1 _ _ ____ _ 2 ___| | | | _ \| | 3 / __| | | | |_) | | 4 | (__| |_| | _ <| |___ 5 \___|\___/|_| \_\_____| 6 7 Known Bugs 8 9These are problems and bugs known to exist at the time of this release. Feel 10free to join in and help us correct one or more of these. Also be sure to 11check the changelog of the current development status, as one or more of these 12problems may have been fixed or changed somewhat since this was written. 13 14 1. HTTP 15 1.2 hyper is slow 16 1.5 Expect-100 meets 417 17 18 2. TLS 19 2.1 IMAPS connection fails with rustls error 20 2.3 Unable to use PKCS12 certificate with Secure Transport 21 2.4 Secure Transport will not import PKCS#12 client certificates without a password 22 2.5 Client cert handling with Issuer DN differs between backends 23 2.7 Client cert (MTLS) issues with Schannel 24 2.11 Schannel TLS 1.2 handshake bug in old Windows versions 25 2.13 CURLOPT_CERTINFO results in CURLE_OUT_OF_MEMORY with Schannel 26 27 3. Email protocols 28 3.1 IMAP SEARCH ALL truncated response 29 3.2 No disconnect command 30 3.3 POP3 expects "CRLF.CRLF" eob for some single-line responses 31 3.4 AUTH PLAIN for SMTP is not working on all servers 32 3.5 APOP authentication fails on POP3 33 3.6 POP3 issue when reading small chunks 34 35 4. Command line 36 37 5. Build and portability issues 38 5.1 OS400 port requires deprecated IBM library 39 5.2 curl-config --libs contains private details 40 5.3 building for old macOS fails with gcc 41 5.5 cannot handle Unicode arguments in non-Unicode builds on Windows 42 5.6 cygwin: make install installs curl-config.1 twice 43 5.9 Utilize Requires.private directives in libcurl.pc 44 5.11 configure --with-gssapi with Heimdal is ignored on macOS 45 5.12 flaky CI builds 46 5.13 long paths are not fully supported on Windows 47 5.14 Windows Unicode builds use homedir in current locale 48 5.15 Unicode on Windows 49 50 6. Authentication 51 6.1 NTLM authentication and unicode 52 6.2 MIT Kerberos for Windows build 53 6.3 NTLM in system context uses wrong name 54 6.5 NTLM does not support password with § character 55 6.6 libcurl can fail to try alternatives with --proxy-any 56 6.7 Do not clear digest for single realm 57 6.9 SHA-256 digest not supported in Windows SSPI builds 58 6.10 curl never completes Negotiate over HTTP 59 6.11 Negotiate on Windows fails 60 6.12 cannot use Secure Transport with Crypto Token Kit 61 6.13 Negotiate against Hadoop HDFS 62 63 7. FTP 64 7.1 FTP upload fails if remembered dir is deleted 65 7.2 Implicit FTPS upload timeout 66 7.3 FTP with NOBODY and FAILONERROR 67 7.4 FTP with ACCT 68 7.5 FTPS upload, FileZilla, GnuTLS and close_notify 69 7.11 FTPS upload data loss with TLS 1.3 70 7.12 FTPS directory listing hangs on Windows with Schannel 71 72 9. SFTP and SCP 73 9.1 SFTP does not do CURLOPT_POSTQUOTE correct 74 9.2 wolfssh: publickey auth does not work 75 9.3 Remote recursive folder creation with SFTP 76 9.4 libssh blocking and infinite loop problem 77 9.5 cygwin: "WARNING: UNPROTECTED PRIVATE KEY FILE!" 78 79 10. SOCKS 80 10.3 FTPS over SOCKS 81 82 11. Internals 83 11.1 gssapi library name + version is missing in curl_version_info() 84 11.2 error buffer not set if connection to multiple addresses fails 85 11.4 HTTP test server 'connection-monitor' problems 86 11.5 Connection information when using TCP Fast Open 87 88 12. LDAP 89 12.1 OpenLDAP hangs after returning results 90 12.2 LDAP on Windows does authentication wrong? 