1.\"- 2.\" Copyright (c) 1998-2013 Dag-Erling Smørgrav 3.\" Copyright (c) 2013 Michael Gmelin <freebsd@grem.de> 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.\" $FreeBSD: head/lib/libfetch/fetch.3 253805 2013-07-30 13:07:55Z des $ 28.\" 29.Dd July 30, 2013 30.Dt FETCH 3 31.Os 32.Sh NAME 33.Nm fetchMakeURL , 34.Nm fetchParseURL , 35.Nm fetchFreeURL , 36.Nm fetchXGetURL , 37.Nm fetchGetURL , 38.Nm fetchPutURL , 39.Nm fetchStatURL , 40.Nm fetchListURL , 41.Nm fetchXGet , 42.Nm fetchGet , 43.Nm fetchPut , 44.Nm fetchStat , 45.Nm fetchList , 46.Nm fetchXGetFile , 47.Nm fetchGetFile , 48.Nm fetchPutFile , 49.Nm fetchStatFile , 50.Nm fetchListFile , 51.Nm fetchXGetHTTP , 52.Nm fetchGetHTTP , 53.Nm fetchPutHTTP , 54.Nm fetchStatHTTP , 55.Nm fetchListHTTP , 56.Nm fetchXGetFTP , 57.Nm fetchGetFTP , 58.Nm fetchPutFTP , 59.Nm fetchStatFTP , 60.Nm fetchListFTP 61.Nd file transfer functions 62.Sh LIBRARY 63.Lb libfetch 64.Sh SYNOPSIS 65.In sys/param.h 66.In stdio.h 67.In fetch.h 68.Ft struct url * 69.Fn fetchMakeURL "const char *scheme" "const char *host" "int port" "const char *doc" "const char *user" "const char *pwd" 70.Ft struct url * 71.Fn fetchParseURL "const char *URL" 72.Ft void 73.Fn fetchFreeURL "struct url *u" 74.Ft FILE * 75.Fn fetchXGetURL "const char *URL" "struct url_stat *us" "const char *flags" 76.Ft FILE * 77.Fn fetchGetURL "const char *URL" "const char *flags" 78.Ft FILE * 79.Fn fetchPutURL "const char *URL" "const char *flags" 80.Ft int 81.Fn fetchStatURL "const char *URL" "struct url_stat *us" "const char *flags" 82.Ft struct url_ent * 83.Fn fetchListURL "const char *URL" "const char *flags" 84.Ft FILE * 85.Fn fetchXGet "struct url *u" "struct url_stat *us" "const char *flags" 86.Ft FILE * 87.Fn fetchGet "struct url *u" "const char *flags" 88.Ft FILE * 89.Fn fetchPut "struct url *u" "const char *flags" 90.Ft int 91.Fn fetchStat "struct url *u" "struct url_stat *us" "const char *flags" 92.Ft struct url_ent * 93.Fn fetchList "struct url *u" "const char *flags" 94.Ft FILE * 95.Fn fetchXGetFile "struct url *u" "struct url_stat *us" "const char *flags" 96.Ft FILE * 97.Fn fetchGetFile "struct url *u" "const char *flags" 98.Ft FILE * 99.Fn fetchPutFile "struct url *u" "const char *flags" 100.Ft int 101.Fn fetchStatFile "struct url *u" "struct url_stat *us" "const char *flags" 102.Ft struct url_ent * 103.Fn fetchListFile "struct url *u" "const char *flags" 104.Ft FILE * 105.Fn fetchXGetHTTP "struct url *u" "struct url_stat *us" "const char *flags" 106.Ft FILE * 107.Fn fetchGetHTTP "struct url *u" "const char *flags" 108.Ft FILE * 109.Fn fetchPutHTTP "struct url *u" "const char *flags" 110.Ft int 111.Fn fetchStatHTTP "struct url *u" "struct url_stat *us" "const char *flags" 112.Ft struct url_ent * 113.Fn fetchListHTTP "struct url *u" "const char *flags" 114.Ft FILE * 115.Fn fetchXGetFTP "struct url *u" "struct url_stat *us" "const char *flags" 116.Ft FILE * 117.Fn fetchGetFTP "struct url *u" "const char *flags" 118.Ft FILE * 119.Fn fetchPutFTP "struct url *u" "const char *flags" 120.Ft int 121.Fn fetchStatFTP "struct url *u" "struct url_stat *us" "const char *flags" 122.Ft struct url_ent * 123.Fn fetchListFTP "struct url *u" "const char *flags" 124.Sh DESCRIPTION 125These functions implement a high-level library for retrieving and 126uploading files using Uniform Resource Locators (URLs). 127.Pp 128.Fn fetchParseURL 129takes a URL in the form of a null-terminated string and splits it into 130its components function according to the Common Internet Scheme Syntax 131detailed in RFC1738. 132A regular expression which produces this syntax is: 133.Bd -literal 134 <scheme>:(//(<user>(:<pwd>)?@)?<host>(:<port>)?)?/(<document>)? 135.Ed 136.Pp 137If the URL does not seem to begin with a scheme name, the following 138syntax is assumed: 139.Bd -literal 140 ((<user>(:<pwd>)?@)?<host>(:<port>)?)?