summaryrefslogtreecommitdiffstats
path: root/lib/dns/gssapictx.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:59:48 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:59:48 +0000
commit3b9b6d0b8e7f798023c9d109c490449d528fde80 (patch)
tree2e1c188dd7b8d7475cd163de9ae02c428343669b /lib/dns/gssapictx.c
parentInitial commit. (diff)
downloadbind9-3b9b6d0b8e7f798023c9d109c490449d528fde80.tar.xz
bind9-3b9b6d0b8e7f798023c9d109c490449d528fde80.zip
Adding upstream version 1:9.18.19.upstream/1%9.18.19upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/dns/gssapictx.c')
-rw-r--r--lib/dns/gssapictx.c962
1 files changed, 962 insertions, 0 deletions
diff --git a/lib/dns/gssapictx.c b/lib/dns/gssapictx.c
new file mode 100644
index 0000000..6eed756
--- /dev/null
+++ b/lib/dns/gssapictx.c
@@ -0,0 +1,962 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#include <ctype.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#if HAVE_GSSAPI_GSSAPI_H
+#include <gssapi/gssapi.h>
+#elif HAVE_GSSAPI_H
+#include <gssapi.h>
+#endif
+
+#if HAVE_GSSAPI_GSSAPI_KRB5_H
+#include <gssapi/gssapi_krb5.h>
+#elif HAVE_GSSAPI_KRB5_H
+#include <gssapi_krb5.h>
+#endif
+
+#if HAVE_KRB5_KRB5_H
+#include <krb5/krb5.h>
+#elif HAVE_KRB5_H
+#include <krb5.h>
+#endif
+
+#include <isc/buffer.h>
+#include <isc/dir.h>
+#include <isc/file.h>
+#include <isc/lex.h>
+#include <isc/mem.h>
+#include <isc/once.h>
+#include <isc/print.h>
+#include <isc/random.h>
+#include <isc/result.h>
+#include <isc/string.h>
+#include <isc/time.h>
+#include <isc/util.h>
+
+#include <dns/fixedname.h>
+#include <dns/keyvalues.h>
+#include <dns/log.h>
+#include <dns/name.h>
+#include <dns/rdata.h>
+#include <dns/rdataclass.h>
+#include <dns/types.h>
+
+#include <dst/gssapi.h>
+
+#include "dst_internal.h"
+
+#if HAVE_GSSAPI
+
+#ifndef GSS_KRB5_MECHANISM
+static unsigned char krb5_mech_oid_bytes[] = { 0x2a, 0x86, 0x48, 0x86, 0xf7,
+ 0x12, 0x01, 0x02, 0x02 };
+static gss_OID_desc __gss_krb5_mechanism_oid_desc = {
+ sizeof(krb5_mech_oid_bytes), krb5_mech_oid_bytes
+};
+#define GSS_KRB5_MECHANISM (&__gss_krb5_mechanism_oid_desc)
+#endif /* ifndef GSS_KRB5_MECHANISM */
+
+#ifndef GSS_SPNEGO_MECHANISM
+static unsigned char spnego_mech_oid_bytes[] = { 0x2b, 0x06, 0x01,
+ 0x05, 0x05, 0x02 };
+static gss_OID_desc __gss_spnego_mechanism_oid_desc = {
+ sizeof(spnego_mech_oid_bytes), spnego_mech_oid_bytes
+};
+#define GSS_SPNEGO_MECHANISM (&__gss_spnego_mechanism_oid_desc)
+#endif /* ifndef GSS_SPNEGO_MECHANISM */
+
+#define REGION_TO_GBUFFER(r, gb) \
+ do { \
+ (gb).length = (r).length; \
+ (gb).value = (r).base; \
+ } while (0)
+
+#define GBUFFER_TO_REGION(gb, r) \
+ do { \
+ (r).length = (unsigned int)(gb).length; \
+ (r).base = (gb).value; \
+ } while (0)
+
+#define RETERR(x) \
+ do { \
+ result = (x); \
+ if (result != ISC_R_SUCCESS) \
+ goto out; \
+ } while (0)
+
+static void
+name_to_gbuffer(const dns_name_t *name, isc_buffer_t *buffer,
+ gss_buffer_desc *gbuffer) {
+ dns_name_t tname;
+ const dns_name_t *namep;
+ isc_region_t r;
+ isc_result_t result;
+
+ if (!dns_name_isabsolute(name)) {
+ namep = name;
+ } else {
+ unsigned int labels;
+ dns_name_init(&tname, NULL);
