1 files changed, 417 insertions, 0 deletions
diff --git a/crypto/openssh/canohost.c b/crypto/openssh/canohost.c
new file mode 100644
index 0000000..2345cc3
--- /dev/null
+++ b/crypto/openssh/canohost.c
@@ -0,0 +1,417 @@
+/* $OpenBSD: canohost.c,v 1.61 2006/08/03 03:34:41 deraadt Exp $ */
+/*
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ *                    All rights reserved
+ * Functions for returning the canonical host name of the remote site.
+ *
+ * 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"
+
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+
+#include "xmalloc.h"
+#include "packet.h"
+#include "log.h"
+#include "canohost.h"
+
+static void check_ip_options(int, char *);
+
+/*
+ * Return the canonical name of the host at the other end of the socket. The
+ * caller should free the returned string with xfree.
+ */
+
+static char *
+get_remote_hostname(int sock, int use_dns)
+{
+	struct sockaddr_storage from;
+	int i;
+	socklen_t fromlen;
+	struct addrinfo hints, *ai, *aitop;
+	char name[NI_MAXHOST], ntop[NI_MAXHOST], ntop2[NI_MAXHOST];
+
+	/* Get IP address of client. */
+	fromlen = sizeof(from);
+	memset(&from, 0, sizeof(from));
+	if (getpeername(sock, (struct sockaddr *)&from, &fromlen) < 0) {
+		debug("getpeername failed: %.100s", strerror(errno));
+		cleanup_exit(255);
+	}
+
+	if (from.ss_family == AF_INET)
+		check_ip_options(sock, ntop);
+
+	ipv64_normalise_mapped(&from, &fromlen);
+
+	if (from.ss_family == AF_INET6)
+		fromlen = sizeof(struct sockaddr_in6);
+
+	if (getnameinfo((struct sockaddr *)&from, fromlen, ntop, sizeof(ntop),
+	    NULL, 0, NI_NUMERICHOST) != 0)
+		fatal("get_remote_hostname: getnameinfo NI_NUMERICHOST failed");
+
+	if (!use_dns)
+		return xstrdup(ntop);
+
+	debug3("Trying to reverse map address %.100s.", ntop);
+	/* Map the IP address to a host name. */
+	if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name),
+	    NULL, 0, NI_NAMEREQD) != 0) {
+		/* Host name not found.  Use ip address. */
+		return xstrdup(ntop);
+	}
+
+	/*
+	 * if reverse lookup result looks like a numeric hostname,
+	 * someone is trying to trick us by PTR record like following:
+	 *	1.1.1.10.in-addr.arpa.	IN PTR	2.3.4.5
+	 */
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
+	hints.ai_flags = AI_NUMERICHOST;
+	if (getaddrinfo(name, "0", &hints, &ai) == 0) {
+		logit("Nasty PTR record \"%s\" is set up for %s, ignoring",
+		    name, ntop);
+		freeaddrinfo(ai);
+		return xstrdup(ntop);
+	}
+
+	/*
+	 * Convert it to all lowercase (which is expected by the rest
+	 * of this software).
+	 */
+	for (i = 0; name[i]; i++)
+		if (isupper(name[i]))
+			name[i] = (char)tolower(name[i]);
+	/*
+	 * Map it back to an IP address and check that the given
+	 * address actually is an address of this host.  This is
+	 * necessary because anyone with access to a name server can
+	 * define arbitrary names for an IP address. Mapping from
+	 * name to IP address can be trusted better (but can still be
+	 * fooled if the intruder has access to the name server of
+	 * the domain).
+	 */
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = from.ss_family;
+	hints.ai_socktype = SOCK_STREAM;
+	if (getaddrinfo(name, NULL, &hints, &aitop) != 0) {
+		logit("reverse mapping checking getaddrinfo for %.700s "
+		    "[%s] failed - POSSIBLE BREAK-IN ATTEMPT!", name, ntop);
+		return xstrdup(ntop);
+	}
+	/* Look for the address from the list of addresses. */
+	for (ai = aitop; ai; ai = ai->ai_next) {
+		if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2,
+		    sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 &&
+		    (strcmp(ntop, ntop2) == 0))
+				break;
+	}
+	freeaddrinfo(aitop);
+	/* If we reached the end of the list, the address was not there. */
+	if (!ai) {
+		/* Address not found for the host name. */
+		logit("Address %.100s maps to %.600s, but this does not "
+		    "map back to the address - POSSIBLE BREAK-IN ATTEMPT!",
+		    ntop, name);
+		return xstrdup(ntop);
+	}
+	return xstrdup(name);
+}
+
+/*
+ * If IP options are supported, make sure there are none (log and
+ * disconnect them if any are found).  Basically we are worried about
+ * source routing; it can be used to pretend you are somebody
+ * (ip-address) you are not. That itself may be "almost acceptable"
+ * under certain circumstances, but rhosts autentication is useless
+ * if source routing is accepted. Notice also that if we just dropped
+ * source routing here, the other side could use IP spoofing to do
+ * rest of the interaction and could still bypass security.  So we
+ * exit here if we detect any IP options.