/(<document>)? 141.Ed 142.Pp 143Note that some components of the URL are not necessarily relevant to 144all URL schemes. 145For instance, the file scheme only needs the <scheme> and <document> 146components. 147.Pp 148.Fn fetchMakeURL 149and 150.Fn fetchParseURL 151return a pointer to a 152.Vt url 153structure, which is defined as follows in 154.In fetch.h : 155.Bd -literal 156#define URL_SCHEMELEN 16 157#define URL_USERLEN 256 158#define URL_PWDLEN 256 159 160struct url { 161 char scheme[URL_SCHEMELEN+1]; 162 char user[URL_USERLEN+1]; 163 char pwd[URL_PWDLEN+1]; 164 char host[MAXHOSTNAMELEN+1]; 165 int port; 166 char *doc; 167 off_t offset; 168 size_t length; 169 time_t ims_time; 170}; 171.Ed 172.Pp 173The 174.Va ims_time 175field stores the time value for 176.Li If-Modified-Since 177HTTP requests. 178.Pp 179The pointer returned by 180.Fn fetchMakeURL 181or 182.Fn fetchParseURL 183should be freed using 184.Fn fetchFreeURL . 185.Pp 186.Fn fetchXGetURL , 187.Fn fetchGetURL , 188and 189.Fn fetchPutURL 190constitute the recommended interface to the 191.Nm fetch 192library. 193They examine the URL passed to them to determine the transfer 194method, and call the appropriate lower-level functions to perform the 195actual transfer. 196.Fn fetchXGetURL 197also returns the remote document's metadata in the 198.Vt url_stat 199structure pointed to by the 200.Fa us 201argument. 202.Pp 203The 204.Fa flags 205argument is a string of characters which specify transfer options. 206The 207meaning of the individual flags is scheme-dependent, and is detailed 208in the appropriate section below. 209.Pp 210.Fn fetchStatURL 211attempts to obtain the requested document's metadata and fill in the 212structure pointed to by its second argument. 213The 214.Vt url_stat 215structure is defined as follows in 216.In fetch.h : 217.Bd -literal 218struct url_stat { 219 off_t size; 220 time_t atime; 221 time_t mtime; 222}; 223.Ed 224.Pp 225If the size could not be obtained from the server, the 226.Fa size 227field is set to -1. 228If the modification time could not be obtained from the server, the 229.Fa mtime 230field is set to the epoch. 231If the access time could not be obtained from the server, the 232.Fa atime 233field is set to the modification time. 234.Pp 235.Fn fetchListURL 236attempts to list the contents of the directory pointed to by the URL 237provided. 238If successful, it returns a malloced array of 239.Vt url_ent 240structures. 241The 242.Vt url_ent 243structure is defined as follows in 244.In fetch.h : 245.Bd -literal 246struct url_ent { 247 char name[PATH_MAX]; 248 struct url_stat stat; 249}; 250.Ed 251.Pp 252The list is terminated by an entry with an empty name. 253.Pp 254The pointer returned by 255.Fn fetchListURL 256should be freed using 257.Fn free . 258.Pp 259.Fn fetchXGet , 260.Fn fetchGet , 261.Fn fetchPut 262and 263.Fn fetchStat 264are similar to 265.Fn fetchXGetURL , 266.Fn fetchGetURL , 267.Fn fetchPutURL 268and 269.Fn fetchStatURL , 270except that they expect a pre-parsed URL in the form of a pointer to 271a 272.Vt struct url 273rather than a string. 274.Pp 275All of the 276.Fn fetchXGetXXX , 277.Fn fetchGetXXX 278and 279.Fn fetchPutXXX 280functions return a pointer to a stream which can be used to read or 281write data from or to the requested document, respectively. 282Note that 283although the implementation details of the individual access methods 284vary, it can generally be assumed that a stream returned by one of the 285.Fn fetchXGetXXX 286or 287.Fn fetchGetXXX 288functions is read-only, and that a stream returned by one of the 289.Fn fetchPutXXX 290functions is write-only. 291.Sh FILE SCHEME 292.Fn fetchXGetFile , 293.Fn fetchGetFile 294and 295.Fn fetchPutFile 296provide access to documents which are files in a locally mounted file 297system. 