+ labels = dns_name_countlabels(name);
+ dns_name_getlabelsequence(name, 0, labels - 1, &tname);
+ namep = &tname;
+ }
+
+ result = dns_name_toprincipal(namep, buffer);
+ RUNTIME_CHECK(result == ISC_R_SUCCESS);
+ isc_buffer_putuint8(buffer, 0);
+ isc_buffer_usedregion(buffer, &r);
+ REGION_TO_GBUFFER(r, *gbuffer);
+}
+
+static void
+log_cred(const gss_cred_id_t cred) {
+ OM_uint32 gret, minor, lifetime;
+ gss_name_t gname;
+ gss_buffer_desc gbuffer;
+ gss_cred_usage_t usage;
+ const char *usage_text;
+ char buf[1024];
+
+ gret = gss_inquire_cred(&minor, cred, &gname, &lifetime, &usage, NULL);
+ if (gret != GSS_S_COMPLETE) {
+ gss_log(3, "failed gss_inquire_cred: %s",
+ gss_error_tostring(gret, minor, buf, sizeof(buf)));
+ return;
+ }
+
+ gret = gss_display_name(&minor, gname, &gbuffer, NULL);
+ if (gret != GSS_S_COMPLETE) {
+ gss_log(3, "failed gss_display_name: %s",
+ gss_error_tostring(gret, minor, buf, sizeof(buf)));
+ } else {
+ switch (usage) {
+ case GSS_C_BOTH:
+ usage_text = "GSS_C_BOTH";
+ break;
+ case GSS_C_INITIATE:
+ usage_text = "GSS_C_INITIATE";
+ break;
+ case GSS_C_ACCEPT:
+ usage_text = "GSS_C_ACCEPT";
+ break;
+ default:
+ usage_text = "???";
+ }
+ gss_log(3, "gss cred: \"%s\", %s, %lu", (char *)gbuffer.value,
+ usage_text, (unsigned long)lifetime);
+ }
+
+ if (gret == GSS_S_COMPLETE) {
+ if (gbuffer.length != 0U) {
+ gret = gss_release_buffer(&minor, &gbuffer);
+ if (gret != GSS_S_COMPLETE) {
+ gss_log(3, "failed gss_release_buffer: %s",
+ gss_error_tostring(gret, minor, buf,
+ sizeof(buf)));
+ }
+ }
+ }
+
+ gret = gss_release_name(&minor, &gname);
+ if (gret != GSS_S_COMPLETE) {
+ gss_log(3, "failed gss_release_name: %s",
+ gss_error_tostring(gret, minor, buf, sizeof(buf)));
+ }
+}
+
+/*
+ * check for the most common configuration errors.
+ *
+ * The errors checked for are:
+ * - tkey-gssapi-credential doesn't start with DNS/
+ * - the default realm in /etc/krb5.conf and the
+ * tkey-gssapi-credential bind config option don't match
+ *
+ * Note that if tkey-gssapi-keytab is set then these configure checks
+ * are not performed, and runtime errors from gssapi are used instead
+ */
+static void
+check_config(const char *gss_name) {
+ const char *p;
+ krb5_context krb5_ctx;
+ char *krb5_realm_name = NULL;
+
+ if (strncasecmp(gss_name, "DNS/", 4) != 0) {
+ gss_log(ISC_LOG_ERROR,
+ "tkey-gssapi-credential (%s) "
+ "should start with 'DNS/'",
+ gss_name);
+ return;
+ }
+
+ if (krb5_init_context(&krb5_ctx) != 0) {
+ gss_log(ISC_LOG_ERROR, "Unable to initialise krb5 context");
+ return;
+ }
+ if (krb5_get_default_realm(krb5_ctx, &krb5_realm_name) != 0) {
+ gss_log(ISC_LOG_ERROR, "Unable to get krb5 default realm");
+ krb5_free_context(krb5_ctx);
+ return;
+ }
+ p = strchr(gss_name, '@');
+ if (p == NULL) {
+ gss_log(ISC_LOG_ERROR,
+ "badly formatted "
+ "tkey-gssapi-credentials (%s)",
+ gss_name);
+ krb5_free_context(krb5_ctx);
+ return;
+ }
+ if (strcasecmp(p + 1, krb5_realm_name) != 0) {
+ gss_log(ISC_LOG_ERROR,
+ "default realm from krb5.conf (%s) "
+ "does not match tkey-gssapi-credential (%s)",
+ krb5_realm_name, gss_name);
+ krb5_free_context(krb5_ctx);
