TODO all s4:auth/gensec_gssapi: add NT_STATUS_NO_MEMORY checks
[metze/samba/wip.git] / source4 / auth / gensec / gensec_gssapi.c
index 2ae2e23f3d204bdf32f4df804117ee0e96763693..506af56170d5df91ca5ca1dc1f75980f113efb21 100644 (file)
@@ -22,6 +22,8 @@
 */
 
 #include "includes.h"
+#include <tevent.h>
+#include "lib/util/tevent_ntstatus.h"
 #include "lib/events/events.h"
 #include "system/kerberos.h"
 #include "system/gssapi.h"
@@ -50,7 +52,7 @@ gss_OID_desc spnego_mech_oid_desc =
 #define gss_mech_spnego (&spnego_mech_oid_desc)
 #endif
 
-_PUBLIC_ NTSTATUS gensec_gssapi_init(void);
+_PUBLIC_ NTSTATUS gensec_gssapi_init(TALLOC_CTX *);
 
 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security);
 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security);
@@ -83,6 +85,56 @@ static int gensec_gssapi_destructor(struct gensec_gssapi_state *gensec_gssapi_st
        return 0;
 }
 
+static NTSTATUS gensec_gssapi_setup_server_principal(TALLOC_CTX *mem_ctx,
+                                                    const char *target_principal,
+                                                    const char *service,
+                                                    const char *hostname,
+                                                    const char *realm,
+                                                    const gss_OID mech,
+                                                    char **pserver_principal,
+                                                    gss_name_t *pserver_name)
+{
+       char *server_principal = NULL;
+       gss_buffer_desc name_token;
+       gss_OID name_type;
+       OM_uint32 maj_stat, min_stat = 0;
+
+       if (target_principal != NULL) {
+               server_principal = talloc_strdup(mem_ctx, target_principal);
+               name_type = GSS_C_NULL_OID;
+       } else {
+               server_principal = talloc_asprintf(mem_ctx,
+                                                  "%s/%s@%s",
+                                                  service, hostname, realm);
+               name_type = GSS_C_NT_USER_NAME;
+       }
+       if (server_principal == NULL) {
+               return NT_STATUS_NO_MEMORY;
+       }
+
+       name_token.value = (uint8_t *)server_principal;
+       name_token.length = strlen(server_principal);
+
+       maj_stat = gss_import_name(&min_stat,
+                                  &name_token,
+                                  name_type,
+                                  pserver_name);
+       if (maj_stat) {
+               DBG_WARNING("GSS Import name of %s failed: %s\n",
+                           server_principal,
+                           gssapi_error_string(mem_ctx,
+                                               maj_stat,
+                                               min_stat,
+                                               mech));
+               TALLOC_FREE(server_principal);
+               return NT_STATUS_INVALID_PARAMETER;
+       }
+
+       *pserver_principal = server_principal;
+
+       return NT_STATUS_OK;
+}
+
 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 {
        struct gensec_gssapi_state *gensec_gssapi_state;
@@ -125,6 +177,9 @@ static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
                gensec_gssapi_state->gss_want_flags |= GSS_C_SEQUENCE_FLAG;
        }
 
+       if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
+               gensec_gssapi_state->gss_want_flags |= GSS_C_INTEG_FLAG;
+       }
        if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
                gensec_gssapi_state->gss_want_flags |= GSS_C_INTEG_FLAG;
        }
@@ -304,9 +359,6 @@ static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_securi
        struct gensec_gssapi_state *gensec_gssapi_state;
        struct cli_credentials *creds = gensec_get_credentials(gensec_security);
        NTSTATUS nt_status;
-       gss_buffer_desc name_token;
-       gss_OID name_type;
-       OM_uint32 maj_stat, min_stat;
        const char *target_principal = NULL;
        const char *hostname = gensec_get_target_hostname(gensec_security);
        const char *service = gensec_get_target_service(gensec_security);
@@ -353,33 +405,6 @@ do_start:
                gensec_gssapi_state->gss_want_flags &= ~(GSS_C_DELEG_FLAG|GSS_C_DELEG_POLICY_FLAG);
        }
 