298Only the <document> component of the URL is used. 299.Pp 300.Fn fetchXGetFile 301and 302.Fn fetchGetFile 303do not accept any flags. 304.Pp 305.Fn fetchPutFile 306accepts the 307.Ql a 308(append to file) flag. 309If that flag is specified, the data written to 310the stream returned by 311.Fn fetchPutFile 312will be appended to the previous contents of the file, instead of 313replacing them. 314.Sh FTP SCHEME 315.Fn fetchXGetFTP , 316.Fn fetchGetFTP 317and 318.Fn fetchPutFTP 319implement the FTP protocol as described in RFC959. 320.Pp 321If the 322.Ql P 323(not passive) flag is specified, an active (rather than passive) 324connection will be attempted. 325.Pp 326The 327.Ql p 328flag is supported for compatibility with earlier versions where active 329connections were the default. 330It has precedence over the 331.Ql P 332flag, so if both are specified, 333.Nm 334will use a passive connection. 335.Pp 336If the 337.Ql l 338(low) flag is specified, data sockets will be allocated in the low (or 339default) port range instead of the high port range (see 340.Xr ip 4 ) . 341.Pp 342If the 343.Ql d 344(direct) flag is specified, 345.Fn fetchXGetFTP , 346.Fn fetchGetFTP 347and 348.Fn fetchPutFTP 349will use a direct connection even if a proxy server is defined. 350.Pp 351If no user name or password is given, the 352.Nm fetch 353library will attempt an anonymous login, with user name "anonymous" 354and password "anonymous@<hostname>". 355.Sh HTTP SCHEME 356The 357.Fn fetchXGetHTTP , 358.Fn fetchGetHTTP 359and 360.Fn fetchPutHTTP 361functions implement the HTTP/1.1 protocol. 362With a little luck, there is 363even a chance that they comply with RFC2616 and RFC2617. 364.Pp 365If the 366.Ql d 367(direct) flag is specified, 368.Fn fetchXGetHTTP , 369.Fn fetchGetHTTP 370and 371.Fn fetchPutHTTP 372will use a direct connection even if a proxy server is defined. 373.Pp 374If the 375.Ql i 376(if-modified-since) flag is specified, and 377the 378.Va ims_time 379field is set in 380.Vt "struct url" , 381then 382.Fn fetchXGetHTTP 383and 384.Fn fetchGetHTTP 385will send a conditional 386.Li If-Modified-Since 387HTTP header to only fetch the content if it is newer than 388.Va ims_time . 389.Pp 390Since there seems to be no good way of implementing the HTTP PUT 391method in a manner consistent with the rest of the 392.Nm fetch 393library, 394.Fn fetchPutHTTP 395is currently unimplemented. 396.Sh HTTPS SCHEME 397Based on HTTP SCHEME. 398By default the peer is verified using the CA bundle located in 399.Pa /etc/ssl/cert.pem . 400The file may contain multiple CA certificates. 401A common source of a current CA bundle is 402.Pa \%security/ca_root_nss . 403.Pp 404The CA bundle used for peer verification can be changed by setting the 405environment variables 406.Ev SSL_CA_CERT_FILE 407to point to a concatenated bundle of trusted certificates and 408.Ev SSL_CA_CERT_PATH 409to point to a directory containing hashes of trusted CAs (see 410.Xr verify 1 ) . 411.Pp 412A certificate revocation list (CRL) can be used by setting the 413environment variable 414.Ev SSL_CRL_FILE 415(see 416.Xr crl 1 ) . 417.Pp 418Peer verification can be disabled by setting the environment variable 419.Ev SSL_NO_VERIFY_PEER . 420Note that this also disables CRL checking. 421.Pp 422By default the service identity is verified according to the rules 423detailed in RFC6125 (also known as hostname verification). 424This feature can be disabled by setting the environment variable 425.Ev SSL_NO_VERIFY_HOSTNAME . 426.Pp 427Client certificate based authentication is supported. 428The environment variable 429.Ev SSL_CLIENT_CERT_FILE 430should be set to point to a file containing key and client certificate 431to be used in PEM format. In case the key is stored in a separate 432file, the environment variable 433.Ev SSL_CLIENT_KEY_FILE 434can be set to point to the key in PEM format. 