/* * imap.c -- IMAP2bis/IMAP4 protocol methods * * Copyright 1997 by Eric S. Raymond * For license terms, see the file COPYING in this directory. */ #include "config.h" #include #include #include #if defined(STDC_HEADERS) #include #endif #include "fetchmail.h" #include "socket.h" #ifdef KERBEROS_V4 #ifdef KERBEROS_V5 #include #include #else #if defined (__bsdi__) #include #define krb_get_err_text(e) (krb_err_txt[e]) #endif #if defined(__NetBSD__) || (__FreeBSD__) || defined(__linux__) #define krb_get_err_text(e) (krb_err_txt[e]) #endif #include #endif #endif /* KERBEROS_V4 */ #ifdef GSSAPI #ifdef HAVE_GSSAPI_H #include #endif #ifdef HAVE_GSSAPI_GSSAPI_H #include #endif #ifdef HAVE_GSSAPI_GSSAPI_GENERIC_H #include #endif #ifndef HAVE_GSS_C_NT_HOSTBASED_SERVICE #define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name #endif #endif #include "i18n.h" #if OPIE_ENABLE #include #endif /* OPIE_ENABLE */ #ifndef strstr /* glibc-2.1 declares this as a macro */ extern char *strstr(); /* needed on sysV68 R3V7.1. */ #endif /* strstr */ /* imap_version values */ #define IMAP2 -1 /* IMAP2 or IMAP2BIS, RFC1176 */ #define IMAP4 0 /* IMAP4 rev 0, RFC1730 */ #define IMAP4rev1 1 /* IMAP4 rev 1, RFC2060 */ static int count, unseen, deletions, imap_version, preauth; static int expunged, expunge_period, saved_timeout; static flag do_idle; static char capabilities[MSGBUFSIZE+1]; static unsigned int *unseen_messages; int imap_ok(int sock, char *argbuf) /* parse command response */ { char buf[MSGBUFSIZE+1]; do { int ok; char *cp; if ((ok = gen_recv(sock, buf, sizeof(buf)))) return(ok); /* all tokens in responses are caseblind */ for (cp = buf; *cp; cp++) if (islower(*cp)) *cp = toupper(*cp); /* interpret untagged status responses */ if (strstr(buf, "* CAPABILITY")) strncpy(capabilities, buf + 12, sizeof(capabilities)); else if (strstr(buf, "EXISTS")) { count = atoi(buf+2); /* * Nasty kluge to handle RFC2177 IDLE. If we know we're idling * we can't wait for the tag matching the IDLE; we have to tell the * server the IDLE is finished by shipping back a DONE when we * see an EXISTS. Only after that will a tagged response be * shipped. The idling flag also gets cleared on a timeout. */ if (stage == STAGE_IDLE) { /* we do our own write and report here to disable tagging */ SockWrite(sock, "DONE\r\n", 6); if (outlevel >= O_MONITOR) report(stdout, "IMAP> DONE\n"); mytimeout = saved_timeout; stage = STAGE_FETCH; } } else if (strstr(buf, "PREAUTH")) preauth = TRUE; } while (tag[0] != '\0' && strncmp(buf, tag, strlen(tag))); if (tag[0] == '\0') { if (argbuf) strcpy(argbuf, buf); return(PS_SUCCESS); } else { char *cp; /* skip the tag */ for (cp = buf; !isspace(*cp); cp++) continue; while (isspace(*cp)) cp++; if (strncmp(cp, "OK", 2) == 0) { if (argbuf) strcpy(argbuf, cp); return(PS_SUCCESS); } else if (strncmp(cp, "BAD", 3) == 0) return(PS_ERROR); else if (strncmp(cp, "NO", 2) == 0) { if (stage == STAGE_GETAUTH) return(PS_AUTHFAIL); /* RFC2060, 6.2.2 */ else return(PS_ERROR); } else return(PS_PROTOCOL); } } #if OPIE_ENABLE static int do_otp(int sock, struct query *ctl) { int i, rval; char buffer[128]; char challenge[OPIE_CHALLENGE_MAX+1]; char response[OPIE_RESPONSE_MAX+1]; gen_send(sock, "AUTHENTICATE X-OTP"); if (rval = gen_recv(sock, buffer, sizeof(buffer))) return rval; if ((i = from64tobits(challenge, buffer)) < 0) { report(stderr, _("Could not decode initial BASE64 challenge\n")); return PS_AUTHFAIL; }; to64frombits(buffer, ctl->remotename, strlen(ctl->remotename)); if (outlevel >= O_MONITOR) report(stdout, "IMAP> %s\n", buffer); /* best not to count on the challenge code handling multiple writes */ strcat(buffer, "\r\n"); SockWrite(sock, buffer, strlen(buffer)); if (rval = gen_recv(sock, buffer, sizeof(buffer))) return rval; if ((i = from64tobits(challenge, buffer)) < 0) { report(stderr, _("Could not decode OTP challenge\n")); return PS_AUTHFAIL; }; rval = opiegenerator(challenge, !strcmp(ctl->password, "opie") ? "" : ctl->password, response); if ((rval == -2) && !run.poll_interval) { char secret[OPIE_SECRET_MAX+1]; fprintf(stderr, _("Secret pass phrase: ")); if (opiereadpass(secret, sizeof(secret), 0)) rval = opiegenerator(challenge, secret, response); memset(secret, 0, sizeof(secret)); }; if (rval) return(PS_AUTHFAIL); to64frombits(buffer, response, strlen(response)); if (outlevel >= O_MONITOR) report(stdout, "IMAP> %s\n", buffer); strcat(buffer, "\r\n"); SockWrite(sock, buffer, strlen(buffer)); if (rval = gen_recv(sock, buffer, sizeof(buffer))) return rval; if (strstr(buffer, "OK")) return PS_SUCCESS; else return PS_AUTHFAIL; }; #endif /* OPIE_ENABLE */ #ifdef KERBEROS_V4 #if SIZEOF_INT == 4 typedef int int32; #elif SIZEOF_SHORT == 4 typedef short int32; #elif SIZEOF_LONG == 4 typedef long int32; #else #error Cannot deduce a 32-bit-type #endif static int do_rfc1731(int sock, char *truename) /* authenticate as per RFC1731 -- note 32-bit integer requirement here */ { int result = 0, len; char buf1[4096], buf2[4096]; union { int32 cint; char cstr[4]; } challenge1, challenge2; char srvinst[INST_SZ]; char *p; char srvrealm[REALM_SZ]; KTEXT_ST authenticator; CREDENTIALS credentials; char tktuser[MAX_K_NAME_SZ+1+INST_SZ+1+REALM_SZ+1]; char tktinst[INST_SZ]; char tktrealm[REALM_SZ]; des_cblock session; des_key_schedule schedule; gen_send(sock, "AUTHENTICATE KERBEROS_V4"); /* The data encoded in the first ready response contains a random * 32-bit number in network byte order. The client should respond * with a Kerberos ticket and an authenticator for the principal * "imap.hostname@realm", where "hostname" is the first component * of the host name of the server with all letters in lower case * and where "realm" is the Kerberos realm of the server. The * encrypted checksum field included within the Kerberos * authenticator should contain the server provided 32-bit number * in network byte order. */ if (result = gen_recv(sock, buf1, sizeof buf1)) { return result; } len = from64tobits(challenge1.cstr, buf1); if (len < 0) { report(stderr, _("could not decode initial BASE64 challenge\n")); return PS_AUTHFAIL; } /* this patch by Dan Root solves an endianess * problem. */ { char tmp[4]; *(int *)tmp = ntohl(*(int *) challenge1.cstr); memcpy(challenge1.cstr, tmp, sizeof(tmp)); } /* Client responds with a Kerberos ticket and an authenticator for * the principal "imap.hostname@realm" where "hostname" is the * first component of the host name of the server with all letters * in lower case and where "realm" is the Kerberos realm of the * server. The encrypted checksum field included within the * Kerberos authenticator should contain the server-provided * 32-bit number in network byte order. */ strncpy(srvinst, truename, (sizeof srvinst)-1); srvinst[(sizeof srvinst)-1] = '\0'; for (p = srvinst; *p; p++) { if (isupper(*p)) { *p = tolower(*p); } } strncpy(srvrealm, (char *)krb_realmofhost(srvinst), (sizeof srvrealm)-1); srvrealm[(sizeof srvrealm)-1] = '\0'; if (p = strchr(srvinst, '.')) { *p = '\0'; } result = krb_mk_req(&authenticator, "imap", srvinst, srvrealm, 0); if (result) { report(stderr, "krb_mq_req: %s\n", krb_get_err_text(result)); return PS_AUTHFAIL; } result = krb_get_cred("imap", srvinst, srvrealm, &credentials); if (result) { report(stderr, "krb_get_cred: %s\n", krb_get_err_text(result)); return PS_AUTHFAIL; } memcpy(session, credentials.session, sizeof session); memset(&credentials, 0, sizeof credentials); des_key_sched(session, schedule); result = krb_get_tf_fullname(TKT_FILE, tktuser, tktinst, tktrealm); if (result) { report(stderr, "krb_get_tf_fullname: %s\n", krb_get_err_text(result)); return PS_AUTHFAIL; } #ifdef __UNUSED__ /* * Andrew H. Chatham alleges that this check * is not necessary and has consistently been messing him up. */ if (strcmp(tktuser, user) != 0) { report(stderr, _("principal %s in ticket does not match -u %s\n"), tktuser, user); return PS_AUTHFAIL; } #endif /* __UNUSED__ */ if (tktinst[0]) { report(stderr, _("non-null instance (%s) might cause strange behavior\n"), tktinst); strcat(tktuser, "."); strcat(tktuser, tktinst); } if (strcmp(tktrealm, srvrealm) != 0) { strcat(tktuser, "@"); strcat(tktuser, tktrealm); } result = krb_mk_req(&authenticator, "imap", srvinst, srvrealm, challenge1.cint); if (result) { report(stderr, "krb_mq_req: %s\n", krb_get_err_text(result)); return PS_AUTHFAIL; } to64frombits(buf1, authenticator.dat, authenticator.length); if (outlevel >= O_MONITOR) { report(stdout, "IMAP> %s\n", buf1); } strcat(buf1, "\r\n"); SockWrite(sock, buf1, strlen(buf1)); /* Upon decrypting and verifying the ticket and authenticator, the * server should verify that the contained checksum field equals * the original server provided random 32-bit number. Should the * verification