/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file http_ssl.h
* @brief SSL protocol handling
*
* @defgroup APACHE_CORE_PROTO SSL Protocol Handling
* @ingroup APACHE_CORE
* @{
*/
#ifndef APACHE_HTTP_SSL_H
#define APACHE_HTTP_SSL_H
#include "httpd.h"
#include "apr_portable.h"
#include "apr_mmap.h"
#ifdef __cplusplus
extern "C" {
#endif
struct ap_conf_vector_t;
/**
* This hook allows modules that manage SSL connection to register their
* inquiry function for checking if a connection is using SSL from them.
* @param c The current connection
* @return OK if the connection is using SSL, DECLINED if not.
* @ingroup hooks
*/
AP_DECLARE_HOOK(int,ssl_conn_is_ssl,(conn_rec *c))
/**
* Return != 0 iff the connection is encrypted with SSL.
* @param c the connection
*/
AP_DECLARE(int) ap_ssl_conn_is_ssl(conn_rec *c);
/**
* This hook declares a connection to be outgoing and the configuration that applies to it.
* This hook can be called several times in the lifetime of an outgoing connection, e.g.
* when it is re-used in different request contexts. It will at least be called after the
* connection was created and before the pre-connection hooks is invoked.
* All outgoing-connection hooks are run until one returns something other than DECLINE.
* if enable_ssl != 0, a hook that sets up SSL for the connection needs to return OK
* to prevent subsequent hooks from doing the same.
*
* @param c The connection on which requests/data are to be sent.
* @param dir_conf The directory configuration in which this connection is being used.
* @param enable_ssl If != 0, the SSL protocol should be enabled for this connection.
* @return DECLINED, OK when ssl was enabled
*/
AP_DECLARE_HOOK(int, ssl_bind_outgoing,
(conn_rec *c, struct ap_conf_vector_t *dir_conf, int enable_ssl))
/**
* Assures the connection is marked as outgoing and invokes the ssl_bind_outgoing hook.
* This may be called several times on an outgoing connection with varying dir_conf
* values. require_ssl is not allowed to change on the same connection.
*
* @param c The connection on which requests/data are to be sent.
* @param dir_conf The directory configuration in which this connection is being used.
* @param require_ssl != 0 iff this connection needs to be secured by SSL/TLS protocol.
* @return OK iff ssl was required and is enabled, DECLINED otherwise
*/
AP_DECLARE(int) ap_ssl_bind_outgoing(conn_rec *c, struct ap_conf_vector_t *dir_conf,
int require_ssl);
/**
* Return != 0 iff handlers/hooks for outgoing connections are registered.
*/
AP_DECLARE(int) ap_ssl_has_outgoing_handlers(void);
/**
* This hook allows modules to look up SSL related variables for a
* server/connection/request, depending on what they inquire. Some
* variables will only be available for a connection/request, for example.
* @param p The pool to allocate a returned value in, MUST be provided
* @param s The server to inquire a value for, maybe NULL
* @param c The current connection, maybe NULL
* @param r The current request, maybe NULL
* @param name The name of the variable to retrieve, MUST be provided
* @return value or the variable or NULL if not provided/available
* @ingroup hooks
*/
AP_DECLARE_HOOK(const char *,ssl_var_lookup,
(apr_pool_t *p, server_rec *s, conn_rec *c, request_rec *r, const char *name))
/**
* Lookup an SSL related variable for the server/connection/request or a global
* value when all those parameters are set to NULL. Pool and name must always be
* provided and the returned value (if not NULL) will be allocated from the pool.
* @param p The pool to allocate a returned value in, MUST be provided
* @param s The server to inquire a value for, maybe NULL
* @param c The current connection, maybe NULL
* @param r The current request, maybe NULL
* @param name The name of the variable to retrieve, MUST be provided
* @return value or the variable or NULL if not provided/available
*/
AP_DECLARE(const char *) ap_ssl_var_lookup(apr_pool_t *p, server_rec *s,
conn_rec *c, request_rec *r,
const char *name);
/**
* Register to provide certificate/key files for servers. Certificate files are
* expected to contain the certificate chain, beginning with the server's certificate,
* excluding the trust anchor, in PEM format.
