net-misc/openssh: fix USE=kerberos build #590382

2 files changed, 351 insertions, 1 deletions

diff --git a/net-misc/openssh/files/openssh-7.3_p1-GSSAPI-dns.patch b/net-misc/openssh/files/openssh-7.3_p1-GSSAPI-dns.patch
new file mode 100644
index 000000000000..d6798e2a8615
--- /dev/null
+++ b/net-misc/openssh/files/openssh-7.3_p1-GSSAPI-dns.patch
@@ -0,0 +1,350 @@
+http://bugs.gentoo.org/165444
+https://bugzilla.mindrot.org/show_bug.cgi?id=1008
+
+--- a/readconf.c
++++ b/readconf.c
+@@ -148,6 +148,7 @@
+ 	oClearAllForwardings, oNoHostAuthenticationForLocalhost,
+ 	oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout,
+ 	oAddressFamily, oGssAuthentication, oGssDelegateCreds,
++	oGssTrustDns,
+ 	oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly,
+ 	oSendEnv, oControlPath, oControlMaster, oControlPersist,
+ 	oHashKnownHosts,
+@@ -194,9 +195,11 @@
+ #if defined(GSSAPI)
+ 	{ "gssapiauthentication", oGssAuthentication },
+ 	{ "gssapidelegatecredentials", oGssDelegateCreds },
++	{ "gssapitrustdns", oGssTrustDns },
+ #else
+ 	{ "gssapiauthentication", oUnsupported },
+ 	{ "gssapidelegatecredentials", oUnsupported },
++	{ "gssapitrustdns", oUnsupported },
+ #endif
+ 	{ "fallbacktorsh", oDeprecated },
+ 	{ "usersh", oDeprecated },
+@@ -930,6 +933,10 @@
+ 		intptr = &options->gss_deleg_creds;
+ 		goto parse_flag;
+ 
++	case oGssTrustDns:
++		intptr = &options->gss_trust_dns;
++		goto parse_flag;
++
+ 	case oBatchMode:
+ 		intptr = &options->batch_mode;
+ 		goto parse_flag;
+@@ -1649,6 +1656,7 @@
+ 	options->challenge_response_authentication = -1;
+ 	options->gss_authentication = -1;
+ 	options->gss_deleg_creds = -1;
++	options->gss_trust_dns = -1;
+ 	options->password_authentication = -1;
+ 	options->kbd_interactive_authentication = -1;
+ 	options->kbd_interactive_devices = NULL;
+@@ -1779,6 +1787,8 @@
+ 		options->gss_authentication = 0;
+ 	if (options->gss_deleg_creds == -1)
+ 		options->gss_deleg_creds = 0;
++	if (options->gss_trust_dns == -1)
++		options->gss_trust_dns = 0;
+ 	if (options->password_authentication == -1)
+ 		options->password_authentication = 1;
+ 	if (options->kbd_interactive_authentication == -1)
+--- a/readconf.h
++++ b/readconf.h
+@@ -46,6 +46,7 @@
+ 					/* Try S/Key or TIS, authentication. */
+ 	int     gss_authentication;	/* Try GSS authentication */
+ 	int     gss_deleg_creds;	/* Delegate GSS credentials */
++	int	gss_trust_dns;		/* Trust DNS for GSS canonicalization */
+ 	int     password_authentication;	/* Try password
+ 						 * authentication. */
+ 	int     kbd_interactive_authentication; /* Try keyboard-interactive auth. */
+--- a/ssh_config.5
++++ b/ssh_config.5
+@@ -830,6 +830,16 @@
+ Forward (delegate) credentials to the server.
+ The default is
+ .Dq no .
++Note that this option applies to protocol version 2 connections using GSSAPI.
++.It Cm GSSAPITrustDns
++Set to
++.Dq yes to indicate that the DNS is trusted to securely canonicalize
++the name of the host being connected to. If
++.Dq no, the hostname entered on the
++command line will be passed untouched to the GSSAPI library.
++The default is
++.Dq no .
++This option only applies to protocol version 2 connections using GSSAPI.
+ .It Cm HashKnownHosts
+ Indicates that
+ .Xr ssh 1
+--- a/sshconnect2.c
++++ b/sshconnect2.c
+@@ -656,6 +656,12 @@
+ 	static u_int mech = 0;
+ 	OM_uint32 min;
+ 	int ok = 0;
++	const char *gss_host;
++
++	if (options.gss_trust_dns)
++		gss_host = auth_get_canonical_hostname(active_state, 1);
++	else
++		gss_host = authctxt->host;
+ 
+ 	/* Try one GSSAPI method at a time, rather than sending them all at
+ 	 * once. */
+@@ -668,7 +674,7 @@
+ 		/* My DER encoding requires length<128 */
+ 		if (gss_supported->elements[mech].length < 128 &&
+ 		    ssh_gssapi_check_mechanism(&gssctxt, 
+-		    &gss_supported->elements[mech], authctxt->host)) {
++		    &gss_supported->elements[mech], gss_host)) {
+ 			ok = 1; /* Mechanism works */
+ 		} else {
+ 			mech++;
+
+need to move these two funcs back to canohost so they're available to clients
+and the server.  auth.c is only used in the server.
+
+--- a/auth.c
++++ b/auth.c
+@@ -784,117 +784,3 @@ fakepw(void)
+ 
+ 	return (&fake);
+ }
+-
+-/*
+- * Returns the remote DNS hostname as a string. The returned string must not
+- * be freed. NB. this will usually trigger a DNS query the first time it is
+- * called.
+- * This function does additional checks on the hostname to mitigate some
+- * attacks on legacy rhosts-style authentication.
+- * XXX is RhostsRSAAuthentication vulnerable to these?
