httpclient: support authentication Store the last-seen credential challenges (eg, all the 'WWW-Authenticate' headers in a response message). Given some credentials, find the best (first) challenge whose mechanism supports these credentials. (eg, 'Basic' supports username/password credentials, 'Negotiate' supports default credentials). Set up an authentication context for this mechanism and these credentials. Continue exchanging challenge/responses until we're authenticated.
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diff --git a/src/transports/httpclient.c b/src/transports/httpclient.c
index 6c5e9ce..54c4fc5 100644
--- a/src/transports/httpclient.c
+++ b/src/transports/httpclient.c
@@ -13,17 +13,30 @@
#include "global.h"
#include "httpclient.h"
#include "http.h"
+#include "auth.h"
+#include "auth_negotiate.h"
+#include "auth_ntlm.h"
+#include "git2/sys/cred.h"
#include "net.h"
#include "stream.h"
#include "streams/socket.h"
#include "streams/tls.h"
#include "auth.h"
+static git_http_auth_scheme auth_schemes[] = {
+ { GIT_HTTP_AUTH_NEGOTIATE, "Negotiate", GIT_CREDTYPE_DEFAULT, git_http_auth_negotiate },
+ { GIT_HTTP_AUTH_NTLM, "NTLM", GIT_CREDTYPE_USERPASS_PLAINTEXT, git_http_auth_ntlm },
+ { GIT_HTTP_AUTH_BASIC, "Basic", GIT_CREDTYPE_USERPASS_PLAINTEXT, git_http_auth_basic },
+};
+
#define GIT_READ_BUFFER_SIZE 8192
typedef struct {
git_net_url url;
git_stream *stream;
+
+ git_vector auth_challenges;
+ git_http_auth_context *auth_context;
} git_http_server;
typedef enum {
@@ -45,6 +58,7 @@ typedef enum {
typedef enum {
PARSE_STATUS_OK,
+ PARSE_STATUS_NO_OUTPUT,
PARSE_STATUS_ERROR
} parse_status;
@@ -116,6 +130,7 @@ void git_http_response_dispose(git_http_response *response)
static int on_header_complete(http_parser *parser)
{
http_parser_context *ctx = (http_parser_context *) parser->data;
+ git_http_client *client = ctx->client;
git_http_response *response = ctx->response;
git_buf *name = &ctx->parse_header_name;
@@ -148,6 +163,18 @@ static int on_header_complete(http_parser *parser)
}
response->content_length = (size_t)len;
+ } else if (!strcasecmp("Proxy-Authenticate", git_buf_cstr(name))) {
+ char *dup = git__strndup(value->ptr, value->size);
+ GIT_ERROR_CHECK_ALLOC(dup);
+
+ if (git_vector_insert(&client->proxy.auth_challenges, dup) < 0)
+ return -1;
+ } else if (!strcasecmp("WWW-Authenticate", name->ptr)) {
+ char *dup = git__strndup(value->ptr, value->size);
+ GIT_ERROR_CHECK_ALLOC(dup);
+
+ if (git_vector_insert(&client->server.auth_challenges, dup) < 0)
+ return -1;
} else if (!strcasecmp("Location", name->ptr)) {
if (response->location) {
git_error_set(GIT_ERROR_NET,
@@ -220,6 +247,71 @@ static int on_header_value(http_parser *parser, const char *str, size_t len)
return 0;
}
+GIT_INLINE(bool) challenge_matches_scheme(
+ const char *challenge,
+ git_http_auth_scheme *scheme)
+{
+ const char *scheme_name = scheme->name;
+ size_t scheme_len = strlen(scheme_name);
+
+ if (!strncasecmp(challenge, scheme_name, scheme_len) &&
+ (challenge[scheme_len] == '\0' || challenge[scheme_len] == ' '))
+ return true;
+
+ return false;
+}
+
+static git_http_auth_scheme *scheme_for_challenge(const char *challenge)
+{
+ size_t i;
+
+ for (i = 0; i < ARRAY_SIZE(auth_schemes); i++) {
+ if (challenge_matches_scheme(challenge, &auth_schemes[i]))
+ return &auth_schemes[i];
+ }
+
+ return NULL;
+}
+
+GIT_INLINE(void) collect_authinfo(
+ unsigned int *schemetypes,
+ unsigned int *credtypes,
+ git_vector *challenges)
+{
+ git_http_auth_scheme *scheme;
+ const char *challenge;
+ size_t i;
+
+ *schemetypes = 0;
+ *credtypes = 0;
+
+ git_vector_foreach(challenges, i, challenge) {
+ if ((scheme = scheme_for_challenge(challenge)) != NULL) {
+ *schemetypes |= scheme->type;
+ *credtypes |= scheme->credtypes;
+ }
+ }
+}
+
+static int resend_needed(git_http_client *client, git_http_response *response)
+{
+ git_http_auth_context *auth_context;
+
+ if (response->status == 401 &&
+ (auth_context = client->server.auth_context) &&
+ auth_context->is_complete &&
+ !auth_context->is_complete(auth_context))
+ return 1;
+
+ if (response->status == 407 &&
+ (auth_context = client->proxy.auth_context) &&
+ auth_context->is_complete &&