be successful, the server must add one to the * checksum and construct 8 octets of data, with the first four * octets containing the incremented checksum in network byte * order, the fifth octet containing a bit-mask specifying the * protection mechanisms supported by the server, and the sixth * through eighth octets containing, in network byte order, the * maximum cipher-text buffer size the server is able to receive. * The server must encrypt the 8 octets of data in the session key * and issue that encrypted data in a second ready response. The * client should consider the server authenticated if the first * four octets the un-encrypted data is equal to one plus the * checksum it previously sent. */ if (result = gen_recv(sock, buf1, sizeof buf1)) return result; /* The client must construct data with the first four octets * containing the original server-issued checksum in network byte * order, the fifth octet containing the bit-mask specifying the * selected protection mechanism, the sixth through eighth octets * containing in network byte order the maximum cipher-text buffer * size the client is able to receive, and the following octets * containing a user name string. The client must then append * from one to eight octets so that the length of the data is a * multiple of eight octets. The client must then PCBC encrypt the * data with the session key and respond to the second ready * response with the encrypted data. The server decrypts the data * and verifies the contained checksum. The username field * identifies the user for whom subsequent IMAP operations are to * be performed; the server must verify that the principal * identified in the Kerberos ticket is authorized to connect as * that user. After these verifications, the authentication * process is complete. */ len = from64tobits(buf2, buf1); if (len < 0) { report(stderr, _("could not decode BASE64 ready response\n")); return PS_AUTHFAIL; } des_ecb_encrypt((des_cblock *)buf2, (des_cblock *)buf2, schedule, 0); memcpy(challenge2.cstr, buf2, 4); if (ntohl(challenge2.cint) != challenge1.cint + 1) { report(stderr, _("challenge mismatch\n")); return PS_AUTHFAIL; } memset(authenticator.dat, 0, sizeof authenticator.dat); result = htonl(challenge1.cint); memcpy(authenticator.dat, &result, sizeof result); /* The protection mechanisms and their corresponding bit-masks are as * follows: * * 1 No protection mechanism * 2 Integrity (krb_mk_safe) protection * 4 Privacy (krb_mk_priv) protection */ authenticator.dat[4] = 1; len = strlen(tktuser); strncpy(authenticator.dat+8, tktuser, len); authenticator.length = len + 8 + 1; while (authenticator.length & 7) { authenticator.length++; } des_pcbc_encrypt((des_cblock *)authenticator.dat, (des_cblock *)authenticator.dat, authenticator.length, schedule, &session, 1); to64frombits(buf1, authenticator.dat, authenticator.length); if (outlevel >= O_MONITOR) { report(stdout, "IMAP> %s\n", buf1); } strcat(buf1, "\r\n"); SockWrite(sock, buf1, strlen(buf1)); if (result = gen_recv(sock, buf1, sizeof buf1)) return result; if (strstr(buf1, "OK")) { return PS_SUCCESS; } else { return PS_AUTHFAIL; } } #endif /* KERBEROS_V4 */ #ifdef GSSAPI #define GSSAUTH_P_NONE 1 #define GSSAUTH_P_INTEGRITY 2 #define GSSAUTH_P_PRIVACY 4 static int do_gssauth(int sock, char *hostname, char *username) { gss_buffer_desc request_buf, send_token; gss_buffer_t sec_token; gss_name_t target_name; gss_ctx_id_t context; gss_OID mech_name; gss_qop_t quality; int cflags; OM_uint32 maj_stat, min_stat; char buf1[8192], buf2[8192], server_conf_flags; unsigned long buf_size; int result; /* first things first: get an imap ticket for host */ sprintf(buf1, "imap@%s", hostname); request_buf.value = buf1; request_buf.length = strlen(buf1) + 1; maj_stat = gss_import_name(&min_stat, &request_buf, GSS_C_NT_HOSTBASED_SERVICE, &target_name); if (maj_stat != GSS_S_COMPLETE) { report(stderr, _("Couldn't get service name for [%s]\n"), buf1); return PS_AUTHFAIL; } else if (outlevel >= O_DEBUG) { maj_stat = gss_display_name(&min_stat, target_name, &request_buf, &mech_name); report(stderr, _("Using service name [%s]\n"),request_buf.value); maj_stat = gss_release_buffer(&min_stat, &request_buf); } gen_send(sock, "AUTHENTICATE GSSAPI"); /* upon receipt of the GSSAPI authentication request, server returns * null data ready response. */ if (result = gen_recv(sock, buf1, sizeof buf1)) { return result; } /* now start the security context initialisation loop... */ sec_token = GSS_C_NO_BUFFER; context = GSS_C_NO_CONTEXT; if (outlevel >= O_VERBOSE) report(stdout, _("Sending credentials\n")); do { send_token.length = 0; send_token.value = NULL; maj_stat = gss_init_sec_context(&min_stat, GSS_C_NO_CREDENTIAL, &context, target_name, GSS_C_NO_OID, GSS_C_MUTUAL_FLAG | GSS_C_SEQUENCE_FLAG, 0, GSS_C_NO_CHANNEL_BINDINGS, sec_token, NULL, &send_token, NULL, NULL); if (maj_stat!