p3pmail.c

一个用于扫描邮件服务器的好程序

      Modified this to check decoded quoted-printable.
   */
   if (firstline) {
      firstline = 0;
   } else if (strlen(lastfew) > 0 && (
      (config->image&&(strcasecmp(lastfew,"sr")==0&&strncasecmp(buffer,"c",4)==0))||
      (config->image&&(strcasecmp(lastfew,"s")==0&&strncasecmp(buffer,"rc",5)==0))||
      (config->link&&(strcasecmp(lastfew,"hre")==0&&strncasecmp(buffer,"f",4)==0))||
      (config->link&&(strcasecmp(lastfew,"hr")==0&&strncasecmp(buffer,"ef",5)==0))||
      (config->link&&(strcasecmp(lastfew,"h")==0&&strncasecmp(buffer,"ref",6)==0)))){
      // Ok, we have a match
      buffer[0] = 'x'; // this is enough to scramble the attribute
   }
   /*
      If there is a blank reasonably near the end of the line
      then we save the last few characters of current line for
      further processing with next line else we save an empty string
   */
   p = rindex(buffer, ' ');
   //if (p && (bufferlength  - (p - buffer) - 1 <= FEWCHARACTERS) && (buffer[bufferlength - 1] == '=')) {
   if (p && (bufferlength  - (p - buffer) - 1 <= FEWCHARACTERS)) {
      strcpy(lastfew, p + 1);
   } else {
      lastfew[0] = '\0';
   }
}

void finib64(FILE *bin,FILE *bout,char *line2){

   rewind(bin);
   decode64(bin,bout);
   rewind(bin);
   rewind(bout);
   while((fgets(line2,MAX_BUF_SIZE,bout))!=NULL){
#ifdef DEBUG
      printf("debug-pre64: %i:%s",strlen(line2),line2);
#endif
      parsehtml(line2,strlen(line2));
#ifdef DEBUG
      printf("debug-post64: %i:%s",strlen(line2),line2);
#endif
      fputs(line2,bin);
   }
   rewind(bin);
   rewind(bout);
   encode64(bin,bout);
   rewind(bout);
   while((fgets(line2,MAX_BUF_SIZE,bout))!=NULL){
      printf("%s",line2);
   }
   /* Base64 bug - Treat the symptom */
   printf("\n");
   return;
}

void printversion(){
   printf(
   "\n"
   PROGNAME " " VERSION "\n"
   "(C) 2004 by Jack S. Lai, <[e-mail]>\n"
   "         and Gabriele Carioli, <[e-mail]>\n"
   "\n"
   );
}

void usage(){

   printversion();
   printf(
   "Usage: %s [options]\n"
   "\n"
   "where options are:\n"
   "  -h, --help     Prints this text\n"
   "  -i, --image    Allow html image src tag\n"
   "                 (default obfuscate)\n"
   "  -l, --link     Allow html link tag\n"
   "                 (default obfuscate)\n"
   "  -v, --version  Prints version information\n"
   ,PROGNAME);
}

int main(int argc, char **argv){
   char line[MAX_BUF_SIZE],line2[MAX_BUF_SIZE];
   int pasthdr=0,html=0,b64=0,toggle=0,skip=0,qp=0,bdone=0,eom=0;
   int newlen=0;
   FILE *qin=NULL;
   FILE *qout=NULL;
   FILE *bin=NULL;
   FILE *bout=NULL;

   //parse options:
   struct option long_options[] = {
      {"help",    no_argument, NULL, 'h'},
      {"image",   no_argument, NULL, 'i'},
      {"link",    no_argument, NULL, 'l'},
      {"version", no_argument, NULL, 'v'},
      {NULL,      no_argument, NULL, 0 }
   };

   char getoptparam[] = "hilv";
   void switchoption(char opt, char * arg, char * optstr, char * where, int state){
      switch (opt){
         case 'h':
            usage();
            exit(0);
            break;
         case 'i':
            config->image=0;
            break;
         case 'l':
            config->link=0;
            break;
         case 'v':
            printversion();
            exit(0);
            break;
      default:
         fprintf(stderr, "p3scan: %s Option '%s' isn't known\n", where, optstr);
         exit(1);
      }
   }

   void parseargs(int c, char **v, char * where, int state){
      int option, option_index = 0;
      opterr=0;
      optind=1;
      while (1){
         option = getopt_long(c, v, getoptparam,
         long_options, &option_index);
         if (option == EOF) break;
         switchoption(option, optarg, v[optind-1], where, state);
      }
      if (state != 1 && optind < c){
         while (optind < c)
      fprintf(stderr, "%s Unknown option '%s'\n", where, v[optind++]);
      }
   }
   if ((config=malloc(sizeof(struct configuration_t)))==NULL){
      fprintf(stderr, "malloc error\n");
      exit(1);
   }
   /* set defaults */
   config->image=1;
   config->link=1;
   parseargs(argc, argv, "\t[cmdlineparm]", 1);

