/* * smtp.c -- code for speaking SMTP to a listener port * * Concept due to Harry Hochheiser. Implementation by ESR. Cleanup and * strict RFC821 compliance by Cameron MacPherson. * * Copyright 1997 Eric S. Raymond * For license terms, see the file COPYING in this directory. */ #include <stdio.h> #include <unistd.h> #include <string.h> #include "fetchmail.h" #include "socket.h" #include "smtp.h" #include "config.h" #include "i18n.h" struct opt { const char *name; int value; }; static struct opt extensions[] = { {"8BITMIME", ESMTP_8BITMIME}, {"SIZE", ESMTP_SIZE}, {"ETRN", ESMTP_ETRN}, {"AUTH ", ESMTP_AUTH}, #ifdef ODMR_ENABLE {"ATRN", ESMTP_ATRN}, #endif /* ODMR_ENABLE */ {(char *)NULL, 0}, }; char smtp_response[MSGBUFSIZE]; static char smtp_mode = 'S'; void SMTP_setmode(char sl) /* set whether we are speaking SMTP or LMTP */ { smtp_mode = sl; } int SMTP_helo(int sock,const char *host) /* send a "HELO" message to the SMTP listener */ { int ok; SockPrintf(sock,"HELO %s\r\n", host); if (outlevel >= O_MONITOR) report(stdout, "SMTP> HELO %s\n", host); ok = SMTP_ok(sock); return ok; } static void SMTP_auth_error(int sock, char *msg) { SockPrintf(sock, "*\r\n"); SockRead(sock, smtp_response, sizeof(smtp_response) - 1); if (outlevel >= O_MONITOR) report(stdout, msg); } static void SMTP_auth(int sock, char *username, char *password, char *buf) /* ESMTP Authentication support for fetchmail by Wojciech Polak */ { int c; char *p = 0; char b64buf[512]; char tmp[512]; if (!username || !password) return; memset(b64buf, 0, sizeof(b64buf)); memset(tmp, 0, sizeof(tmp)); if (strstr(buf, "CRAM-MD5")) { unsigned char digest[16]; memset(digest, 0, sizeof(digest)); if (outlevel >= O_MONITOR) report(stdout, GT_("ESMTP CRAM-MD5 Authentication...\n")); SockPrintf(sock, "AUTH CRAM-MD5\r\n"); SockRead(sock, smtp_response, sizeof(smtp_response) - 1); strncpy(tmp, smtp_response, sizeof(tmp)); if (strncmp(tmp, "334 ", 4)) { /* Server rejects AUTH */ SMTP_auth_error(sock, GT_("Server rejected the AUTH command.\n")); return; } p = strchr(tmp, ' '); p++; /* (hmh) from64tobits will not NULL-terminate strings! */ if (from64tobits(b64buf, p, sizeof(b64buf) - 1) <= 0) { SMTP_auth_error(sock, GT_("Bad base64 reply from server.\n")); return; } if (outlevel >= O_DEBUG) report(stdout, GT_("Challenge decoded: %s\n"), b64buf); hmac_md5(password, strlen(password), b64buf, strlen(b64buf), digest, sizeof(digest)); #ifdef HAVE_SNPRINTF snprintf(tmp, sizeof(tmp), #else sprintf(tmp, #endif /* HAVE_SNPRINTF */ "%s %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x", username, digest[0], digest[1], digest[2], digest[3], digest[4], digest[5], digest[6], digest[7], digest[8], digest[9], digest[10], digest[11], digest[12], digest[13], digest[14], digest[15]); to64frombits(b64buf, tmp, strlen(tmp)); SockPrintf(sock, "%s\r\n", b64buf); SMTP_ok(sock); } else if (strstr(buf, "PLAIN")) { int len; if (outlevel >= O_MONITOR) report(stdout, GT_("ESMTP PLAIN Authentication...\n")); #ifdef HAVE_SNPRINTF snprintf(tmp, sizeof(tmp), #else sprintf(tmp, #endif /* HAVE_SNPRINTF */ "^%s^%s", username, password); len = strlen(tmp); for (c = len - 1; c >= 0; c--) { if (tmp[c] == '^') tmp[c] = '\0'; } to64frombits(b64buf, tmp, len); SockPrintf(sock, "AUTH PLAIN %s\r\n", b64buf); SMTP_ok(sock); } else if (strstr(buf, "LOGIN")) { if (outlevel >= O_MONITOR) report(stdout, GT_("ESMTP LOGIN Authentication...\n")); SockPrintf(sock, "AUTH LOGIN\r\n"); SockRead(sock, smtp_response, sizeof(smtp_response) - 1); strncpy(tmp, smtp_response, sizeof(tmp)); if (strncmp(tmp, "334 ", 4)) { /* Server rejects AUTH */ SMTP_auth_error(sock, GT_("Server rejected the AUTH command.\n")); return; } p = strchr(tmp, ' '); p++; if (from64tobits(b64buf, p, sizeof(b64buf) - 1) <= 0) { SMTP_auth_error(sock, GT_("Bad base64 reply from server.\n")); return; } to64frombits(b64buf, username, strlen(username)); SockPrintf(sock, "%s\r\n", b64buf); SockRead(sock, smtp_response, sizeof(smtp_response) - 1); strncpy(tmp, smtp_response, sizeof(tmp)); p = strchr(tmp, ' '); if (!p) { SMTP_auth_error(sock, GT_("Bad base64 reply from server.\n")); return; } p++; memset(b64buf, 0, sizeof(b64buf)); if (from64tobits(b64buf, p, sizeof(b64buf) - 1) <= 0) { SMTP_auth_error(sock, GT_("Bad base64 reply from server.