/*--- file ripemsoc.c -- Socket-related routines for RIPEM * * Mark Riordan 16 June 1992 * This code is hereby replaced in the public domain. */ #include #include #include #include #ifdef SVR4 #include extern int gettimeofday(struct timeval *); extern int gethostname(const char *, int); #endif #ifdef USE_SOCKETS #include #ifdef AIX #include #endif #ifdef SVR4 #include #endif #if defined(MSDOS) || defined(_MSDOS) #include <4bsddefs.h> /* #include */ #include #endif #include #include #if 1 #include #else extern char *inet_ntoa(); #endif #include #include #ifdef AIX #include #endif #endif #include "global.h" #include "rsaref.h" #include "ripem.h" #include "ripemsop.h" #include "ripemglo.h" #include "keyfield.h" #include "protserv.h" #include "strutilp.h" #include "pubinfop.h" #include "list.h" #include "p.h" #ifdef USE_SOCKETS char *SetupGoodServer P((TypListEntry **entry , struct sockaddr_in *sockName , int *sock )); char *SetupSocket P((char *serverName , int port , struct sockaddr_in *sockName , int *sock )); #endif #ifdef SYSV #define bcopy(a, b, c) memcpy(b, a, c) #endif #ifdef mips extern int errno; #endif /*--- function GetUserRecordFromServer --------------------------------- * * Retrieve a user record (which principally contains the user's * public key) from a server. * * Entry: user is the name of the user whose record is being retrieved. * source is a struct containing the server address. * bytes is the place to put the result. * maxBytes is the size of the "bytes" buffer; * * Exit: bytes has the result of the query (if any), zero-terminated. * serverOK is TRUE if the server seems to be working, else * FALSE if we shouldn't even bother to contact it * again during the execution of this program. * Useful for avoiding multiple long timeouts. * Returns NULL upon success, else error message. */ char * GetUserRecordFromServer(user,source,bytes,maxBytes,serverOK,found) char *user; TypKeySource *source; char *bytes; int maxBytes; BOOL *serverOK; BOOL *found; { #define BUFSIZE 8192 #define LINELEN 128 #define MAX_REDIRECT 3 #define MAX_TRY_TIMEOUT 2 BOOL sending=TRUE; char *err_msg = NULL; #ifdef USE_SOCKETS struct sockaddr_in from_sock_name; static BOOL hostent_is_orig=FALSE; struct timeval timeout; fd_set readfds; #ifdef __MACH__ int sel_width = getdtablesize(); #elif defined(sun) int sel_width = (int) ulimit(4,0L); #else int sel_width = FD_SETSIZE; #endif int retval; int trynum = 1, timeout_sec=4; int sendsize, fromlen, flags=0, received_bytes; struct timeval begtime,endtime; #ifndef SVR4 struct timezone tzone; extern char *inet_ntoa(); #endif long int elapsed; static BOOL first_call = 1; static int sock; static struct sockaddr_in sockname; static char *buf, *reply; static TypListEntry *entry; TypServer *server_ent; char *cptr; BOOL right_user; char temp_buf[LINELEN]; *found = FALSE; /* First time through, allocate some memory from the heap * (this saves room on the stack for those dumb DOS machines), * and find out the IP address of the server, to avoid name * lookups for each user. */ if(first_call) { first_call = 0; buf = malloc(BUFSIZE); reply = malloc(BUFSIZE); sock = socket(AF_INET,SOCK_DGRAM,0); if(sock < 0) { sprintf(ErrMsgTxt,"Error %d opening socket to key server.",errno); return ErrMsgTxt; } } if(!hostent_is_orig) { entry = source->serverlist.firstptr; if(!entry) { *serverOK = FALSE; return "No key server specified."; } err_msg = SetupGoodServer(&entry,&sockname,&sock); if(err_msg) { *serverOK = FALSE; return err_msg; } hostent_is_orig = TRUE; } sprintf(buf,"%s\n%s %s\n",CMD_LOOKUSER_TXT,USER_FIELD,user); sendsize = strlen(buf)+1; while(sending) { trynum++; if(Debug > 1) { fprintf(DebugStream,"Sending request: %s",buf); } #ifdef SVR4 if(Debug>1) gettimeofday(&begtime); #else if(Debug>1) gettimeofday(&begtime,&tzone); #endif /* Send the key request packet to the