source: vbox/trunk/include/iprt/http.h

/* $Id: http.h 98103 2023-01-17 14:15:46Z vboxsync $ */
/** @file
 * IPRT - Simple HTTP/HTTPS Client API.
 */

/*
 * Copyright (C) 2012-2023 Oracle and/or its affiliates.
 *
 * This file is part of VirtualBox base platform packages, as
 * available from https://www.virtualbox.org.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation, in version 3 of the
 * License.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <https://www.gnu.org/licenses>.
 *
 * The contents of this file may alternatively be used under the terms
 * of the Common Development and Distribution License Version 1.0
 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
 * in the VirtualBox distribution, in which case the provisions of the
 * CDDL are applicable instead of those of the GPL.
 *
 * You may elect to license modified versions of this file under the
 * terms and conditions of either the GPL or the CDDL or both.
 *
 * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
 */

#ifndef IPRT_INCLUDED_http_h
#define IPRT_INCLUDED_http_h
#ifndef RT_WITHOUT_PRAGMA_ONCE
# pragma once
#endif

#include <iprt/types.h>
#include <iprt/http-common.h>

RT_C_DECLS_BEGIN

/** @defgroup grp_rt_http   RTHttp - Simple HTTP/HTTPS Client API
 * @ingroup grp_rt
 * @{
 */

/** @todo the following three definitions may move the iprt/types.h later. */
/** HTTP/HTTPS client handle. */
typedef R3PTRTYPE(struct RTHTTPINTERNAL *)      RTHTTP;
/** Pointer to a HTTP/HTTPS client handle. */
typedef RTHTTP                                 *PRTHTTP;
/** Nil HTTP/HTTPS client handle. */
#define NIL_RTHTTP                              ((RTHTTP)0)


/**
 * Creates a HTTP client instance.
 *
 * @returns IPRT status code.
 * @param   phHttp      Where to store the HTTP handle.
 */
RTR3DECL(int) RTHttpCreate(PRTHTTP phHttp);

/**
 * Resets a HTTP client instance.
 *
 * @returns IPRT status code.
 * @param   hHttp       Handle to the HTTP interface.
 * @param   fFlags      Flags, RTHTTP_RESET_F_XXX.
 */
RTR3DECL(int) RTHttpReset(RTHTTP hHttp, uint32_t fFlags);

/** @name RTHTTP_RESET_F_XXX - Flags for RTHttpReset.
 * @{ */
/** Keep the headers. */
#define RTHTTP_RESET_F_KEEP_HEADERS     RT_BIT_32(0)
/** Mask containing the valid flags. */
#define RTHTTP_RESET_F_VALID_MASK       UINT32_C(0x00000001)
/** @} */


/**
 * Destroys a HTTP client instance.
 *
 * @returns IPRT status code.
 * @param   hHttp       Handle to the HTTP interface.
 */
RTR3DECL(int) RTHttpDestroy(RTHTTP hHttp);


/**
 * Retrieve the redir location for 301 responses.
 *
 * @param   hHttp               Handle to the HTTP interface.
 * @param   ppszRedirLocation   Where to store the string.  To be freed with
 *                              RTStrFree().
 */
RTR3DECL(int) RTHttpGetRedirLocation(RTHTTP hHttp, char **ppszRedirLocation);

/**
 * Perform a simple blocking HTTP GET request.
 *
 * This is a just a convenient wrapper around RTHttpGetBinary that returns a
 * different type and sheds a parameter.
 *
 * @returns iprt status code.
 *
 * @param   hHttp           The HTTP client handle.
 * @param   pszUrl          URL.
 * @param   ppszNotUtf8     Where to return the pointer to the HTTP response.
 *                          The string is of course zero terminated.  Use
 *                          RTHttpFreeReponseText to free.
 *
 * @remarks BIG FAT WARNING!
 *
 *          This function does not guarantee the that returned string is valid UTF-8 or
 *          any other kind of text encoding!
 *
 *          The caller must determine and validate the string encoding _before_
 *          passing it along to functions that expect UTF-8!
 *
 *          Also, this function does not guarantee that the returned string
 *          doesn't have embedded zeros and provides the caller no way of
 *          finding out!  If you are worried about the response from the HTTPD
 *          containing embedded zero's, use RTHttpGetBinary instead.
 */
RTR3DECL(int) RTHttpGetText(RTHTTP hHttp, const char *pszUrl, char **ppszNotUtf8);