\n")); return; } to64frombits(b64buf, password, strlen(password)); SockPrintf(sock, "%s\r\n", b64buf); SMTP_ok(sock); } return; } int SMTP_ehlo(int sock, const char *host, char *name, char *password, int *opt) /* send a "EHLO" message to the SMTP listener, return extension status bits */ { struct opt *hp; char auth_response[511]; SockPrintf(sock,"%cHLO %s\r\n", (smtp_mode == 'S') ? 'E' : smtp_mode, host); if (outlevel >= O_MONITOR) report(stdout, "%cMTP> %cHLO %s\n", smtp_mode, (smtp_mode == 'S') ? 'E' : smtp_mode, host); *opt = 0; while ((SockRead(sock, smtp_response, sizeof(smtp_response)-1)) != -1) { int n = strlen(smtp_response); if (smtp_response[strlen(smtp_response)-1] == '\n') smtp_response[strlen(smtp_response)-1] = '\0'; if (smtp_response[strlen(smtp_response)-1] == '\r') smtp_response[strlen(smtp_response)-1] = '\0'; if (n < 4) return SM_ERROR; smtp_response[n] = '\0'; if (outlevel >= O_MONITOR) report(stdout, "SMTP< %s\n", smtp_response); for (hp = extensions; hp->name; hp++) if (!strncasecmp(hp->name, smtp_response+4, strlen(hp->name))) { *opt |= hp->value; if (strncmp(hp->name, "AUTH ", 5) == 0) strncpy(auth_response, smtp_response, sizeof(auth_response)); } if ((smtp_response[0] == '1' || smtp_response[0] == '2' || smtp_response[0] == '3') && smtp_response[3] == ' ') { if (*opt & ESMTP_AUTH) SMTP_auth(sock, name, password, auth_response); return SM_OK; } else if (smtp_response[3] != '-') return SM_ERROR; } return SM_UNRECOVERABLE; } int SMTP_from(int sock, const char *from, const char *opts) /* send a "MAIL FROM:" message to the SMTP listener */ { int ok; char buf[MSGBUFSIZE]; if (strchr(from, '<')) #ifdef HAVE_SNPRINTF snprintf(buf, sizeof(buf), #else sprintf(buf, #endif /* HAVE_SNPRINTF */ "MAIL FROM: %s", from); else #ifdef HAVE_SNPRINTF snprintf(buf, sizeof(buf), #else sprintf(buf, #endif /* HAVE_SNPRINTF */ "MAIL FROM:<%s>", from); if (opts) #ifdef HAVE_SNPRINTF snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "%s", opts); #else strcat(buf, opts); #endif /* HAVE_SNPRINTF */ SockPrintf(sock,"%s\r\n", buf); if (outlevel >= O_MONITOR) report(stdout, "%cMTP> %s\n", smtp_mode, buf); ok = SMTP_ok(sock); return ok; } int SMTP_rcpt(int sock, const char *to) /* send a "RCPT TO:" message to the SMTP listener */ { int ok; SockPrintf(sock,"RCPT TO:<%s>\r\n", to); if (outlevel >= O_MONITOR) report(stdout, "%cMTP> RCPT TO:<%s>\n", smtp_mode, to); ok = SMTP_ok(sock); return ok; } int SMTP_data(int sock) /* send a "DATA" message to the SMTP listener */ { int ok; SockPrintf(sock,"DATA\r\n"); if (outlevel >= O_MONITOR) report(stdout, "%cMTP> DATA\n", smtp_mode); ok = SMTP_ok(sock); return ok; } int SMTP_rset(int sock) /* send a "RSET" message to the SMTP listener */ { int ok; SockPrintf(sock,"RSET\r\n"); if (outlevel >= O_MONITOR) report(stdout, "%cMTP> RSET\n", smtp_mode); ok = SMTP_ok(sock); return ok; } int SMTP_quit(int sock) /* send a "QUIT" message to the SMTP listener */ { int ok; SockPrintf(sock,"QUIT\r\n"); if (outlevel >= O_MONITOR) report(stdout, "%cMTP> QUIT\n", smtp_mode); ok = SMTP_ok(sock); return ok; } int SMTP_eom(int sock) /* send a message data terminator to the SMTP listener */ { int ok; SockPrintf(sock,".\r\n"); if (outlevel >= O_MONITOR) report(stdout, "%cMTP>. (EOM)\n", smtp_mode); /* * When doing LMTP, must process many of these at the outer level. */ if (smtp_mode == 'S') ok = SMTP_ok(sock); else ok = SM_OK; return ok; } int SMTP_ok(int sock) /* returns status of SMTP connection */ { while ((SockRead(sock, smtp_response, sizeof(smtp_response)-1)) != -1) { int n = strlen(smtp_response); if (smtp_response[strlen(smtp_response)-1] == '\n') smtp_response[strlen(smtp_response)-1] = '\0'; if (smtp_response[strlen(smtp_response)-1] == '\r') smtp_response[strlen(smtp_response)-1] = '\0'; if (n < 4) return SM_ERROR; smtp_response[n] = '\0'; if (outlevel >= O_MONITOR) report(stdout, "%cMTP< %s\n", smtp_mode, smtp_response); if ((smtp_response[0] == '1' || smtp_response[0] == '2' || smtp_response[0] == '3') && smtp_response[3] == ' ') return SM_OK; else if (smtp_response[3] != '-') return SM_ERROR; } return SM_UNRECOVERABLE; } /* smtp.c ends here */