key server. */ if(sendto(sock, buf, sendsize, 0, (struct sockaddr *)&sockname, sizeof(sockname)) < 0) { sprintf(ErrMsgTxt,"Error %d sending datagram.",errno); return ErrMsgTxt; } /* Wait for reply. */ FD_ZERO(&readfds); FD_SET(sock,&readfds); timeout.tv_sec = timeout_sec; timeout.tv_usec = 0; retval = select(sel_width,&readfds,NULL,NULL,&timeout); if(retval > 0) { /* This must be the reply we're waiting for. Read it. */ fromlen = sizeof(from_sock_name); received_bytes = recvfrom(sock, reply, BUFSIZE, flags, (struct sockaddr *)&from_sock_name, &fromlen); if(received_bytes < 0) { perror("reading reply datagram socket"); sending = FALSE; } else { /* Received a packet */ if(strncmp(reply,RESP_USERINFO_TXT,strlen(RESP_USERINFO_TXT))==0) { /* Server says user info found. */ /* Check to make sure it's for the right user */ right_user = FindUserInRecord(user,reply); if(right_user) { int bytes_to_copy = received_bytes>maxBytes-1 ? maxBytes-1 : received_bytes; /* Copy the result into the caller's buffer */ R_memcpy((unsigned char *)bytes,(unsigned char *)reply, bytes_to_copy); bytes[bytes_to_copy] = '\0'; /* zero terminate buffer */ sending = FALSE; *serverOK = TRUE; *found = TRUE; } else { /* Got reply, but it didn't have the user's key */ goto check_trynum; } } else if(strncmp(reply, RESP_REDIRECT_TXT, strlen(RESP_REDIRECT_TXT))==0) { /* Server has asked that we redirect this request to * another server. */ if(trynum > MAX_REDIRECT) { return "Too many key server redirects"; } if(!CrackKeyField(reply,SERVER_FIELD,temp_buf,LINELEN)) { /* Reply from server is in bad format. */ return "Bad REDIRECT from server."; } else { err_msg = SetupSocket(temp_buf,0, &sockname,&sock); hostent_is_orig = FALSE; if(err_msg) { *serverOK = FALSE; return err_msg; } } if(Debug>1) { fprintf(DebugStream,"Redirected to server %s\n", temp_buf); } } else { /* Server says something else, indicating error. */ /* If the problem is simply that the server does not * have this key on file, try the next server in the list. */ if(strncmp(reply,RESP_NOTFOUND_TXT, strlen(RESP_NOTFOUND_TXT)) == 0) goto try_next_server; sending = FALSE; *found = FALSE; /* Construct error return. */ for(cptr=reply; *cptr!='\n'; cptr++); *cptr = '\0'; sprintf(ErrMsgTxt,"Server could not find key: %s",reply); err_msg = ErrMsgTxt; } if(Debug>1) { /* Do some instrumentation to see how long it took. */ #ifdef SVR4 gettimeofday(&endtime); #else gettimeofday(&endtime,&tzone); #endif if(begtime.tv_usec > endtime.tv_usec) { endtime.tv_usec += 1000000L; endtime.tv_sec--; } elapsed = 1000*(endtime.tv_sec - begtime.tv_sec) + (endtime.tv_usec - begtime.tv_usec)/1000; fprintf(DebugStream," Key server responded in %ld milliseconds.\n",elapsed); } } } else if(retval == 0) { /* We have timed out waiting for a reply to this datagram. * Datagrams do get lost on the Internet, even on good quality * connections (from my benchmarks), so give it a few tries * before giving up. */ fprintf(DebugStream," %s\n", "Timed out waiting for reply from key server."); check_trynum:; if(trynum > MAX_TRY_TIMEOUT) { /* OK, we have sent several datagrams to this server with * no response. So, move to the next server in the list, * if any. */ try_next_server:; entry = entry->nextptr; if(entry) { server_ent = (TypServer *)entry->dataptr; err_msg = SetupGoodServer(&entry,&sockname,&sock); if(err_msg) { *serverOK = FALSE; return err_msg; } trynum = 0; } else { /* No more servers in the list and all previous servers * have timed out with no response. */ if(trynum > MAX_TRY_TIMEOUT) { err_msg = "Timed out waiting for reply from key server."; } else { err_msg = "Requested key not on server."; } sending=FALSE; *serverOK = FALSE; } } } else { /* We shouldn't ever get here... */ perror("upon select:"); } } #else *serverOK = FALSE; err_msg = "Sockets not implemented in this build of RIPEM."; #endif