+ return;
+ }
+ krb5_free_context(krb5_ctx);
+}
+
+static OM_uint32
+mech_oid_set_create(OM_uint32 *minor, gss_OID_set *mech_oid_set) {
+ OM_uint32 gret;
+
+ gret = gss_create_empty_oid_set(minor, mech_oid_set);
+ if (gret != GSS_S_COMPLETE) {
+ return (gret);
+ }
+
+ gret = gss_add_oid_set_member(minor, GSS_KRB5_MECHANISM, mech_oid_set);
+ if (gret != GSS_S_COMPLETE) {
+ goto release;
+ }
+
+ gret = gss_add_oid_set_member(minor, GSS_SPNEGO_MECHANISM,
+ mech_oid_set);
+ if (gret != GSS_S_COMPLETE) {
+ goto release;
+ }
+
+release:
+ REQUIRE(gss_release_oid_set(minor, mech_oid_set) == GSS_S_COMPLETE);
+
+ return (gret);
+}
+
+static void
+mech_oid_set_release(gss_OID_set *mech_oid_set) {
+ OM_uint32 minor;
+
+ REQUIRE(gss_release_oid_set(&minor, mech_oid_set) == GSS_S_COMPLETE);
+}
+
+isc_result_t
+dst_gssapi_acquirecred(const dns_name_t *name, bool initiate,
+ dns_gss_cred_id_t *cred) {
+ isc_result_t result;
+ isc_buffer_t namebuf;
+ gss_name_t gname;
+ gss_buffer_desc gnamebuf;
+ unsigned char array[DNS_NAME_MAXTEXT + 1];
+ OM_uint32 gret, minor;
+ OM_uint32 lifetime;
+ gss_cred_usage_t usage;
+ char buf[1024];
+ gss_OID_set mech_oid_set;
+
+ REQUIRE(cred != NULL && *cred == NULL);
+
+ /*
+ * XXXSRA In theory we could use GSS_C_NT_HOSTBASED_SERVICE
+ * here when we're in the acceptor role, which would let us
+ * default the hostname and use a compiled in default service
+ * name of "DNS", giving one less thing to configure in
+ * named.conf. Unfortunately, this creates a circular
+ * dependency due to DNS-based realm lookup in at least one
+ * GSSAPI implementation (Heimdal). Oh well.
+ */
+ if (name != NULL) {
+ isc_buffer_init(&namebuf, array, sizeof(array));
+ name_to_gbuffer(name, &namebuf, &gnamebuf);
+ gret = gss_import_name(&minor, &gnamebuf, GSS_C_NO_OID, &gname);
+ if (gret != GSS_S_COMPLETE) {
+ check_config((char *)array);
+
+ gss_log(3, "failed gss_import_name: %s",
+ gss_error_tostring(gret, minor, buf,
+ sizeof(buf)));
+ return (ISC_R_FAILURE);
+ }
+ } else {
+ gname = NULL;
+ }
+
+ /* Get the credentials. */
+ if (gname != NULL) {
+ gss_log(3, "acquiring credentials for %s",
+ (char *)gnamebuf.value);
+ } else {
+ /* XXXDCL does this even make any sense? */
+ gss_log(3, "acquiring credentials for ?");
+ }
+
+ if (initiate) {
+ usage = GSS_C_INITIATE;
+ } else {
+ usage = GSS_C_ACCEPT;
+ }
+
+ gret = mech_oid_set_create(&minor, &mech_oid_set);
+ if (gret != GSS_S_COMPLETE) {
+ gss_log(3, "failed to create OID_set: %s",
+ gss_error_tostring(gret, minor, buf, sizeof(buf)));
+ return (ISC_R_FAILURE);
+ }
+
+ gret = gss_acquire_cred(&minor, gname, GSS_C_INDEFINITE, mech_oid_set,
+ usage, (gss_cred_id_t *)cred, NULL, &lifetime);
+
+ if (gret != GSS_S_COMPLETE) {
+ gss_log(3, "failed to acquire %s credentials for %s: %s",
+ initiate ? "initiate" : "accept",
+ (gname != NULL) ? (char *)gnamebuf.value : "?",
+ gss_error_tostring(gret, minor, buf, sizeof(buf)));
+ if (gname != NULL) {
+ check_config((char *)array);
+ }
+ result = ISC_R_FAILURE;
+ goto cleanup;
+ }
+
+ gss_log(4, "acquired %s credentials for %s",
+ initiate ? "initiate" : "accept",
+ (gname != NULL) ? (char *)gnamebuf.value : "?");