/**
 * Perform a simple blocking HTTP HEAD request.
 *
 * This is a just a convenient wrapper around RTHttpGetBinary that returns a
 * different type and sheds a parameter.
 *
 * @returns iprt status code.
 *
 * @param   hHttp           The HTTP client handle.
 * @param   pszUrl          URL.
 * @param   ppszNotUtf8     Where to return the pointer to the HTTP response.
 *                          The string is of course zero terminated.  Use
 *                          RTHttpFreeReponseText to free.
 *
 * @remarks BIG FAT WARNING!
 *
 *          This function does not guarantee the that returned string is valid UTF-8 or
 *          any other kind of text encoding!
 *
 *          The caller must determine and validate the string encoding _before_
 *          passing it along to functions that expect UTF-8!
 *
 *          Also, this function does not guarantee that the returned string
 *          doesn't have embedded zeros and provides the caller no way of
 *          finding out!  If you are worried about the response from the HTTPD
 *          containing embedded zero's, use RTHttpGetHeaderBinary instead.
 */
RTR3DECL(int) RTHttpGetHeaderText(RTHTTP hHttp, const char *pszUrl, char **ppszNotUtf8);

/**
 * Frees memory returned by RTHttpGetText.
 *
 * @param   pszNotUtf8      What RTHttpGetText returned.
 */
RTR3DECL(void) RTHttpFreeResponseText(char *pszNotUtf8);

/**
 * Perform a simple blocking HTTP GET request.
 *
 * @returns iprt status code.
 *
 * @param   hHttp           The HTTP client handle.
 * @param   pszUrl          The URL.
 * @param   ppvResponse     Where to store the HTTP response data.  Use
 *                          RTHttpFreeResponse to free.
 * @param   pcb             Size of the returned buffer.
 *
 * @note    There is a limit on how much this function allows to be downloaded,
 *          given that the return requires a single heap allocation and all
 *          that.  Currently 32 MB on 32-bit hosts and 64 MB on 64-bit hosts.
 *          Use RTHttpGetFile or RTHttpSetDownloadCallback for larger transfers.
 */
RTR3DECL(int) RTHttpGetBinary(RTHTTP hHttp, const char *pszUrl, void **ppvResponse, size_t *pcb);

/**
 * Perform a simple blocking HTTP HEAD request.
 *
 * @returns iprt status code.
 *
 * @param   hHttp           The HTTP client handle.
 * @param   pszUrl          The URL.
 * @param   ppvResponse     Where to store the HTTP response data.  Use
 *                          RTHttpFreeResponse to free.
 * @param   pcb             Size of the returned buffer.
 */
RTR3DECL(int) RTHttpGetHeaderBinary(RTHTTP hHttp, const char *pszUrl, void **ppvResponse, size_t *pcb);

/**
 * Frees memory returned by RTHttpGetBinary.
 *
 * @param   pvResponse      What RTHttpGetBinary returned.
 */
RTR3DECL(void) RTHttpFreeResponse(void *pvResponse);

/**
 * Perform a simple blocking HTTP request, writing the output to a file.
 *
 * @returns iprt status code.
 *
 * @param   hHttp           The HTTP client handle.
 * @param   pszUrl          The URL.
 * @param   pszDstFile      The destination file name.
 */
RTR3DECL(int) RTHttpGetFile(RTHTTP hHttp, const char *pszUrl, const char *pszDstFile);