   //start processing input:
   while ((fgets(line,MAX_BUF_SIZE,stdin))!=NULL){
      if (strncasecmp(line,"Content-Type: text/html",23)==0) html=1;
      if (strncasecmp(line,"Content-Type: text/plain",23)==0) html=0;
      if (strncasecmp(line,"Content-Type: image",19)==0) skip=1;
      if (strncasecmp(line,"Content-Type: audio",19)==0) skip=1;
      if (strncasecmp(line,"Content-Type: video",19)==0) skip=1;
      if (strncasecmp(line,"Content-Type: application",25)==0) skip=1;
      if (strncasecmp(line,"Content-Disposition: attachment",31)==0) skip=1;
      if (strncasecmp(line,"Content-Transfer-Encoding: base64",33)==0 && !skip){
         b64=1;
         bin=tmpfile();
         bout=tmpfile();
#ifdef DEBUG
         if (html) printf("\nFound HTML, Base64 only\n");
#endif
      }
      //if ((strncasecmp(line,"Content-Transfer-Encoding: quoted-printable",43)==0) && html){
      if ((strcasecmp(line,"Content-Transfer-Encoding: quoted-printable\n")==0) && html){
         qp=1;
         qin=tmpfile();
         qout=tmpfile();
#ifdef DEBUG
         printf("\nFound HTML, quoted-printable\n");
#endif
      }
      // at end of message?
      if ((strncmp(line,".\n",2)==0) || (strncmp(line,".\r",2)==0)) eom=1;
      /* Look for end of header*/
      if (!pasthdr){
         if ((*line == '\n') || (*line == '\r')){
            pasthdr=1;
            printf("X-HTML-Parser: %s %s by %s\n",PROGNAME,VERSION,AUTHOR);
            toggle++;
         }
         printf("%s",line);
      } else {
         if (html){
            // Quoted Printable
            if (qp > 1){
               // Done?
               if((strncmp(line,"--",2)==0) || eom){
#ifdef DEBUG
                  printf("\nfound end of qp\n");
#endif
                  qp=0;
                  rewind(qin);
#ifdef DEBUG
                  while((fgets(line2,MAX_BUF_SIZE,qin))!=NULL) printf("pre-decode: %s",line2);
                  rewind(qin);
                  printf("\ngoing to decode...\n");
#endif
                  qdecode(qin,qout);
#ifdef DEBUG
                  printf("\ndecode complete.\n");
#endif
                  rewind(qin);
                  rewind(qout);
                  while((fgets(line2,MAX_BUF_SIZE,qout))!=NULL){
#ifdef DEBUG
                     printf("debug-qp: %s",line2);
#endif
                     parsehtml(line2,strlen(line2));
                     fputs(line2,qin);
                  }
                  rewind(qin);
                  rewind(qout);
                  qencode(qin,qout);
                  fclose(qin); // don't need it anymore
                  rewind(qout);
                  while((fgets(line2,MAX_BUF_SIZE,qout))!=NULL){
                     printf("%s",line2);
                  }
                  fclose(qout); // don't need it anymore
               }
               // No, not done, continue...
               // writing eom, reset eom variable so it is not written again
               //if ((strncmp(line,".\n",2)==0) || (strncmp(line,".\r",2)==0)) eom=0;
               if (qp) fputs(line,qin);
            }
            // Base64
            if (b64){
               if(skip){
                  printf("%s",line);
               }else{
                  if (strncasecmp(line,"Content-Transfer-Encoding: base64",33)==0) printf("%s",line);
                  // Done?
                  if (eom) bdone=1;
                  if (bdone){
                     b64=0;
                     finib64(bin,bout,line2);
                     fclose(bin); // don't need it anymore
                     fclose(bout); // don't need it anymore
                  }
                  // No, continue...
                  // do we have a base64 encoded line?
                  if (newlen==0 && strlen(line) > 40) newlen = strlen(line) -1; // 40 is an arbitrary number
                  if (newlen > 0){
                     fputs(line,bin);
                     if(strlen(line)==1) bdone=1;
                     // wrote eom, reset eom variable so it is not written again
                     //if((strncmp(line,".\n",2)) || (strncmp(line,".\r",2))) eom=0;
                  }
#ifdef DEBUG
                  printf("len:%i-bdone-%i:%s",strlen(line),bdone,line);
#endif
               }
            }
            if (!qp && !b64){
#ifdef DEBUG
               printf("debug: %s",line);
#endif
               parsehtml(line,strlen(line));
               // writing eom, reset eom variable so it is not written again
               //if ((strncmp(line,".\n",2)==0) || (strncmp(line,".\r",2)==0)) eom=0;
               printf("%s",line);
            }
            if ((*line == '\n') || (*line =='\r')) toggle++;
            if (qp==1){
               printf("%s",line);
               qp++;
            }
         } else {
           /* dont parse non-html*/
            // writing eom, reset eom variable so it is not written again
            //if ((strncmp(line,".\n",2)==0) || (strncmp(line,".\r",2)==0)) eom=0;
            if (!bdone) printf("%s",line);
         }
         /* Keep skipping until past the header */
      }
   }
   /* All done, clean up */
   if(b64){ // we are not done!
      b64=0;
#ifdef DEBUG
      printf("\nBase64 incomplete, finishing...\n"      );
#endif
      finib64(bin,bout,line2);
   }
/*
   if (eom){
      // eom was not written.
#ifdef DEBUG
      printf("\nGenerating eom\n");
#endif
      printf("\n.");
   }
*/
#ifdef DEBUG2
   fprintf(stderr,"%i",b64eom);
#endif
   return 0;
}