+ !auth_context->is_complete(auth_context))
+ return 1;
+
+ return 0;
+}
+
static int on_headers_complete(http_parser *parser)
{
http_parser_context *ctx = (http_parser_context *) parser->data;
@@ -245,6 +337,17 @@ static int on_headers_complete(http_parser *parser)
ctx->response->status = parser->status_code;
ctx->client->keepalive = http_should_keep_alive(parser);
+ /* Prepare for authentication */
+ collect_authinfo(&ctx->response->server_auth_schemetypes,
+ &ctx->response->server_auth_credtypes,
+ &ctx->client->server.auth_challenges);
+ collect_authinfo(&ctx->response->proxy_auth_schemetypes,
+ &ctx->response->proxy_auth_credtypes,
+ &ctx->client->proxy.auth_challenges);
+
+ ctx->response->resend_credentials = resend_needed(ctx->client,
+ ctx->response);
+
/* Stop parsing. */
http_parser_pause(parser, 1);
@@ -305,26 +408,201 @@ const char *name_for_method(git_http_method method)
return NULL;
}
+/*
+ * Find the scheme that is suitable for the given credentials, based on the
+ * server's auth challenges.
+ */
+static bool best_scheme_and_challenge(
+ git_http_auth_scheme **scheme_out,
+ const char **challenge_out,
+ git_vector *challenges,
+ git_cred *credentials)
+{
+ const char *challenge;
+ size_t i, j;
+
+ for (i = 0; i < ARRAY_SIZE(auth_schemes); i++) {
+ git_vector_foreach(challenges, j, challenge) {
+ git_http_auth_scheme *scheme = &auth_schemes[i];
+
+ if (challenge_matches_scheme(challenge, scheme) &&
+ (scheme->credtypes & credentials->credtype)) {
+ *scheme_out = scheme;
+ *challenge_out = challenge;
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
+/*
+ * Find the challenge from the server for our current auth context.
+ */
+static const char *challenge_for_context(
+ git_vector *challenges,
+ git_http_auth_context *auth_ctx)
+{
+ const char *challenge;
+ size_t i, j;
+
+ for (i = 0; i < ARRAY_SIZE(auth_schemes); i++) {
+ if (auth_schemes[i].type == auth_ctx->type) {
+ git_http_auth_scheme *scheme = &auth_schemes[i];
+
+ git_vector_foreach(challenges, j, challenge) {
+ if (challenge_matches_scheme(challenge, scheme))
+ return challenge;
+ }
+ }
+ }
+
+ return NULL;
+}
+
+static const char *init_auth_context(
+ git_http_server *server,
+ git_vector *challenges,
+ git_cred *credentials)
+{
+ git_http_auth_scheme *scheme;
+ const char *challenge;
+ int error;
+
+ if (!best_scheme_and_challenge(&scheme, &challenge, challenges, credentials)) {
+ git_error_set(GIT_ERROR_NET, "could not find appropriate mechanism for credentials");
+ return NULL;
+ }
+
+ error = scheme->init_context(&server->auth_context, &server->url);
+
+ if (error == GIT_PASSTHROUGH) {
+ git_error_set(GIT_ERROR_NET, "'%s' authentication is not supported", scheme->name);
+ return NULL;
+ }
+
+ return challenge;
+}
+
+static void free_auth_context(git_http_server *server)
+{
+ if (!server->auth_context)
+ return;
+
+ if (server->auth_context->free)
+ server->auth_context->free(server->auth_context);
+
+ server->auth_context = NULL;
+}
+
+static int apply_credentials(
+ git_buf *buf,
+ git_http_server *server,
+ const char *header_name,
+ git_cred *credentials)
+{
+ git_http_auth_context *auth = server->auth_context;
+ git_vector *challenges = &server->auth_challenges;
+ const char *challenge;
+ git_buf token = GIT_BUF_INIT;
+ int error = 0;
+
+ /* We've started a new request without creds; free the context. */
+ if (auth && !credentials) {
+ free_auth_context(server);
+ return 0;
+ }
+
+ /* We haven't authenticated, nor were we asked to. Nothing to do. */
+ if (!auth && !git_vector_length(challenges))
+ return 0;
+
+ if (!auth) {
+ challenge = init_auth_context(server, challenges, credentials);
+ auth = server->auth_context;
+
+ if (!challenge || !auth) {
+ error = -1;
+ goto done;
+ }
+ } else if (auth->set_challenge) {
+ challenge = challenge_for_context(challenges, auth);
+ }
+
+ if (auth->set_challenge && challenge &&
+ (error = auth->set_challenge(auth, challenge)) < 0)
+ goto done;
+
+ if ((error = auth->next_token(&token, auth, credentials)) < 0)
+ goto done;
+
+ if (auth->is_complete && auth->is_complete(auth)) {
+ /*
+ * If we're done with an auth mechanism with connection affinity,
+ * we don't need to send any more headers and can dispose the context.
