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-rw-r--r--auth/kerberos/gssapi_pac.c348
1 files changed, 348 insertions, 0 deletions
diff --git a/auth/kerberos/gssapi_pac.c b/auth/kerberos/gssapi_pac.c
new file mode 100644
index 0000000..1204399
--- /dev/null
+++ b/auth/kerberos/gssapi_pac.c
@@ -0,0 +1,348 @@
+/*
+ Unix SMB/CIFS implementation.
+ kerberos authorization data (PAC) utility library
+ Copyright (C) Andrew Bartlett <abartlet@samba.org> 2011
+ Copyright (C) Simo Sorce 2010.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_AUTH
+
+#ifdef HAVE_KRB5
+
+#include "auth/kerberos/pac_utils.h"
+
+#if 0
+/* FIXME - need proper configure/waf test
+ * to determine if gss_mech_krb5 and friends
+ * exist. JRA.
+ */
+/*
+ * These are not exported by Solaris -lkrb5
+ * Maybe move to libreplace somewhere?
+ */
+static const gss_OID_desc krb5_gss_oid_array[] = {
+ /* this is the official, rfc-specified OID */
+ { 9, "\052\206\110\206\367\022\001\002\002" },
+ /* this is the pre-RFC mech OID */
+ { 5, "\053\005\001\005\002" },
+ /* this is the unofficial, incorrect mech OID emitted by MS */
+ { 9, "\052\206\110\202\367\022\001\002\002" },
+ { 0, 0 }
+};
+
+const gss_OID_desc * const gss_mech_krb5 = krb5_gss_oid_array+0;
+const gss_OID_desc * const gss_mech_krb5_old = krb5_gss_oid_array+1;
+const gss_OID_desc * const gss_mech_krb5_wrong = krb5_gss_oid_array+2;
+#endif
+
+#ifndef GSS_KRB5_INQ_SSPI_SESSION_KEY_OID
+#define GSS_KRB5_INQ_SSPI_SESSION_KEY_OID_LENGTH 11
+#define GSS_KRB5_INQ_SSPI_SESSION_KEY_OID "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02\x05\x05"
+#endif
+
+gss_OID_desc gse_sesskey_inq_oid = {
+ GSS_KRB5_INQ_SSPI_SESSION_KEY_OID_LENGTH,
+ discard_const(GSS_KRB5_INQ_SSPI_SESSION_KEY_OID)
+};
+
+#ifndef GSS_KRB5_SESSION_KEY_ENCTYPE_OID
+#define GSS_KRB5_SESSION_KEY_ENCTYPE_OID_LENGTH 10
+#define GSS_KRB5_SESSION_KEY_ENCTYPE_OID "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02\x04"
+#endif
+
+gss_OID_desc gse_sesskeytype_oid = {
+ GSS_KRB5_SESSION_KEY_ENCTYPE_OID_LENGTH,
+ discard_const(GSS_KRB5_SESSION_KEY_ENCTYPE_OID)
+};
+
+/* The Heimdal OID for getting the PAC */
+#define EXTRACT_PAC_AUTHZ_DATA_FROM_SEC_CONTEXT_OID_LENGTH 8
+/* EXTRACTION OID AUTHZ ID */
+#define EXTRACT_PAC_AUTHZ_DATA_FROM_SEC_CONTEXT_OID "\x2a\x85\x70\x2b\x0d\x03" "\x81\x00"
+
+NTSTATUS gssapi_obtain_pac_blob(TALLOC_CTX *mem_ctx,
+ gss_ctx_id_t gssapi_context,
+ gss_name_t gss_client_name,
+ DATA_BLOB *pac_blob)
+{
+ NTSTATUS status;
+ OM_uint32 gss_maj, gss_min;
+#ifdef HAVE_GSS_GET_NAME_ATTRIBUTE
+/*
+ * gss_get_name_attribute() in MIT krb5 1.10.0 can return unintialized pac_display_buffer
+ * and later gss_release_buffer() will crash on attempting to release it.
+ *
+ * So always initialize the buffer descriptors.
