| /* |
| * Author: Tatu Ylonen <ylo@cs.hut.fi> |
| * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| * All rights reserved |
| * As far as I am concerned, the code I have written for this software |
| * can be used freely for any purpose. Any derived versions of this |
| * software must be clearly marked as such, and if the derived work is |
| * incompatible with the protocol description in the RFC file, it must be |
| * called by a name other than "ssh" or "Secure Shell". |
| */ |
| |
| #include "includes.h" |
| RCSID("$OpenBSD: auth-options.c,v 1.17 2001/05/30 12:55:06 markus Exp $"); |
| |
| #include "packet.h" |
| #include "xmalloc.h" |
| #include "match.h" |
| #include "log.h" |
| #include "canohost.h" |
| #include "channel.h" |
| #include "auth-options.h" |
| #include "servconf.h" |
| |
| /* Flags set authorized_keys flags */ |
| int no_port_forwarding_flag = 0; |
| int no_agent_forwarding_flag = 0; |
| int no_x11_forwarding_flag = 0; |
| int no_pty_flag = 0; |
| |
| /* "command=" option. */ |
| char *forced_command = NULL; |
| |
| /* "environment=" options. */ |
| struct envstring *custom_environment = NULL; |
| |
| extern ServerOptions options; |
| |
| void |
| auth_clear_options(void) |
| { |
| no_agent_forwarding_flag = 0; |
| no_port_forwarding_flag = 0; |
| no_pty_flag = 0; |
| no_x11_forwarding_flag = 0; |
| while (custom_environment) { |
| struct envstring *ce = custom_environment; |
| custom_environment = ce->next; |
| xfree(ce->s); |
| xfree(ce); |
| } |
| if (forced_command) { |
| xfree(forced_command); |
| forced_command = NULL; |
| } |
| channel_clear_permitted_opens(); |
| } |
| |
| /* |
| * return 1 if access is granted, 0 if not. |
| * side effect: sets key option flags |
| */ |
| int |
| auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum) |
| { |
| const char *cp; |
| int i; |
| |
| /* reset options */ |
| auth_clear_options(); |
| |
| if (!opts) |
| return 1; |
| |
| while (*opts && *opts != ' ' && *opts != '\t') { |
| cp = "no-port-forwarding"; |
| if (strncasecmp(opts, cp, strlen(cp)) == 0) { |
| packet_send_debug("Port forwarding disabled."); |
| no_port_forwarding_flag = 1; |
| opts += strlen(cp); |
| goto next_option; |
| } |
| cp = "no-agent-forwarding"; |
| if (strncasecmp(opts, cp, strlen(cp)) == 0) { |
| packet_send_debug("Agent forwarding disabled."); |
| no_agent_forwarding_flag = 1; |
| opts += strlen(cp); |
| goto next_option; |
| } |
| cp = "no-X11-forwarding"; |
| if (strncasecmp(opts, cp, strlen(cp)) == 0) { |
| packet_send_debug("X11 forwarding disabled."); |
| no_x11_forwarding_flag = 1; |
| opts += strlen(cp); |
| goto next_option; |
| } |
| cp = "no-pty"; |
| if (strncasecmp(opts, cp, strlen(cp)) == 0) { |
| packet_send_debug("Pty allocation disabled."); |
| no_pty_flag = 1; |
| opts += strlen(cp); |
| goto next_option; |
| } |
| cp = "command=\""; |
| if (strncasecmp(opts, cp, strlen(cp)) == 0) { |
| opts += strlen(cp); |
| forced_command = xmalloc(strlen(opts) + 1); |
| i = 0; |
| while (*opts) { |
| if (*opts == '"') |
| break; |
| if (*opts == '\\' && opts[1] == '"') { |
| opts += 2; |
| forced_command[i++] = '"'; |
| continue; |
| } |
| forced_command[i++] = *opts++; |
| } |
| if (!*opts) { |
| debug("%.100s, line %lu: missing end quote", |
| file, linenum); |
| packet_send_debug("%.100s, line %lu: missing end quote", |
| file, linenum); |
| xfree(forced_command); |
| forced_command = NULL; |
| goto bad_option; |
| } |
| forced_command[i] = 0; |
| packet_send_debug("Forced command: %.900s", forced_command); |
| opts++; |
| goto next_option; |
| } |
| cp = "environment=\""; |
| if (strncasecmp(opts, cp, strlen(cp)) == 0) { |
| char *s; |
| struct envstring *new_envstring; |
| |
| opts += strlen(cp); |
| s = xmalloc(strlen(opts) + 1); |
| i = 0; |
| while (*opts) { |
| if (*opts == '"') |
| break; |
| if (*opts == '\\' && opts[1] == '"') { |
| opts += 2; |
| s[i++] = '"'; |
| continue; |
| } |
| s[i++] = *opts++; |
| } |
| if (!*opts) { |