-       if (target_principal != NULL) {
-               name_type = GSS_C_NULL_OID;
-       } else {
-               target_principal = talloc_asprintf(gensec_gssapi_state,
-                                       "%s/%s@%s", service, hostname, realm);
-               if (target_principal == NULL) {
-                       return NT_STATUS_NO_MEMORY;
-               }
-               name_type = GSS_C_NT_USER_NAME;
-       }
-       gensec_gssapi_state->target_principal = target_principal;
-
-       name_token.value  = discard_const_p(uint8_t, gensec_gssapi_state->target_principal);
-       name_token.length = strlen(gensec_gssapi_state->target_principal);
-
-
-       maj_stat = gss_import_name (&min_stat,
-                                   &name_token,
-                                   name_type,
-                                   &gensec_gssapi_state->server_name);
-       if (maj_stat) {
-               DEBUG(2, ("GSS Import name of %s failed: %s\n",
-                         (char *)name_token.value,
-                         gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
-               return NT_STATUS_INVALID_PARAMETER;
-       }
-
        return NT_STATUS_OK;
 }
 
@@ -396,22 +421,10 @@ static NTSTATUS gensec_gssapi_sasl_client_start(struct gensec_security *gensec_s
        return nt_status;
 }
 
-
-/**
- * Next state function for the GSSAPI GENSEC mechanism
- * 
- * @param gensec_gssapi_state GSSAPI State
- * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
- * @param in The request, as a DATA_BLOB
- * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
- * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent, 
- *                or NT_STATUS_OK if the user is authenticated. 
- */
-
-static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security, 
-                                    TALLOC_CTX *out_mem_ctx,
-                                    struct tevent_context *ev,
-                                    const DATA_BLOB in, DATA_BLOB *out)
+static NTSTATUS gensec_gssapi_update_internal(struct gensec_security *gensec_security,
+                                             TALLOC_CTX *out_mem_ctx,
+                                             struct tevent_context *ev,
+                                             const DATA_BLOB in, DATA_BLOB *out)
 {
        struct gensec_gssapi_state *gensec_gssapi_state
                = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
@@ -420,7 +433,12 @@ static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
        OM_uint32 min_stat2;
        gss_buffer_desc input_token = { 0, NULL };
        gss_buffer_desc output_token = { 0, NULL };
-
+       struct cli_credentials *cli_creds = gensec_get_credentials(gensec_security);
+       const char *target_principal = gensec_get_target_principal(gensec_security);
+       const char *hostname = gensec_get_target_hostname(gensec_security);
+       const char *service = gensec_get_target_service(gensec_security);
+       const char *client_realm = cli_credentials_get_realm(cli_creds);
+       const char *server_realm = NULL;
        gss_OID gss_oid_p = NULL;
        OM_uint32 time_req = 0;
        OM_uint32 time_rec = 0;
@@ -433,6 +451,8 @@ static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
        input_token.length = in.length;
        input_token.value = in.data;
 
+       *out = data_blob_null;
+
        switch (gensec_gssapi_state->sasl_state) {
        case STAGE_GSS_NEG:
        {
@@ -442,6 +462,8 @@ static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 #ifdef SAMBA4_USES_HEIMDAL
                        struct gsskrb5_send_to_kdc send_to_kdc;
                        krb5_error_code ret;
+#else
+                       bool fallback = false;
 #endif
 