/**
 * Performs generic blocking HTTP request, optionally returning the body and headers.
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   pszUrl          The URL.
 * @param   enmMethod       The HTTP method for the request.
 * @param   pvReqBody       Pointer to the request body. NULL if none.
 * @param   cbReqBody       Size of the request body. Zero if none.
 * @param   puHttpStatus    Where to return the HTTP status code. Optional.
 * @param   ppvHeaders      Where to return the headers. Optional.
 * @param   pcbHeaders      Where to return the header size.
 * @param   ppvBody         Where to return the body.  Optional.
 * @param   pcbBody         Where to return the body size.
 */
RTR3DECL(int) RTHttpPerform(RTHTTP hHttp, const char *pszUrl, RTHTTPMETHOD enmMethod, void const *pvReqBody, size_t cbReqBody,
                            uint32_t *puHttpStatus, void **ppvHeaders, size_t *pcbHeaders, void **ppvBody, size_t *pcbBody);


/**
 * Abort a pending HTTP request. A blocking RTHttpGet() call will return with
 * VERR_HTTP_ABORTED. It may take some time (current cURL implementation needs
 * up to 1 second) before the request is aborted.
 *
 * @returns iprt status code.
 *
 * @param   hHttp           The HTTP client handle.
 */
RTR3DECL(int) RTHttpAbort(RTHTTP hHttp);

/**
 * Tells the HTTP interface to use the system proxy configuration.
 *
 * @returns iprt status code.
 * @param   hHttp           The HTTP client handle.
 */
RTR3DECL(int) RTHttpUseSystemProxySettings(RTHTTP hHttp);

/**
 * Sets up the proxy according to the specified URL.
 *
 * @returns IPRT status code.
 * @retval  VWRN_WRONG_TYPE if the type isn't known/supported and we defaulted to 'http'.
 *
 * @param   hHttp           The HTTP client handle.
 * @param   pszUrl          The proxy URL (libproxy style):
 *
 *                          [{type}"://"][{userid}[\@{password}]:]{server}[":"{port}]
 *
 *                          Valid proxy types are: http (default), https, socks4, socks4a,
 *                          socks5, socks5h and direct.  Support for the socks and https
 *                          ones depends on the HTTP library we use.
 *
 *                          The port number defaults to 80 for http, 443 for https and 1080
 *                          for the socks ones.
 *
 *                          If this starts with "direct://", then no proxy will be used.
 *                          An empty or NULL string is equivalent to calling
 *                          RTHttpUseSystemProxySettings().
 */
RTR3DECL(int) RTHttpSetProxyByUrl(RTHTTP hHttp, const char *pszUrl);

/**
 * Specify proxy settings.
 *
 * @returns iprt status code.
 *
 * @param   hHttp           The HTTP client handle.
 * @param   pszProxyUrl     URL of the proxy server.
 * @param   uPort           port number of the proxy, use 0 for not specifying a port.
 * @param   pszProxyUser    Username, pass NULL for no authentication.
 * @param   pszProxyPwd     Password, pass NULL for no authentication.
 *
 * @todo    This API does not allow specifying the type of proxy server... We're
 *          currently assuming it's a HTTP proxy.
 *
 * @deprecated Use RTHttpSetProxyByUrl.
 */
RTR3DECL(int) RTHttpSetProxy(RTHTTP hHttp, const char *pszProxyUrl, uint32_t uPort,
                             const char *pszProxyUser, const char *pszProxyPwd);

/**
 * Set follow redirects (3xx)
 *
 * @returns iprt status code.
 *
 * @param   hHttp           The HTTP client handle.
 * @param   cMaxRedirects   Max number of redirects to follow.  Zero if no
 *                          redirects should be followed but instead returned
 *                          to caller.
 */
RTR3DECL(int) RTHttpSetFollowRedirects(RTHTTP hHttp, uint32_t cMaxRedirects);

/**
 * Gets the follow redirect setting.
 *
 * @returns cMaxRedirects value, 0 means not to follow.
 * @param   hHttp           The HTTP client handle.
 */
RTR3DECL(uint32_t) RTHttpGetFollowRedirects(RTHTTP hHttp);