return err_msg; } #ifdef USE_SOCKETS /*--- function SetupGoodServer ----------------------------------------- * * Set up a socket for the next available server in the list * of servers. Skip servers which cannot be looked up via * name service, etc. * * Entry: entry points to a pointer to a list entry for the * next server. * * Exit: entry points to this server; it may be different than * upon entry if we had to skip some servers. * sockName describes the server/port with which we will * be communicating. * sock is a socket bound to the desired address. * Returns NULL if success, else a pointer to error message. */ char * SetupGoodServer(entry,sockName,sock) TypListEntry **entry; struct sockaddr_in *sockName; int *sock; { TypServer *server_ent; BOOL need_server = TRUE; char *err_msg=NULL; while(need_server && *entry) { server_ent = (TypServer *)(*entry)->dataptr; err_msg = SetupSocket(server_ent->servername,server_ent->serverport, sockName,sock); if(err_msg) { if(Debug > 1) { fprintf(DebugStream,"%s\n",err_msg); } *entry = (*entry)->nextptr; } else { need_server = FALSE; } } if(!*entry) { err_msg = "No more key servers in list; giving up on key servers."; } return err_msg; } /*--- function SetupSocket --------------------------------------------- * * Set up a socket. * * Entry: serverName is the name of a server to which the socket * will be bound. * port is the port number on that server. * * Exit: sockName is a structure describing the server/port * with which we will be communicating. * sock is a socket bound to the desired address. * Returns NULL if all OK, else pointer to error message. */ char * SetupSocket(serverName,port,sockName,sock) char *serverName; int port; struct sockaddr_in *sockName; int *sock; { struct hostent *server_ent; int to_port = htons(SERVER_PORT); char *cptr; #if defined(MSDOS) || defined(_MSDOS) int retval; #endif if(serverName) { server_ent = gethostbyname(serverName); } else { return "No public key server was specified."; } if(server_ent == 0) { sprintf(ErrMsgTxt,"Server host unknown: %s.",serverName); return ErrMsgTxt; } bcopy((char *)server_ent->h_addr, (char *) &sockName->sin_addr, server_ent->h_length); sockName->sin_family = AF_INET; if(port) to_port = htons(port); sockName->sin_port = to_port; if(Debug > 2) { cptr = inet_ntoa(sockName->sin_addr); fprintf(DebugStream,"Key server %s's IP addr=%s port=%d\n", serverName,cptr,to_port); } #if defined(MSDOS) || defined(_MSDOS) retval = bind(*sock, (struct sockaddr *)sockName, sizeof(*sockName)); if(retval) { return "Error binding socket."; } #endif return NULL; } #endif /*--- function GetUserRecordFromFinger --------------------------------- * * Retrieve a user record (which principally contains the user's * public key) by accessing the "finger" server on the user's machine. * * Entry: user is the name of the user whose record is being retrieved. * bytes is the place to put the result. * maxBytes is the size of the "bytes" buffer; * * Exit: bytes has the result of the query (if any). * found indicates whether something that looks like a * public key has been obtained. * Returns NULL upon success, else error message. */ char * GetUserRecordFromFinger(user,bytes,maxBytes,found) char *user; char *bytes; int maxBytes; int *found; { BOOL sending=TRUE; char *err_msg = NULL; char *reply = NULL; #ifdef USE_SOCKETS #define FINGER_PORT 79 char username[LINELEN],hostname[LINELEN]; struct hostent *server_ent; struct timeval timeout; fd_set readfds, writefds; #ifdef __MACH__ int sel_width = getdtablesize(); #elif defined(sun) int sel_width = (int) ulimit(4,0L); #else int sel_width = FD_SETSIZE; #endif int retval; int timeout_sec=12; int to_port = htons(FINGER_PORT); int received_bytes; int bytes_so_far=0, bytes_free; struct timeval begtime,endtime; #ifndef SVR4 struct timezone tzone; #endif long int