+ */
+ if (auth->connection_affinity)
+ free_auth_context(server);
+ } else if (!token.size) {
+ git_error_set(GIT_ERROR_NET, "failed to respond to authentication challange");
+ error = -1;
+ goto done;
+ }
+
+ if (token.size > 0)
+ error = git_buf_printf(buf, "%s: %s\r\n", header_name, token.ptr);
+
+done:
+ git_buf_dispose(&token);
+ return error;
+}
+
+GIT_INLINE(int) apply_server_credentials(
+ git_buf *buf,
+ git_http_client *client,
+ git_http_request *request)
+{
+ return apply_credentials(buf,
+ &client->server,
+ "Authorization",
+ request->credentials);
+}
+
+GIT_INLINE(int) apply_proxy_credentials(
+ git_buf *buf,
+ git_http_client *client,
+ git_http_request *request)
+{
+ return apply_credentials(buf,
+ &client->proxy,
+ "Proxy-Authorization",
+ request->proxy_credentials);
+}
+
static int generate_request(
git_http_client *client,
git_http_request *request)
{
- const char *method, *path, *sep, *query;
git_buf *buf;
size_t i;
+ int error;
assert(client && request);
git_buf_clear(&client->request_msg);
buf = &client->request_msg;
- method = name_for_method(request->method);
- path = request->url->path ? request->url->path : "/";
- sep = request->url->query ? "?" : "";
- query = request->url->query ? request->url->query : "";
+ /* GET|POST path HTTP/1.1 */
+ git_buf_puts(buf, name_for_method(request->method));
+ git_buf_putc(buf, ' ');
- git_buf_printf(buf, "%s %s%s%s HTTP/1.1\r\n",
- method, path, sep, query);
+ if (request->proxy && strcmp(request->url->scheme, "https"))
+ git_net_url_fmt(buf, request->url);
+ else
+ git_net_url_fmt_path(buf, request->url);
+
+ git_buf_puts(buf, " HTTP/1.1\r\n");
git_buf_puts(buf, "User-Agent: ");
git_http__user_agent(buf);
@@ -355,6 +633,10 @@ static int generate_request(
if (request->expect_continue)
git_buf_printf(buf, "Expect: 100-continue\r\n");
+ if ((error = apply_server_credentials(buf, client, request)) < 0 ||
+ (error = apply_proxy_credentials(buf, client, request)) < 0)
+ return error;
+
if (request->custom_headers) {
for (i = 0; i < request->custom_headers->count; i++) {
const char *hdr = request->custom_headers->strings[i];
@@ -424,6 +706,24 @@ static int stream_connect(
return error;
}
+static void reset_auth_connection(git_http_server *server)
+{
+ /*
+ * If we've authenticated and we're doing "normal"
+ * authentication with a request affinity (Basic, Digest)
+ * then we want to _keep_ our context, since authentication
+ * survives even through non-keep-alive connections. If
+ * we've authenticated and we're doing connection-based
+ * authentication (NTLM, Negotiate) - indicated by the presence
+ * of an `is_complete` callback - then we need to restart
+ * authentication on a new connection.