/**
 * Set custom raw headers.
 *
 * @returns iprt status code.
 *
 * @param   hHttp           The HTTP client handle.
 * @param   cHeaders        Number of custom headers.
 * @param   papszHeaders    Array of headers in form "foo: bar".
 */
RTR3DECL(int) RTHttpSetHeaders(RTHTTP hHttp, size_t cHeaders, const char * const *papszHeaders);

/** @name RTHTTPADDHDR_F_XXX - Flags for RTHttpAddRawHeader and RTHttpAddHeader
 * @{ */
#define RTHTTPADDHDR_F_BACK     UINT32_C(0) /**< Append the header. */
#define RTHTTPADDHDR_F_FRONT    UINT32_C(1) /**< Prepend the header. */
/** @} */

/**
 * Adds a raw header.
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   pszHeader       Header string on the form "foo: bar".
 * @param   fFlags          RTHTTPADDHDR_F_FRONT or RTHTTPADDHDR_F_BACK.
 */
RTR3DECL(int) RTHttpAddRawHeader(RTHTTP hHttp, const char *pszHeader, uint32_t fFlags);

/**
 * Adds a header field and value.
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   pszField        The header field name.
 * @param   pszValue        The header field value.
 * @param   cchValue        The value length or RTSTR_MAX.
 * @param   fFlags          Only RTHTTPADDHDR_F_FRONT or RTHTTPADDHDR_F_BACK,
 *                          may be extended with encoding controlling flags if
 *                          needed later.
 */
RTR3DECL(int) RTHttpAddHeader(RTHTTP hHttp, const char *pszField, const char *pszValue, size_t cchValue, uint32_t fFlags);

/**
 * Gets a header previously added using RTHttpSetHeaders, RTHttpAppendRawHeader
 * or RTHttpAppendHeader.
 *
 * @returns Pointer to the header value on if found, otherwise NULL.
 * @param   hHttp           The HTTP client handle.
 * @param   pszField        The field name (no colon).
 * @param   cchField        The length of the field name or RTSTR_MAX.
 */
RTR3DECL(const char *) RTHttpGetHeader(RTHTTP hHttp, const char *pszField, size_t cchField);

/**
 * Gets the number of headers specified by RTHttpAddHeader, RTHttpAddRawHeader or RTHttpSetHeaders.
 *
 * @returns Number of headers.
 * @param   hHttp           The HTTP client handle.
 * @note    This can be slow and is only really intended for test cases and debugging!
 */
RTR3DECL(size_t)    RTHttpGetHeaderCount(RTHTTP hHttp);

/**
 * Gets a header by ordinal.
 *
 * Can be used together with RTHttpGetHeaderCount by test case and debug code to
 * iterate headers specified by RTHttpAddHeader, RTHttpAddRawHeader or RTHttpSetHeaders.
 *
 * @returns The header string ("field: value").
 * @param   hHttp           The HTTP client handle.
 * @param   iOrdinal        The number of the header to get.
 * @note    This can be slow and is only really intended for test cases and debugging!
 */
RTR3DECL(const char *) RTHttpGetByOrdinal(RTHTTP hHttp, size_t iOrdinal);

/**
 * Sign all headers present according to pending "Signing HTTP Messages" RFC.
 *
 * Currently hardcoded RSA-SHA-256 algorithm choice.
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   enmMethod       The HTTP method that will be used for the request.
 * @param   pszUrl          The target URL for the request.
 * @param   hKey            The RSA key to use when signing.
 * @param   pszKeyId        The key ID string corresponding to @a hKey.
 * @param   fFlags          Reserved for future, MBZ.
 *
 * @note    Caller is responsible for making all desired fields are present before
 *          making the call.
 *
 * @remarks Latest RFC draft at the time of writing:
 *          https://tools.ietf.org/html/draft-cavage-http-signatures-10
 */
RTR3DECL(int) RTHttpSignHeaders(RTHTTP hHttp, RTHTTPMETHOD enmMethod, const char *pszUrl,
                                RTCRKEY hKey, const char *pszKeyId, uint32_t fFlags);