91 12.3 LDAP on Windows does not work 92 12.4 LDAPS requests to ActiveDirectory server hang 93 94 13. TCP/IP 95 13.2 Trying local ports fails on Windows 96 97 15. CMake 98 15.1 cmake outputs: no version information available 99 15.2 support build with GnuTLS 100 15.3 unusable tool_hugehelp.c with MinGW 101 15.6 uses -lpthread instead of Threads::Threads 102 15.7 generated .pc file contains strange entries 103 15.11 ExternalProject_Add does not set CURL_CA_PATH 104 15.13 CMake build with MIT Kerberos does not work 105 106 16. aws-sigv4 107 16.1 aws-sigv4 does not sign requests with * correctly 108 16.6 aws-sigv4 does not behave well with AWS VPC Lattice 109 110 17. HTTP/2 111 17.1 HTTP/2 prior knowledge over proxy 112 17.2 HTTP/2 frames while in the connection pool kill reuse 113 17.3 ENHANCE_YOUR_CALM causes infinite retries 114 115 18. HTTP/3 116 18.1 connection migration does not work 117 118 19. RTSP 119 19.1 Some methods do not support response bodies 120 121============================================================================== 122 1231. HTTP 124 1251.2 hyper is slow 126 127 When curl is built to use hyper for HTTP, it is unnecessary slow. 128 129 https://github.com/curl/curl/issues/11203 130 1311.5 Expect-100 meets 417 132 133 If an upload using Expect: 100-continue receives an HTTP 417 response, it 134 ought to be automatically resent without the Expect:. A workaround is for 135 the client application to redo the transfer after disabling Expect:. 136 https://curl.se/mail/archive-2008-02/0043.html 137 1382. TLS 139 1402.1 IMAPS connection fails with rustls error 141 142 https://github.com/curl/curl/issues/10457 143 1442.3 Unable to use PKCS12 certificate with Secure Transport 145 146 See https://github.com/curl/curl/issues/5403 147 1482.4 Secure Transport will not import PKCS#12 client certificates without a password 149 150 libcurl calls SecPKCS12Import with the PKCS#12 client certificate, but that 151 function rejects certificates that do not have a password. 152 https://github.com/curl/curl/issues/1308 153 1542.5 Client cert handling with Issuer DN differs between backends 155 156 When the specified client certificate does not match any of the 157 server-specified DNs, the OpenSSL and GnuTLS backends behave differently. 158 The github discussion may contain a solution. 159 160 See https://github.com/curl/curl/issues/1411 161 1622.7 Client cert (MTLS) issues with Schannel 163 164 See https://github.com/curl/curl/issues/3145 165 1662.11 Schannel TLS 1.2 handshake bug in old Windows versions 167 168 In old versions of Windows such as 7 and 8.1 the Schannel TLS 1.2 handshake 169 implementation likely has a bug that can rarely cause the key exchange to 170 fail, resulting in error SEC_E_BUFFER_TOO_SMALL or SEC_E_MESSAGE_ALTERED. 171 172 https://github.com/curl/curl/issues/5488 173 1742.13 CURLOPT_CERTINFO results in CURLE_OUT_OF_MEMORY with Schannel 175 176 https://github.com/curl/curl/issues/8741 177 1783. Email protocols 179 1803.1 IMAP SEARCH ALL truncated response 181 182 IMAP "SEARCH ALL" truncates output on large boxes. "A quick search of the 183 code reveals that pingpong.c contains some truncation code, at line 408, when 184 it deems the server response to be too large truncating it to 40 characters" 185 https://curl.se/bug/view.cgi?id=1366 186 1873.2 No disconnect command 188 189 The disconnect commands (LOGOUT and QUIT) may not be sent by IMAP, POP3 and 190 SMTP if a failure occurs during the authentication phase of a connection. 191 1923.3 POP3 expects "CRLF.CRLF" eob for some single-line responses 193 194 You have to tell libcurl not to expect a body, when dealing with one line 195 response commands. Please see the POP3 examples and test cases which show 196 this for the NOOP and DELE commands. https://curl.se/bug/?i=740 197 1983.4 AUTH PLAIN for SMTP is not working on all servers 199 200 Specifying "--login-options AUTH=PLAIN" on the command line does not seem to 201 work correctly. 202 203 See https://github.com/curl/curl/issues/4080 204 2053.5 APOP authentication fails on POP3 206 207 See https://github.com/curl/curl/issues/10073 208 2093.6 POP3 issue when reading small chunks 210 211 CURL_DBG_SOCK_RMAX=4 ./runtests.pl -v 982 212 213 See https://github.com/curl/curl/issues/12063 214 2154. Command line 216 2175. Build and portability issues 218 2195.1 OS400 port requires deprecated IBM library 220 221 curl for OS400 requires QADRT to build, which provides ASCII wrappers for 222 libc/POSIX functions in the ILE, but IBM no longer supports or even offers 223 this library to download. 