435In case the key uses a password, the user will be prompted on standard 436input (see 437.Xr PEM 3 ) . 438.Pp 439By default 440.Nm libfetch 441allows SSLv3 and TLSv1 when negotiating the connecting with the remote 442peer. 443You can change this behavior by setting the environment variable 444.Ev SSL_ALLOW_SSL2 445to allow SSLv2 (not recommended) and 446.Ev SSL_NO_SSL3 447or 448.Ev SSL_NO_TLS1 449to disable the respective methods. 450.Sh AUTHENTICATION 451Apart from setting the appropriate environment variables and 452specifying the user name and password in the URL or the 453.Vt struct url , 454the calling program has the option of defining an authentication 455function with the following prototype: 456.Pp 457.Ft int 458.Fn myAuthMethod "struct url *u" 459.Pp 460The callback function should fill in the 461.Fa user 462and 463.Fa pwd 464fields in the provided 465.Vt struct url 466and return 0 on success, or any other value to indicate failure. 467.Pp 468To register the authentication callback, simply set 469.Va fetchAuthMethod 470to point at it. 471The callback will be used whenever a site requires authentication and 472the appropriate environment variables are not set. 473.Pp 474This interface is experimental and may be subject to change. 475.Sh RETURN VALUES 476.Fn fetchParseURL 477returns a pointer to a 478.Vt struct url 479containing the individual components of the URL. 480If it is 481unable to allocate memory, or the URL is syntactically incorrect, 482.Fn fetchParseURL 483returns a NULL pointer. 484.Pp 485The 486.Fn fetchStat 487functions return 0 on success and -1 on failure. 488.Pp 489All other functions return a stream pointer which may be used to 490access the requested document, or NULL if an error occurred. 491.Pp 492The following error codes are defined in 493.In fetch.h : 494.Bl -tag -width 18n 495.It Bq Er FETCH_ABORT 496Operation aborted 497.It Bq Er FETCH_AUTH 498Authentication failed 499.It Bq Er FETCH_DOWN 500Service unavailable 501.It Bq Er FETCH_EXISTS 502File exists 503.It Bq Er FETCH_FULL 504File system full 505.It Bq Er FETCH_INFO 506Informational response 507.It Bq Er FETCH_MEMORY 508Insufficient memory 509.It Bq Er FETCH_MOVED 510File has moved 511.It Bq Er FETCH_NETWORK 512Network error 513.It Bq Er FETCH_OK 514No error 515.It Bq Er FETCH_PROTO 516Protocol error 517.It Bq Er FETCH_RESOLV 518Resolver error 519.It Bq Er FETCH_SERVER 520Server error 521.It Bq Er FETCH_TEMP 522Temporary error 523.It Bq Er FETCH_TIMEOUT 524Operation timed out 525.It Bq Er FETCH_UNAVAIL 526File is not available 527.It Bq Er FETCH_UNKNOWN 528Unknown error 529.It Bq Er FETCH_URL 530Invalid URL 531.El 532.Pp 533The accompanying error message includes a protocol-specific error code 534and message, e.g.\& "File is not available (404 Not Found)" 535.Sh ENVIRONMENT 536.Bl -tag -width ".Ev FETCH_BIND_ADDRESS" 537.It Ev FETCH_BIND_ADDRESS 538Specifies a hostname or IP address to which sockets used for outgoing 539connections will be bound. 540.It Ev FTP_LOGIN 541Default FTP login if none was provided in the URL. 542.It Ev FTP_PASSIVE_MODE 543If set to 544.Ql no , 545forces the FTP code to use active mode. 546If set to any other value, forces passive mode even if the application 547requested active mode. 548.It Ev FTP_PASSWORD 549Default FTP password if the remote server requests one and none was 550provided in the URL. 551.It Ev FTP_PROXY 552URL of the proxy to use for FTP requests. 553The document part is ignored. 554FTP and HTTP proxies are supported; if no scheme is specified, FTP is 555assumed. 556If the proxy is an FTP proxy, 557.Nm libfetch 558will send 559.Ql user@host 560as user name to the proxy, where 561.Ql user 562is the real user name, and 563.Ql host 564is the name of the FTP server. 565.Pp 566If this variable is set to an empty string, no proxy will be used for 567FTP requests, even if the 568.Ev HTTP_PROXY 569variable is set. 570.It Ev ftp_proxy 571Same as 572.Ev FTP_PROXY , 573for compatibility. 