                        nt_status = gensec_gssapi_client_creds(gensec_security, ev);
@@ -459,6 +481,129 @@ static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
                                return NT_STATUS_INTERNAL_ERROR;
                        }
 #endif
+
+                       /*
+                        * With credentials for
+                        * administrator@FOREST1.EXAMPLE.COM this patch changes
+                        * the target_principal for the ldap service of host
+                        * dc2.forest2.example.com from
+                        *
+                        *   ldap/dc2.forest2.example.com@FOREST1.EXAMPLE.COM
+                        *
+                        * to
+                        *
+                        *   ldap/dc2.forest2.example.com@FOREST2.EXAMPLE.COM
+                        *
+                        * Typically
+                        * ldap/dc2.forest2.example.com@FOREST1.EXAMPLE.COM
+                        * should be used in order to allow the KDC of
+                        * FOREST1.EXAMPLE.COM to generate a referral ticket
+                        * for krbtgt/FOREST2.EXAMPLE.COM@FOREST1.EXAMPLE.COM.
+                        *
+                        * The problem is that KDCs only return such referral
+                        * tickets if there's a forest trust between
+                        * FOREST1.EXAMPLE.COM and FOREST2.EXAMPLE.COM. If
+                        * there's only an external domain trust between
+                        * FOREST1.EXAMPLE.COM and FOREST2.EXAMPLE.COM the KDC
+                        * of FOREST1.EXAMPLE.COM will respond with
+                        * S_PRINCIPAL_UNKNOWN when being asked for
+                        * ldap/dc2.forest2.example.com@FOREST1.EXAMPLE.COM.
+                        *
+                        * In the case of an external trust the client can
+                        * still ask explicitly for
+                        * krbtgt/FOREST2.EXAMPLE.COM@FOREST1.EXAMPLE.COM and
+                        * the KDC of FOREST1.EXAMPLE.COM will generate it.
+                        *
+                        * From there the client can use the
+                        * krbtgt/FOREST2.EXAMPLE.COM@FOREST1.EXAMPLE.COM
+                        * ticket and ask a KDC of FOREST2.EXAMPLE.COM for a
+                        * service ticket for
+                        * ldap/dc2.forest2.example.com@FOREST2.EXAMPLE.COM.
+                        *
+                        * With Heimdal we'll get the fallback on
+                        * S_PRINCIPAL_UNKNOWN behavior when we pass
+                        * ldap/dc2.forest2.example.com@FOREST2.EXAMPLE.COM as
+                        * target principal. As _krb5_get_cred_kdc_any() first
+                        * calls get_cred_kdc_referral() (which always starts
+                        * with the client realm) and falls back to
+                        * get_cred_kdc_capath() (which starts with the given
+                        * realm).
+                        *
+                        * MIT krb5 only tries the given realm of the target
+                        * principal, if we want to autodetect support for
+                        * transitive forest trusts, would have to do the
+                        * fallback ourself.
+                        */
+#ifndef SAMBA4_USES_HEIMDAL
+                       if (gensec_gssapi_state->server_name == NULL) {
+                               nt_status = gensec_gssapi_setup_server_principal(gensec_gssapi_state,
+                                                                                target_principal,
+                                                                                service,
+                                                                                hostname,
+                                                                                client_realm,
+                                                                                gensec_gssapi_state->gss_oid,
+                                                                                &gensec_gssapi_state->target_principal,
+                                                                                &gensec_gssapi_state->server_name);
+                               if (!NT_STATUS_IS_OK(nt_status)) {
+                                       return nt_status;
+                               }
+
+                               maj_stat = gss_init_sec_context(&min_stat,
+                                                               gensec_gssapi_state->client_cred->creds,
+                                                               &gensec_gssapi_state->gssapi_context,
+                                                               gensec_gssapi_state->server_name,
+                                                               gensec_gssapi_state->gss_oid,
+                                                               gensec_gssapi_state->gss_want_flags,
+                                                               time_req,
+                                                               gensec_gssapi_state->input_chan_bindings,
+                                                               &input_token,
+                                                               &gss_oid_p,
+                                                               &output_token,
+                                                               &gensec_gssapi_state->gss_got_flags, /* ret flags */
+                                                               &time_rec);
+                               if (maj_stat != GSS_S_FAILURE) {
+                                       goto init_sec_context_done;
+                               }
+                               if (min_stat != (OM_uint32)KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN) {
+                                       goto init_sec_context_done;
+                               }
+                               if (target_principal != NULL) {
+                                       goto init_sec_context_done;
+                               }
+
+                               fallback = true;
+                               TALLOC_FREE(gensec_gssapi_state->target_principal);
+                               gss_release_name(&min_stat2, &gensec_gssapi_state->server_name);
+                       }
+#endif /* !SAMBA4_USES_HEIMDAL */
+                       if (gensec_gssapi_state->server_name == NULL) {
+                               server_realm = smb_krb5_get_realm_from_hostname(gensec_gssapi_state,
+                                                                               hostname,
+                                                                               client_realm);
+                               if (server_realm == NULL) {
+                                       return NT_STATUS_NO_MEMORY;
+                               }
+
+#ifndef SAMBA4_USES_HEIMDAL
+                               if (fallback &&
+                                   strequal(client_realm, server_realm)) {
+                                       goto init_sec_context_done;
+                               }
+#endif /* !SAMBA4_USES_HEIMDAL */
+
+                               nt_status = gensec_gssapi_setup_server_principal(gensec_gssapi_state,
+                                                                                target_principal,
+                                                                                service,
+                                                                                hostname,
+                                                                                server_realm,
+                                                                                gensec_gssapi_state->gss_oid,
+                                                                                &gensec_gssapi_state->target_principal,
+                                                                                &gensec_gssapi_state->server_name);
+                               if (!NT_STATUS_IS_OK(nt_status)) {
+                                       return nt_status;
+                               }
+                       }
+
                        maj_stat = gss_init_sec_context(&min_stat, 
                                                        gensec_gssapi_state->client_cred->creds,
                                                        &gensec_gssapi_state->gssapi_context, 
@@ -472,6 +617,9 @@ static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
                                                        &output_token, 
                                                        &gensec_gssapi_state->gss_got_flags, /* ret flags */
                                                        &time_rec);
+                       goto init_sec_context_done;
+                       /* JUMP! */
+init_sec_context_done:
                        if (gss_oid_p) {
                                gensec_gssapi_state->gss_oid = gss_oid_p;
                        }
@@ -514,9 +662,16 @@ static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
                gensec_gssapi_state->gss_exchange_count++;
 