+ */
+/* IPv4 only */
+static void
+check_ip_options(int sock, char *ipaddr)
+{
+#ifdef IP_OPTIONS
+	u_char options[200];
+	char text[sizeof(options) * 3 + 1];
+	socklen_t option_size;
+	u_int i;
+	int ipproto;
+	struct protoent *ip;
+
+	if ((ip = getprotobyname("ip")) != NULL)
+		ipproto = ip->p_proto;
+	else
+		ipproto = IPPROTO_IP;
+	option_size = sizeof(options);
+	if (getsockopt(sock, ipproto, IP_OPTIONS, options,
+	    &option_size) >= 0 && option_size != 0) {
+		text[0] = '\0';
+		for (i = 0; i < option_size; i++)
+			snprintf(text + i*3, sizeof(text) - i*3,
+			    " %2.2x", options[i]);
+		fatal("Connection from %.100s with IP options:%.800s",
+		    ipaddr, text);
+	}
+#endif /* IP_OPTIONS */
+}
+
+void
+ipv64_normalise_mapped(struct sockaddr_storage *addr, socklen_t *len)
+{
+	struct sockaddr_in6 *a6 = (struct sockaddr_in6 *)addr;
+	struct sockaddr_in *a4 = (struct sockaddr_in *)addr;
+	struct in_addr inaddr;
+	u_int16_t port;
+
+	if (addr->ss_family != AF_INET6 ||
+	    !IN6_IS_ADDR_V4MAPPED(&a6->sin6_addr))
+		return;
+
+	debug3("Normalising mapped IPv4 in IPv6 address");
+
+	memcpy(&inaddr, ((char *)&a6->sin6_addr) + 12, sizeof(inaddr));
+	port = a6->sin6_port;
+
+	memset(addr, 0, sizeof(*a4));
+
+	a4->sin_family = AF_INET;
+	*len = sizeof(*a4);
+	memcpy(&a4->sin_addr, &inaddr, sizeof(inaddr));
+	a4->sin_port = port;
+}
+
+/*
+ * Return the canonical name of the host in the other side of the current
+ * connection.  The host name is cached, so it is efficient to call this
+ * several times.
+ */
+
+const char *
+get_canonical_hostname(int use_dns)
+{
+	char *host;
+	static char *canonical_host_name = NULL;
+	static char *remote_ip = NULL;
+
+	/* Check if we have previously retrieved name with same option. */
+	if (use_dns && canonical_host_name != NULL)
+		return canonical_host_name;
+	if (!use_dns && remote_ip != NULL)
+		return remote_ip;
+
+	/* Get the real hostname if socket; otherwise return UNKNOWN. */
+	if (packet_connection_is_on_socket())
+		host = get_remote_hostname(packet_get_connection_in(), use_dns);
+	else
+		host = "UNKNOWN";
+
+	if (use_dns)
+		canonical_host_name = host;
+	else
+		remote_ip = host;
+	return host;
+}
+
+/*
+ * Returns the local/remote IP-address/hostname of socket as a string.
+ * The returned string must be freed.