+
+ log_cred(*cred);
+ result = ISC_R_SUCCESS;
+
+cleanup:
+ mech_oid_set_release(&mech_oid_set);
+
+ if (gname != NULL) {
+ gret = gss_release_name(&minor, &gname);
+ if (gret != GSS_S_COMPLETE) {
+ gss_log(3, "failed gss_release_name: %s",
+ gss_error_tostring(gret, minor, buf,
+ sizeof(buf)));
+ }
+ }
+
+ return (result);
+}
+
+bool
+dst_gssapi_identitymatchesrealmkrb5(const dns_name_t *signer,
+ const dns_name_t *name,
+ const dns_name_t *realm, bool subdomain) {
+ char sbuf[DNS_NAME_FORMATSIZE];
+ char rbuf[DNS_NAME_FORMATSIZE];
+ char *sname;
+ char *rname;
+ isc_buffer_t buffer;
+ isc_result_t result;
+
+ /*
+ * It is far, far easier to write the names we are looking at into
+ * a string, and do string operations on them.
+ */
+ isc_buffer_init(&buffer, sbuf, sizeof(sbuf));
+ result = dns_name_toprincipal(signer, &buffer);
+ RUNTIME_CHECK(result == ISC_R_SUCCESS);
+ isc_buffer_putuint8(&buffer, 0);
+ dns_name_format(realm, rbuf, sizeof(rbuf));
+
+ /*
+ * Find the realm portion. This is the part after the @. If it
+ * does not exist, we don't have something we like, so we fail our
+ * compare.
+ */
+ rname = strchr(sbuf, '@');
+ if (rname == NULL) {
+ return (false);
+ }
+ *rname = '\0';
+ rname++;
+
+ if (strcmp(rname, rbuf) != 0) {
+ return (false);
+ }
+
+ /*
+ * Find the host portion of the signer's name. We do this by
+ * searching for the first / character. We then check to make
+ * certain the instance name is "host"
+ *
+ * This will work for
+ * host/example.com@EXAMPLE.COM
+ */
+ sname = strchr(sbuf, '/');
+ if (sname == NULL) {
+ return (false);
+ }
+ *sname = '\0';
+ sname++;
+ if (strcmp(sbuf, "host") != 0) {
+ return (false);
+ }
+
+ /*
+ * If name is non NULL check that it matches against the
+ * machine name as expected.
+ */
+ if (name != NULL) {
+ dns_fixedname_t fixed;
+ dns_name_t *machine;
+
+ machine = dns_fixedname_initname(&fixed);
+ result = dns_name_fromstring(machine, sname, 0, NULL);
+ if (result != ISC_R_SUCCESS) {
+ return (false);
+ }
+ if (subdomain) {
+ return (dns_name_issubdomain(name, machine));
+ }
+ return (dns_name_equal(name, machine));
+ }
+
+ return (true);
+}
+
+bool
+dst_gssapi_identitymatchesrealmms(const dns_name_t *signer,
+ const dns_name_t *name,
+ const dns_name_t *realm, bool subdomain) {
+ char sbuf[DNS_NAME_FORMATSIZE];
+ char rbuf[DNS_NAME_FORMATSIZE];
+ char *sname;
+ char *rname;
+ isc_buffer_t buffer;
+ isc_result_t result;
+
+ /*
+ * It is far, far easier to write the names we are looking at into
+ * a string, and do string operations on them.
+ */
+ isc_buffer_init(&buffer, sbuf, sizeof(sbuf));
+ result = dns_name_toprincipal(signer, &buffer);
+ RUNTIME_CHECK(result == ISC_R_SUCCESS);
+ isc_buffer_putuint8(&buffer, 0);
+ dns_name_format(realm, rbuf, sizeof(rbuf));
+
+ /*
+ * Find the realm portion. This is the part after the @. If it
+ * does not exist, we don't have something we like, so we fail our
+ * compare.
+ */
+ rname = strchr(sbuf, '@');
+ if (rname == NULL) {
+ return (false);
+ }
+ sname = strchr(sbuf, '$');
+ if (sname == NULL) {
+ return (false);
+ }
+
+ /*
+ * Verify that the $ and @ follow one another.