                if (maj_stat == GSS_S_COMPLETE) {
-                       *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
-                       gss_release_buffer(&min_stat2, &output_token);
-                       
+                       if (output_token.length) {
+                               *out = data_blob_talloc(out_mem_ctx,
+                                                       output_token.value,
+                                                       output_token.length);
+                               gss_release_buffer(&min_stat2, &output_token);
+                               if (out->data == NULL) {
+                                       return NT_STATUS_NO_MEMORY;
+                               }
+                       }
+
                        if (gensec_gssapi_state->gss_got_flags & GSS_C_DELEG_FLAG &&
                            gensec_gssapi_state->delegated_cred_handle != GSS_C_NO_CREDENTIAL) {
                                DEBUG(5, ("gensec_gssapi: credentials were delegated\n"));
@@ -546,9 +701,16 @@ static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
                                return NT_STATUS_OK;
                        }
                } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
-                       *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
-                       gss_release_buffer(&min_stat2, &output_token);
-                       
+                       if (output_token.length) {
+                               *out = data_blob_talloc(out_mem_ctx,
+                                                       output_token.value,
+                                                       output_token.length);
+                               gss_release_buffer(&min_stat2, &output_token);
+                               if (out->data == NULL) {
+                                       return NT_STATUS_NO_MEMORY;
+                               }
+                       }
+
                        return NT_STATUS_MORE_PROCESSING_REQUIRED;
                } else if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
                        gss_cred_id_t creds = NULL;
@@ -890,6 +1052,65 @@ static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
        }
 }
 