/**
 * Tells the HTTP client instance to gather system CA certificates into a
 * temporary file and use it for HTTPS connections.
 *
 * This will be called automatically if a 'https' URL is presented and
 * RTHttpSetCaFile hasn't been called yet.
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   pErrInfo        Where to store additional error/warning information.
 *                          Optional.
 */
RTR3DECL(int) RTHttpUseTemporaryCaFile(RTHTTP hHttp, PRTERRINFO pErrInfo);

/**
 * Set a custom certification authority file, containing root certificates.
 *
 * @returns iprt status code.
 *
 * @param   hHttp           The HTTP client handle.
 * @param   pszCAFile       File name containing root certificates.
 *
 * @remarks For portable HTTPS support, use RTHttpGatherCaCertsInFile and pass
 */
RTR3DECL(int) RTHttpSetCAFile(RTHTTP hHttp, const char *pszCAFile);

/**
 * Gathers certificates into a cryptographic (certificate) store
 *
 * This is a just a combination of RTHttpGatherCaCertsInStore and
 * RTCrStoreCertExportAsPem.
 *
 * @returns IPRT status code.
 * @param   hStore          The certificate store to gather the certificates
 *                          in.
 * @param   fFlags          RTHTTPGATHERCACERT_F_XXX.
 * @param   pErrInfo        Where to store additional error/warning information.
 *                          Optional.
 */
RTR3DECL(int) RTHttpGatherCaCertsInStore(RTCRSTORE hStore, uint32_t fFlags, PRTERRINFO pErrInfo);

/**
 * Gathers certificates into a file that can be used with RTHttpSetCAFile.
 *
 * This is a just a combination of RTHttpGatherCaCertsInStore and
 * RTCrStoreCertExportAsPem.
 *
 * @returns IPRT status code.
 * @param   pszCaFile       The output file.
 * @param   fFlags          RTHTTPGATHERCACERT_F_XXX.
 * @param   pErrInfo        Where to store additional error/warning information.
 *                          Optional.
 */
RTR3DECL(int) RTHttpGatherCaCertsInFile(const char *pszCaFile, uint32_t fFlags, PRTERRINFO pErrInfo);

/**
 * Set whether to verify the peer's SSL certificate.
 *
 * The default is to verify it.  It can however sometimes be useful or even
 * necessary to skip this.
 *
 * @returns iprt status code.
 *
 * @param   hHttp           The HTTP client handle.
 * @param   fVerify         Verify the certificate if @a true.
 */
RTR3DECL(int) RTHttpSetVerifyPeer(RTHTTP hHttp, bool fVerify);

/**
 * Get the state of the peer's SSL certificate setting.
 *
 * @returns  true if we verify the SSL certificate, false if not.
 * @param   hHttp           The HTTP client handle.
 */
RTR3DECL(bool) RTHttpGetVerifyPeer(RTHTTP hHttp);

/**
 * Callback function to be called during RTHttpGet*().
 *
 * Register it using RTHttpSetDownloadProgressCallback().
 *
 * @param   hHttp           The HTTP client handle.
 * @param   pvUser          The user parameter specified when registering the callback.
 * @param   cbDownloadTotal The content-length value, if available.
 *                          Warning! Not entirely clear what it will be if
 *                                   unavailable, probably 0.
 * @param   cbDownloaded    How much was downloaded thus far.
 */
typedef DECLCALLBACKTYPE(void, FNRTHTTPDOWNLDPROGRCALLBACK,(RTHTTP hHttp, void *pvUser, uint64_t cbDownloadTotal,
                                                            uint64_t cbDownloaded));
/** Pointer to a download progress callback. */
typedef FNRTHTTPDOWNLDPROGRCALLBACK *PFNRTHTTPDOWNLDPROGRCALLBACK;

