split auth-rsa option parsing into auth-options

add options support to authorized_keys2

1 files changed, 208 insertions, 0 deletions

diff --git a/usr.bin/ssh/auth-options.c b/usr.bin/ssh/auth-options.c
new file mode 100644
index 00000000000..9e02c14b7d0
--- /dev/null
+++ b/usr.bin/ssh/auth-options.c
@@ -0,0 +1,208 @@
+#include "includes.h"
+RCSID("$Id: auth-options.c,v 1.1 2000/06/18 04:05:01 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;
+}