224 225 See https://github.com/curl/curl/issues/5176 226 2275.2 curl-config --libs contains private details 228 229 "curl-config --libs" will include details set in LDFLAGS when configure is 230 run that might be needed only for building libcurl. Further, curl-config 231 --cflags suffers from the same effects with CFLAGS/CPPFLAGS. 232 2335.3 building for old macOS fails with gcc 234 235 Building curl for certain old macOS versions fails when gcc is used. We 236 command using clang in those cases. 237 238 See https://github.com/curl/curl/issues/11441 239 2405.5 cannot handle Unicode arguments in non-Unicode builds on Windows 241 242 If a URL or filename cannot be encoded using the user's current codepage then 243 it can only be encoded properly in the Unicode character set. Windows uses 244 UTF-16 encoding for Unicode and stores it in wide characters, however curl 245 and libcurl are not equipped for that at the moment except when built with 246 _UNICODE and UNICODE defined. And, except for Cygwin, Windows cannot use UTF-8 247 as a locale. 248 249 https://curl.se/bug/?i=345 250 https://curl.se/bug/?i=731 251 https://curl.se/bug/?i=3747 252 2535.6 cygwin: make install installs curl-config.1 twice 254 255 https://github.com/curl/curl/issues/8839 256 2575.9 Utilize Requires.private directives in libcurl.pc 258 259 https://github.com/curl/curl/issues/864 260 2615.11 configure --with-gssapi with Heimdal is ignored on macOS 262 263 ... unless you also pass --with-gssapi-libs 264 265 https://github.com/curl/curl/issues/3841 266 2675.12 flaky CI builds 268 269 We run many CI builds for each commit and PR on github, and especially a 270 number of the Windows builds are flaky. This means that we rarely get all CI 271 builds go green and complete without errors. This is unfortunate as it makes 272 us sometimes miss actual build problems and it is surprising to newcomers to 273 the project who (rightfully) do not expect this. 274 275 See https://github.com/curl/curl/issues/6972 276 2775.13 long paths are not fully supported on Windows 278 279 curl on Windows cannot access long paths (paths longer than 260 characters). 280 However, as a workaround, the Windows path prefix \\?\ which disables all path 281 interpretation may work to allow curl to access the path. For example: 282 \\?\c:\longpath. 283 284 See https://github.com/curl/curl/issues/8361 285 2865.14 Windows Unicode builds use homedir in current locale 287 288 The Windows Unicode builds of curl use the current locale, but expect Unicode 289 UTF-8 encoded paths for internal use such as open, access and stat. The user's 290 home directory is retrieved via curl_getenv in the current locale and not as 291 UTF-8 encoded Unicode. 292 293 See https://github.com/curl/curl/pull/7252 and 294 https://github.com/curl/curl/pull/7281 295 2965.15 Unicode on Windows 297 298 Passing in a unicode filename with -o: 299 300 https://github.com/curl/curl/issues/11461 301 302 Passing in unicode character with -d: 303 304 https://github.com/curl/curl/issues/12231 305 3066. Authentication 307 3086.1 NTLM authentication and unicode 309 310 NTLM authentication involving unicode user name or password only works 311 properly if built with UNICODE defined together with the Schannel 312 backend. The original problem was mentioned in: 313 https://curl.se/mail/lib-2009-10/0024.html 314 https://curl.se/bug/view.cgi?id=896 315 316 The Schannel version verified to work as mentioned in 317 https://curl.se/mail/lib-2012-07/0073.html 318 3196.2 MIT Kerberos for Windows build 320 321 libcurl fails to build with MIT Kerberos for Windows (KfW) due to KfW's 322 library header files exporting symbols/macros that should be kept private to 323 the KfW library. See ticket #5601 at https://krbdev.mit.edu/rt/ 324 3256.3 NTLM in system context uses wrong name 326 327 NTLM authentication using SSPI (on Windows) when (lib)curl is running in 328 "system context" will make it use wrong(?) user name - at least when compared 329 to what winhttp does. See https://curl.se/bug/view.cgi?id=535 330 3316.5 