| debug("%.100s, line %lu: missing end quote", |
| file, linenum); |
| packet_send_debug("%.100s, line %lu: missing end quote", |
| file, linenum); |
| xfree(s); |
| goto bad_option; |
| } |
| s[i] = 0; |
| packet_send_debug("Adding to environment: %.900s", s); |
| debug("Adding to environment: %.900s", s); |
| opts++; |
| new_envstring = xmalloc(sizeof(struct envstring)); |
| new_envstring->s = s; |
| new_envstring->next = custom_environment; |
| custom_environment = new_envstring; |
| goto next_option; |
| } |
| cp = "from=\""; |
| if (strncasecmp(opts, cp, strlen(cp)) == 0) { |
| int mname, mip; |
| const char *remote_ip = get_remote_ipaddr(); |
| const char *remote_host = get_canonical_hostname( |
| options.reverse_mapping_check); |
| char *patterns = xmalloc(strlen(opts) + 1); |
| |
| opts += strlen(cp); |
| i = 0; |
| while (*opts) { |
| if (*opts == '"') |
| break; |
| if (*opts == '\\' && opts[1] == '"') { |
| opts += 2; |
| patterns[i++] = '"'; |
| continue; |
| } |
| patterns[i++] = *opts++; |
| } |
| if (!*opts) { |
| debug("%.100s, line %lu: missing end quote", |
| file, linenum); |
| packet_send_debug("%.100s, line %lu: missing end quote", |
| file, linenum); |
| xfree(patterns); |
| goto bad_option; |
| } |
| patterns[i] = 0; |
| opts++; |
| /* |
| * Deny access if we get a negative |
| * match for the hostname or the ip |
| * or if we get not match at all |
| */ |
| mname = match_hostname(remote_host, patterns, |
| strlen(patterns)); |
| mip = match_hostname(remote_ip, patterns, |
| strlen(patterns)); |
| xfree(patterns); |
| if (mname == -1 || mip == -1 || |
| (mname != 1 && mip != 1)) { |
| log("Authentication tried for %.100s with " |
| "correct key but not from a permitted " |
| "host (host=%.200s, ip=%.200s).", |
| pw->pw_name, remote_host, remote_ip); |
| packet_send_debug("Your host '%.200s' is not " |
| "permitted to use this key for login.", |
| remote_host); |
| /* deny access */ |
| return 0; |
| } |
| /* Host name matches. */ |
| goto next_option; |
| } |
| cp = "permitopen=\""; |
| if (strncasecmp(opts, cp, strlen(cp)) == 0) { |
| u_short port; |
| char *c, *ep; |
| char *patterns = xmalloc(strlen(opts) + 1); |
| |
| opts += strlen(cp); |
| i = 0; |
| while (*opts) { |
| if (*opts == '"') |
| break; |
| if (*opts == '\\' && opts[1] == '"') { |
| opts += 2; |
| patterns[i++] = '"'; |
| continue; |
| } |
| patterns[i++] = *opts++; |
| } |
| if (!*opts) { |
| debug("%.100s, line %lu: missing end quote", |
| file, linenum); |
| packet_send_debug("%.100s, line %lu: missing end quote", |
| file, linenum); |
| xfree(patterns); |
| goto bad_option; |
| } |
| patterns[i] = 0; |
| opts++; |
| c = strchr(patterns, ':'); |
| if (c == NULL) { |
| debug("%.100s, line %lu: permitopen: missing colon <%.100s>", |
| file, linenum, patterns); |
| packet_send_debug("%.100s, line %lu: missing colon", |
| file, linenum); |
| xfree(patterns); |
| goto bad_option; |
| } |
| *c = 0; |
| c++; |
| port = strtol(c, &ep, 0); |
| if (c == ep) { |
| debug("%.100s, line %lu: permitopen: missing port <%.100s>", |
| file, linenum, patterns); |
| packet_send_debug("%.100s, line %lu: missing port", |
| file, linenum); |
| xfree(patterns); |
| goto bad_option; |
| } |
| if (options.allow_tcp_forwarding) |
| channel_add_permitted_opens(patterns, port); |
| xfree(patterns); |
| goto next_option; |
| } |
| next_option: |
| /* |
| * Skip the comma, and move to the next option |
| * (or break out if there are no more). |
| */ |
| if (!*opts) |
| fatal("Bugs in auth-options.c option processing."); |
| if (*opts == ' ' || *opts == '\t') |
| break; /* End of options. */ |
| if (*opts != ',') |
| goto bad_option; |
| opts++; |
| /* Process the next option. */ |
| } |
| /* grant access */ |
| return 1; |
| |
| bad_option: |
| log("Bad options in %.100s file, line %lu: %.50s", |
| file, linenum, opts); |
| packet_send_debug("Bad options in %.100s file, line %lu: %.50s", |
| file, linenum, opts); |
| /* deny access */ |
| return 0; |
| } |