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/*
*
* Copyright 2015, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "src/core/security/auth.h"
#include <string.h>
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include "src/core/support/string.h"
#include "src/core/channel/channel_stack.h"
#include "src/core/security/security_connector.h"
#include "src/core/security/credentials.h"
#include "src/core/surface/call.h"
#define MAX_CREDENTIALS_METADATA_COUNT 4
/* We can have a per-call credentials. */
typedef struct {
grpc_credentials *creds;
grpc_mdstr *host;
grpc_mdstr *method;
grpc_call_op op;
grpc_linked_mdelem md_links[MAX_CREDENTIALS_METADATA_COUNT];
} call_data;
/* We can have a per-channel credentials. */
typedef struct {
grpc_channel_security_connector *security_connector;
grpc_mdctx *md_ctx;
grpc_mdstr *authority_string;
grpc_mdstr *path_string;
grpc_mdstr *error_msg_key;
grpc_mdstr *status_key;
} channel_data;
static void bubbleup_error(grpc_call_element *elem, const char *error_msg) {
grpc_call_element_recv_status(elem, GRPC_STATUS_UNAUTHENTICATED, error_msg);
grpc_call_element_send_cancel(elem);
}
static void on_credentials_metadata(void *user_data, grpc_mdelem **md_elems,
size_t num_md,
grpc_credentials_status status) {
grpc_call_element *elem = (grpc_call_element *)user_data;
call_data *calld = elem->call_data;
grpc_call_op op = calld->op;
size_t i;
GPR_ASSERT(num_md <= MAX_CREDENTIALS_METADATA_COUNT);
for (i = 0; i < num_md; i++) {
grpc_metadata_batch_add_tail(&op.data.metadata, &calld->md_links[i],
grpc_mdelem_ref(md_elems[i]));
}
grpc_call_next_op(elem, &op);
}
static char *build_service_url(const char *url_scheme, call_data *calld) {
char *service_url;
char *service = gpr_strdup(grpc_mdstr_as_c_string(calld->method));
char *last_slash = strrchr(service, '/');
if (last_slash == NULL) {
gpr_log(GPR_ERROR, "No '/' found in fully qualified method name");
service[0] = '\0';
} else if (last_slash == service) {
/* No service part in fully qualified method name: will just be "/". */
service[1] = '\0';
} else {
*last_slash = '\0';
}
if (url_scheme == NULL) url_scheme = "";
gpr_asprintf(&service_url, "%s://%s%s", url_scheme,
grpc_mdstr_as_c_string(calld->host), service);
gpr_free(service);
return service_url;
}
static void send_security_metadata(grpc_call_element *elem, grpc_call_op *op) {
/* grab pointers to our data from the call element */
call_data *calld = elem->call_data;
channel_data *channeld = elem->channel_data;
grpc_credentials *channel_creds =
channeld->security_connector->request_metadata_creds;
/* TODO(jboeuf):
Decide on the policy in this case:
- populate both channel and call?
- the call takes precedence over the channel?
- leave this decision up to the channel credentials? */
if (calld->creds != NULL) {
gpr_log(GPR_ERROR, "Ignoring per call credentials for now.");
}
if (channel_creds != NULL &&
grpc_credentials_has_request_metadata(channel_creds)) {
char *service_url =
build_service_url(channeld->security_connector->base.url_scheme, calld);
calld->op = *op; /* Copy op (originates from the caller's stack). */
grpc_credentials_get_request_metadata(channel_creds, service_url,
on_credentials_metadata, elem);
gpr_free(service_url);
} else {
grpc_call_next_op(elem, op);
}
}
static void on_host_checked(void *user_data, grpc_security_status status) {
grpc_call_element *elem = (grpc_call_element *)user_data;
call_data *calld = elem->call_data;
if (status == GRPC_SECURITY_OK) {
send_security_metadata(elem, &calld->op);
} else {
char *error_msg;
gpr_asprintf(&error_msg, "Invalid host %s set in :authority metadata.",
grpc_mdstr_as_c_string(calld->host));
bubbleup_error(elem, error_msg);
grpc_metadata_batch_destroy(&calld->op.data.metadata);
gpr_free(error_msg);
calld->op.done_cb(calld->op.user_data, GRPC_OP_ERROR);
}
}
/* Called either:
- in response to an API call (or similar) from above, to send something
- a network event (or similar) from below, to receive something
op contains type and call direction information, in addition to the data
that is being sent or received. */
static void call_op(grpc_call_element *elem, grpc_call_element *from_elem,
grpc_call_op *op) {
/* grab pointers to our data from the call element */
call_data *calld = elem->call_data;
channel_data *channeld = elem->channel_data;
grpc_linked_mdelem *l;
switch (op->type) {
case GRPC_SEND_METADATA:
for (l = op->data.metadata.list.head; l != NULL; l = l->next) {
grpc_mdelem *md = l->md;
/* Pointer comparison is OK for md_elems created from the same context.