+ */
+ if (rname - sname != 1) {
+ return (false);
+ }
+
+ /*
+ * Find the host portion of the signer's name. Zero out the $ so
+ * it terminates the signer's name, and skip past the @ for
+ * the realm.
+ *
+ * All service principals in Microsoft format seem to be in
+ * machinename$@EXAMPLE.COM
+ * format.
+ */
+ rname++;
+ *sname = '\0';
+
+ if (strcmp(rname, rbuf) != 0) {
+ return (false);
+ }
+
+ /*
+ * Now, we check that the realm matches (case sensitive) and that
+ * 'name' matches against 'machinename' qualified with 'realm'.
+ */
+ if (name != NULL) {
+ dns_fixedname_t fixed;
+ dns_name_t *machine;
+
+ machine = dns_fixedname_initname(&fixed);
+ result = dns_name_fromstring2(machine, sbuf, realm, 0, NULL);
+ if (result != ISC_R_SUCCESS) {
+ return (false);
+ }
+ if (subdomain) {
+ return (dns_name_issubdomain(name, machine));
+ }
+ return (dns_name_equal(name, machine));
+ }
+
+ return (true);
+}
+
+isc_result_t
+dst_gssapi_releasecred(dns_gss_cred_id_t *cred) {
+ OM_uint32 gret, minor;
+ char buf[1024];
+
+ REQUIRE(cred != NULL && *cred != NULL);
+
+ gret = gss_release_cred(&minor, (gss_cred_id_t *)cred);
+ if (gret != GSS_S_COMPLETE) {
+ /* Log the error, but still free the credential's memory */
+ gss_log(3, "failed releasing credential: %s",
+ gss_error_tostring(gret, minor, buf, sizeof(buf)));
+ }
+ *cred = NULL;
+
+ return (ISC_R_SUCCESS);
+}
+
+/*
+ * Format a gssapi error message info into a char ** on the given memory
+ * context. This is used to return gssapi error messages back up the
+ * call chain for reporting to the user.
+ */
+static void
+gss_err_message(isc_mem_t *mctx, uint32_t major, uint32_t minor,
+ char **err_message) {
+ char buf[1024];
+ char *estr;
+
+ if (err_message == NULL || mctx == NULL) {
+ /* the caller doesn't want any error messages */
+ return;
+ }
+
+ estr = gss_error_tostring(major, minor, buf, sizeof(buf));
+ if (estr != NULL) {
+ (*err_message) = isc_mem_strdup(mctx, estr);
+ }
+}
+
+isc_result_t
+dst_gssapi_initctx(const dns_name_t *name, isc_buffer_t *intoken,
+ isc_buffer_t *outtoken, dns_gss_ctx_id_t *gssctx,
+ isc_mem_t *mctx, char **err_message) {
+ isc_region_t r;
+ isc_buffer_t namebuf;
+ gss_name_t gname;
+ OM_uint32 gret, minor, ret_flags, flags;
+ gss_buffer_desc gintoken, *gintokenp, gouttoken = GSS_C_EMPTY_BUFFER;
+ isc_result_t result;
+ gss_buffer_desc gnamebuf;
+ unsigned char array[DNS_NAME_MAXTEXT + 1];
+
+ /* Client must pass us a valid gss_ctx_id_t here */
+ REQUIRE(gssctx != NULL);
+ REQUIRE(mctx != NULL);
+
+ isc_buffer_init(&namebuf, array, sizeof(array));
+ name_to_gbuffer(name, &namebuf, &gnamebuf);
+
+ /* Get the name as a GSS name */
+ gret = gss_import_name(&minor, &gnamebuf, GSS_C_NO_OID, &gname);
+ if (gret != GSS_S_COMPLETE) {
+ gss_err_message(mctx, gret, minor, err_message);
+ result = ISC_R_FAILURE;
+ goto out;
+ }
+
+ if (intoken != NULL) {
+ /* Don't call gss_release_buffer for gintoken! */
+ REGION_TO_GBUFFER(*intoken, gintoken);
+ gintokenp = &gintoken;
+ } else {
+ gintokenp = NULL;
+ }
+
+ /*
+ * Note that we don't set GSS_C_SEQUENCE_FLAG as Windows DNS
+ * servers don't like it.