=GSS_S_COMPLETE && maj_stat!=GSS_S_CONTINUE_NEEDED) { report(stderr, _("Error exchanging credentials\n")); gss_release_name(&min_stat, &target_name); /* wake up server and await NO response */ SockWrite(sock, "\r\n", 2); if (result = gen_recv(sock, buf1, sizeof buf1)) return result; return PS_AUTHFAIL; } to64frombits(buf1, send_token.value, send_token.length); gss_release_buffer(&min_stat, &send_token); strcat(buf1, "\r\n"); SockWrite(sock, buf1, strlen(buf1)); if (outlevel >= O_MONITOR) report(stdout, "IMAP> %s\n", buf1); if (maj_stat == GSS_S_CONTINUE_NEEDED) { if (result = gen_recv(sock, buf1, sizeof buf1)) { gss_release_name(&min_stat, &target_name); return result; } request_buf.length = from64tobits(buf2, buf1 + 2); request_buf.value = buf2; sec_token = &request_buf; } } while (maj_stat == GSS_S_CONTINUE_NEEDED); gss_release_name(&min_stat, &target_name); /* get security flags and buffer size */ if (result = gen_recv(sock, buf1, sizeof buf1)) { return result; } request_buf.length = from64tobits(buf2, buf1 + 2); request_buf.value = buf2; maj_stat = gss_unwrap(&min_stat, context, &request_buf, &send_token, &cflags, &quality); if (maj_stat != GSS_S_COMPLETE) { report(stderr, _("Couldn't unwrap security level data\n")); gss_release_buffer(&min_stat, &send_token); return PS_AUTHFAIL; } if (outlevel >= O_DEBUG) report(stdout, _("Credential exchange complete\n")); /* first octet is security levels supported. We want none, for now */ server_conf_flags = ((char *)send_token.value)[0]; if ( !(((char *)send_token.value)[0] & GSSAUTH_P_NONE) ) { report(stderr, _("Server requires integrity and/or privacy\n")); gss_release_buffer(&min_stat, &send_token); return PS_AUTHFAIL; } ((char *)send_token.value)[0] = 0; buf_size = ntohl(*((long *)send_token.value)); /* we don't care about buffer size if we don't wrap data */ gss_release_buffer(&min_stat, &send_token); if (outlevel >= O_DEBUG) { report(stdout, _("Unwrapped security level flags: %s%s%s\n"), server_conf_flags & GSSAUTH_P_NONE ? "N" : "-", server_conf_flags & GSSAUTH_P_INTEGRITY ? "I" : "-", server_conf_flags & GSSAUTH_P_PRIVACY ? "C" : "-"); report(stdout, _("Maximum GSS token size is %ld\n"),buf_size); } /* now respond in kind (hack!!!) */ buf_size = htonl(buf_size); /* do as they do... only matters if we do enc */ memcpy(buf1, &buf_size, 4); buf1[0] = GSSAUTH_P_NONE; strcpy(buf1+4, username); /* server decides if princ is user */ request_buf.length = 4 + strlen(username) + 1; request_buf.value = buf1; maj_stat = gss_wrap(&min_stat, context, 0, GSS_C_QOP_DEFAULT, &request_buf, &cflags, &send_token); if (maj_stat != GSS_S_COMPLETE) { report(stderr, _("Error creating security level request\n")); return PS_AUTHFAIL; } to64frombits(buf1, send_token.value, send_token.length); if (outlevel >= O_DEBUG) { report(stdout, _("Requesting authorization as %s\n"), username); report(stdout, "IMAP> %s\n",buf1); } strcat(buf1, "\r\n"); SockWrite(sock, buf1, strlen(buf1)); /* we should be done. Get status and finish up */ do { if (result = gen_recv(sock, buf1, sizeof buf1)) return result; } while(strncmp(buf1, tag, strlen(tag)) != 0); if (strstr(buf1, "OK")) { /* flush security context */ if (outlevel >= O_DEBUG) report(stdout, _("Releasing GSS credentials\n")); maj_stat = gss_delete_sec_context(&min_stat, &context, &send_token); if (maj_stat != GSS_S_COMPLETE) { report(stderr, _("Error releasing credentials\n")); return PS_AUTHFAIL; } /* send_token may contain a notification to the server to flush * credentials. RFC 1731 doesn't specify what to do, and since this * support is only for authentication, we'll assume the server * knows enough to flush its own credentials */ gss_release_buffer(&min_stat, &send_token); return PS_SUCCESS; } return PS_AUTHFAIL; } #endif /* GSSAPI */ #if NTLM_ENABLE #include "ntlm.h" static tSmbNtlmAuthRequest request; static