* They must be accompanied by a private key file, also in PEM format.
*
* @param s the server certificates are collected for
* @param p the pool to use for allocations
* @param cert_files an array of const char* with the path to the certificate chain
* @param key_files an array of const char* with the path to the private key file
* @return OK if files were added, DECLINED if not, or other for error.
*/
AP_DECLARE_HOOK(int, ssl_add_cert_files, (server_rec *s, apr_pool_t *p,
apr_array_header_t *cert_files,
apr_array_header_t *key_files))
/**
* Collect certificate/key files from all providers registered. This includes
* providers registered at the global 'ssl_add_cert_files', as well as those
* installed in the OPTIONAL 'ssl_add_cert_files' hook as may be provided by
* ssl modules.
*
* @param s the server certificates are collected for
* @param p the pool to use for allocations
* @param cert_files an array of const char* with the path to the certificate chain
* @param key_files an array of const char* with the path to the private key file
*/
AP_DECLARE(apr_status_t) ap_ssl_add_cert_files(server_rec *s, apr_pool_t *p,
apr_array_header_t *cert_files,
apr_array_header_t *key_files);
/**
* Register to provide 'fallback' certificates in case no 'real' certificates
* have been configured/added by other providers. Modules using these certificates
* are encouraged to answer requests to this server with a 503 response code.
*
* @param s the server certificates are collected for
* @param p the pool to use for allocations
* @param cert_files an array of const char* with the path to the certificate chain
* @param key_files an array of const char* with the path to the private key file
* @return OK if files were added, DECLINED if not, or other for error.
*/
AP_DECLARE_HOOK(int, ssl_add_fallback_cert_files, (server_rec *s, apr_pool_t *p,
apr_array_header_t *cert_files,
apr_array_header_t *key_files))
/**
* Collect 'fallback' certificate/key files from all registered providers, either
* in the global 'ssl_add_fallback_cert_files' hook or the optional one of similar
* name as provided by mod_ssl and sorts.
* Certificates obtained this way are commonly self signed, temporary crutches.
* To be used to the time it takes to retrieve a 'read', trusted certificate.
* A module using fallbacks is encouraged to answer all requests with a 503.
*
* @param s the server certificates are collected for
* @param p the pool to use for allocations
* @param cert_files an array of const char* with the path to the certificate chain
* @param key_files an array of const char* with the path to the private key file
*/
AP_DECLARE(apr_status_t) ap_ssl_add_fallback_cert_files(server_rec *s, apr_pool_t *p,
apr_array_header_t *cert_files,
apr_array_header_t *key_files);
/**
* On TLS connections that do not relate to a configured virtual host
* allow modules to provide a certificate and key to be used on the connection.
*
* A Certificate PEM added must be accompanied by a private key PEM. The private
* key PEM may be given by a NULL pointer, in which case it is expected to be found in
* the certificate PEM string.
*/
AP_DECLARE_HOOK(int, ssl_answer_challenge, (conn_rec *c, const char *server_name,
const char **pcert_pem, const char **pkey_pem))
/**
* Returns != 0 iff the connection is a challenge to the server, for example
* as defined in RFC 8555 for the 'tls-alpn-01' domain verification, and needs
* a specific certificate as answer in the handshake.
*
* ALPN protocol negotiation via the hooks 'protocol_propose' and 'protocol_switch'
* need to have run before this call is made.
*
* Certificate PEMs added must be accompanied by a private key PEM. The private
* key PEM may be given by a NULL pointer, in which case it is expected to be found in
* the certificate PEM string.
*
* A certificate provided this way needs to replace any other certificates selected
* by configuration or 'ssl_add_cert_pems` on this connection.
*/
AP_DECLARE(int) ap_ssl_answer_challenge(conn_rec *c, const char *server_name,
const char **pcert_pem, const char **pkey_pem);
/**
* Setup optional functions for ssl related queries so that functions
* registered by old-style SSL module functions are interrogated by the
* the new ap_is_ssl() and friends. Installs own optional functions, so that
* old modules looking for these find one and get the correct results (shadowing).
*
* Needs to run in core's very early POST_CONFIG hook.