+struct gensec_gssapi_update_state {
+       NTSTATUS status;
+       DATA_BLOB out;
+};
+
+static struct tevent_req *gensec_gssapi_update_send(TALLOC_CTX *mem_ctx,
+                                                   struct tevent_context *ev,
+                                                   struct gensec_security *gensec_security,
+                                                   const DATA_BLOB in)
+{
+       struct tevent_req *req = NULL;
+       struct gensec_gssapi_update_state *state = NULL;
+       NTSTATUS status;
+
+       req = tevent_req_create(mem_ctx, &state,
+                               struct gensec_gssapi_update_state);
+       if (req == NULL) {
+               return NULL;
+       }
+
+       status = gensec_gssapi_update_internal(gensec_security,
+                                              state, ev, in,
+                                              &state->out);
+       state->status = status;
+       if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
+               tevent_req_done(req);
+               return tevent_req_post(req, ev);
+       }
+       if (tevent_req_nterror(req, status)) {
+               return tevent_req_post(req, ev);
+       }
+
+       tevent_req_done(req);
+       return tevent_req_post(req, ev);
+}
+
+static NTSTATUS gensec_gssapi_update_recv(struct tevent_req *req,
+                                         TALLOC_CTX *out_mem_ctx,
+                                         DATA_BLOB *out)
+{
+       struct gensec_gssapi_update_state *state =
+               tevent_req_data(req,
+               struct gensec_gssapi_update_state);
+       NTSTATUS status;
+
+       *out = data_blob_null;
+
+       if (tevent_req_is_nterror(req, &status)) {
+               tevent_req_received(req);
+               return status;
+       }
+
+       *out = state->out;
+       talloc_steal(out_mem_ctx, state->out.data);
+       status = state->status;
+       tevent_req_received(req);
+       return status;
+}
+
 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security, 
                                   TALLOC_CTX *mem_ctx, 
                                   const DATA_BLOB *in, 
@@ -1219,15 +1440,7 @@ static bool gensec_gssapi_have_feature(struct gensec_security *gensec_security,
                return true;
        }
        if (feature & GENSEC_FEATURE_SIGN_PKT_HEADER) {
-               if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
-                       return true;
-               }
-
-               if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
-                       return true;
-               }
-
-               return false;
+               return true;
        }
        return false;
 }
@@ -1389,6 +1602,19 @@ static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security, si
        return gensec_gssapi_state->sig_size;
 }
 
