/* * Copyright notice from original mutt: * Copyright (C) 1999-2000 Brendan Cully * * This file is part of mutt-ng, see http://www.muttng.org/. * It's licensed under the GNU General Public License, * please see the file GPL in the top level source directory. */ /* GSS login/authentication code */ #if HAVE_CONFIG_H # include "config.h" #endif #include "mutt.h" #include "imap_private.h" #include "auth.h" #include "lib/intl.h" #include "lib/debug.h" #include #ifdef HAVE_HEIMDAL # include # define gss_nt_service_name GSS_C_NT_HOSTBASED_SERVICE #else # include # include #endif #define GSS_BUFSIZE 8192 #define GSS_AUTH_P_NONE 1 #define GSS_AUTH_P_INTEGRITY 2 #define GSS_AUTH_P_PRIVACY 4 /* imap_auth_gss: AUTH=GSSAPI support. */ imap_auth_res_t imap_auth_gss (IMAP_DATA * idata, const char *method) { 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[GSS_BUFSIZE], buf2[GSS_BUFSIZE], server_conf_flags; unsigned long buf_size; int rc; if (!mutt_bit_isset (idata->capabilities, AGSSAPI)) return IMAP_AUTH_UNAVAIL; if (mutt_account_getuser (&idata->conn->account)) return IMAP_AUTH_FAILURE; /* get an IMAP service ticket for the server */ snprintf (buf1, sizeof (buf1), "imap@%s", idata->conn->account.host); request_buf.value = buf1; request_buf.length = str_len (buf1) + 1; maj_stat = gss_import_name (&min_stat, &request_buf, gss_nt_service_name, &target_name); if (maj_stat != GSS_S_COMPLETE) { debug_print (2, ("Couldn't get service name for [%s]\n", buf1)); return IMAP_AUTH_UNAVAIL; } #ifdef DEBUG else if (DebugLevel >= 2) { maj_stat = gss_display_name (&min_stat, target_name, &request_buf, &mech_name); debug_print (2, ("Using service name [%s]\n", (char *) request_buf.value)); maj_stat = gss_release_buffer (&min_stat, &request_buf); } #endif /* Acquire initial credentials - without a TGT GSSAPI is UNAVAIL */ sec_token = GSS_C_NO_BUFFER; context = GSS_C_NO_CONTEXT; /* build token */ 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, (unsigned int *) &cflags, NULL); if (maj_stat != GSS_S_COMPLETE && maj_stat != GSS_S_CONTINUE_NEEDED) { debug_print (1, ("Error acquiring credentials - no TGT?\n")); gss_release_name (&min_stat, &target_name); return IMAP_AUTH_UNAVAIL; } /* now begin login */ mutt_message _("Authenticating (GSSAPI)..."); imap_cmd_start (idata, "AUTHENTICATE GSSAPI"); /* expect a null continuation response ("+") */ do rc = imap_cmd_step (idata); while (rc == IMAP_CMD_CONTINUE); if (rc != IMAP_CMD_RESPOND) { debug_print (2, ("Invalid response from server: %s\n", buf1)); gss_release_name (&min_stat, &target_name); goto bail; } /* now start the security context initialisation loop... */ debug_print (2, ("Sending credentials\n")); mutt_to_base64 ((unsigned char *) buf1, send_token.value, send_token.length, sizeof (buf1) - 2); gss_release_buffer (&min_stat, &send_token); str_cat (buf1, sizeof (buf1), "\r\n"); mutt_socket_write (idata->conn, buf1); while (maj_stat == GSS_S_CONTINUE_NEEDED) { /* Read server data */ do rc = imap_cmd_step (idata); while (rc == IMAP_CMD_CONTINUE); if (rc != IMAP_CMD_RESPOND) { debug_print (1, ("Error receiving server response.