tSmbNtlmAuthChallenge challenge; static tSmbNtlmAuthResponse response; /* * NTLM support by Grant Edwards. * * Handle MS-Exchange NTLM authentication method. This is the same * as the NTLM auth used by Samba for SMB related services. We just * encode the packets in base64 instead of sending them out via a * network interface. * * Much source (ntlm.h, smb*.c smb*.h) was borrowed from Samba. */ static int do_imap_ntlm(int sock, struct query *ctl) { char msgbuf[2048]; int result,len; gen_send(sock, "AUTHENTICATE NTLM"); if ((result = gen_recv(sock, msgbuf, sizeof msgbuf))) return result; if (msgbuf[0] != '+') return PS_AUTHFAIL; buildSmbNtlmAuthRequest(&request,ctl->remotename,NULL); if (outlevel >= O_DEBUG) dumpSmbNtlmAuthRequest(stdout, &request); memset(msgbuf,0,sizeof msgbuf); to64frombits (msgbuf, (unsigned char*)&request, SmbLength(&request)); if (outlevel >= O_MONITOR) report(stdout, "IMAP> %s\n", msgbuf); strcat(msgbuf,"\r\n"); SockWrite (sock, msgbuf, strlen (msgbuf)); if ((gen_recv(sock, msgbuf, sizeof msgbuf))) return result; len = from64tobits ((unsigned char*)&challenge, msgbuf); if (outlevel >= O_DEBUG) dumpSmbNtlmAuthChallenge(stdout, &challenge); buildSmbNtlmAuthResponse(&challenge, &response,ctl->remotename,ctl->password); if (outlevel >= O_DEBUG) dumpSmbNtlmAuthResponse(stdout, &response); memset(msgbuf,0,sizeof msgbuf); to64frombits (msgbuf, (unsigned char*)&response, SmbLength(&response)); if (outlevel >= O_MONITOR) report(stdout, "IMAP> %s\n", msgbuf); strcat(msgbuf,"\r\n"); SockWrite (sock, msgbuf, strlen (msgbuf)); if ((result = gen_recv (sock, msgbuf, sizeof msgbuf))) return result; if (strstr (msgbuf, "OK")) return PS_SUCCESS; else return PS_AUTHFAIL; } #endif /* NTLM */ int imap_canonicalize(char *result, char *raw, int maxlen) /* encode an IMAP password as per RFC1730's quoting conventions */ { int i, j; j = 0; for (i = 0; i < strlen(raw) && i < maxlen; i++) { if ((raw[i] == '\\') || (raw[i] == '"')) result[j++] = '\\'; result[j++] = raw[i]; } result[j] = '\0'; return(i); } int imap_getauth(int sock, struct query *ctl, char *greeting) /* apply for connection authorization */ { int ok = 0; /* probe to see if we're running IMAP4 and can use RFC822.PEEK */ capabilities[0] = '\0'; if ((ok = gen_transact(sock, "CAPABILITY")) == PS_SUCCESS) { /* UW-IMAP server 10.173 notifies in all caps */ if (strstr(capabilities, "IMAP4REV1")) { imap_version = IMAP4rev1; if (outlevel >= O_DEBUG) report(stdout, _("Protocol identified as IMAP4 rev 1\n")); } else { imap_version = IMAP4; if (outlevel >= O_DEBUG) report(stdout, _("Protocol identified as IMAP4 rev 0\n")); } } else if (ok == PS_ERROR) { imap_version = IMAP2; if (outlevel >= O_DEBUG) report(stdout, _("Protocol identified as IMAP2 or IMAP2BIS\n")); } else return(ok); peek_capable = (imap_version >= IMAP4); /* * Assumption: expunges are cheap, so we want to do them * after every message unless user said otherwise. */ if (NUM_SPECIFIED(ctl->expunge)) expunge_period = NUM_VALUE_OUT(ctl->expunge); else expunge_period = 1; /* * Handle idling. We depend on coming through here on startup * and after each timeout (including timeouts during idles). */ if (strstr(capabilities, "IDLE") && ctl->idle) { do_idle = TRUE; if (outlevel >= O_VERBOSE) report(stdout, _("will idle after poll\n")); } /* * If either (a) we saw a PREAUTH token in the greeting, or * (b) the user specified ssh preauthentication, then we're done. */ if (preauth || ctl->server.preauthenticate == A_SSH) { preauth = FALSE; /* reset for the next session */ return(PS_SUCCESS); } #if OPIE_ENABLE if ((ctl->server.protocol == P_IMAP) && strstr(capabilities, "AUTH=X-OTP")) { if (outlevel >= O_DEBUG) report(stdout, _("OTP authentication is supported\n")); if (do_otp(sock, ctl) == PS_SUCCESS) return(PS_SUCCESS); }; #endif /* OPIE_ENABLE */ #ifdef GSSAPI if (strstr(capabilities, "AUTH=GSSAPI")) { if (ctl->server.protocol == P_IMAP_GSS) { if (outlevel >= O_DEBUG) report(stdout, _("GSS authentication is supported\n")); return do_gssauth(sock, ctl->server.truename, ctl->remotename); } } else if (ctl->server.protocol == P_IMAP_GSS) { report(stderr, _("Required GSS capability not supported by server\n")); return(PS_AUTHFAIL); } #endif /* GSSAPI */ #ifdef KERBEROS_V4 if (strstr(capabilities, "AUTH=KERBEROS_V4")) { if (outlevel >= O_DEBUG) report(stdout, _("KERBEROS_V4 authentication is