s3-libads: Use gensec GSSAPI for ads_sasl_gssapi_bind()
authorStefan Metzmacher <metze@samba.org>
Tue, 1 Mar 2016 20:25:13 +0000 (21:25 +0100)
committerStefan Metzmacher <metze@samba.org>
Mon, 18 Feb 2019 12:46:06 +0000 (13:46 +0100)
Signed-off-by: Stefan Metzmacher <metze@samba.org>
source3/libads/sasl.c

index 010a2538206d4676b14662410726639f11aec61e..98d683788be53a491e044461bf6f99c0e6e71631 100644 (file)
@@ -351,149 +351,6 @@ static ADS_STATUS ads_sasl_spnego_gensec_bind(ADS_STRUCT *ads,
        return ADS_ERROR(rc);
 }
 
-#ifdef HAVE_KRB5
-static ADS_STATUS ads_init_gssapi_cred(ADS_STRUCT *ads, gss_cred_id_t *cred)
-{
-       ADS_STATUS status;
-       krb5_context kctx;
-       krb5_error_code kerr;
-       krb5_ccache kccache = NULL;
-       uint32_t maj, min;
-
-       *cred = GSS_C_NO_CREDENTIAL;
-
-       if (!ads->auth.ccache_name) {
-               return ADS_SUCCESS;
-       }
-
-       kerr = smb_krb5_init_context_common(&kctx);
-       if (kerr) {
-           DBG_ERR("kerberos init context failed (%s)\n",
-                   error_message(kerr));
-               return ADS_ERROR_KRB5(kerr);
-       }
-
-       kerr = krb5_cc_resolve(kctx, ads->auth.ccache_name, &kccache);
-       if (kerr) {
-               status = ADS_ERROR_KRB5(kerr);
-               goto done;
-       }
-
-       maj = smb_gss_krb5_import_cred(&min, kctx, kccache, NULL, NULL, cred);
-       if (maj != GSS_S_COMPLETE) {
-               status = ADS_ERROR_GSS(maj, min);
-               goto done;
-       }
-
-       status = ADS_SUCCESS;
-
-done:
-       if (!ADS_ERR_OK(status) && kccache != NULL) {
-               krb5_cc_close(kctx, kccache);
-       }
-       krb5_free_context(kctx);
-       return status;
-}
-
-static ADS_STATUS ads_sasl_gssapi_wrap(struct ads_saslwrap *wrap, uint8_t *buf, uint32_t len)
-{
-       gss_ctx_id_t context_handle = (gss_ctx_id_t)wrap->wrap_private_data;
-       ADS_STATUS status;
-       int gss_rc;
-       uint32_t minor_status;
-       gss_buffer_desc unwrapped, wrapped;
-       int conf_req_flag, conf_state;
-
-       unwrapped.value         = buf;
-       unwrapped.length        = len;
-
-       /* for now request sign and seal */
-       conf_req_flag   = (wrap->wrap_type == ADS_SASLWRAP_TYPE_SEAL);
-
-       gss_rc = gss_wrap(&minor_status, context_handle,
-                         conf_req_flag, GSS_C_QOP_DEFAULT,
-                         &unwrapped, &conf_state,
-                         &wrapped);
-       status = ADS_ERROR_GSS(gss_rc, minor_status);
-       if (!ADS_ERR_OK(status)) return status;
-
-       if (conf_req_flag && conf_state == 0) {
-               return ADS_ERROR_NT(NT_STATUS_ACCESS_DENIED);
-       }
-
-       if ((wrap->out.size - 4) < wrapped.length) {
-               return ADS_ERROR_NT(NT_STATUS_INTERNAL_ERROR);
-       }
-
-       /* copy the wrapped blob to the right location */
-       memcpy(wrap->out.buf + 4, wrapped.value, wrapped.length);
-
-       /* set how many bytes must be written to the underlying socket */
-       wrap->out.left = 4 + wrapped.length;
-
-       gss_release_buffer(&minor_status, &wrapped);
-
-       return ADS_SUCCESS;
-}
-
-static ADS_STATUS ads_sasl_gssapi_unwrap(struct ads_saslwrap *wrap)
-{
-       gss_ctx_id_t context_handle = (gss_ctx_id_t)wrap->wrap_private_data;
-       ADS_STATUS status;
-       int gss_rc;
-       uint32_t minor_status;
-       gss_buffer_desc unwrapped, wrapped;
-       int conf_state;
-
-       wrapped.value   = wrap->in.buf + 4;
-       wrapped.length  = wrap->in.ofs - 4;
-
-       gss_rc = gss_unwrap(&minor_status, context_handle,
-                           &wrapped, &unwrapped,
-                           &conf_state, GSS_C_QOP_DEFAULT);
-       status = ADS_ERROR_GSS(gss_rc, minor_status);
-       if (!ADS_ERR_OK(status)) return status;
-
-       if (wrap->wrap_type == ADS_SASLWRAP_TYPE_SEAL && conf_state == 0) {
-               return ADS_ERROR_NT(NT_STATUS_ACCESS_DENIED);
-       }
-
-       if (wrapped.length < unwrapped.length) {
-               return ADS_ERROR_NT(NT_STATUS_INTERNAL_ERROR);
-       }
-
-       /* copy the wrapped blob to the right location */
-       memcpy(wrap->in.buf + 4, unwrapped.value, unwrapped.length);
-
-       /* set how many bytes must be written to the underlying socket */
-       wrap->in.left   = unwrapped.length;
-       wrap->in.ofs    = 4;
-
-       gss_release_buffer(&minor_status, &unwrapped);
-
-       return ADS_SUCCESS;
-}
-
-static void ads_sasl_gssapi_disconnect(struct ads_saslwrap *wrap)
-{
-       gss_ctx_id_t context_handle = (gss_ctx_id_t)wrap->wrap_private_data;
-       uint32_t minor_status;
-
-       gss_delete_sec_context(&minor_status, &context_handle, GSS_C_NO_BUFFER);
-
-       wrap->wrap_ops = NULL;
-       wrap->wrap_private_data = NULL;
-}
-
-static const struct ads_saslwrap_ops ads_sasl_gssapi_ops = {
-       .name           = "gssapi",
-       .wrap           = ads_sasl_gssapi_wrap,
-       .unwrap         = ads_sasl_gssapi_unwrap,
-       .disconnect     = ads_sasl_gssapi_disconnect
-};
-
-#endif /* HAVE_KRB5 */
-
 #ifdef HAVE_KRB5
 struct ads_service_principal {
        char *service;
@@ -810,220 +667,6 @@ done:
 }
 