NTLM does not support password with § character 332 333 https://github.com/curl/curl/issues/2120 334 3356.6 libcurl can fail to try alternatives with --proxy-any 336 337 When connecting via a proxy using --proxy-any, a failure to establish an 338 authentication will cause libcurl to abort trying other options if the 339 failed method has a higher preference than the alternatives. As an example, 340 --proxy-any against a proxy which advertise Negotiate and NTLM, but which 341 fails to set up Kerberos authentication will not proceed to try authentication 342 using NTLM. 343 344 https://github.com/curl/curl/issues/876 345 3466.7 Do not clear digest for single realm 347 348 https://github.com/curl/curl/issues/3267 349 3506.9 SHA-256 digest not supported in Windows SSPI builds 351 352 Windows builds of curl that have SSPI enabled use the native Windows API calls 353 to create authentication strings. The call to InitializeSecurityContext fails 354 with SEC_E_QOP_NOT_SUPPORTED which causes curl to fail with CURLE_AUTH_ERROR. 355 356 Microsoft does not document supported digest algorithms and that SEC_E error 357 code is not a documented error for InitializeSecurityContext (digest). 358 359 https://github.com/curl/curl/issues/6302 360 3616.10 curl never completes Negotiate over HTTP 362 363 Apparently it is not working correctly...? 364 365 See https://github.com/curl/curl/issues/5235 366 3676.11 Negotiate on Windows fails 368 369 When using --negotiate (or NTLM) with curl on Windows, SSL/TLS handshake 370 fails despite having a valid kerberos ticket cached. Works without any issue 371 in Unix/Linux. 372 373 https://github.com/curl/curl/issues/5881 374 3756.12 cannot use Secure Transport with Crypto Token Kit 376 377 https://github.com/curl/curl/issues/7048 378 3796.13 Negotiate authentication against Hadoop HDFS 380 381 https://github.com/curl/curl/issues/8264 382 3837. FTP 384 3857.1 FTP upload fails if remembered dir is deleted 386 387 curl's FTP code assumes that the directory it entered in a previous transfer 388 still exists when it comes back to do a second transfer, and does not respond 389 well if it was indeed deleted in the mean time. 390 391 https://github.com/curl/curl/issues/12181 392 3937.2 Implicit FTPS upload timeout 394 395 https://github.com/curl/curl/issues/11720 396 3977.3 FTP with NOBODY and FAILONERROR 398 399 It seems sensible to be able to use CURLOPT_NOBODY and CURLOPT_FAILONERROR 400 with FTP to detect if a file exists or not, but it is not working: 401 https://curl.se/mail/lib-2008-07/0295.html 402 4037.4 FTP with ACCT 404 405 When doing an operation over FTP that requires the ACCT command (but not when 406 logging in), the operation will fail since libcurl does not detect this and 407 thus fails to issue the correct command: 408 https://curl.se/bug/view.cgi?id=635 409 4107.5 FTPS upload, FileZilla, GnuTLS and close_notify 411 412 An issue where curl does not send the TLS alert close_notify, which triggers 413 the wrath of GnuTLS in FileZilla server, and a FTP reply 426 ECONNABORTED. 414 415 https://github.com/curl/curl/issues/11383 416 4177.11 FTPS upload data loss with TLS 1.3 418 419 During FTPS upload curl does not attempt to read TLS handshake messages sent 420 after the initial handshake. OpenSSL servers running TLS 1.3 may send such a 421 message. When curl closes the upload connection if unread data has been 422 received (such as a TLS handshake message) then the TCP protocol sends an 423 RST to the server, which may cause the server to discard or truncate the 424 upload if it has not read all sent data yet, and then return an error to curl 425 on the control channel connection. 426 427 Since 7.78.0 this is mostly fixed. curl will do a single read before closing 428 TLS connections (which causes the TLS library to read handshake messages), 429 however there is still possibility of an RST if more messages need to be read 430 or a message arrives after the read but before close (network race condition). 