxy);
		      proxy=strdup(&start[11]);
		    }
		}
	    }
#if 0
	  else if(ascii_strcasecmp(start,"try-dns-srv")==0)
	    {
	      if(no)
		http_flags&=~HTTP_FLAG_TRY_SRV;
	      else
		http_flags|=HTTP_FLAG_TRY_SRV;
	    }
#endif
	  continue;
	}
    }


  if(!opt->scheme)
    {
      fprintf(console,"gpgkeys: no scheme supplied!\n");
      ret=KEYSERVER_SCHEME_NOT_FOUND;
      goto fail;
    }

  if(ascii_strcasecmp(opt->scheme,"hkps")==0)
    {
      proto="https://";
      port="443";
    }
  else
    {
      proto="http://";
      port="11371";
    }

  if(opt->port)
    port=opt->port;

  if(!opt->host)
    {
      fprintf(console,"gpgkeys: no keyserver host provided\n");
      goto fail;
    }

  if(opt->timeout && register_timeout()==-1)
    {
      fprintf(console,"gpgkeys: unable to register timeout handler\n");
      return KEYSERVER_INTERNAL_ERROR;
    }

  curl_global_init(CURL_GLOBAL_DEFAULT);
  curl=curl_easy_init();
  if(!curl)
    {
      fprintf(console,"gpgkeys: unable to initialize curl\n");
      ret=KEYSERVER_INTERNAL_ERROR;
      goto fail;
    }

  curl_easy_setopt(curl,CURLOPT_ERRORBUFFER,errorbuffer);

  if(opt->auth)
    curl_easy_setopt(curl,CURLOPT_USERPWD,opt->auth);

  if(opt->debug)
    {
      fprintf(console,"gpgkeys: curl version = %s\n",curl_version());
      curl_easy_setopt(curl,CURLOPT_STDERR,console);
      curl_easy_setopt(curl,CURLOPT_VERBOSE,1L);
    }

  curl_easy_setopt(curl,CURLOPT_SSL_VERIFYPEER,(long)opt->flags.check_cert);
  curl_easy_setopt(curl,CURLOPT_CAINFO,opt->ca_cert_file);

  if(proxy)
    curl_easy_setopt(curl,CURLOPT_PROXY,proxy);

#if 0
  /* By suggested convention, if the user gives a :port, then disable
     SRV. */
  if(opt->port)
    http_flags&=~HTTP_FLAG_TRY_SRV;
#endif

  /* If it's a GET or a SEARCH, the next thing to come in is the
     keyids.  If it's a SEND, then there are no keyids. */

  if(opt->action==KS_SEND)
    while(fgets(line,MAX_LINE,input)!=NULL && line[0]!='\n');
  else if(opt->action==KS_GET
	  || opt->action==KS_GETNAME || opt->action==KS_SEARCH)
    {
      for(;;)
	{
	  struct keylist *work;

	  if(fgets(line,MAX_LINE,input)==NULL)
	    break;
	  else
	    {
	      if(line[0]=='\n' || line[0]=='\0')
		break;

	      work=malloc(sizeof(struct keylist));
	      if(work==NULL)
		{
		  fprintf(console,"gpgkeys: out of memory while "
			  "building key list\n");
		  ret=KEYSERVER_NO_MEMORY;
		  goto fail;
		}

	      strcpy(work->str,line);

	      /* Trim the trailing \n */
	      work->str[strlen(line)-1]='\0';

	      work->next=NULL;

	      /* Always attach at the end to keep the list in proper
                 order for searching */
	      if(keylist==NULL)
		keylist=work;
	      else
		keyptr->next=work;

	      keyptr=work;
	    }
	}
    }
  else
    {
      fprintf(console,"gpgkeys: no keyserver command specified\n");
      goto fail;
    }

  /* Send the response */

  fprintf(output,"VERSION %d\n",KEYSERVER_PROTO_VERSION);
  fprintf(output,"PROGRAM %s %s\n\n",VERSION,curl_version());

  if(opt->verbose>1)
    {
      fprintf(console,"Host:\t\t%s\n",opt->host);
      if(opt->port)
	fprintf(console,"Port:\t\t%s\n",opt->port);
      if(strcmp(opt->path,"/")!=0)
	fprintf(console,"Path:\t\t%s\n",opt->path);
      fprintf(console,"Command:\t%s\n",ks_action_to_string(opt->action));
    }

  if(opt->action==KS_GET)
    {
      keyptr=keylist;

      while(keyptr!=NULL)
	{
	  set_timeout(opt->timeout);

	  if(get_key(keyptr->str)!=KEYSERVER_OK)
	    failed++;

	  keyptr=keyptr->next;
	}
    }
  else if(opt->action==KS_GETNAME)
    {
      keyptr=keylist;

      while(keyptr!=NULL)
	{
	  set_timeout(opt->timeout);

	  if(get_name(keyptr->str)!=KEYSERVER_OK)
	    failed++;

	  keyptr=keyptr->next;
	}
    }
  else if(opt->action==KS_SEND)
    {
      int eof=0;

      do
	{
	  set_timeout(opt->timeout);

	  if(send_key(&eof)!=KEYSERVER_OK)
	    failed++;
	}
      while(!eof);
    }
  else if(opt->action==KS_SEARCH)
    {
      char *searchkey=NULL;
      int len=0;

      set_timeout(opt->timeout);

      /* To search, we stick a space in between each key to search
	 for. */

      keyptr=keylist;
      while(keyptr!=NULL)
	{
	  len+=strlen(keyptr->str)+1;
	  keyptr=keyptr->next;
	}

      searchkey=malloc(len+1);
      if(searchkey==NULL)
	{
	  ret=KEYSERVER_NO_MEMORY;
	  fail_all(keylist,KEYSERVER_NO_MEMORY);
	  goto fail;
	}

      searchkey[0]='\0';

      keyptr=keylist;
      while(keyptr!=NULL)
	{
	  strcat(searchkey,keyptr->str);
	  strcat(searchkey," ");
	  keyptr=keyptr->next;
	}

      /* Nail that last space */
      if(*searchkey)
	searchkey[strlen(searchkey)-1]='\0';

      if(search_key(searchkey)!=KEYSERVER_OK)
	failed++;

      free(searchkey);
    }
  else
    abort();

  if(!failed)
    ret=KEYSERVER_OK;

 fail:
  while(keylist!=NULL)
    {
      struct keylist *current=keylist;
      keylist=keylist->next;
      free(current);
    }

  if(input!=stdin)
    fclose(input);

  if(output!=stdout)
    fclose(output);

  free_ks_options(opt);

  if(curl)
    curl_easy_cleanup(curl);

  free(proxy);

  return ret;
}