 #ifdef HAVE_KRB5
-#define MAX_GSS_PASSES 3
-
-/* this performs a SASL/gssapi bind
-   we avoid using cyrus-sasl to make Samba more robust. cyrus-sasl
-   is very dependent on correctly configured DNS whereas
-   this routine is much less fragile
-   see RFC2078 and RFC2222 for details
-*/
-static ADS_STATUS ads_sasl_gssapi_do_bind(ADS_STRUCT *ads, const gss_name_t serv_name)
-{
-       uint32_t minor_status;
-       gss_cred_id_t gss_cred = GSS_C_NO_CREDENTIAL;
-       gss_ctx_id_t context_handle = GSS_C_NO_CONTEXT;
-       gss_OID mech_type = GSS_C_NULL_OID;
-       gss_buffer_desc output_token, input_token;
-       uint32_t req_flags, ret_flags;
-       int conf_state;
-       struct berval cred;
-       struct berval *scred = NULL;
-       int i=0;
-       int gss_rc, rc;
-       uint8_t *p;
-       uint32_t max_msg_size = ADS_SASL_WRAPPING_OUT_MAX_WRAPPED;
-       uint8_t wrap_type = ADS_SASLWRAP_TYPE_PLAIN;
-       ADS_STATUS status;
-       struct ads_saslwrap *wrap = &ads->ldap_wrap_data;
-
-       input_token.value = NULL;
-       input_token.length = 0;
-
-       status = ads_init_gssapi_cred(ads, &gss_cred);
-       if (!ADS_ERR_OK(status)) {
-               goto failed;
-       }
-
-       /*
-        * Note: here we always ask the gssapi for sign and seal
-        *       as this is negotiated later after the mutal
-        *       authentication
-        */
-       req_flags = GSS_C_MUTUAL_FLAG | GSS_C_REPLAY_FLAG | GSS_C_INTEG_FLAG | GSS_C_CONF_FLAG;
-
-       for (i=0; i < MAX_GSS_PASSES; i++) {
-               gss_rc = gss_init_sec_context(&minor_status,
-                                         gss_cred,
-                                         &context_handle,
-                                         serv_name,
-                                         mech_type,
-                                         req_flags,
-                                         0,
-                                         NULL,
-                                         &input_token,
-                                         NULL,
-                                         &output_token,
-                                         &ret_flags,
-                                         NULL);
-               if (scred) {
-                       ber_bvfree(scred);
-                       scred = NULL;
-               }
-               if (gss_rc && gss_rc != GSS_S_CONTINUE_NEEDED) {
-                       status = ADS_ERROR_GSS(gss_rc, minor_status);
-                       goto failed;
-               }
-
-               cred.bv_val = (char *)output_token.value;
-               cred.bv_len = output_token.length;
-
-               rc = ldap_sasl_bind_s(ads->ldap.ld, NULL, "GSSAPI", &cred, NULL, NULL, 
-                                     &scred);
-               if (rc != LDAP_SASL_BIND_IN_PROGRESS) {
-                       status = ADS_ERROR(rc);
-                       goto failed;
-               }
-
-               if (output_token.value) {
-                       gss_release_buffer(&minor_status, &output_token);
-               }
-
-               if (scred) {
-                       input_token.value = scred->bv_val;
-                       input_token.length = scred->bv_len;
-               } else {
-                       input_token.value = NULL;
-                       input_token.length = 0;
-               }
-
-               if (gss_rc == 0) break;
-       }
-
-       gss_rc = gss_unwrap(&minor_status,context_handle,&input_token,&output_token,
-                           &conf_state,NULL);
-       if (scred) {
-               ber_bvfree(scred);
-               scred = NULL;
-       }
-       if (gss_rc) {
-               status = ADS_ERROR_GSS(gss_rc, minor_status);
-               goto failed;
-       }
-
-       p = (uint8_t *)output_token.value;
-
-#if 0
-       file_save("sasl_gssapi.dat", output_token.value, output_token.length);
-#endif
-
-       if (p) {
-               wrap_type = CVAL(p,0);
-               SCVAL(p,0,0);
-               max_msg_size = RIVAL(p,0);
-       }
-