\n")); gss_release_name (&min_stat, &target_name); goto bail; } request_buf.length = mutt_from_base64 (buf2, idata->cmd.buf + 2); request_buf.value = buf2; sec_token = &request_buf; /* Write client data */ 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, (unsigned int *) &cflags, NULL); if (maj_stat != GSS_S_COMPLETE && maj_stat != GSS_S_CONTINUE_NEEDED) { debug_print (1, ("Error exchanging credentials\n")); gss_release_name (&min_stat, &target_name); goto err_abort_cmd; } mutt_to_base64 ((unsigned char *) buf1, send_token.value, send_token.length, sizeof (buf1) - 2); gss_release_buffer (&min_stat, &send_token); str_cat (buf1, sizeof (buf1), "\r\n"); mutt_socket_write (idata->conn, buf1); } gss_release_name (&min_stat, &target_name); /* get security flags and buffer size */ do rc = imap_cmd_step (idata); while (rc == IMAP_CMD_CONTINUE); if (rc != IMAP_CMD_RESPOND) { debug_print (1, ("Error receiving server response.\n")); goto bail; } request_buf.length = mutt_from_base64 (buf2, idata->cmd.buf + 2); request_buf.value = buf2; maj_stat = gss_unwrap (&min_stat, context, &request_buf, &send_token, &cflags, &quality); if (maj_stat != GSS_S_COMPLETE) { debug_print (2, ("Couldn't unwrap security level data\n")); gss_release_buffer (&min_stat, &send_token); goto err_abort_cmd; } debug_print (2, ("Credential exchange complete\n")); /* first octet is security levels supported. We want NONE */ server_conf_flags = ((char *) send_token.value)[0]; if (!(((char *) send_token.value)[0] & GSS_AUTH_P_NONE)) { debug_print (2, ("Server requires integrity or privacy\n")); gss_release_buffer (&min_stat, &send_token); goto err_abort_cmd; } /* we don't care about buffer size if we don't wrap content. But here it is */ ((char *) send_token.value)[0] = 0; buf_size = ntohl (*((long *) send_token.value)); gss_release_buffer (&min_stat, &send_token); debug_print (2, ("Unwrapped security level flags: %c%c%c\n", server_conf_flags & GSS_AUTH_P_NONE ? 'N' : '-', server_conf_flags & GSS_AUTH_P_INTEGRITY ? 'I' : '-', server_conf_flags & GSS_AUTH_P_PRIVACY ? 'P' : '-')); debug_print (2, ("Maximum GSS token size is %ld\n", buf_size)); /* agree to terms (hack!) */ buf_size = htonl (buf_size); /* not relevant without integrity/privacy */ memcpy (buf1, &buf_size, 4); buf1[0] = GSS_AUTH_P_NONE; /* server decides if principal can log in as user */ strncpy (buf1 + 4, idata->conn->account.user, sizeof (buf1) - 4); request_buf.value = buf1; request_buf.length = 4 + str_len (idata->conn->account.user) + 1; maj_stat = gss_wrap (&min_stat, context, 0, GSS_C_QOP_DEFAULT, &request_buf, &cflags, &send_token); if (maj_stat != GSS_S_COMPLETE) { debug_print (2, ("Error creating login request\n")); goto err_abort_cmd; } mutt_to_base64 ((unsigned char *) buf1, send_token.value, send_token.length, sizeof (buf1) - 2); debug_print (2, ("Requesting authorisation as %s\n", idata->conn->account.user)); str_cat (buf1, sizeof (buf1), "\r\n"); mutt_socket_write (idata->conn, buf1); /* Joy of victory or agony of defeat? */ do rc = imap_cmd_step (idata); while (rc == IMAP_CMD_CONTINUE); if (rc == IMAP_CMD_RESPOND) { debug_print (1, ("Unexpected server continuation request.\n")); goto err_abort_cmd; } if (imap_code (idata->cmd.buf)) { /* flush the security context */ debug_print (2, ("Releasing GSS credentials\n")); maj_stat = gss_delete_sec_context (&min_stat, &context, &send_token); if (maj_stat != GSS_S_COMPLETE) debug_print (1, ("Error releasing credentials\n")); /* 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 IMAP_AUTH_SUCCESS; } else goto bail; err_abort_cmd: mutt_socket_write (idata->conn, "*\r\n"); do rc = imap_cmd_step (idata); while (rc == IMAP_CMD_CONTINUE); bail: mutt_error _("GSSAPI authentication failed."); mutt_sleep (2); return IMAP_AUTH_FAILURE; }