574.It Ev HTTP_ACCEPT 575Specifies the value of the 576.Va Accept 577header for HTTP requests. 578If empty, no 579.Va Accept 580header is sent. 581The default is 582.Dq */* . 583.It Ev HTTP_AUTH 584Specifies HTTP authorization parameters as a colon-separated list of 585items. 586The first and second item are the authorization scheme and realm 587respectively; further items are scheme-dependent. 588Currently, the 589.Dq basic 590and 591.Dq digest 592authorization methods are supported. 593.Pp 594Both methods require two parameters: the user name and 595password, in that order. 596.Pp 597This variable is only used if the server requires authorization and 598no user name or password was specified in the URL. 599.It Ev HTTP_PROXY 600URL of the proxy to use for HTTP requests. 601The document part is ignored. 602Only HTTP proxies are supported for HTTP requests. 603If no port number is specified, the default is 3128. 604.Pp 605Note that this proxy will also be used for FTP documents, unless the 606.Ev FTP_PROXY 607variable is set. 608.It Ev http_proxy 609Same as 610.Ev HTTP_PROXY , 611for compatibility. 612.It Ev HTTP_PROXY_AUTH 613Specifies authorization parameters for the HTTP proxy in the same 614format as the 615.Ev HTTP_AUTH 616variable. 617.Pp 618This variable is used if and only if connected to an HTTP proxy, and 619is ignored if a user and/or a password were specified in the proxy 620URL. 621.It Ev HTTP_REFERER 622Specifies the referrer URL to use for HTTP requests. 623If set to 624.Dq auto , 625the document URL will be used as referrer URL. 626.It Ev HTTP_USER_AGENT 627Specifies the User-Agent string to use for HTTP requests. 628This can be useful when working with HTTP origin or proxy servers that 629differentiate between user agents. 630.It Ev NETRC 631Specifies a file to use instead of 632.Pa ~/.netrc 633to look up login names and passwords for FTP sites. 634See 635.Xr ftp 1 636for a description of the file format. 637This feature is experimental. 638.It Ev NO_PROXY 639Either a single asterisk, which disables the use of proxies 640altogether, or a comma- or whitespace-separated list of hosts for 641which proxies should not be used. 642.It Ev no_proxy 643Same as 644.Ev NO_PROXY , 645for compatibility. 646.It Ev SSL_ALLOW_SSL2 647Allow SSL version 2 when negotiating the connection (not recommended). 648.It Ev SSL_CA_CERT_FILE 649CA certificate bundle containing trusted CA certificates. 650Default value: 651.Pa /etc/ssl/cert.pem . 652.It Ev SSL_CA_CERT_PATH 653Path containing trusted CA hashes. 654.It Ev SSL_CLIENT_CERT_FILE 655PEM encoded client certificate/key which will be used in 656client certificate authentication. 657.It Ev SSL_CLIENT_KEY_FILE 658PEM encoded client key in case key and client certificate 659are stored separately. 660.It Ev SSL_CRL_FILE 661File containing certificate revocation list. 662.It Ev SSL_NO_SSL3 663Don't allow SSL version 3 when negotiating the connection. 664.It Ev SSL_NO_TLS1 665Don't allow TLV version 1 when negotiating the connection. 666.It Ev SSL_NO_VERIFY_HOSTNAME 667If set, do not verify that the hostname matches the subject of the 668certificate presented by the server. 669.It Ev SSL_NO_VERIFY_PEER 670If set, do not verify the peer certificate against trusted CAs. 671.El 672.Sh EXAMPLES 673To access a proxy server on 674.Pa proxy.example.com 675port 8080, set the 676.Ev HTTP_PROXY 677environment variable in a manner similar to this: 678.Pp 679.Dl HTTP_PROXY=http://proxy.example.com:8080 680.Pp 681If the proxy server requires authentication, there are 682two options available for passing the authentication data. 683The first method is by using the proxy URL: 684.Pp 685.Dl HTTP_PROXY=http://<user>:<pwd>@proxy.example.com:8080 686.Pp 687The second method is by using