* Modules providing such functions register their own optionals during
* register_hooks(). Modules using such functions retrieve them often
* in their own post-config or in the even later retrieval hook. When shadowing
* other modules functions, core's early post-config is a good time.
* @param pool The pool to use for allocations
*/
AP_DECLARE(void) ap_setup_ssl_optional_fns(apr_pool_t *pool);
/**
* Providers of OCSP status responses register at this hook. Installed hooks returning OK
* are expected to provide later OCSP responses via a 'ap_ssl_ocsp_get_resp_hook'.
* @param s the server being configured
* @params p a memory pool to use
* @param id opaque data uniquely identifying the certificate, provided by caller
* @param pem PEM data of certificate first, followed by PEM of issuer cert
* @return OK iff stapling is being provided
*/
AP_DECLARE_HOOK(int, ssl_ocsp_prime_hook, (server_rec *s, apr_pool_t *p,
const char *id, apr_size_t id_len,
const char *pem))
/**
* Registering a certificate for Provisioning of OCSP responses. It is the caller's
* responsibility to provide a global (apache instance) unique id for the certificate
* that is then used later in retrieving the OCSP response.
* A certificate can be primed this way more than once, however the same identifier
* has to be provided each time (byte-wise same, not pointer same).
* The memory pointed to by `id` and `pem` is only valid for the duration of the call.
*
* @param s the server being configured
* @params p a memory pool to use
* @param id opaque data uniquely identifying the certificate, provided by caller
* @param pem PEM data of certificate first, followed by chain certs, at least the issuer
* @return APR_SUCCESS iff OCSP responses will be provided.
* APR_ENOENT when no provided was found or took responsibility.
*/
AP_DECLARE(apr_status_t) ap_ssl_ocsp_prime(server_rec *s, apr_pool_t *p,
const char *id, apr_size_t id_len,
const char *pem);
/**
* Callback to copy over the OCSP response data. If OCSP response data is not
* available, this will be called with NULL, 0 parameters!
*
* Memory allocation methods and lifetime of data will vary per module and
* SSL library used. The caller requesting OCSP data will need to make a copy
* for his own use.
* Any passed data may only be valid for the duration of the call.
*/
typedef void ap_ssl_ocsp_copy_resp(const unsigned char *der, apr_size_t der_len, void *userdata);
/**
* Asking for OCSP response DER data for a certificate formerly primed.
* @param s the (SNI selected) server of the connection
* @param c the connection
* @param id identifier for the certifate, as used in ocsp_stapling_prime()
* @param cb callback to invoke when response data is available
* @param userdata caller supplied data passed to callback
* @return OK iff response data has been provided, DECLINED otherwise
*/
AP_DECLARE_HOOK(int, ssl_ocsp_get_resp_hook,
(server_rec *s, conn_rec *c, const char *id, apr_size_t id_len,
ap_ssl_ocsp_copy_resp *cb, void *userdata))
/**
* Retrieve the OCSP response data for a previously primed certificate. The id needs
* to be byte-wise identical to the one used on priming. If the call return ARP_SUCCESS,
* the callback has been invoked with the OCSP response DER data.
* Otherwise, a different status code must be returned. Callers in SSL connection
* handshakes are encouraged to continue the handshake without OCSP data for
* server reliability. The decision to accept or reject a handshake with missing
* OCSP stapling data needs to be done by the client.
* For similar reasons, providers of responses might return seemingly expired ones
* if they were unable to refresh a response in time.
*
* The memory pointed to by `id` is only valid for the duration of the call.
* Also, the DER data passed to the callback is only valid for the duration
* of the call.
*
* @param s the (SNI selected) server of the connection
* @param c the connection
* @param id identifier for the certifate, as used in ocsp_stapling_prime()
* @param cb callback to invoke when response data is available
* @param userdata caller supplied data passed to callback
* @return APR_SUCCESS iff data has been provided
*/
AP_DECLARE(apr_status_t) ap_ssl_ocsp_get_resp(server_rec *s, conn_rec *c,
const char *id, apr_size_t id_len,
ap_ssl_ocsp_copy_resp *cb, void *userdata);
#ifdef __cplusplus
}
#endif
#endif /* !APACHE_HTTP_SSL_H */
/** @} */