+ */
+ flags = GSS_C_REPLAY_FLAG | GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG;
+
+ gret = gss_init_sec_context(
+ &minor, GSS_C_NO_CREDENTIAL, (gss_ctx_id_t *)gssctx, gname,
+ GSS_SPNEGO_MECHANISM, flags, 0, NULL, gintokenp, NULL,
+ &gouttoken, &ret_flags, NULL);
+
+ if (gret != GSS_S_COMPLETE && gret != GSS_S_CONTINUE_NEEDED) {
+ gss_err_message(mctx, gret, minor, err_message);
+ if (err_message != NULL && *err_message != NULL) {
+ gss_log(3, "Failure initiating security context: %s",
+ *err_message);
+ } else {
+ gss_log(3, "Failure initiating security context");
+ }
+
+ result = ISC_R_FAILURE;
+ goto out;
+ }
+
+ /*
+ * XXXSRA Not handled yet: RFC 3645 3.1.1: check ret_flags
+ * MUTUAL and INTEG flags, fail if either not set.
+ */
+
+ /*
+ * RFC 2744 states the a valid output token has a non-zero length.
+ */
+ if (gouttoken.length != 0U) {
+ GBUFFER_TO_REGION(gouttoken, r);
+ RETERR(isc_buffer_copyregion(outtoken, &r));
+ }
+
+ if (gret == GSS_S_COMPLETE) {
+ result = ISC_R_SUCCESS;
+ } else {
+ result = DNS_R_CONTINUE;
+ }
+
+out:
+ if (gouttoken.length != 0U) {
+ (void)gss_release_buffer(&minor, &gouttoken);
+ }
+ (void)gss_release_name(&minor, &gname);
+ return (result);
+}
+
+isc_result_t
+dst_gssapi_acceptctx(dns_gss_cred_id_t cred, const char *gssapi_keytab,
+ isc_region_t *intoken, isc_buffer_t **outtoken,
+ dns_gss_ctx_id_t *ctxout, dns_name_t *principal,
+ isc_mem_t *mctx) {
+ isc_region_t r;
+ isc_buffer_t namebuf;
+ gss_buffer_desc gnamebuf = GSS_C_EMPTY_BUFFER, gintoken,
+ gouttoken = GSS_C_EMPTY_BUFFER;
+ OM_uint32 gret, minor;
+ gss_ctx_id_t context = GSS_C_NO_CONTEXT;
+ gss_name_t gname = NULL;
+ isc_result_t result;
+ char buf[1024];
+
+ REQUIRE(outtoken != NULL && *outtoken == NULL);
+
+ REGION_TO_GBUFFER(*intoken, gintoken);
+
+ if (*ctxout == NULL) {
+ context = GSS_C_NO_CONTEXT;
+ } else {
+ context = *ctxout;
+ }
+
+ if (gssapi_keytab != NULL) {
+#if HAVE_GSSAPI_GSSAPI_KRB5_H || HAVE_GSSAPI_KRB5_H
+ gret = gsskrb5_register_acceptor_identity(gssapi_keytab);
+ if (gret != GSS_S_COMPLETE) {
+ gss_log(3,
+ "failed "
+ "gsskrb5_register_acceptor_identity(%s): %s",
+ gssapi_keytab,
+ gss_error_tostring(gret, 0, buf, sizeof(buf)));
+ return (DNS_R_INVALIDTKEY);
+ }
+#else
+ /*
+ * Minimize memory leakage by only setting KRB5_KTNAME
+ * if it needs to change.