/**
 * Set the callback function which is called during (GET)
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   pfnCallback     Progress function to be called. Set it to
 *                          NULL to disable the callback.
 * @param   pvUser          Convenience pointer for the callback function.
 */
RTR3DECL(int) RTHttpSetDownloadProgressCallback(RTHTTP hHttp, PFNRTHTTPDOWNLDPROGRCALLBACK pfnCallback, void *pvUser);

/**
 * Callback function for receiving body data.
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   pvBuf           Pointer to buffer with body bytes.
 * @param   cbBuf           Number of bytes in the buffer.
 * @param   uHttpStatus     The HTTP status code.
 * @param   offContent      The byte offset corresponding to the start of @a pvBuf.
 * @param   cbContent       The content length field value, UINT64_MAX if not available.
 * @param   pvUser          The user parameter.
 *
 * @note    The @a offContent parameter does not imply random access or anthing
 *          like that, it is just a convenience provided by the caller.  The
 *          value is the sum of the previous @a cbBuf values.
 */
typedef DECLCALLBACKTYPE(int, FNRTHTTPDOWNLOADCALLBACK,(RTHTTP hHttp, void const *pvBuf, size_t cbBuf, uint32_t uHttpStatus,
                                                        uint64_t offContent, uint64_t cbContent, void *pvUser));
/** Pointer to a download data receiver callback. */
typedef FNRTHTTPDOWNLOADCALLBACK *PFNRTHTTPDOWNLOADCALLBACK;

/**
 * Set the callback function for downloading data (HTTP GET).
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   fFlags          RTHTTPDOWNLOAD_F_XXX.
 * @param   pfnCallback     The callback function.  Pass NULL to reset the callback.
 * @param   pvUser          Convenience pointer for the callback function.
 *
 * @remarks There can only be one download callback, so it is not possible to
 *          call this method for different status codes.  Only the last one
 *          with be honored.
 *
 * @note    This only works reliably with RTHttpPerform at the moment.
 */
RTR3DECL(int) RTHttpSetDownloadCallback(RTHTTP hHttp, uint32_t fFlags, PFNRTHTTPDOWNLOADCALLBACK pfnCallback, void *pvUser);

/** @name RTHTTPDOWNLOAD_F_XXX
 * @{ */
/** The lower 10 bits gives the HTTP status required by the callback.
 * For all other status codes, any body data will be returned via the
 * RTHttpPerform ppvBody/pcbBody return parameters. */
#define RTHTTPDOWNLOAD_F_ONLY_STATUS_MASK       UINT32_C(0x000003ff)
/** Callback requires no special HTTP status. */
#define RTHTTPDOWNLOAD_F_ANY_STATUS             UINT32_C(0x000003ff)
/** @} */


/**
 * Callback function for producing body data for uploading.
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   pvBuf           Where to put the data to upload
 * @param   cbBuf           Max number of bytes to provide.
 * @param   offContent      The byte offset corresponding to the start of @a pvBuf.
 * @param   pcbActual       Actual number of bytes provided.
 * @param   pvUser          The user parameter.
 *
 * @note    The @a offContent parameter does not imply random access or anthing
 *          like that, it is just a convenience provided by the caller.  The
 *          value is the sum of the previously returned @a *pcbActual values.
 */
typedef DECLCALLBACKTYPE(int, FNRTHTTPUPLOADCALLBACK,(RTHTTP hHttp, void *pvBuf, size_t cbBuf, uint64_t offContent,
                                                      size_t *pcbActual, void *pvUser));
/** Pointer to an upload data producer callback. */
typedef FNRTHTTPUPLOADCALLBACK *PFNRTHTTPUPLOADCALLBACK;