+ */
+static char *
+get_socket_address(int sock, int remote, int flags)
+{
+	struct sockaddr_storage addr;
+	socklen_t addrlen;
+	char ntop[NI_MAXHOST];
+	int r;
+
+	/* Get IP address of client. */
+	addrlen = sizeof(addr);
+	memset(&addr, 0, sizeof(addr));
+
+	if (remote) {
+		if (getpeername(sock, (struct sockaddr *)&addr, &addrlen)
+		    < 0)
+			return NULL;
+	} else {
+		if (getsockname(sock, (struct sockaddr *)&addr, &addrlen)
+		    < 0)
+			return NULL;
+	}
+
+	/* Work around Linux IPv6 weirdness */
+	if (addr.ss_family == AF_INET6)
+		addrlen = sizeof(struct sockaddr_in6);
+
+	ipv64_normalise_mapped(&addr, &addrlen);
+
+	/* Get the address in ascii. */
+	if ((r = getnameinfo((struct sockaddr *)&addr, addrlen, ntop,
+	    sizeof(ntop), NULL, 0, flags)) != 0) {
+		error("get_socket_address: getnameinfo %d failed: %s", flags,
+		    r == EAI_SYSTEM ? strerror(errno) : gai_strerror(r));
+		return NULL;
+	}
+	return xstrdup(ntop);
+}
+
+char *
+get_peer_ipaddr(int sock)
+{
+	char *p;
+
+	if ((p = get_socket_address(sock, 1, NI_NUMERICHOST)) != NULL)
+		return p;
+	return xstrdup("UNKNOWN");
+}
+
+char *
+get_local_ipaddr(int sock)
+{
+	char *p;
+
+	if ((p = get_socket_address(sock, 0, NI_NUMERICHOST)) != NULL)
+		return p;
+	return xstrdup("UNKNOWN");
+}
+
+char *
+get_local_name(int sock)
+{
+	return get_socket_address(sock, 0, NI_NAMEREQD);
+}
+
+/*
+ * Returns the IP-address of the remote host as a string.  The returned
+ * string must not be freed.
+ */
+
+const char *
+get_remote_ipaddr(void)
+{
+	static char *canonical_host_ip = NULL;
+
+	/* Check whether we have cached the ipaddr. */
+	if (canonical_host_ip == NULL) {
+		if (packet_connection_is_on_socket()) {
+			canonical_host_ip =
+			    get_peer_ipaddr(packet_get_connection_in());
+			if (canonical_host_ip == NULL)
+				cleanup_exit(255);
+		} else {
+			/* If not on socket, return UNKNOWN. */
+			canonical_host_ip = xstrdup("UNKNOWN");
+		}
+	}
+	return canonical_host_ip;
+}
+
+const char *
+get_remote_name_or_ip(u_int utmp_len, int use_dns)
+{
+	static const char *remote = "";
+	if (utmp_len > 0)
+		remote = get_canonical_hostname(use_dns);
+	if (utmp_len == 0 || strlen(remote) > utmp_len)
+		remote = get_remote_ipaddr();
+	return remote;
+}
+
+/* Returns the local/remote port for the socket. */
+
+static int
+get_sock_port(int sock, int local)
+{
+	struct sockaddr_storage from;
+	socklen_t fromlen;
+	char strport[NI_MAXSERV];
+	int r;
+
+	/* Get IP address of client. */
+	fromlen = sizeof(from);
+	memset(&from, 0, sizeof(from));
+	if (local) {
+		if (getsockname(sock, (struct sockaddr *)&from, &fromlen) < 0) {
+			error("getsockname failed: %.100s", strerror(errno));
+			return 0;
+		}
+	} else {
+		if (getpeername(sock, (struct sockaddr *)&from, &fromlen) < 0) {
+			debug("getpeername failed: %.100s", strerror(errno));
+			return -1;
+		}
+	}
+
+	/* Work around Linux IPv6 weirdness */
+	if (from.ss_family == AF_INET6)
+		fromlen = sizeof(struct sockaddr_in6);
+
+	/* Return port number. */
+	if ((r = getnameinfo((struct sockaddr *)&from, fromlen, NULL, 0,
+	    strport, sizeof(strport), NI_NUMERICSERV)) != 0)
+		fatal("get_sock_port: getnameinfo NI_NUMERICSERV failed: %s",
+		    r == EAI_SYSTEM ? strerror(errno) : gai_strerror(r));
+	return atoi(strport);
+}
+
+/* Returns remote/local port number for the current connection. */
+
+static int
+get_port(int local)
+{
+	/*
+	 * If the connection is not a socket, return 65535.  This is
+	 * intentionally chosen to be an unprivileged port number.
+	 */
+	if (!packet_connection_is_on_socket())
+		return 65535;
+
+	/* Get socket and return the port number. */
+	return get_sock_port(packet_get_connection_in(), local);
+}
+
+int
+get_peer_port(int sock)
+{
+	return get_sock_port(sock, 0);
+}
+
+int
+get_remote_port(void)
+{
+	static int port = -1;
+
+	/* Cache to avoid getpeername() on a dead connection */
+	if (port == -1)
+		port = get_port(0);
+
+	return port;
+}
+
+int
+get_local_port(void)
+{
+	return get_port(1);
+}