/* $Cambridge: exim/src/src/auths/dovecot.c,v 1.2 2006/10/16 13:43:22 ph10 Exp $ */ /* * Copyright (c) 2004 Andrey Panin * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published * by the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ #include "../exim.h" #include "dovecot.h" #define VERSION_MAJOR 1 #define VERSION_MINOR 0 /* Options specific to the authentication mechanism. */ optionlist auth_dovecot_options[] = { { "server_socket", opt_stringptr, (void *)(offsetof(auth_dovecot_options_block, server_socket)) }, }; /* Size of the options list. An extern variable has to be used so that its address can appear in the tables drtables.c. */ int auth_dovecot_options_count = sizeof(auth_dovecot_options) / sizeof(optionlist); /* Default private options block for the authentication method. */ auth_dovecot_options_block auth_dovecot_option_defaults = { NULL, /* server_socket */ }; /************************************************* * Initialization entry point * *************************************************/ /* Called for each instance, after its options have been read, to enable consistency checks to be done, or anything else that needs to be set up. */ void auth_dovecot_init(auth_instance *ablock) { auth_dovecot_options_block *ob = (auth_dovecot_options_block *)(ablock->options_block); if (ablock->public_name == NULL) ablock->public_name = ablock->name; if (ob->server_socket != NULL) ablock->server = TRUE; ablock->client = FALSE; } static int strcut(char *str, char **ptrs, int nptrs) { char *tmp = str; int n; for (n = 0; n < nptrs; n++) ptrs[n] = NULL; n = 1; while (*str) { if (*str == '\t') { if (n <= nptrs) { *ptrs++ = tmp; tmp = str + 1; *str = 0; } n++; } str++; } if (n < nptrs) *ptrs = tmp; return n; } #define CHECK_COMMAND(str, arg_min, arg_max) do { \ if (strcasecmp((str), args[0]) != 0) \ goto out; \ if (nargs - 1 < (arg_min)) \ goto out; \ if (nargs - 1 > (arg_max)) \ goto out; \ } while (0) #define OUT(msg) do { \ auth_defer_msg = (US msg); \ goto out; \ } while(0) /************************************************* * Server entry point * *************************************************/ int auth_dovecot_server(auth_instance *ablock, uschar *data) { auth_dovecot_options_block *ob = (auth_dovecot_options_block *)(ablock->options_block); struct sockaddr_un sa; char buffer[4096]; char *args[8]; uschar *auth_command; uschar *auth_extra_data = US""; int nargs, tmp; int cuid = 0, cont = 1, found = 0, fd, ret = DEFER; FILE *f; HDEBUG(D_auth) debug_printf("dovecot authentication\n"); memset(&sa, 0, sizeof(sa)); sa.sun_family = AF_UNIX; /* This was the original code here: it is nonsense because strncpy() does not return an integer. I have converted this to use the function that formats and checks length. PH */ /* if (strncpy(sa.sun_path, ob->server_socket, sizeof(sa.sun_path)) < 0) { */ if (!string_format(US sa.sun_path, sizeof(sa.sun_path), "%s", ob->server_socket)) { auth_defer_msg = US"authentication socket path too long"; return DEFER; } auth_defer_msg = US"authentication socket connection error"; fd = socket(PF_UNIX, SOCK_STREAM, 0); if (fd < 0) return DEFER; if (connect(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0) goto out; f = fdopen(fd, "a+"); if (f == NULL) goto out; auth_defer_msg = US"authentication socket protocol error"; while (cont) { if (fgets(buffer, sizeof(buffer), f) == NULL) OUT("authentication socket read error or premature eof"); buffer[strlen(buffer) - 1] = 0; HDEBUG(D_auth) debug_printf("received: %s\n", buffer); nargs = strcut(buffer, args, sizeof(args) / sizeof(args[0])); switch (toupper(*args[0])) { case 'C': CHECK_COMMAND("CUID", 1, 1); cuid = atoi(args[1]); break; case 'D': CHECK_COMMAND("DONE", 0, 0); cont = 0; break; case 'M': CHECK_COMMAND("MECH", 1, INT_MAX); if (strcmpic(US args[1], ablock->public_name) == 0) found = 1; break; case 'S': CHECK_COMMAND("SPID", 1, 1); break; case 'V': CHECK_COMMAND("VERSION", 2, 2); if (atoi(args[1]) != VERSION_MAJOR) OUT("authentication socket protocol version mismatch"); break; default: goto out; } } if (!found) goto out; /* Added by PH: data must not contain tab (as it is b64 it shouldn't, but check for safety). */ if (Ustrchr(data, '\t') != NULL) { ret = FAIL; goto out; } /* Added by PH: extra fields when TLS is in use or if the TCP/IP connection is local. */ if (tls_cipher != NULL) auth_extra_data = string_sprintf("secured\t%s%s", tls_certificate_verified? "valid-client-cert" : "", tls_certificate_verified? "\t" : ""); else if (Ustrcmp(sender_host_address, interface_address) == 0) auth_extra_data = US"secured\t"; /**************************************************************************** The code below was the original code here. It didn't work. A reading of the file auth-protocol.txt.gz that came with Dovecot 1.0_beta8 indicated that this was not right. Maybe something changed. I changed it to move the service indication into the AUTH command, and it seems to be better. PH fprintf(f, "VERSION\t%d\t%d\r\nSERVICE\tSMTP\r\nCPID\t%d\r\n" "AUTH\t%d\t%s\trip=%s\tlip=%s\tresp=%s\r\n", VERSION_MAJOR, VERSION_MINOR, getpid(), cuid, ablock->public_name, sender_host_address, interface_address, data ? (char *) data : ""); Subsequently, the command was modified to add "secured" and "valid-client- cert" when relevant. ****************************************************************************/ auth_command = string_sprintf("VERSION\t%d\t%d\nCPID\t%d\n" "AUTH\t%d\t%s\tservice=smtp\t%srip=%s\tlip=%s\tresp=%s\n", VERSION_MAJOR, VERSION_MINOR, getpid(), cuid, ablock->public_name, auth_extra_data, sender_host_address, interface_address, data ? (char *) data : ""); fprintf(f, "%s", auth_command); HDEBUG(D_auth) debug_printf("sent: %s", auth_command); while (1) { if (fgets(buffer, sizeof(buffer), f) == NULL) { auth_defer_msg = US"authentication socket read error or premature eof"; goto out; } buffer[strlen(buffer) - 1] = 0; HDEBUG(D_auth) debug_printf("received: %s\n", buffer); nargs = strcut(buffer, args, sizeof(args) / sizeof(args[0])); if (atoi(args[1]) != cuid) OUT("authentication socket connection id mismatch"); switch (toupper(*args[0])) { case 'C': CHECK_COMMAND("CONT", 1, 2); tmp = auth_get_no64_data(&data, US args[2]); if (tmp != OK) { ret = tmp; goto out; } /* Added by PH: data must not contain tab (as it is b64 it shouldn't, but check for safety). */ if (Ustrchr(data, '\t') != NULL) { ret = FAIL; goto out; } if (fprintf(f, "CONT\t%d\t%s\r\n", cuid, data) < 0) OUT("authentication socket write error"); break; case 'F': CHECK_COMMAND("FAIL", 1, 2); /* FIXME: add proper response handling */ if (args[2]) { uschar *p = US strchr(args[2], '='); if (p) { ++p; expand_nstring[1] = auth_vars[0] = p; expand_nlength[1] = Ustrlen(p); expand_nmax = 1; } } ret = FAIL; goto out; case 'O': CHECK_COMMAND("OK", 2, 2); { /* FIXME: add proper response handling */ uschar *p = US strchr(args[2], '='); if (!p) OUT("authentication socket protocol error, username missing"); p++; expand_nstring[1] = auth_vars[0] = p; expand_nlength[1] = Ustrlen(p); expand_nmax = 1; } ret = OK; /* fallthrough */ default: goto out; } } out: close(fd); return ret; }