+ *
+ * See following links for more details:
+ * http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=658514
+ * http://krbdev.mit.edu/rt/Ticket/Display.html?user=guest&pass=guest&id=7087
+ */
+ gss_buffer_desc pac_buffer = {
+ .value = NULL,
+ .length = 0
+ };
+ gss_buffer_desc pac_display_buffer = {
+ .value = NULL,
+ .length = 0
+ };
+ gss_buffer_desc pac_name = {
+ .value = discard_const("urn:mspac:"),
+ .length = sizeof("urn:mspac:")-1
+ };
+ int more = -1;
+ int authenticated = false;
+ int complete = false;
+
+ gss_maj = gss_get_name_attribute(
+ &gss_min, gss_client_name, &pac_name,
+ &authenticated, &complete,
+ &pac_buffer, &pac_display_buffer, &more);
+
+ if (gss_maj != 0) {
+ gss_OID oid = discard_const(gss_mech_krb5);
+ DBG_NOTICE("obtaining PAC via GSSAPI gss_get_name_attribute "
+ "failed: %s\n", gssapi_error_string(mem_ctx,
+ gss_maj, gss_min,
+ oid));
+ return NT_STATUS_ACCESS_DENIED;
+ } else if (authenticated && complete) {
+ /* The PAC blob is returned directly */
+ *pac_blob = data_blob_talloc(mem_ctx, pac_buffer.value,
+ pac_buffer.length);
+
+ if (!pac_blob->data) {
+ status = NT_STATUS_NO_MEMORY;
+ } else {
+ status = NT_STATUS_OK;
+ }
+
+ gss_release_buffer(&gss_min, &pac_buffer);
+ gss_release_buffer(&gss_min, &pac_display_buffer);
+ return status;
+ } else {
+ DEBUG(0, ("obtaining PAC via GSSAPI failed: authenticated: %s, complete: %s, more: %s\n",
+ authenticated ? "true" : "false",
+ complete ? "true" : "false",
+ more ? "true" : "false"));
+ return NT_STATUS_ACCESS_DENIED;
+ }
+
+#elif defined(HAVE_GSS_INQUIRE_SEC_CONTEXT_BY_OID)
+ gss_OID_desc pac_data_oid = {
+ .elements = discard_const(EXTRACT_PAC_AUTHZ_DATA_FROM_SEC_CONTEXT_OID),
+ .length = EXTRACT_PAC_AUTHZ_DATA_FROM_SEC_CONTEXT_OID_LENGTH
+ };
+
+ gss_buffer_set_t set = GSS_C_NO_BUFFER_SET;
+
+ /* If we didn't have the routine to get a verified, validated
+ * PAC (supplied only by MIT at the time of writing), then try
+ * with the Heimdal OID (fetches the PAC directly and always
+ * validates) */
+ gss_maj = gss_inquire_sec_context_by_oid(
+ &gss_min, gssapi_context,
+ &pac_data_oid, &set);
+
+ /* First check for the error MIT gives for an unknown OID */
+ if (gss_maj == GSS_S_UNAVAILABLE) {
+ DEBUG(1, ("unable to obtain a PAC against this GSSAPI library. "
+ "GSSAPI secured connections are available only with Heimdal or MIT Kerberos >= 1.8\n"));
+ } else if (gss_maj != 0) {
+ DEBUG(2, ("obtaining PAC via GSSAPI gss_inquire_sec_context_by_oid (Heimdal OID) failed: %s\n",
+ gssapi_error_string(mem_ctx, gss_maj, gss_min, gss_mech_krb5)));
+ } else {
+ if (set == GSS_C_NO_BUFFER_SET) {
+ DEBUG(0, ("gss_inquire_sec_context_by_oid returned unknown "
+ "data in results.\n"));
+ return NT_STATUS_INTERNAL_ERROR;
+ }
+
+ /* The PAC blob is returned directly */
+ *pac_blob = data_blob_talloc(mem_ctx, set->elements[0].value,
+ set->elements[0].length);
+ if (!pac_blob->data) {
+ status = NT_STATUS_NO_MEMORY;
+ } else {
+ status = NT_STATUS_OK;
+ }
+
+ gss_maj = gss_release_buffer_set(&gss_min, &set);
+ return status;
+ }
+#else
+ DEBUG(1, ("unable to obtain a PAC against this GSSAPI library. "
+ "GSSAPI secured connections are available only with Heimdal or MIT Kerberos >= 1.8\n"));
+#endif
+ return NT_STATUS_ACCESS_DENIED;
+}
+
+NTSTATUS gssapi_get_session_key(TALLOC_CTX *mem_ctx,
+ gss_ctx_id_t gssapi_context,
+ DATA_BLOB *session_key,
+ uint32_t *keytype)
+{
+ OM_uint32 gss_min, gss_maj;
+ gss_buffer_set_t set = GSS_C_NO_BUFFER_SET;
+
+ gss_maj = gss_inquire_sec_context_by_oid(
+ &gss_min, gssapi_context,
+ &gse_sesskey_inq_oid, &set);
+ if (gss_maj) {
+ DEBUG(0, ("gss_inquire_sec_context_by_oid failed [%s]\n",
+ gssapi_error_string(mem_ctx,