431 432 https://github.com/curl/curl/issues/6149 433 4347.12 FTPS server compatibility on Windows with Schannel 435 436 FTPS is not widely used with the Schannel TLS backend and so there may be more 437 bugs compared to other TLS backends such as OpenSSL. In the past users have 438 reported hanging and failed connections. It's very likely some changes to curl 439 since then fixed the issues. None of the reported issues can be reproduced any 440 longer. 441 442 If you encounter an issue connecting to your server via FTPS with the latest 443 curl and Schannel then please search for open issues or file a new issue. 444 4459. SFTP and SCP 446 4479.1 SFTP does not do CURLOPT_POSTQUOTE correct 448 449 When libcurl sends CURLOPT_POSTQUOTE commands when connected to a SFTP server 450 using the multi interface, the commands are not being sent correctly and 451 instead the connection is "cancelled" (the operation is considered done) 452 prematurely. There is a half-baked (busy-looping) patch provided in the bug 453 report but it cannot be accepted as-is. See 454 https://curl.se/bug/view.cgi?id=748 455 4569.2 wolfssh: publickey auth does not work 457 458 When building curl to use the wolfSSH backend for SFTP, the publickey 459 authentication does not work. This is simply functionality not written for curl 460 yet, the necessary API for make this work is provided by wolfSSH. 461 462 See https://github.com/curl/curl/issues/4820 463 4649.3 Remote recursive folder creation with SFTP 465 466 On this servers, the curl fails to create directories on the remote server 467 even when the CURLOPT_FTP_CREATE_MISSING_DIRS option is set. 468 469 See https://github.com/curl/curl/issues/5204 470 4719.4 libssh blocking and infinite loop problem 472 473 In the SSH_SFTP_INIT state for libssh, the ssh session working mode is set to 474 blocking mode. If the network is suddenly disconnected during sftp 475 transmission, curl will be stuck, even if curl is configured with a timeout. 476 477 https://github.com/curl/curl/issues/8632 478 4799.5 cygwin: "WARNING: UNPROTECTED PRIVATE KEY FILE!" 480 481 Running SCP and SFTP tests on cygwin makes this warning message appear. 482 483 https://github.com/curl/curl/issues/11244 484 48510. SOCKS 486 48710.3 FTPS over SOCKS 488 489 libcurl does not support FTPS over a SOCKS proxy. 490 491 49211. Internals 493 49411.1 gssapi library name + version is missing in curl_version_info() 495 496 The struct needs to be expanded and code added to store this info. 497 498 See https://github.com/curl/curl/issues/13492 499 50011.2 error buffer not set if connection to multiple addresses fails 501 502 If you ask libcurl to resolve a hostname like example.com to IPv6 addresses 503 only. But you only have IPv4 connectivity. libcurl will correctly fail with 504 CURLE_COULDNT_CONNECT. But the error buffer set by CURLOPT_ERRORBUFFER 505 remains empty. Issue: https://github.com/curl/curl/issues/544 506 50711.4 HTTP test server 'connection-monitor' problems 508 509 The 'connection-monitor' feature of the sws HTTP test server does not work 510 properly if some tests are run in unexpected order. Like 1509 and then 1525. 511 512 See https://github.com/curl/curl/issues/868 513 51411.5 Connection information when using TCP Fast Open 515 516 CURLINFO_LOCAL_PORT (and possibly a few other) fails when TCP Fast Open is 517 enabled. 518 519 See https://github.com/curl/curl/issues/1332 and 520 https://github.com/curl/curl/issues/4296 521 52212. LDAP 523 52412.1 OpenLDAP hangs after returning results 525 526 By configuration defaults, OpenLDAP automatically chase referrals on 527 secondary socket descriptors. The OpenLDAP backend is asynchronous and thus 528 should monitor all socket descriptors involved. Currently, these secondary 529 descriptors are not monitored, causing OpenLDAP library to never receive 530 data from them. 531 532 As a temporary workaround, disable referrals chasing by configuration. 533 534 The fix is not easy: proper automatic referrals chasing requires a 535 synchronous bind callback and monitoring an arbitrary number of socket 536 descriptors for a single easy handle (currently limited to 5). 