-       gss_release_buffer(&minor_status, &output_token);
-
-       if (!(wrap_type & wrap->wrap_type)) {
-               /*
-                * the server doesn't supports the wrap
-                * type we want :-(
-                */
-               DEBUG(0,("The ldap sasl wrap type doesn't match wanted[%d] server[%d]\n",
-                       wrap->wrap_type, wrap_type));
-               DEBUGADD(0,("You may want to set the 'client ldap sasl wrapping' option\n"));
-               status = ADS_ERROR_NT(NT_STATUS_NOT_SUPPORTED);
-               goto failed;
-       }
-
-       /* 0x58 is the minimum windows accepts */
-       if (max_msg_size < 0x58) {
-               max_msg_size = 0x58;
-       }
-
-       output_token.length = 4;
-       output_token.value = SMB_MALLOC(output_token.length);
-       if (!output_token.value) {
-               output_token.length = 0;
-               status = ADS_ERROR_NT(NT_STATUS_NO_MEMORY);
-               goto failed;
-       }
-       p = (uint8_t *)output_token.value;
-
-       RSIVAL(p,0,max_msg_size);
-       SCVAL(p,0,wrap->wrap_type);
-
-       /*
-        * we used to add sprintf("dn:%s", ads->config.bind_path) here.
-        * but using ads->config.bind_path is the wrong! It should be
-        * the DN of the user object!
-        *
-        * w2k3 gives an error when we send an incorrect DN, but sending nothing
-        * is ok and matches the information flow used in GSS-SPNEGO.
-        */
-
-       gss_rc = gss_wrap(&minor_status, context_handle,0,GSS_C_QOP_DEFAULT,
-                       &output_token, /* used as *input* here. */
-                       &conf_state,
-                       &input_token); /* Used as *output* here. */
-       if (gss_rc) {
-               status = ADS_ERROR_GSS(gss_rc, minor_status);
-               output_token.length = 0;
-               SAFE_FREE(output_token.value);
-               goto failed;
-       }
-
-       /* We've finished with output_token. */
-       SAFE_FREE(output_token.value);
-       output_token.length = 0;
-
-       cred.bv_val = (char *)input_token.value;
-       cred.bv_len = input_token.length;
-
-       rc = ldap_sasl_bind_s(ads->ldap.ld, NULL, "GSSAPI", &cred, NULL, NULL, 
-                             &scred);
-       gss_release_buffer(&minor_status, &input_token);
-       status = ADS_ERROR(rc);
-       if (!ADS_ERR_OK(status)) {
-               goto failed;
-       }
-
-       if (wrap->wrap_type > ADS_SASLWRAP_TYPE_PLAIN) {
-               gss_rc = gss_wrap_size_limit(&minor_status, context_handle,
-                                            (wrap->wrap_type == ADS_SASLWRAP_TYPE_SEAL),
-                                            GSS_C_QOP_DEFAULT,
-                                            max_msg_size, &wrap->out.max_unwrapped);
-               if (gss_rc) {
-                       status = ADS_ERROR_GSS(gss_rc, minor_status);
-                       goto failed;
-               }
-
-               wrap->out.sig_size = max_msg_size - wrap->out.max_unwrapped;
-               wrap->in.min_wrapped = 0x2C; /* taken from a capture with LDAP unbind */
-               wrap->in.max_wrapped = ADS_SASL_WRAPPING_IN_MAX_WRAPPED;
-               status = ads_setup_sasl_wrapping(wrap->wrap_private_data, ads->ldap.ld,
-                                                &ads_sasl_gssapi_ops,
-                                                context_handle);
-               if (!ADS_ERR_OK(status)) {
-                       DEBUG(0, ("ads_setup_sasl_wrapping() failed: %s\n",
-                               ads_errstr(status)));
-                       goto failed;
-               }
-               /* make sure we don't free context_handle */
-               context_handle = GSS_C_NO_CONTEXT;
-       }
-
-failed:
-       if (gss_cred != GSS_C_NO_CREDENTIAL)
-               gss_release_cred(&minor_status, &gss_cred);
-       if (context_handle != GSS_C_NO_CONTEXT)
-               gss_delete_sec_context(&minor_status, &context_handle, GSS_C_NO_BUFFER);
-
-       if(scred)
-               ber_bvfree(scred);
-       return status;
-}
 