supported\n")); if (ctl->server.protocol == P_IMAP_K4) { if ((ok = do_rfc1731(sock, ctl->server.truename))) /* SASL cancellation of authentication */ gen_send(sock, "*"); return(ok); } /* else fall through to ordinary AUTH=LOGIN case */ } else if (ctl->server.protocol == P_IMAP_K4) { report(stderr, _("Required KERBEROS_V4 capability not supported by server\n")); return(PS_AUTHFAIL); } #endif /* KERBEROS_V4 */ if (strstr(capabilities, "AUTH=CRAM-MD5")) { if (outlevel >= O_DEBUG) report (stdout, _("CRAM-MD5 authentication is supported\n")); if (ctl->server.protocol != P_IMAP_LOGIN) { if ((ok = do_cram_md5 (sock, ctl))) /* SASL cancellation of authentication */ gen_send(sock, "*"); return(ok); } } else if (ctl->server.protocol == P_IMAP_CRAM_MD5) { report(stderr, _("Required CRAM-MD5 capability not supported by server\n")); return(PS_AUTHFAIL); } #ifdef NTLM_ENABLE if (strstr (capabilities, "AUTH=NTLM")) { if (outlevel >= O_DEBUG) report (stdout, _("NTLM authentication is supported\n")); return do_imap_ntlm (sock, ctl); } #endif /* NTLM_ENABLE */ #ifdef __UNUSED__ /* The Cyrus IMAP4rev1 server chokes on this */ /* this handles either AUTH=LOGIN or AUTH-LOGIN */ if ((imap_version >= IMAP4rev1) && (!strstr(capabilities, "LOGIN"))) { report(stderr, _("Required LOGIN capability not supported by server\n")); return PS_AUTHFAIL; }; #endif /* __UNUSED__ */ { /* these sizes guarantee no buffer overflow */ char remotename[NAMELEN*2+1], password[PASSWORDLEN*2+1]; imap_canonicalize(remotename, ctl->remotename, NAMELEN); imap_canonicalize(password, ctl->password, PASSWORDLEN); ok = gen_transact(sock, "LOGIN \"%s\" \"%s\"", remotename, password); } if (ok) return(ok); return(PS_SUCCESS); } static int internal_expunge(int sock) /* ship an expunge, resetting associated counters */ { int ok; if ((ok = gen_transact(sock, "EXPUNGE"))) return(ok); expunged += deletions; deletions = 0; #ifdef IMAP_UID /* not used */ expunge_uids(ctl); #endif /* IMAP_UID */ return(PS_SUCCESS); } static int imap_idle(int sock) /* start an RFC2177 IDLE */ { stage = STAGE_IDLE; saved_timeout = mytimeout; mytimeout = 0; return (gen_transact(sock, "IDLE")); } static int imap_getrange(int sock, struct query *ctl, const char *folder, int *countp, int *newp, int *bytes) /* get range of messages to be fetched */ { int ok; char buf[MSGBUFSIZE+1], *cp; /* find out how many messages are waiting */ *bytes = -1; if (pass > 1) { /* * We have to have an expunge here, otherwise the re-poll will * infinite-loop picking up un-expunged messages -- unless the * expunge period is one and we've been nuking each message * just after deletion. */ ok = 0; if (deletions && expunge_period != 1) ok = internal_expunge(sock); count = -1; if (do_idle) ok = imap_idle(sock); if (ok || gen_transact(sock, "NOOP")) { report(stderr, _("re-poll failed\n")); return(ok); } else if (count == -1) /* no EXISTS response to NOOP/IDLE */ { count = 0; } if (outlevel >= O_DEBUG) report(stdout, _("%d messages waiting after re-poll\n"), count); } else { ok = gen_transact(sock, check_only ? "EXAMINE \"%s\"" : "SELECT \"%s\"", folder ? folder : "INBOX"); if (ok != 0) { report(stderr, _("mailbox selection failed\n")); return(ok); } else if (outlevel >= O_DEBUG) report(stdout, _("%d messages waiting after first poll\n"), count); /* no messages? then we may need to idle until we get some */ if (count == 0 && do_idle) imap_idle(sock); } *countp = count; /* OK, now get a count of unseen messages and their indices */ if (!ctl->fetchall && count > 0) { if (unseen_messages) free(unseen_messages); unseen_messages = xmalloc(count * sizeof(unsigned int)); memset(unseen_messages, 0, count * sizeof(unsigned int)); unseen = 0; gen_send(sock, "SEARCH UNSEEN"); do { ok = gen_recv(sock, buf, sizeof(buf)); if (ok != 0) { report(stderr, _("search for unseen messages failed\n")); return(PS_PROTOCOL); } else if ((cp = strstr(buf, "* SEARCH"))) { char *ep; cp += 8; /* skip "* SEARCH" */ while (*cp && unseen < count) { /* skip whitespace */ while (*cp && isspace(*cp)) cp++; if (*cp) { /* * Message numbers are between 1 and 2^32 inclusive, * so unsigned int is large enough. */ unseen_messages[unseen]=(unsigned int)strtol(cp,&ep,10); if (outlevel >= O_DEBUG) report(stdout, _("%u is unseen\n"), unseen_messages[unseen]); unseen++; cp = ep; } } } } while (tag[0] != '\0' && strncmp(buf, tag, strlen(tag))); } *newp = unseen; expunged = 0; return(PS_SUCCESS); } static int imap_getsizes(int sock, int count, int *sizes) /* capture the sizes of all messages */ { char buf [MSGBUFSIZE+1]; /* * Some servers (as in, PMDF5.1-9.1 under OpenVMS 6.1) * won't accept 1:1 as valid set syntax. Some implementors * should be taken out and shot for excessive anality. * * Microsoft Exchange (brain-dead piece of crap that it is) * sometimes gets its knickers in a knot about bodiless messages. * You may see responses like this: * * fetchmail: IMAP> A0004 FETCH 1:9 RFC822.SIZE * fetchmail: IMAP< * 2 FETCH (RFC822.SIZE 1187) * fetchmail: IMAP< * 3 FETCH (RFC822.SIZE 3954) * fetchmail: IMAP< * 4 FETCH (RFC822.SIZE 1944) * fetchmail: IMAP< * 5 FETCH (RFC822.SIZE 2933) * fetchmail: IMAP< * 6 FETCH (RFC822.SIZE 1854) * fetchmail: IMAP< * 7 FETCH (RFC822.SIZE 34054) * fetchmail: IMAP< * 8 FETCH (RFC822.SIZE 5561) * fetchmail: IMAP< * 9 FETCH (RFC822.SIZE 1101) * fetchmail: IMAP< A0004 NO The requested item could not be found. * * This means message 1 has only headers. For kicks and grins * you can telnet in and look: * A003 FETCH 1 FULL * A003 NO The requested item could not be found. * A004 fetch 1 rfc822.header * A004 NO The requested item could not be found. * A006 FETCH 1 BODY * * 1 FETCH (BODY ("TEXT" "PLAIN" ("CHARSET" "US-ASCII") NIL NIL "7BIT" 35 3)) * A006 OK FETCH completed. * * To get around this, we terminate the read loop on a NO and count * on the fact that the sizes array has been preinitialized with a * known-bad size value. */ if (count == 1) gen_send(sock, "FETCH 1 RFC822.SIZE", count); else gen_send(sock, "FETCH 1:%d RFC822.SIZE", count); for (;;) { int num, size, ok; if ((ok = gen_recv(sock, buf, sizeof(buf)))) return(ok); else if (strstr(buf, "OK") || strstr(buf, "NO")) break; else if (sscanf(buf, "* %d FETCH (RFC822.SIZE %d)", &num, &size) == 2) sizes[num - 1] = size; } return(PS_SUCCESS); } static int imap_is_old(int sock, struct query *ctl, int number) /* is the given message old? */ { flag seen = TRUE; int i; /* * Expunges change the fetch numbers, but unseen_messages contains * indices from before any expungees were done. So neither the * argument nor the values in message_sequence need to be decremented. */ seen = TRUE; for (i = 0; i < unseen; i++) if (unseen_messages[i] == number) { seen = FALSE; break; } return(seen); } static int imap_fetch_headers(int sock, struct query *ctl,int number,int *lenp) /* request headers of nth message */ { char buf [MSGBUFSIZE+1]; int num; /* expunges change the fetch numbers */ number -= expunged; /* * This is blessed by RFC1176, RFC1730, RFC2060. * According to the RFCs, it should *not* set the \Seen flag. */ gen_send(sock, "FETCH %d RFC822.HEADER", number); /* looking for FETCH response */ do { int ok; if ((ok = gen_recv(sock, buf, sizeof(buf)))) return(ok); } while (sscanf(buf+2, "%d FETCH (%*s {%d}", &num, lenp) != 2); if (num != number) return(PS_ERROR); else return(PS_SUCCESS); } static int imap_fetch_body(int sock, struct query *ctl, int number, int *lenp) /* request body of nth message */ { char buf [MSGBUFSIZE+1], *cp; int num; /* expunges change the fetch numbers */ number -= expunged; /* * If we're using IMAP4, we can fetch the message without setting its * seen flag. This is good! It means that if the protocol exchange * craps out during the message, it will still be marked `unseen' on * the server. * * However...*don't* do this if we're using keep to suppress deletion! * In that case, marking the seen flag is the only way to prevent the * message from being re-fetched on subsequent runs (and according * to RFC2060 p.43 this fetch should set Seen as a side effect). * * According to RFC2060, and Mark Crispin the IMAP maintainer, * FETCH %d BODY[TEXT] and RFC822.TEXT are "functionally * equivalent". However, we know of at least one server that * treats them differently in the presence of MIME attachments; * the latter form downloads the attachment, the former does not. * The server is InterChange, and the fool who implemented this * misfeature ought to be strung up by his thumbs. * * When I tried working around this by disabling use of the 4rev1 form, * I found that doing this breaks operation with M$ Exchange. * Annoyingly enough, Exchange's refusal to cope is technically legal * under RFC2062. Trust Microsoft, the Great Enemy of interoperability * standards, to find a way to make standards compliance irritating.... */ switch (imap_version) { case IMAP4rev1: /* RFC 2060 */ if (!ctl->keep) gen_send(sock, "FETCH %d BODY.PEEK[TEXT]", number); else gen_send(sock, "FETCH %d BODY[TEXT]", number); break; case IMAP4: /* RFC 1730 */ if (!ctl->keep) gen_send(sock, "FETCH %d RFC822.TEXT.PEEK", number); else gen_send(sock, "FETCH %d RFC822.TEXT", number); break; default: /* RFC 1176 */ gen_send(sock, "FETCH %d RFC822.TEXT", number); break; } /* looking for FETCH response */ do { int ok; if ((ok = gen_recv(sock, buf, sizeof(buf)))) return(ok); } while (!strstr(buf+4, "FETCH") || sscanf(buf+2, "%d", &num) != 1); if (num != number) return(PS_ERROR); /* * Try to extract a length from the FETCH response. RFC2060 requires * it to be present, but at least one IMAP server (Novell GroupWise) * botches this. */ if ((cp = strchr(buf, '{'))) *lenp = atoi(cp + 1); else *lenp = -1; /* missing length part in FETCH reponse */ return(PS_SUCCESS); } static int imap_trail(int sock, struct query *ctl, int number) /* discard tail of FETCH response after reading message text */ { /* expunges change the fetch numbers */ /* number -= expunged; */ for (;;) { char buf[MSGBUFSIZE+1]; int ok; if ((ok = gen_recv(sock, buf, sizeof(buf)))) return(ok); /* UW IMAP returns "OK FETCH", Cyrus returns "OK Completed" */ if (strstr(buf, "OK")) break; #ifdef __UNUSED__ /* * Any IMAP server that fails to set Seen on a BODY[TEXT] * fetch violates RFC2060 p.43 (top). This becomes an issue * when keep is on, because seen messages aren't deleted and * get refetched on each poll. As a workaround, if keep is on * we can set the Seen flag explicitly. * * This code isn't used yet because we don't know of any IMAP * servers broken in this way. */ if (ctl->keep) if ((ok = gen_transact(sock, imap_version == IMAP4 ? "STORE %d +FLAGS.SILENT (\\Seen)" : "STORE %d +FLAGS (\\Seen)", number))) return(ok); #endif /* __UNUSED__ */ } return(PS_SUCCESS); } static int imap_delete(int sock, struct query *ctl, int number) /* set delete flag for given message */ { int ok; /* expunges change the fetch numbers */ number -= expunged; /* * Use SILENT if possible as a minor throughput optimization. * Note: this has been dropped from IMAP4rev1. * * We set Seen because there are some IMAP servers (notably HP * OpenMail) that do message-receipt DSNs, but only when the seen * bit is set. This is the appropriate time -- we get here right * after the local SMTP response that says delivery was * successful. */ if ((ok = gen_transact(sock, imap_version == IMAP4 ? "STORE %d +FLAGS.SILENT (\\Seen \\Deleted)" : "STORE %d +FLAGS (\\Seen \\Deleted)", number))) return(ok); else deletions++; /* * We do an expunge after expunge_period messages, rather than * just before quit, so that a line hit during a long session * won't result in lots of messages being fetched again during * the next session. */ if (NUM_NONZERO(expunge_period) && (deletions % expunge_period) == 0) internal_expunge(sock); return(PS_SUCCESS); } static int imap_logout(int sock, struct query *ctl) /* send logout command */ { /* if any un-expunged deletions remain, ship an expunge now */ if (deletions) internal_expunge(sock); #ifdef USE_SEARCH /* Memory clean-up */ if (unseen_messages) free(unseen_messages); #endif /* USE_SEARCH */ return(gen_transact(sock, "LOGOUT")); } const static struct method imap = { "IMAP", /* Internet Message Access Protocol */ #if INET6_ENABLE "imap", "imaps", #else /* INET6_ENABLE */ 143, /* standard IMAP2bis/IMAP4 port */ 993, /* ssl IMAP2bis/IMAP4 port */ #endif /* INET6_ENABLE */ TRUE, /* this is a tagged protocol */ FALSE, /* no message delimiter */ imap_ok, /* parse command response */ imap_canonicalize, /* deal with embedded slashes and spaces */ imap_getauth, /* get authorization */ imap_getrange, /* query range of messages */ imap_getsizes, /* get sizes of messages (used for ESMTP SIZE option) */ imap_is_old, /* no UID check */ imap_fetch_headers, /* request given message headers */ imap_fetch_body, /* request given message body */ imap_trail, /* eat message trailer */ imap_delete, /* delete the message */ imap_logout, /* expunge and exit */ TRUE, /* yes, we can re-poll */ }; int doIMAP(struct query *ctl) /* retrieve messages using IMAP Version 2bis or Version 4 */ { return(do_protocol(ctl, &imap)); } /* imap.c ends here */