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author | Kris Kennaway <kris@FreeBSD.org> | 2000-09-10 08:31:17 +0000 |
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committer | Kris Kennaway <kris@FreeBSD.org> | 2000-09-10 08:31:17 +0000 |
commit | b66f2d16a0435b7e7f3edde6101797004ae8d3b9 (patch) | |
tree | c42b17e610c0f98d5a0dda76cbd9035109d60303 /crypto/openssh/auth-options.c | |
parent | 2632b0c8756f2f5db4401143acdd2ebb7a871636 (diff) | |
download | src-test2-b66f2d16a0435b7e7f3edde6101797004ae8d3b9.tar.gz src-test2-b66f2d16a0435b7e7f3edde6101797004ae8d3b9.zip |
Notes
Diffstat (limited to 'crypto/openssh/auth-options.c')
-rw-r--r-- | crypto/openssh/auth-options.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/crypto/openssh/auth-options.c b/crypto/openssh/auth-options.c new file mode 100644 index 000000000000..da6965266af3 --- /dev/null +++ b/crypto/openssh/auth-options.c @@ -0,0 +1,223 @@ +/* + * Author: Tatu Ylonen <ylo@cs.hut.fi> + * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland + * All rights reserved + * RSA-based authentication. This code determines whether to admit a login + * based on RSA authentication. This file also contains functions to check + * validity of the host key. + * + * 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 1.4 2000/09/07 21:13:36 markus Exp $"); + +#include "ssh.h" +#include "packet.h" +#include "xmalloc.h" +#include "match.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; + +/* return 1 if access is granted, 0 if not. side effect: sets key option flags */ +int +auth_parse_options(struct passwd *pw, char *options, unsigned long linenum) +{ + const char *cp; + if (!options) + return 1; + while (*options && *options != ' ' && *options != '\t') { + cp = "no-port-forwarding"; + if (strncmp(options, cp, strlen(cp)) == 0) { + packet_send_debug("Port forwarding disabled."); + no_port_forwarding_flag = 1; + options += strlen(cp); + goto next_option; + } + cp = "no-agent-forwarding"; + if (strncmp(options, cp, strlen(cp)) == 0) { + packet_send_debug("Agent forwarding disabled."); + no_agent_forwarding_flag = 1; + options += strlen(cp); + goto next_option; + } + cp = "no-X11-forwarding"; + if (strncmp(options, cp, strlen(cp)) == 0) { + packet_send_debug("X11 forwarding disabled."); + no_x11_forwarding_flag = 1; + options += strlen(cp); + goto next_option; + } + cp = "no-pty"; + if (strncmp(options, cp, strlen(cp)) == 0) { + packet_send_debug("Pty allocation disabled."); + no_pty_flag = 1; + options += strlen(cp); + goto next_option; + } + cp = "command=\""; + if (strncmp(options, cp, strlen(cp)) == 0) { + int i; + options += strlen(cp); + forced_command = xmalloc(strlen(options) + 1); + i = 0; + while (*options) { + if (*options == '"') + break; + if (*options == '\\' && options[1] == '"') { + options += 2; + forced_command[i++] = '"'; + continue; + } + forced_command[i++] = *options++; + } + if (!*options) { + debug("%.100s, line %lu: missing end quote", + SSH_USER_PERMITTED_KEYS, linenum); + packet_send_debug("%.100s, line %lu: missing end quote", + SSH_USER_PERMITTED_KEYS, linenum); + continue; + } + forced_command[i] = 0; + packet_send_debug("Forced command: %.900s", forced_command); + options++; + goto next_option; + } + cp = "environment=\""; + if (strncmp(options, cp, strlen(cp)) == 0) { + int i; + char *s; + struct envstring *new_envstring; + options += strlen(cp); + s = xmalloc(strlen(options) + 1); + i = 0; + while (*options) { + if (*options == '"') + break; + if (*options == '\\' && options[1] == '"') { + options += 2; + s[i++] = '"'; + continue; + } + s[i++] = *options++; + } + if (!*options) { + debug("%.100s, line %lu: missing end quote", + SSH_USER_PERMITTED_KEYS, linenum); + packet_send_debug("%.100s, line %lu: missing end quote", + SSH_USER_PERMITTED_KEYS, linenum); + continue; + } + s[i] = 0; + packet_send_debug("Adding to environment: %.900s", s); + debug("Adding to environment: %.900s", s); + options++; + 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 (strncmp(options, cp, strlen(cp)) == 0) { + int mname, mip; + char *patterns = xmalloc(strlen(options) + 1); + int i; + options += strlen(cp); + i = 0; + while (*options) { + if (*options == '"') + break; + if (*options == '\\' && options[1] == '"') { + options += 2; + patterns[i++] = '"'; + continue; + } + patterns[i++] = *options++; + } + if (!*options) { + debug("%.100s, line %lu: missing end quote", + SSH_USER_PERMITTED_KEYS, linenum); + packet_send_debug("%.100s, line %lu: missing end quote", + SSH_USER_PERMITTED_KEYS, linenum); + continue; + } + patterns[i] = 0; + options++; + /* + * 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(get_canonical_hostname(), + patterns, strlen(patterns)); + mip = match_hostname(get_remote_ipaddr(), + 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, get_canonical_hostname(), + get_remote_ipaddr()); + packet_send_debug("Your host '%.200s' is not permitted to use this key for login.", + get_canonical_hostname()); + /* key invalid for this host, reset flags */ + 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; + } + /* deny access */ + return 0; + } + /* Host name matches. */ + goto next_option; + } +next_option: + /* + * Skip the comma, and move to the next option + * (or break out if there are no more). + */ + if (!*options) + fatal("Bugs in auth-options.c option processing."); + if (*options == ' ' || *options == '\t') + break; /* End of options. */ + if (*options != ',') + goto bad_option; + options++; + /* Process the next option. */ + } + /* grant access */ + return 1; + +bad_option: + log("Bad options in %.100s file, line %lu: %.50s", + SSH_USER_PERMITTED_KEYS, linenum, options); + packet_send_debug("Bad options in %.100s file, line %lu: %.50s", + SSH_USER_PERMITTED_KEYS, linenum, options); + /* deny access */ + return 0; +} |