537 538 Generic LDAP is synchronous: OK. 539 540 See https://github.com/curl/curl/issues/622 and 541 https://curl.se/mail/lib-2016-01/0101.html 542 54312.2 LDAP on Windows does authentication wrong? 544 545 https://github.com/curl/curl/issues/3116 546 54712.3 LDAP on Windows does not work 548 549 A simple curl command line getting "ldap://ldap.forumsys.com" returns an 550 error that says "no memory" ! 551 552 https://github.com/curl/curl/issues/4261 553 55412.4 LDAPS requests to ActiveDirectory server hang 555 556 https://github.com/curl/curl/issues/9580 557 55813. TCP/IP 559 56013.2 Trying local ports fails on Windows 561 562 This makes '--local-port [range]' to not work since curl cannot properly 563 detect if a port is already in use, so it will try the first port, use that and 564 then subsequently fail anyway if that was actually in use. 565 566 https://github.com/curl/curl/issues/8112 567 56815. CMake 569 57015.1 cmake outputs: no version information available 571 572 Something in the SONAME generation seems to be wrong in the cmake build. 573 574 https://github.com/curl/curl/issues/11158 575 57615.2 support build with GnuTLS 577 57815.3 unusable tool_hugehelp.c with MinGW 579 580 see https://github.com/curl/curl/issues/3125 581 58215.6 uses -lpthread instead of Threads::Threads 583 584 See https://github.com/curl/curl/issues/6166 585 58615.7 generated .pc file contains strange entries 587 588 The Libs.private field of the generated .pc file contains -lgcc -lgcc_s -lc 589 -lgcc -lgcc_s 590 591 See https://github.com/curl/curl/issues/6167 592 59315.11 ExternalProject_Add does not set CURL_CA_PATH 594 595 CURL_CA_BUNDLE and CURL_CA_PATH are not set properly when cmake's 596 ExternalProject_Add is used to build curl as a dependency. 597 598 See https://github.com/curl/curl/issues/6313 599 60015.13 CMake build with MIT Kerberos does not work 601 602 Minimum CMake version was bumped in curl 7.71.0 (#5358) Since CMake 3.2 603 try_compile started respecting the CMAKE_EXE_FLAGS. The code dealing with 604 MIT Kerberos detection sets few variables to potentially weird mix of space, 605 and ;-separated flags. It had to blow up at some point. All the CMake checks 606 that involve compilation are doomed from that point, the configured tree 607 cannot be built. 608 609 https://github.com/curl/curl/issues/6904 610 61116. aws-sigv4 612 61316.1 aws-sigv4 does not sign requests with * correctly 614 615 https://github.com/curl/curl/issues/7559 616 61716.6 aws-sigv4 does not behave well with AWS VPC Lattice 618 619 https://github.com/curl/curl/issues/11007 620 62117. HTTP/2 622 62317.1 HTTP/2 prior knowledge over proxy 624 625 https://github.com/curl/curl/issues/12641 626 62717.2 HTTP/2 frames while in the connection pool kill reuse 628 629 If the server sends HTTP/2 frames (like for example an HTTP/2 PING frame) to 630 curl while the connection is held in curl's connection pool, the socket will 631 be found readable when considered for reuse and that makes curl think it is 632 dead and then it will be closed and a new connection gets created instead. 633 634 This is *best* fixed by adding monitoring to connections while they are kept 635 in the pool so that pings can be responded to appropriately. 636 63717.3 ENHANCE_YOUR_CALM causes infinite retries 638 639 Infinite retries with 2 parallel requests on one connection receiving GOAWAY 640 with ENHANCE_YOUR_CALM error code. 641 642 See https://github.com/curl/curl/issues/5119 643 64418. HTTP/3 645 64618.1 connection migration does not work 647 648 https://github.com/curl/curl/issues/7695 649 65019. RTSP 651 65219.1 Some methods do not support response bodies 653 654 The RTSP implementation is written to assume that a number of RTSP methods 655 will always get responses without bodies, even though there seems to be no 656 indication in the RFC that this is always the case. 657 658 https://github.com/curl/curl/issues/12414 659