curl/lib/vtls/vtls_int.h
Max Faxälv 0a5ea09a91
spnego_gssapi: implement TLS channel bindings for openssl
Channel Bindings are used to tie the session context to a specific TLS
channel. This is to provide additional proof of valid identity,
mitigating authentication relay attacks.

Major web servers have the ability to require (None/Accept/Require)
GSSAPI channel binding, rendering Curl unable to connect to such
websites unless support for channel bindings is implemented.

IIS calls this feature Extended Protection (EPA), which is used in
Enterprise environments using Kerberos for authentication.

This change require krb5 >= 1.19, otherwise channel bindings won't be
forwarded through SPNEGO.

Co-Authored-By: Steffen Kieß <947515+steffen-kiess@users.noreply.github.com>
Closes #13098
2024-08-12 19:16:54 +02:00

233 lines
8.9 KiB
C

#ifndef HEADER_CURL_VTLS_INT_H
#define HEADER_CURL_VTLS_INT_H
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "curl_setup.h"
#include "cfilters.h"
#include "urldata.h"
#ifdef USE_SSL
/* see https://www.iana.org/assignments/tls-extensiontype-values/ */
#define ALPN_HTTP_1_1_LENGTH 8
#define ALPN_HTTP_1_1 "http/1.1"
#define ALPN_H2_LENGTH 2
#define ALPN_H2 "h2"
#define ALPN_H3_LENGTH 2
#define ALPN_H3 "h3"
/* conservative sizes on the ALPN entries and count we are handling,
* we can increase these if we ever feel the need or have to accommodate
* ALPN strings from the "outside". */
#define ALPN_NAME_MAX 10
#define ALPN_ENTRIES_MAX 3
#define ALPN_PROTO_BUF_MAX (ALPN_ENTRIES_MAX * (ALPN_NAME_MAX + 1))
struct alpn_spec {
const char entries[ALPN_ENTRIES_MAX][ALPN_NAME_MAX];
size_t count; /* number of entries */
};
struct alpn_proto_buf {
unsigned char data[ALPN_PROTO_BUF_MAX];
int len;
};
CURLcode Curl_alpn_to_proto_buf(struct alpn_proto_buf *buf,
const struct alpn_spec *spec);
CURLcode Curl_alpn_to_proto_str(struct alpn_proto_buf *buf,
const struct alpn_spec *spec);
CURLcode Curl_alpn_set_negotiated(struct Curl_cfilter *cf,
struct Curl_easy *data,
const unsigned char *proto,
size_t proto_len);
/* enum for the nonblocking SSL connection state machine */
typedef enum {
ssl_connect_1,
ssl_connect_2,
ssl_connect_3,
ssl_connect_done
} ssl_connect_state;
typedef enum {
ssl_connection_none,
ssl_connection_negotiating,
ssl_connection_complete
} ssl_connection_state;
#define CURL_SSL_IO_NEED_NONE (0)
#define CURL_SSL_IO_NEED_RECV (1<<0)
#define CURL_SSL_IO_NEED_SEND (1<<1)
/* Information in each SSL cfilter context: cf->ctx */
struct ssl_connect_data {
struct ssl_peer peer;
const struct alpn_spec *alpn; /* ALPN to use or NULL for none */
void *backend; /* vtls backend specific props */
struct cf_call_data call_data; /* data handle used in current call */
struct curltime handshake_done; /* time when handshake finished */
ssl_connection_state state;
ssl_connect_state connecting_state;
int io_need; /* TLS signals special SEND/RECV needs */
BIT(use_alpn); /* if ALPN shall be used in handshake */
BIT(peer_closed); /* peer has closed connection */
};
#undef CF_CTX_CALL_DATA
#define CF_CTX_CALL_DATA(cf) \
((struct ssl_connect_data *)(cf)->ctx)->call_data
/* Definitions for SSL Implementations */
struct Curl_ssl {
/*
* This *must* be the first entry to allow returning the list of available
* backends in curl_global_sslset().
*/
curl_ssl_backend info;
unsigned int supports; /* bitfield, see above */
size_t sizeof_ssl_backend_data;
int (*init)(void);
void (*cleanup)(void);
size_t (*version)(char *buffer, size_t size);
int (*check_cxn)(struct Curl_cfilter *cf, struct Curl_easy *data);
CURLcode (*shut_down)(struct Curl_cfilter *cf, struct Curl_easy *data,
bool send_shutdown, bool *done);
bool (*data_pending)(struct Curl_cfilter *cf,
const struct Curl_easy *data);
/* return 0 if a find random is filled in */
CURLcode (*random)(struct Curl_easy *data, unsigned char *entropy,
size_t length);
bool (*cert_status_request)(void);