/**
 * Set the callback function for providing upload data (HTTP PUT / POST).
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   cbContent       The content length, UINT64_MAX if not know or specified separately.
 * @param   pfnCallback     The callback function.  Pass NULL to reset the callback.
 * @param   pvUser          Convenience pointer for the callback function.
 *
 * @note    This only works reliably with RTHttpPerform at the moment.
 */
RTR3DECL(int) RTHttpSetUploadCallback(RTHTTP hHttp, uint64_t cbContent, PFNRTHTTPUPLOADCALLBACK pfnCallback, void *pvUser);


/**
 * Callback for consuming header fields.
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   uMatchWord      Match word constructed by RTHTTP_MAKE_HDR_MATCH_WORD
 * @param   pchField        The field name (not zero terminated).
 *                          Not necessarily valid UTF-8!
 * @param   cchField        The length of the field.
 * @param   pchValue        The field value (not zero terminated).
 *                          Not necessarily valid UTF-8!
 * @param   cchValue        The length of the value.
 * @param   pvUser          The user parameter.
 *
 * @remarks This is called with two fictitious header fields too:
 *              - ':http-status-line' -- the HTTP/{version} {status-code} stuff.
 *              - ':end-of-headers'   -- marks the end of header callbacks.
 */
typedef DECLCALLBACKTYPE(int, FNRTHTTPHEADERCALLBACK,(RTHTTP hHttp, uint32_t uMatchWord, const char *pchField, size_t cchField,
                                                      const char *pchValue, size_t cchValue, void *pvUser));
/** Pointer to a header field consumer callback. */
typedef FNRTHTTPHEADERCALLBACK *PFNRTHTTPHEADERCALLBACK;

/**
 * Forms a fast header match word.
 *
 * @returns Fast header match word.
 * @param   a_cchField      The length of the header field name.
 * @param   a_chLower1      The first character in the name, lowercased.
 * @param   a_chLower2      The second character in the name, lowercased.
 * @param   a_chLower3      The third character in the name, lowercased.
 */
#define RTHTTP_MAKE_HDR_MATCH_WORD(a_cchField, a_chLower1, a_chLower2, a_chLower3)   \
    RT_MAKE_U32_FROM_U8(a_cchField, a_chLower1, a_chLower2, a_chLower3)

/**
 * Set the callback function for processing header fields in the response.
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   pfnCallback     The callback function.  Pass NULL to reset the callback.
 * @param   pvUser          Convenience pointer for the callback function.
 *
 * @note    This only works reliably with RTHttpPerform at the moment.
 */
RTR3DECL(int) RTHttpSetHeaderCallback(RTHTTP hHttp, PFNRTHTTPHEADERCALLBACK pfnCallback, void *pvUser);


/**
 * Supported proxy types.
 */
typedef enum RTHTTPPROXYTYPE
{
    RTHTTPPROXYTYPE_INVALID = 0,
    RTHTTPPROXYTYPE_NOPROXY,
    RTHTTPPROXYTYPE_HTTP,
    RTHTTPPROXYTYPE_HTTPS,
    RTHTTPPROXYTYPE_SOCKS4,
    RTHTTPPROXYTYPE_SOCKS5,
    RTHTTPPROXYTYPE_UNKNOWN,
    RTHTTPPROXYTYPE_END,
    RTHTTPPROXYTYPE_32BIT_HACK = 0x7fffffff
} RTHTTPPROXYTYPE;

/**
 * Proxy information returned by RTHttpQueryProxyInfoForUrl.
 */
typedef struct RTHTTPPROXYINFO
{
    /** Proxy host name. */
    char               *pszProxyHost;
    /** Proxy port number (UINT32_MAX if not specified). */
    uint32_t            uProxyPort;
    /** The proxy type (RTHTTPPROXYTYPE_HTTP, RTHTTPPROXYTYPE_SOCKS5, ++). */
    RTHTTPPROXYTYPE     enmProxyType;
    /** Proxy username. */
    char               *pszProxyUsername;
    /** Proxy password. */
    char               *pszProxyPassword;
} RTHTTPPROXYINFO;
/** A pointer to proxy information structure. */
typedef RTHTTPPROXYINFO *PRTHTTPPROXYINFO;