+ */
+
+ if (server->auth_context &&
+ server->auth_context->connection_affinity)
+ free_auth_context(server);
+}
+
/*
* Updates the server data structure with the new URL; returns 1 if the server
* has changed and we need to reconnect, returns 0 otherwise.
@@ -511,6 +811,9 @@ static int http_client_connect(git_http_client *client)
client->proxy.stream = NULL;
}
+ reset_auth_connection(&client->server);
+ reset_auth_connection(&client->proxy);
+
reset_parser(client);
client->connected = 0;
@@ -611,7 +914,6 @@ GIT_INLINE(http_parser_settings *) http_client_parser_settings(void)
return &parser_settings;
}
-
GIT_INLINE(int) client_read_and_parse(git_http_client *client)
{
http_parser *parser = &client->parser;
@@ -743,6 +1045,7 @@ int git_http_client_send_request(
complete_response_body(client);
http_parser_init(&client->parser, HTTP_RESPONSE);
+ git_buf_clear(&client->read_buf);
if (git_trace_level() >= GIT_TRACE_DEBUG) {
git_buf url = GIT_BUF_INIT;
@@ -844,6 +1147,11 @@ int git_http_client_read_response(
goto done;
}
+ git_http_response_dispose(response);
+
+ git_vector_free_deep(&client->server.auth_challenges);
+ git_vector_free_deep(&client->proxy.auth_challenges);
+
client->state = READING_RESPONSE;
client->parser.data = &parser_context;
@@ -913,6 +1221,40 @@ done:
return error;
}
+int git_http_client_skip_body(git_http_client *client)
+{
+ http_parser_context parser_context = {0};
+ int error;
+
+ if (client->state == DONE)
+ return 0;
+
+ if (client->state != READING_BODY) {
+ git_error_set(GIT_ERROR_NET, "client is in invalid state");
+ return -1;
+ }
+
+ parser_context.client = client;
+ client->parser.data = &parser_context;
+
+ do {
+ error = client_read_and_parse(client);
+
+ if (parser_context.error != HPE_OK ||
+ (parser_context.parse_status != PARSE_STATUS_OK &&
+ parser_context.parse_status != PARSE_STATUS_NO_OUTPUT)) {
+ git_error_set(GIT_ERROR_NET,
+ "unexpected data handled in callback");
+ error = -1;
+ }
+ } while (!error);
+
+ if (error < 0)
+ client->connected = 0;
+
+ return error;
+}
+
/*
* Create an http_client capable of communicating with the given remote
* host.
@@ -947,6 +1289,9 @@ GIT_INLINE(void) http_server_close(git_http_server *server)
}
git_net_url_dispose(&server->url);
+
+ git_vector_free_deep(&server->auth_challenges);
+ free_auth_context(server);
}
static void http_client_close(git_http_client *client)
diff --git a/src/transports/httpclient.h b/src/transports/httpclient.h
index 73ae356..5f3c2ca 100644
--- a/src/transports/httpclient.h
+++ b/src/transports/httpclient.h
@@ -28,6 +28,8 @@ typedef struct {
/* Headers */
const char *accept; /**< Contents of the Accept header */
const char *content_type; /**< Content-Type header (for POST) */
+ git_cred *credentials; /**< Credentials to authenticate with */
+ git_cred *proxy_credentials; /**< Credentials for proxy */
git_strarray *custom_headers; /**< Additional headers to deliver */
/* To POST a payload, either set content_length OR set chunked. */
@@ -43,6 +45,15 @@ typedef struct {
char *content_type;
size_t content_length;
char *location;
+
+ /* Authentication headers */
+ unsigned server_auth_schemetypes; /**< Schemes requested by remote */
+ unsigned server_auth_credtypes; /**< Supported cred types for remote */
+
+ unsigned proxy_auth_schemetypes; /**< Schemes requested by proxy */
+ unsigned proxy_auth_credtypes; /**< Supported cred types for proxy */
+
+ unsigned resend_credentials : 1; /**< Resend with authentication */
} git_http_response;
typedef struct {
@@ -121,6 +132,15 @@ extern int git_http_client_read_body(
size_t buffer_size);
/**
+ * Reads all of the (remainder of the) body of the response and ignores it.
+ * None of the data from the body will be returned to the caller.
+ *
+ * @param client the client to read the response from
+ * @return 0 or an error code
+ */
+extern int git_http_client_skip_body(git_http_client *client);
+
+/**
* Examines the status code of the response to determine if it is a
* redirect of any type (eg, 301, 302, etc).
*