+ */
+ const char *old = getenv("KRB5_KTNAME");
+ if (old == NULL || strcmp(old, gssapi_keytab) != 0) {
+ size_t size;
+ char *kt;
+
+ size = strlen(gssapi_keytab) + 13;
+ kt = malloc(size);
+ if (kt == NULL) {
+ return (ISC_R_NOMEMORY);
+ }
+ snprintf(kt, size, "KRB5_KTNAME=%s", gssapi_keytab);
+ if (putenv(kt) != 0) {
+ return (ISC_R_NOMEMORY);
+ }
+ }
+#endif
+ }
+
+ log_cred(cred);
+
+ gret = gss_accept_sec_context(&minor, &context, cred, &gintoken,
+ GSS_C_NO_CHANNEL_BINDINGS, &gname, NULL,
+ &gouttoken, NULL, NULL, NULL);
+
+ result = ISC_R_FAILURE;
+
+ switch (gret) {
+ case GSS_S_COMPLETE:
+ case GSS_S_CONTINUE_NEEDED:
+ break;
+ case GSS_S_DEFECTIVE_TOKEN:
+ case GSS_S_DEFECTIVE_CREDENTIAL:
+ case GSS_S_BAD_SIG:
+ case GSS_S_DUPLICATE_TOKEN:
+ case GSS_S_OLD_TOKEN:
+ case GSS_S_NO_CRED:
+ case GSS_S_CREDENTIALS_EXPIRED:
+ case GSS_S_BAD_BINDINGS:
+ case GSS_S_NO_CONTEXT:
+ case GSS_S_BAD_MECH:
+ case GSS_S_FAILURE:
+ result = DNS_R_INVALIDTKEY;
+ /* fall through */
+ default:
+ gss_log(3, "failed gss_accept_sec_context: %s",
+ gss_error_tostring(gret, minor, buf, sizeof(buf)));
+ if (gouttoken.length > 0U) {
+ (void)gss_release_buffer(&minor, &gouttoken);
+ }
+ return (result);
+ }
+
+ if (gouttoken.length > 0U) {
+ isc_buffer_allocate(mctx, outtoken,
+ (unsigned int)gouttoken.length);
+ GBUFFER_TO_REGION(gouttoken, r);
+ RETERR(isc_buffer_copyregion(*outtoken, &r));
+ (void)gss_release_buffer(&minor, &gouttoken);
+ }
+
+ if (gret == GSS_S_COMPLETE) {
+ gret = gss_display_name(&minor, gname, &gnamebuf, NULL);
+ if (gret != GSS_S_COMPLETE) {
+ gss_log(3, "failed gss_display_name: %s",
+ gss_error_tostring(gret, minor, buf,
+ sizeof(buf)));
+ RETERR(ISC_R_FAILURE);
+ }
+
+ /*
+ * Compensate for a bug in Solaris8's implementation
+ * of gss_display_name(). Should be harmless in any
+ * case, since principal names really should not
+ * contain null characters.
+ */
+ if (gnamebuf.length > 0U &&
+ ((char *)gnamebuf.value)[gnamebuf.length - 1] == '\0')
+ {
+ gnamebuf.length--;
+ }
+
+ gss_log(3, "gss-api source name (accept) is %.*s",
+ (int)gnamebuf.length, (char *)gnamebuf.value);
+
+ GBUFFER_TO_REGION(gnamebuf, r);
+ isc_buffer_init(&namebuf, r.base, r.length);
+ isc_buffer_add(&namebuf, r.length);
+
+ RETERR(dns_name_fromtext(principal, &namebuf, dns_rootname, 0,
+ NULL));
+
+ if (gnamebuf.length != 0U) {
+ gret = gss_release_buffer(&minor, &gnamebuf);
+ if (gret != GSS_S_COMPLETE) {
+ gss_log(3, "failed gss_release_buffer: %s",
+ gss_error_tostring(gret, minor, buf,
+ sizeof(buf)));
+ }
+ }
+ } else {
+ result = DNS_R_CONTINUE;
+ }
+
+ *ctxout = context;
+
+out:
+ if (gname != NULL) {
+ gret = gss_release_name(&minor, &gname);
+ if (gret != GSS_S_COMPLETE) {
+ gss_log(3, "failed gss_release_name: %s",
+ gss_error_tostring(gret, minor, buf,
+ sizeof(buf)));
+ }
+ }
+
+ return (result);
+}
+
+isc_result_t
+dst_gssapi_deletectx(isc_mem_t *mctx, dns_gss_ctx_id_t *gssctx) {
+ OM_uint32 gret, minor;
+ char buf[1024];
+
+ UNUSED(mctx);
+
+ REQUIRE(gssctx != NULL && *gssctx != NULL);
+
+ /* Delete the context from the GSS provider */
+ gret = gss_delete_sec_context(&minor, (gss_ctx_id_t *)gssctx,
+ GSS_C_NO_BUFFER);