/**
 * Retrieve system proxy information for the specified URL.
 *
 * @returns IPRT status code.
 * @param   hHttp           The HTTP client handle.
 * @param   pszUrl          The URL that needs to be accessed via proxy.
 * @param   pProxyInfo      Where to return the proxy information.  This must be
 *                          freed up by calling RTHttpFreeProxyInfo() when done.
 */
RTR3DECL(int) RTHttpQueryProxyInfoForUrl(RTHTTP hHttp, const char *pszUrl, PRTHTTPPROXYINFO pProxyInfo);

/**
 * Counter part to RTHttpQueryProxyInfoForUrl that releases any memory returned
 * in the proxy info structure.
 *
 * @returns IPRT status code.
 * @param   pProxyInfo      Pointer to proxy info returned by a successful
 *                          RTHttpQueryProxyInfoForUrl() call.
 */
RTR3DECL(int) RTHttpFreeProxyInfo(PRTHTTPPROXYINFO pProxyInfo);

/** @name thin wrappers for setting one or a few related curl options
 * @remarks Temporary. Will not be included in the 7.0 release!
 * @{ */
typedef DECLCALLBACKTYPE_EX(size_t, RT_NOTHING, FNRTHTTPREADCALLBACKRAW,(void *pbDst, size_t cbItem, size_t cItems, void *pvUser));
typedef FNRTHTTPREADCALLBACKRAW *PFNRTHTTPREADCALLBACKRAW;
#define RT_HTTP_READCALLBACK_ABORT 0x10000000 /* CURL_READFUNC_ABORT */
RTR3DECL(int) RTHttpRawSetReadCallback(RTHTTP hHttp, PFNRTHTTPREADCALLBACKRAW pfnRead, void *pvUser);

typedef DECLCALLBACKTYPE_EX(size_t, RT_NOTHING, FNRTHTTPWRITECALLBACKRAW,(char *pbSrc, size_t cbItem, size_t cItems, void *pvUser));
typedef FNRTHTTPWRITECALLBACKRAW *PFNRTHTTPWRITECALLBACKRAW;
RTR3DECL(int) RTHttpRawSetWriteCallback(RTHTTP hHttp, PFNRTHTTPWRITECALLBACKRAW pfnWrite, void *pvUser);
RTR3DECL(int) RTHttpRawSetWriteHeaderCallback(RTHTTP hHttp, PFNRTHTTPWRITECALLBACKRAW pfnWrite, void *pvUser);

RTR3DECL(int) RTHttpRawSetUrl(RTHTTP hHttp, const char *pszUrl);

RTR3DECL(int) RTHttpRawSetGet(RTHTTP hHttp);
RTR3DECL(int) RTHttpRawSetHead(RTHTTP hHttp);
RTR3DECL(int) RTHttpRawSetPost(RTHTTP hHttp);
RTR3DECL(int) RTHttpRawSetPut(RTHTTP hHttp);
RTR3DECL(int) RTHttpRawSetDelete(RTHTTP hHttp);
RTR3DECL(int) RTHttpRawSetCustomRequest(RTHTTP hHttp, const char *pszVerb);

RTR3DECL(int) RTHttpRawSetPostFields(RTHTTP hHttp, const void *pv, size_t cb);
RTR3DECL(int) RTHttpRawSetInfileSize(RTHTTP hHttp, RTFOFF cb);

RTR3DECL(int) RTHttpRawSetVerbose(RTHTTP hHttp, bool fValue);
RTR3DECL(int) RTHttpRawSetTimeout(RTHTTP hHttp, long sec);

RTR3DECL(int) RTHttpRawPerform(RTHTTP hHttp);

RTR3DECL(int) RTHttpRawGetResponseCode(RTHTTP hHttp, long *plCode);
/** @} */

/** @} */

RT_C_DECLS_END

#endif /* !IPRT_INCLUDED_http_h */