CURLcode (*connect_blocking)(struct Curl_cfilter *cf,
struct Curl_easy *data);
CURLcode (*connect_nonblocking)(struct Curl_cfilter *cf,
struct Curl_easy *data,
bool *done);
/* During handshake/shutdown, adjust the pollset to include the socket
* for POLLOUT or POLLIN as needed. Mandatory. */
void (*adjust_pollset)(struct Curl_cfilter *cf, struct Curl_easy *data,
struct easy_pollset *ps);
void *(*get_internals)(struct ssl_connect_data *connssl, CURLINFO info);
void (*close)(struct Curl_cfilter *cf, struct Curl_easy *data);
void (*close_all)(struct Curl_easy *data);
CURLcode (*set_engine)(struct Curl_easy *data, const char *engine);
CURLcode (*set_engine_default)(struct Curl_easy *data);
struct curl_slist *(*engines_list)(struct Curl_easy *data);
bool (*false_start)(void);
CURLcode (*sha256sum)(const unsigned char *input, size_t inputlen,
unsigned char *sha256sum, size_t sha256sumlen);
bool (*attach_data)(struct Curl_cfilter *cf, struct Curl_easy *data);
void (*detach_data)(struct Curl_cfilter *cf, struct Curl_easy *data);
ssize_t (*recv_plain)(struct Curl_cfilter *cf, struct Curl_easy *data,
char *buf, size_t len, CURLcode *code);
ssize_t (*send_plain)(struct Curl_cfilter *cf, struct Curl_easy *data,
const void *mem, size_t len, CURLcode *code);
CURLcode (*get_channel_binding)(struct Curl_easy *data, int sockindex,
struct dynbuf *binding);
};
extern const struct Curl_ssl *Curl_ssl;
int Curl_none_init(void);
void Curl_none_cleanup(void);
CURLcode Curl_none_shutdown(struct Curl_cfilter *cf, struct Curl_easy *data,
bool send_shutdown, bool *done);
int Curl_none_check_cxn(struct Curl_cfilter *cf, struct Curl_easy *data);
CURLcode Curl_none_random(struct Curl_easy *data, unsigned char *entropy,
size_t length);
void Curl_none_close_all(struct Curl_easy *data);
void Curl_none_session_free(void *ptr);
bool Curl_none_data_pending(struct Curl_cfilter *cf,
const struct Curl_easy *data);
bool Curl_none_cert_status_request(void);
CURLcode Curl_none_set_engine(struct Curl_easy *data, const char *engine);
CURLcode Curl_none_set_engine_default(struct Curl_easy *data);
struct curl_slist *Curl_none_engines_list(struct Curl_easy *data);
bool Curl_none_false_start(void);
void Curl_ssl_adjust_pollset(struct Curl_cfilter *cf, struct Curl_easy *data,
struct easy_pollset *ps);
/**
* Get the SSL filter below the given one or NULL if there is none.
*/
bool Curl_ssl_cf_is_proxy(struct Curl_cfilter *cf);
/* extract a session ID
* Sessionid mutex must be locked (see Curl_ssl_sessionid_lock).
* Caller must make sure that the ownership of returned sessionid object
* is properly taken (e.g. its refcount is incremented
* under sessionid mutex).
*/
bool Curl_ssl_getsessionid(struct Curl_cfilter *cf,
struct Curl_easy *data,
const struct ssl_peer *peer,
void **ssl_sessionid,
size_t *idsize); /* set 0 if unknown */
/* Set a TLS session ID for `peer`. Replaces an existing session ID if
* not already the very same.
* Sessionid mutex must be locked (see Curl_ssl_sessionid_lock).
* Call takes ownership of `ssl_sessionid`, using `sessionid_free_cb`
* to deallocate it. Is called in all outcomes, either right away or
* later when the session cache is cleaned up.
* Caller must ensure that it has properly shared ownership of this sessionid
* object with cache (e.g. incrementing refcount on success)
*/
CURLcode Curl_ssl_set_sessionid(struct Curl_cfilter *cf,
struct Curl_easy *data,
const struct ssl_peer *peer,
void *sessionid,
size_t sessionid_size,
Curl_ssl_sessionid_dtor *sessionid_free_cb);
#include "openssl.h" /* OpenSSL versions */
#include "gtls.h" /* GnuTLS versions */
#include "wolfssl.h" /* wolfSSL versions */
#include "schannel.h" /* Schannel SSPI version */
#include "sectransp.h" /* SecureTransport (Darwin) version */
#include "mbedtls.h" /* mbedTLS versions */
#include "bearssl.h" /* BearSSL versions */
#include "rustls.h" /* rustls versions */
#endif /* USE_SSL */
#endif /* HEADER_CURL_VTLS_INT_H */