elapsed; BOOL sent_request=FALSE; int sock = -1; struct sockaddr_in sockname; char *cptr; *found = FALSE; /* Allocate some memory from the heap for the reply * and find out the IP address of the server. */ reply = malloc(BUFSIZE); if(!reply) return "Can't allocate memory"; bytes_free = BUFSIZE; cptr = BreakUpEmailAddr(user,username,LINELEN-2,hostname,LINELEN); if(cptr) { #ifdef UNIX strncpy(username,user,LINELEN-2); gethostname(hostname,LINELEN); #else err_msg = cptr; goto endit; #endif } server_ent = gethostbyname(hostname); if(server_ent == 0) { sprintf(ErrMsgTxt,"Server host unknown: %s.",hostname); err_msg = ErrMsgTxt; goto endit; } bcopy((char *)server_ent->h_addr, (char *) &sockname.sin_addr, server_ent->h_length); sockname.sin_family = AF_INET; sockname.sin_port = to_port; if(Debug > 2) { cptr = inet_ntoa(sockname.sin_addr); fprintf(DebugStream,"User's Finger server's IP address is %s port %d\n", cptr,to_port); } sock = socket(AF_INET,SOCK_STREAM,0); if(sock < 0) { sprintf(ErrMsgTxt,"Error %d opening socket to key server.",errno); err_msg = ErrMsgTxt; goto endit; } #if defined(MSDOS) || defined(_MSDOS) retval = bind(sock, (struct sockaddr *)&sockname, sizeof(sockname)); if(retval) { err_msg = "Error binding socket."; goto endit; } #endif if(Debug > 1) { fprintf(DebugStream,"Sending finger request to %s\n",hostname); } #ifdef SVR4 if(Debug>1) gettimeofday(&begtime); #else if(Debug>1) gettimeofday(&begtime,&tzone); #endif /* Connect to the user's host. */ if(connect(sock, (struct sockaddr *)&sockname, sizeof(sockname)) < 0) { sprintf(ErrMsgTxt,"Error %d connecting to finger.",errno); err_msg = ErrMsgTxt; goto endit; } while(sending) { /* Wait for reply. */ FD_ZERO(&readfds); FD_ZERO(&writefds); if(sent_request) { FD_SET(sock,&readfds); } else { FD_SET(sock,&writefds); } timeout.tv_sec = timeout_sec; timeout.tv_usec = 0; retval = select(sel_width,&readfds,&writefds,NULL,&timeout); if(Debug>3) { fprintf(DebugStream,"Accessing finger server; select returned %d\n", retval); } if(retval > 0) { if(sent_request) { /* This must be the reply we're waiting for. Read it. */ received_bytes = read(sock,reply+bytes_so_far,bytes_free); if(received_bytes < 0) { perror("reading reply from finger"); sending = FALSE; err_msg = "Could not connect to finger"; } else if(received_bytes == 0) { close(sock); sending = FALSE; } else { /* Received a response */ bytes_free -= received_bytes; bytes_so_far += received_bytes; } } else { char buf[2*LINELEN+2]; sprintf(buf, "/W %s\r\n", username); if(Debug > 1) { fprintf(DebugStream,"Sending request: %s",buf); } /* We just got connected to the finger server; send our request. */ write(sock,buf,strlen(buf)); sent_request = TRUE; } } else if(retval == 0) { err_msg = "Timed out waiting for reply from finger request."; fprintf(DebugStream," %s\n",err_msg); sending = FALSE; } else { /* We shouldn't ever get here... */ perror("Error reaching finger; select"); sending = FALSE; } } reply[bytes_so_far] = '\0'; if(Debug>1) { /* Do some instrumentation to see how long it took. */ #ifdef SVR4 gettimeofday(&endtime); #else gettimeofday(&endtime,&tzone); #endif if(begtime.tv_usec > endtime.tv_usec) { endtime.tv_usec += 1000000L; endtime.tv_sec--; } elapsed = 1000*(endtime.tv_sec - begtime.tv_sec) + (endtime.tv_usec - begtime.tv_usec)/1000; fprintf(DebugStream, " Finger server responded in %ld milliseconds.\n",elapsed); } if(Debug>2) { fprintf(DebugStream,"Response from finger: \n%s\n",reply); } /* Check to see whether we got the response * to our query was positive. */ /* Copy the result into the caller's buffer */ *found = ExtractPublicKeyLines(reply,bytes,maxBytes); #else err_msg = "Sockets not implemented in this build of RIPEM."; #endif endit:; if(reply) free(reply); #ifdef USE_SOCKETS close(sock); /* May not be valid socket, but no harm done. */ #endif return err_msg; }