+ if (gret != GSS_S_COMPLETE) {
+ /* Log the error, but still free the context's memory */
+ gss_log(3, "Failure deleting security context %s",
+ gss_error_tostring(gret, minor, buf, sizeof(buf)));
+ }
+ return (ISC_R_SUCCESS);
+}
+
+char *
+gss_error_tostring(uint32_t major, uint32_t minor, char *buf, size_t buflen) {
+ gss_buffer_desc msg_minor = GSS_C_EMPTY_BUFFER,
+ msg_major = GSS_C_EMPTY_BUFFER;
+ OM_uint32 msg_ctx, minor_stat;
+
+ /* Handle major status */
+ msg_ctx = 0;
+ (void)gss_display_status(&minor_stat, major, GSS_C_GSS_CODE,
+ GSS_C_NULL_OID, &msg_ctx, &msg_major);
+
+ /* Handle minor status */
+ msg_ctx = 0;
+ (void)gss_display_status(&minor_stat, minor, GSS_C_MECH_CODE,
+ GSS_C_NULL_OID, &msg_ctx, &msg_minor);
+
+ snprintf(buf, buflen, "GSSAPI error: Major = %s, Minor = %s.",
+ (char *)msg_major.value, (char *)msg_minor.value);
+
+ if (msg_major.length != 0U) {
+ (void)gss_release_buffer(&minor_stat, &msg_major);
+ }
+ if (msg_minor.length != 0U) {
+ (void)gss_release_buffer(&minor_stat, &msg_minor);
+ }
+ return (buf);
+}
+
+#else
+
+isc_result_t
+dst_gssapi_acquirecred(const dns_name_t *name, bool initiate,
+ dns_gss_cred_id_t *cred) {
+ REQUIRE(cred != NULL && *cred == NULL);
+
+ UNUSED(name);
+ UNUSED(initiate);
+ UNUSED(cred);
+
+ return (ISC_R_NOTIMPLEMENTED);
+}
+
+bool
+dst_gssapi_identitymatchesrealmkrb5(const dns_name_t *signer,
+ const dns_name_t *name,
+ const dns_name_t *realm, bool subdomain) {
+ UNUSED(signer);
+ UNUSED(name);
+ UNUSED(realm);
+ UNUSED(subdomain);
+
+ return (false);
+}
+
+bool
+dst_gssapi_identitymatchesrealmms(const dns_name_t *signer,
+ const dns_name_t *name,
+ const dns_name_t *realm, bool subdomain) {
+ UNUSED(signer);
+ UNUSED(name);
+ UNUSED(realm);
+ UNUSED(subdomain);
+
+ return (false);
+}
+
+isc_result_t
+dst_gssapi_releasecred(dns_gss_cred_id_t *cred) {
+ UNUSED(cred);
+
+ return (ISC_R_NOTIMPLEMENTED);
+}
+
+isc_result_t
+dst_gssapi_initctx(const dns_name_t *name, isc_buffer_t *intoken,
+ isc_buffer_t *outtoken, dns_gss_ctx_id_t *gssctx,
+ isc_mem_t *mctx, char **err_message) {
+ UNUSED(name);
+ UNUSED(intoken);
+ UNUSED(outtoken);
+ UNUSED(gssctx);
+ UNUSED(mctx);
+ UNUSED(err_message);
+
+ return (ISC_R_NOTIMPLEMENTED);
+}
+
+isc_result_t
+dst_gssapi_acceptctx(dns_gss_cred_id_t cred, const char *gssapi_keytab,
+ isc_region_t *intoken, isc_buffer_t **outtoken,
+ dns_gss_ctx_id_t *ctxout, dns_name_t *principal,
+ isc_mem_t *mctx) {
+ UNUSED(cred);
+ UNUSED(gssapi_keytab);
+ UNUSED(intoken);
+ UNUSED(outtoken);
+ UNUSED(ctxout);
+ UNUSED(principal);
+ UNUSED(mctx);
+
+ return (ISC_R_NOTIMPLEMENTED);
+}
+
+isc_result_t
+dst_gssapi_deletectx(isc_mem_t *mctx, dns_gss_ctx_id_t *gssctx) {
+ UNUSED(mctx);
+ UNUSED(gssctx);
+ return (ISC_R_NOTIMPLEMENTED);
+}
+
+char *
+gss_error_tostring(uint32_t major, uint32_t minor, char *buf, size_t buflen) {
+ snprintf(buf, buflen, "GSSAPI error: Major = %u, Minor = %u.", major,
+ minor);
+
+ return (buf);
+}
+
+#endif
+
+void
+gss_log(int level, const char *fmt, ...) {
+ va_list ap;
+
+ va_start(ap, fmt);
+ isc_log_vwrite(dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_TKEY,
+ ISC_LOG_DEBUG(level), fmt, ap);
+ va_end(ap);
+}