+ gss_maj,
+ gss_min,
+ discard_const_p(struct gss_OID_desc_struct,
+ gss_mech_krb5))));
+ return NT_STATUS_NO_USER_SESSION_KEY;
+ }
+
+ if ((set == GSS_C_NO_BUFFER_SET) ||
+ (set->count == 0)) {
+#ifdef HAVE_GSSKRB5_GET_SUBKEY
+ krb5_keyblock *subkey;
+ gss_maj = gsskrb5_get_subkey(&gss_min,
+ gssapi_context,
+ &subkey);
+ if (gss_maj != 0) {
+ DEBUG(1, ("NO session key for this mech\n"));
+ return NT_STATUS_NO_USER_SESSION_KEY;
+ }
+ if (session_key) {
+ *session_key = data_blob_talloc(mem_ctx,
+ KRB5_KEY_DATA(subkey), KRB5_KEY_LENGTH(subkey));
+ }
+ if (keytype) {
+ *keytype = KRB5_KEY_TYPE(subkey);
+ }
+ krb5_free_keyblock(NULL /* should be krb5_context */, subkey);
+ return NT_STATUS_OK;
+#else
+ DEBUG(0, ("gss_inquire_sec_context_by_oid didn't return any session key (and no alternative method available)\n"));
+ return NT_STATUS_NO_USER_SESSION_KEY;
+#endif
+ }
+
+ if (session_key) {
+ *session_key = data_blob_talloc(mem_ctx, set->elements[0].value,
+ set->elements[0].length);
+ }
+
+ if (keytype) {
+ int diflen, i;
+ const uint8_t *p;
+
+ *keytype = 0;
+ if (set->count < 2) {
+
+#ifdef HAVE_GSSKRB5_GET_SUBKEY
+ krb5_keyblock *subkey;
+ gss_maj = gsskrb5_get_subkey(&gss_min,
+ gssapi_context,
+ &subkey);
+ if (gss_maj == 0) {
+ *keytype = KRB5_KEY_TYPE(subkey);
+ krb5_free_keyblock(NULL /* should be krb5_context */, subkey);
+ }
+#endif
+ gss_release_buffer_set(&gss_min, &set);
+
+ return NT_STATUS_OK;
+
+ } else if (memcmp(set->elements[1].value,
+ gse_sesskeytype_oid.elements,
+ gse_sesskeytype_oid.length) != 0) {
+ /* Perhaps a non-krb5 session key */
+ gss_release_buffer_set(&gss_min, &set);
+ return NT_STATUS_OK;
+ }
+ p = (const uint8_t *)set->elements[1].value + gse_sesskeytype_oid.length;
+ diflen = set->elements[1].length - gse_sesskeytype_oid.length;
+ if (diflen <= 0) {
+ gss_release_buffer_set(&gss_min, &set);
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+ for (i = 0; i < diflen; i++) {
+ *keytype = (*keytype << 7) | (p[i] & 0x7f);
+ if (i + 1 != diflen && (p[i] & 0x80) == 0) {
+ gss_release_buffer_set(&gss_min, &set);
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+ }
+ }
+
+ gss_release_buffer_set(&gss_min, &set);
+ return NT_STATUS_OK;
+}
+
+
+char *gssapi_error_string(TALLOC_CTX *mem_ctx,
+ OM_uint32 maj_stat, OM_uint32 min_stat,
+ const gss_OID mech)
+{
+ OM_uint32 disp_min_stat, disp_maj_stat;
+ gss_buffer_desc maj_error_message;
+ gss_buffer_desc min_error_message;
+ char *maj_error_string, *min_error_string;
+ OM_uint32 msg_ctx = 0;
+
+ char *ret;
+
+ maj_error_message.value = NULL;
+ min_error_message.value = NULL;
+ maj_error_message.length = 0;
+ min_error_message.length = 0;
+
+ disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat,
+ GSS_C_GSS_CODE, mech,
+ &msg_ctx, &maj_error_message);
+ if (disp_maj_stat != 0) {
+ maj_error_message.value = NULL;
+ maj_error_message.length = 0;
+ }
+ disp_maj_stat = gss_display_status(&disp_min_stat, min_stat,
+ GSS_C_MECH_CODE, mech,
+ &msg_ctx, &min_error_message);
+ if (disp_maj_stat != 0) {
+ min_error_message.value = NULL;
+ min_error_message.length = 0;
+ }
+
+ maj_error_string = talloc_strndup(mem_ctx,
+ (char *)maj_error_message.value,
+ maj_error_message.length);
+
+ min_error_string = talloc_strndup(mem_ctx,
+ (char *)min_error_message.value,
+ min_error_message.length);
+
+ ret = talloc_asprintf(mem_ctx, "%s: %s",
+ maj_error_string, min_error_string);
+
+ talloc_free(maj_error_string);
+ talloc_free(min_error_string);
+
+ gss_release_buffer(&disp_min_stat, &maj_error_message);
+ gss_release_buffer(&disp_min_stat, &min_error_message);
+
+ return ret;
+}
+
+#endif /* HAVE_KRB5 */
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