+- * XXX Can we remove these checks? (or if not, remove RhostsRSAAuthentication?)
+- */
+-
+-static char *
+-remote_hostname(struct ssh *ssh)
+-{
+-	struct sockaddr_storage from;
+-	socklen_t fromlen;
+-	struct addrinfo hints, *ai, *aitop;
+-	char name[NI_MAXHOST], ntop2[NI_MAXHOST];
+-	const char *ntop = ssh_remote_ipaddr(ssh);
+-
+-	/* Get IP address of client. */
+-	fromlen = sizeof(from);
+-	memset(&from, 0, sizeof(from));
+-	if (getpeername(ssh_packet_get_connection_in(ssh),
+-	    (struct sockaddr *)&from, &fromlen) < 0) {
+-		debug("getpeername failed: %.100s", strerror(errno));
+-		return strdup(ntop);
+-	}
+-
+-	ipv64_normalise_mapped(&from, &fromlen);
+-	if (from.ss_family == AF_INET6)
+-		fromlen = sizeof(struct sockaddr_in6);
+-
+-	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 strdup(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, NULL, &hints, &ai) == 0) {
+-		logit("Nasty PTR record \"%s\" is set up for %s, ignoring",
+-		    name, ntop);
+-		freeaddrinfo(ai);
+-		return strdup(ntop);
+-	}
+-
+-	/* Names are stored in lowercase. */
+-	lowercase(name);
+-
+-	/*
+-	 * 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.", name, ntop);
+-		return strdup(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 == NULL) {
+-		/* Address not found for the host name. */
+-		logit("Address %.100s maps to %.600s, but this does not "
+-		    "map back to the address.", ntop, name);
+-		return strdup(ntop);
+-	}
+-	return strdup(name);
+-}
+-
+-/*
+- * 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 *
+-auth_get_canonical_hostname(struct ssh *ssh, int use_dns)
+-{
+-	static char *dnsname;
+-
+-	if (!use_dns)
+-		return ssh_remote_ipaddr(ssh);
+-	else if (dnsname != NULL)
+-		return dnsname;
+-	else {
+-		dnsname = remote_hostname(ssh);
+-		return dnsname;
+-	}
+-}
+--- a/canohost.c
++++ b/canohost.c
+@@ -202,3 +202,117 @@ get_local_port(int sock)
+ {
+ 	return get_sock_port(sock, 1);
+ }
++
++/*
++ * Returns the remote DNS hostname as a string. The returned string must not
++ * be freed. NB. this will usually trigger a DNS query the first time it is
++ * called.
++ * This function does additional checks on the hostname to mitigate some
++ * attacks on legacy rhosts-style authentication.
++ * XXX is RhostsRSAAuthentication vulnerable to these?
++ * XXX Can we remove these checks? (or if not, remove RhostsRSAAuthentication?)
++ */
++
++static char *
++remote_hostname(struct ssh *ssh)
++{
++	struct sockaddr_storage from;
++	socklen_t fromlen;
++	struct addrinfo hints, *ai, *aitop;
++	char name[NI_MAXHOST], ntop2[NI_MAXHOST];
++	const char *ntop = ssh_remote_ipaddr(ssh);
++
++	/* Get IP address of client. */
++	fromlen = sizeof(from);
++	memset(&from, 0, sizeof(from));
++	if (getpeername(ssh_packet_get_connection_in(ssh),
++	    (struct sockaddr *)&from, &fromlen) < 0) {
++		debug("getpeername failed: %.100s", strerror(errno));
++		return strdup(ntop);
++	}
++
++	ipv64_normalise_mapped(&from, &fromlen);
++	if (from.ss_family == AF_INET6)
++		fromlen = sizeof(struct sockaddr_in6);
++
++	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 strdup(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, NULL, &hints, &ai) == 0) {
++		logit("Nasty PTR record \"%s\" is set up for %s, ignoring",
++		    name, ntop);
++		freeaddrinfo(ai);
++		return strdup(ntop);
++	}
++
++	/* Names are stored in lowercase. */
++	lowercase(name);
++
++	/*
++	 * 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.", name, ntop);
++		return strdup(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 == NULL) {
++		/* Address not found for the host name. */
++		logit("Address %.100s maps to %.600s, but this does not "
++		    "map back to the address.", ntop, name);
++		return strdup(ntop);
++	}
++	return strdup(name);
++}
++
++/*
++ * 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 *
++auth_get_canonical_hostname(struct ssh *ssh, int use_dns)
++{
++	static char *dnsname;
++
++	if (!use_dns)
++		return ssh_remote_ipaddr(ssh);
++	else if (dnsname != NULL)
++		return dnsname;
++	else {
++		dnsname = remote_hostname(ssh);
++		return dnsname;
++	}
++}
diff --git a/net-misc/openssh/openssh-7.3_p1-r1.ebuild b/net-misc/openssh/openssh-7.3_p1-r1.ebuild
index 4a4a2e0441f2..a915481516db 100644
--- a/net-misc/openssh/openssh-7.3_p1-r1.ebuild
+++ b/net-misc/openssh/openssh-7.3_p1-r1.ebuild
@@ -132,7 +132,7 @@ src_prepare() {
 		epatch "${WORKDIR}"/${LDAP_PATCH%.*}
 		save_version LPK
 	fi
-	epatch "${FILESDIR}"/${PN}-7.2_p1-GSSAPI-dns.patch #165444 integrated into gsskex
+	epatch "${FILESDIR}"/${PN}-7.3_p1-GSSAPI-dns.patch #165444 integrated into gsskex
 	epatch "${FILESDIR}"/${PN}-6.7_p1-openssl-ignore-status.patch
 	epatch "${WORKDIR}"/${SCTP_PATCH%.*}
 	if use hpn ; then