+static const char *gensec_gssapi_final_auth_type(struct gensec_security *gensec_security)
+{
+       struct gensec_gssapi_state *gensec_gssapi_state
+               = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
+       /* Only return the string for GSSAPI/Krb5 */
+       if (smb_gss_oid_equal(gensec_gssapi_state->gss_oid,
+                             gss_mech_krb5)) {
+               return GENSEC_FINAL_AUTH_TYPE_KRB5;
+       } else {
+               return "gensec_gssapi: UNKNOWN MECH";
+       }
+}
+
 static const char *gensec_gssapi_krb5_oids[] = { 
        GENSEC_OID_KERBEROS5_OLD,
        GENSEC_OID_KERBEROS5,
@@ -1409,7 +1635,8 @@ static const struct gensec_security_ops gensec_gssapi_spnego_security_ops = {
        .client_start   = gensec_gssapi_client_start,
        .server_start   = gensec_gssapi_server_start,
        .magic          = gensec_magic_check_krb5_oid,
-       .update         = gensec_gssapi_update,
+       .update_send    = gensec_gssapi_update_send,
+       .update_recv    = gensec_gssapi_update_recv,
        .session_key    = gensec_gssapi_session_key,
        .session_info   = gensec_gssapi_session_info,
        .sign_packet    = gensec_gssapi_sign_packet,
@@ -1422,6 +1649,7 @@ static const struct gensec_security_ops gensec_gssapi_spnego_security_ops = {
        .unwrap         = gensec_gssapi_unwrap,
        .have_feature   = gensec_gssapi_have_feature,
        .expire_time    = gensec_gssapi_expire_time,
+       .final_auth_type = gensec_gssapi_final_auth_type,
        .enabled        = false,
        .kerberos       = true,
        .priority       = GENSEC_GSSAPI
@@ -1435,7 +1663,8 @@ static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
        .client_start   = gensec_gssapi_client_start,
        .server_start   = gensec_gssapi_server_start,
        .magic          = gensec_magic_check_krb5_oid,
-       .update         = gensec_gssapi_update,
+       .update_send    = gensec_gssapi_update_send,
+       .update_recv    = gensec_gssapi_update_recv,
        .session_key    = gensec_gssapi_session_key,
        .session_info   = gensec_gssapi_session_info,
        .sig_size       = gensec_gssapi_sig_size,
@@ -1449,6 +1678,7 @@ static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
        .unwrap         = gensec_gssapi_unwrap,
        .have_feature   = gensec_gssapi_have_feature,
        .expire_time    = gensec_gssapi_expire_time,
+       .final_auth_type = gensec_gssapi_final_auth_type,
        .enabled        = true,
        .kerberos       = true,
        .priority       = GENSEC_GSSAPI
@@ -1460,7 +1690,8 @@ static const struct gensec_security_ops gensec_gssapi_sasl_krb5_security_ops = {
        .sasl_name        = "GSSAPI",
        .client_start     = gensec_gssapi_sasl_client_start,
        .server_start     = gensec_gssapi_sasl_server_start,
-       .update           = gensec_gssapi_update,
+       .update_send      = gensec_gssapi_update_send,
+       .update_recv      = gensec_gssapi_update_recv,
        .session_key      = gensec_gssapi_session_key,
        .session_info     = gensec_gssapi_session_info,
        .max_input_size   = gensec_gssapi_max_input_size,
@@ -1469,30 +1700,31 @@ static const struct gensec_security_ops gensec_gssapi_sasl_krb5_security_ops = {
        .unwrap           = gensec_gssapi_unwrap,
        .have_feature     = gensec_gssapi_have_feature,
        .expire_time      = gensec_gssapi_expire_time,
+       .final_auth_type = gensec_gssapi_final_auth_type,
        .enabled          = true,
        .kerberos         = true,
        .priority         = GENSEC_GSSAPI
 };
 
-_PUBLIC_ NTSTATUS gensec_gssapi_init(void)
+_PUBLIC_ NTSTATUS gensec_gssapi_init(TALLOC_CTX *ctx)
 {
        NTSTATUS ret;
 
-       ret = gensec_register(&gensec_gssapi_spnego_security_ops);
+       ret = gensec_register(ctx, &gensec_gssapi_spnego_security_ops);
        if (!NT_STATUS_IS_OK(ret)) {
                DEBUG(0,("Failed to register '%s' gensec backend!\n",
                        gensec_gssapi_spnego_security_ops.name));
                return ret;
        }
 
-       ret = gensec_register(&gensec_gssapi_krb5_security_ops);
+       ret = gensec_register(ctx, &gensec_gssapi_krb5_security_ops);
        if (!NT_STATUS_IS_OK(ret)) {
                DEBUG(0,("Failed to register '%s' gensec backend!\n",
                        gensec_gssapi_krb5_security_ops.name));
                return ret;
        }
 
-       ret = gensec_register(&gensec_gssapi_sasl_krb5_security_ops);
+       ret = gensec_register(ctx, &gensec_gssapi_sasl_krb5_security_ops);
        if (!NT_STATUS_IS_OK(ret)) {
                DEBUG(0,("Failed to register '%s' gensec backend!\n",
                        gensec_gssapi_sasl_krb5_security_ops.name));