the 688.Ev HTTP_PROXY_AUTH 689environment variable: 690.Bd -literal -offset indent 691HTTP_PROXY=http://proxy.example.com:8080 692HTTP_PROXY_AUTH=basic:*:<user>:<pwd> 693.Ed 694.Pp 695To disable the use of a proxy for an HTTP server running on the local 696host, define 697.Ev NO_PROXY 698as follows: 699.Bd -literal -offset indent 700NO_PROXY=localhost,127.0.0.1 701.Ed 702.Pp 703Access HTTPS website without any certificate verification whatsoever: 704.Bd -literal -offset indent 705SSL_NO_VERIFY_PEER=1 706SSL_NO_VERIFY_HOSTNAME=1 707.Ed 708.Pp 709Access HTTPS website using client certificate based authentication 710and a private CA: 711.Bd -literal -offset indent 712SSL_CLIENT_CERT_FILE=/path/to/client.pem 713SSL_CA_CERT_FILE=/path/to/myca.pem 714.Ed 715.Sh SEE ALSO 716.Xr fetch 1 , 717.Xr ftpio 3 , 718.Xr ip 4 719.Rs 720.%A J. Postel 721.%A J. K. Reynolds 722.%D October 1985 723.%B File Transfer Protocol 724.%O RFC959 725.Re 726.Rs 727.%A P. Deutsch 728.%A A. Emtage 729.%A A. Marine. 730.%D May 1994 731.%T How to Use Anonymous FTP 732.%O RFC1635 733.Re 734.Rs 735.%A T. Berners-Lee 736.%A L. Masinter 737.%A M. McCahill 738.%D December 1994 739.%T Uniform Resource Locators (URL) 740.%O RFC1738 741.Re 742.Rs 743.%A R. Fielding 744.%A J. Gettys 745.%A J. Mogul 746.%A H. Frystyk 747.%A L. Masinter 748.%A P. Leach 749.%A T. Berners-Lee 750.%D January 1999 751.%B Hypertext Transfer Protocol -- HTTP/1.1 752.%O RFC2616 753.Re 754.Rs 755.%A J. Franks 756.%A P. Hallam-Baker 757.%A J. Hostetler 758.%A S. Lawrence 759.%A P. Leach 760.%A A. Luotonen 761.%A L. Stewart 762.%D June 1999 763.%B HTTP Authentication: Basic and Digest Access Authentication 764.%O RFC2617 765.Re 766.Sh HISTORY 767The 768.Nm fetch 769library first appeared in 770.Fx 3.0 . 771.Sh AUTHORS 772.An -nosplit 773The 774.Nm fetch 775library was mostly written by 776.An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org 777with numerous suggestions and contributions from 778.An Jordan K. Hubbard Aq Mt jkh@FreeBSD.org , 779.An Eugene Skepner Aq Mt eu@qub.com , 780.An Hajimu Umemoto Aq Mt ume@FreeBSD.org , 781.An Henry Whincup Aq Mt henry@techiebod.com , 782.An Jukka A. Ukkonen Aq Mt jau@iki.fi , 783.An Jean-Fran\(,cois Dockes Aq Mt jf@dockes.org , 784.An Michael Gmelin Aq Mt freebsd@grem.de 785and others. 786It replaces the older 787.Nm ftpio 788library written by 789.An Poul-Henning Kamp Aq Mt phk@FreeBSD.org 790and 791.An Jordan K. Hubbard Aq Mt jkh@FreeBSD.org . 792.Pp 793This manual page was written by 794.An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org 795and 796.An Michael Gmelin Aq Mt freebsd@grem.de . 797.Sh BUGS 798Some parts of the library are not yet implemented. 799The most notable 800examples of this are 801.Fn fetchPutHTTP , 802.Fn fetchListHTTP , 803.Fn fetchListFTP 804and FTP proxy support. 805.Pp 806There is no way to select a proxy at run-time other than setting the 807.Ev HTTP_PROXY 808or 809.Ev FTP_PROXY 810environment variables as appropriate. 811.Pp 812.Nm libfetch 813does not understand or obey 305 (Use Proxy) replies. 814.Pp 815Error numbers are unique only within a certain context; the error 816codes used for FTP and HTTP overlap, as do those used for resolver and 817system errors. 818For instance, error code 202 means "Command not 819implemented, superfluous at this site" in an FTP context and 820"Accepted" in an HTTP context. 821.Pp 822.Fn fetchStatFTP 823does not check that the result of an MDTM command is a valid date. 824.Pp 825In case password protected keys are used for client certificate based 826authentication the user is prompted for the password on each and every 827fetch operation. 828.Pp 829The man page is incomplete, poorly written and produces badly 830formatted text. 831.Pp 832The error reporting mechanism is unsatisfactory. 833.Pp 834Some parts of the code are not fully reentrant. 835