*/
if (md->key == channeld->authority_string) {
if (calld->host != NULL) grpc_mdstr_unref(calld->host);
calld->host = grpc_mdstr_ref(md->value);
} else if (md->key == channeld->path_string) {
if (calld->method != NULL) grpc_mdstr_unref(calld->method);
calld->method = grpc_mdstr_ref(md->value);
}
}
if (calld->host != NULL) {
grpc_security_status status;
const char *call_host = grpc_mdstr_as_c_string(calld->host);
calld->op = *op; /* Copy op (originates from the caller's stack). */
status = grpc_channel_security_connector_check_call_host(
channeld->security_connector, call_host, on_host_checked, elem);
if (status != GRPC_SECURITY_OK) {
if (status == GRPC_SECURITY_ERROR) {
char *error_msg;
gpr_asprintf(&error_msg,
"Invalid host %s set in :authority metadata.",
call_host);
bubbleup_error(elem, error_msg);
grpc_metadata_batch_destroy(&calld->op.data.metadata);
gpr_free(error_msg);
op->done_cb(op->user_data, GRPC_OP_ERROR);
}
break;
}
}
send_security_metadata(elem, op);
break;
default:
/* pass control up or down the stack depending on op->dir */
grpc_call_next_op(elem, op);
break;
}
}
/* Called on special channel events, such as disconnection or new incoming
calls on the server */
static void channel_op(grpc_channel_element *elem,
grpc_channel_element *from_elem, grpc_channel_op *op) {
grpc_channel_next_op(elem, op);
}
/* Constructor for call_data */
static void init_call_elem(grpc_call_element *elem,
const void *server_transport_data) {
/* TODO(jboeuf):
Find a way to pass-in the credentials from the caller here. */
call_data *calld = elem->call_data;
calld->creds = NULL;
calld->host = NULL;
calld->method = NULL;
}
/* Destructor for call_data */
static void destroy_call_elem(grpc_call_element *elem) {
call_data *calld = elem->call_data;
if (calld->creds != NULL) {
grpc_credentials_unref(calld->creds);
}
if (calld->host != NULL) {
grpc_mdstr_unref(calld->host);
}
if (calld->method != NULL) {
grpc_mdstr_unref(calld->method);
}
}
/* Constructor for channel_data */
static void init_channel_elem(grpc_channel_element *elem,
const grpc_channel_args *args,
grpc_mdctx *metadata_context, int is_first,
int is_last) {
grpc_security_connector *ctx = grpc_find_security_connector_in_args(args);
/* grab pointers to our data from the channel element */
channel_data *channeld = elem->channel_data;
/* The first and the last filters tend to be implemented differently to
handle the case that there's no 'next' filter to call on the up or down
path */
GPR_ASSERT(!is_first);
GPR_ASSERT(!is_last);
GPR_ASSERT(ctx != NULL);
/* initialize members */
GPR_ASSERT(ctx->is_client_side);
channeld->security_connector =
(grpc_channel_security_connector *)grpc_security_connector_ref(ctx);
channeld->md_ctx = metadata_context;
channeld->authority_string =
grpc_mdstr_from_string(channeld->md_ctx, ":authority");
channeld->path_string = grpc_mdstr_from_string(channeld->md_ctx, ":path");
channeld->error_msg_key =
grpc_mdstr_from_string(channeld->md_ctx, "grpc-message");
channeld->status_key =
grpc_mdstr_from_string(channeld->md_ctx, "grpc-status");
}
/* Destructor for channel data */
static void destroy_channel_elem(grpc_channel_element *elem) {
/* grab pointers to our data from the channel element */
channel_data *channeld = elem->channel_data;
grpc_channel_security_connector *ctx = channeld->security_connector;
if (ctx != NULL) grpc_security_connector_unref(&ctx->base);
if (channeld->authority_string != NULL) {
grpc_mdstr_unref(channeld->authority_string);
}
if (channeld->error_msg_key != NULL) {
grpc_mdstr_unref(channeld->error_msg_key);
}
if (channeld->status_key != NULL) {
grpc_mdstr_unref(channeld->status_key);
}
if (channeld->path_string != NULL) {
grpc_mdstr_unref(channeld->path_string);
}
}
const grpc_channel_filter grpc_client_auth_filter = {
call_op, channel_op, sizeof(call_data), init_call_elem, destroy_call_elem,
sizeof(channel_data), init_channel_elem, destroy_channel_elem, "auth"};
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