 static ADS_STATUS ads_sasl_gssapi_bind(ADS_STRUCT *ads)
 {
@@ -1037,20 +680,30 @@ static ADS_STATUS ads_sasl_gssapi_bind(ADS_STRUCT *ads)
 
        if (ads->auth.password == NULL ||
            ads->auth.password[0] == '\0') {
-               status = ads_sasl_gssapi_do_bind(ads, p.name);
+               status = ads_sasl_spnego_gensec_bind(ads,
+                                                    "GSSAPI",
+                                                    CRED_MUST_USE_KERBEROS,
+                                                    p.service,
+                                                    p.hostname,
+                                                    data_blob_null);
                if (ADS_ERR_OK(status)) {
                        ads_free_service_principal(&p);
                        return status;
                }
 
-               DEBUG(10,("ads_sasl_gssapi_do_bind failed with: %s, "
+               DEBUG(10,("ads_sasl_spnego_gensec_bind(KRB5) failed with: %s, "
                          "calling kinit\n", ads_errstr(status)));
        }
 
        status = ADS_ERROR_KRB5(ads_kinit_password(ads));
 
        if (ADS_ERR_OK(status)) {
-               status = ads_sasl_gssapi_do_bind(ads, p.name);
+               status = ads_sasl_spnego_gensec_bind(ads,
+                                                    "GSSAPI",
+                                                    CRED_MUST_USE_KERBEROS,
+                                                    p.service,
+                                                    p.hostname,
+                                                    data_blob_null);
        }
 
        ads_free_service_principal(&p);