diff options
Diffstat (limited to 'crypto/openssh/auth-options.c')
| -rw-r--r-- | crypto/openssh/auth-options.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/crypto/openssh/auth-options.c b/crypto/openssh/auth-options.c new file mode 100644 index 0000000..443f541 --- /dev/null +++ b/crypto/openssh/auth-options.c @@ -0,0 +1,300 @@ +/* + * 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 1.16 2001/03/18 12:07:52 markus Exp $"); + +#include "packet.h" +#include "xmalloc.h" +#include "match.h" +#include "log.h" +#include "canohost.h" +#include "channels.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; +} |
