diff options
Diffstat (limited to 'net-misc/openssh/files/openssh-8.7_p1-GSSAPI-dns.patch')
| -rw-r--r-- | net-misc/openssh/files/openssh-8.7_p1-GSSAPI-dns.patch | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/net-misc/openssh/files/openssh-8.7_p1-GSSAPI-dns.patch b/net-misc/openssh/files/openssh-8.7_p1-GSSAPI-dns.patch new file mode 100644 index 000000000000..ffc40b70ae3d --- /dev/null +++ b/net-misc/openssh/files/openssh-8.7_p1-GSSAPI-dns.patch @@ -0,0 +1,357 @@ +diff --git a/auth.c b/auth.c +index 00b168b4..8ee93581 100644 +--- a/auth.c ++++ b/auth.c +@@ -729,118 +729,6 @@ 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 based on conflation of hostnames and IP addresses. +- */ +- +-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) == -1) { +- debug("getpeername failed: %.100s", strerror(errno)); +- return xstrdup(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 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, NULL, &hints, &ai) == 0) { +- logit("Nasty PTR record \"%s\" is set up for %s, ignoring", +- name, ntop); +- freeaddrinfo(ai); +- return xstrdup(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 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 == 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 xstrdup(ntop); +- } +- return xstrdup(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; +- } +-} +- + /* These functions link key/cert options to the auth framework */ + + /* Log sshauthopt options locally and (optionally) for remote transmission */ +diff --git a/canohost.c b/canohost.c +index a810da0e..18e9d8d4 100644 +--- 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) == -1) { ++ debug("getpeername failed: %.100s", strerror(errno)); ++ return xstrdup(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 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, NULL, &hints, &ai) == 0) { ++ logit("Nasty PTR record \"%s\" is set up for %s, ignoring", ++ name, ntop); ++ freeaddrinfo(ai); ++ return xstrdup(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 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 == 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 xstrdup(ntop); ++ } ++ return xstrdup(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/readconf.c b/readconf.c +index 03369a08..b45898ce 100644 +--- a/readconf.c ++++ b/readconf.c +@@ -161,6 +161,7 @@ typedef enum { + oClearAllForwardings, oNoHostAuthenticationForLocalhost, + oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout, + oAddressFamily, oGssAuthentication, oGssDelegateCreds, ++ oGssTrustDns, + oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly, + oSendEnv, oSetEnv, oControlPath, oControlMaster, oControlPersist, + oHashKnownHosts, +@@ -207,9 +208,11 @@ static struct { + #if defined(GSSAPI) + { "gssapiauthentication", oGssAuthentication }, + { "gssapidelegatecredentials", oGssDelegateCreds }, ++ { "gssapitrustdns", oGssTrustDns }, + # else + { "gssapiauthentication", oUnsupported }, + { "gssapidelegatecredentials", oUnsupported }, ++ { "gssapitrustdns", oUnsupported }, + #endif + #ifdef ENABLE_PKCS11 + { "pkcs11provider", oPKCS11Provider }, +@@ -1117,6 +1120,10 @@ parse_time: + 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; +@@ -2307,6 +2314,7 @@ initialize_options(Options * options) + options->pubkey_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; +@@ -2465,6 +2473,8 @@ fill_default_options(Options * options) + 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) +diff --git a/readconf.h b/readconf.h +index f7d53b06..c3a91898 100644 +--- a/readconf.h ++++ b/readconf.h +@@ -40,6 +40,7 @@ typedef struct { + int hostbased_authentication; /* ssh2's rhosts_rsa */ + 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. */ +diff --git a/ssh_config.5 b/ssh_config.5 +index cd0eea86..27101943 100644 +--- a/ssh_config.5 ++++ b/ssh_config.5 +@@ -832,6 +832,16 @@ The default is + Forward (delegate) credentials to the server. + The default is + .Cm 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 +diff --git a/sshconnect2.c b/sshconnect2.c +index fea50fab..aeff639b 100644 +--- a/sshconnect2.c ++++ b/sshconnect2.c +@@ -776,6 +776,13 @@ userauth_gssapi(struct ssh *ssh) + OM_uint32 min; + int r, ok = 0; + gss_OID mech = NULL; ++ const char *gss_host; ++ ++ if (options.gss_trust_dns) { ++ extern const char *auth_get_canonical_hostname(struct ssh *ssh, int use_dns); ++ gss_host = auth_get_canonical_hostname(ssh, 1); ++ } else ++ gss_host = authctxt->host; + + /* Try one GSSAPI method at a time, rather than sending them all at + * once. */ +@@ -790,7 +797,7 @@ userauth_gssapi(struct ssh *ssh) + elements[authctxt->mech_tried]; + /* My DER encoding requires length<128 */ + if (mech->length < 128 && ssh_gssapi_check_mechanism(&gssctxt, +- mech, authctxt->host)) { ++ mech, gss_host)) { + ok = 1; /* Mechanism works */ + } else { + authctxt->mech_tried++; |