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 16 2. TLS 17 2.1 IMAPS connection fails with Rustls error 18 2.3 Unable to use PKCS12 certificate with Secure Transport 19 2.4 Secure Transport does not import PKCS#12 client certificates without a password 20 2.5 Client cert handling with Issuer DN differs between backends 21 2.7 Client cert (MTLS) issues with Schannel 22 2.11 Schannel TLS 1.2 handshake bug in old Windows versions 23 2.13 CURLOPT_CERTINFO results in CURLE_OUT_OF_MEMORY with Schannel 24 2.14 mbedTLS and CURLE_AGAIN handling 25 26 3. Email protocols 27 3.1 IMAP SEARCH ALL truncated response 28 3.2 No disconnect command 29 3.4 AUTH PLAIN for SMTP is not working on all servers 30 3.5 APOP authentication fails on POP3 31 3.6 POP3 issue when reading small chunks 32 33 4. Command line 34 4.1 -T /dev/stdin may upload with an incorrect content length 35 4.2 -T - always uploads chunked 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 LDFLAGS passed too late making libs linked incorrectly 41 5.6 Cygwin: make install installs curl-config.1 twice 42 5.11 configure --with-gssapi with Heimdal is ignored on macOS 43 5.12 flaky CI builds 44 5.13 long paths are not fully supported on Windows 45 5.15 Unicode on Windows 46 47 6. Authentication 48 6.2 MIT Kerberos for Windows build 49 6.3 NTLM in system context uses wrong name 50 6.5 NTLM does not support password with § character 51 6.6 libcurl can fail to try alternatives with --proxy-any 52 6.7 Do not clear digest for single realm 53 6.8 Heimdal memory leaks 54 6.9 SHA-256 digest not supported in Windows SSPI builds 55 6.10 curl never completes Negotiate over HTTP 56 6.11 Negotiate on Windows fails 57 6.12 cannot use Secure Transport with Crypto Token Kit 58 6.13 Negotiate against Hadoop HDFS 59 60 7. FTP 61 7.4 FTP with ACCT 62 7.12 FTPS directory listing hangs on Windows with Schannel 63 64 9. SFTP and SCP 65 9.1 SFTP does not do CURLOPT_POSTQUOTE correct 66 9.2 wolfssh: publickey auth does not work 67 9.3 Remote recursive folder creation with SFTP 68 9.4 libssh blocking and infinite loop problem 69 9.5 Cygwin: "WARNING: UNPROTECTED PRIVATE KEY FILE!" 70 71 10. SOCKS 72 73 11. Internals 74 11.1 gssapi library name + version is missing in curl_version_info() 75 11.2 error buffer not set if connection to multiple addresses fails 76 11.3 TFTP tests fail on OpenBSD 77 11.4 HTTP test server 'connection-monitor' problems 78 11.5 Connection information when using TCP Fast Open 79 11.6 test cases sometimes timeout 80 11.7 CURLOPT_CONNECT_TO does not work for HTTPS proxy 81 11.8 WinIDN test failures 82 11.9 setting a disabled option should return CURLE_NOT_BUILT_IN 83 84 12. LDAP 85 12.1 OpenLDAP hangs after returning results 86 12.2 LDAP on Windows does authentication wrong? 87 12.3 LDAP on Windows does not work 88 12.4 LDAPS requests to ActiveDirectory server hang 89 90 13. TCP/IP 91 13.2 Trying local ports fails on Windows 92 93 15. CMake 94 15.1 cmake outputs: no version information available 95 15.2 support build with GnuTLS 96 15.3 unusable tool_hugehelp.c with MinGW 97 15.6 uses -lpthread instead of Threads::Threads 98 15.7 generated .pc file contains strange entries 99 15.13 CMake build with MIT Kerberos does not work 100 101 16. aws-sigv4 102 16.2 aws-sigv4 does not handle multipart/form-data correctly 103 16.3 aws-sigv4 has problems with particular URLs 104 16.6 aws-sigv4 does not behave well with AWS VPC Lattice 105 106 17. HTTP/2 107 17.1 HTTP/2 prior knowledge over proxy 108 17.2 HTTP/2 frames while in the connection pool kill reuse 109 17.3 ENHANCE_YOUR_CALM causes infinite retries 110 17.4 HTTP/2 + TLS spends a lot of time in recv 111 112 18. HTTP/3 113 18.1 connection migration does not work 114 18.2 quiche: QUIC connection is draining 115 116 19. RTSP 117 19.1 Some methods do not support response bodies 118 119============================================================================== 120 1211. HTTP 122 1232. TLS 124 1252.1 IMAPS connection fails with Rustls error 126 127 https://github.com/curl/curl/issues/10457 128 1292.3 Unable to use PKCS12 certificate with Secure Transport 130 131 See https://github.com/curl/curl/issues/5403 132 1332.4 Secure Transport does not import PKCS#12 client certificates without a password 134 135 libcurl calls SecPKCS12Import with the PKCS#12 client certificate, but that 136 function rejects certificates that do not have a password. 137 https://github.com/curl/curl/issues/1308 138 1392.5 Client cert handling with Issuer DN differs between backends 140 141 When the specified client certificate does not match any of the 142 server-specified DNs, the OpenSSL and GnuTLS backends behave differently. 143 The github discussion may contain a solution. 144 145 See https://github.com/curl/curl/issues/1411 146 1472.7 Client cert (MTLS) issues with Schannel 148 149 See https://github.com/curl/curl/issues/3145 150 1512.11 Schannel TLS 1.2 handshake bug in old Windows versions 152 153 In old versions of Windows such as 7 and 8.1 the Schannel TLS 1.2 handshake 154 implementation likely has a bug that can rarely cause the key exchange to 155 fail, resulting in error SEC_E_BUFFER_TOO_SMALL or SEC_E_MESSAGE_ALTERED. 156 157 https://github.com/curl/curl/issues/5488 158 1592.13 CURLOPT_CERTINFO results in CURLE_OUT_OF_MEMORY with Schannel 160 161 https://github.com/curl/curl/issues/8741 162 1632.14 mbedTLS and CURLE_AGAIN handling 164 165 https://github.com/curl/curl/issues/15801 166 1673. Email protocols 168 1693.1 IMAP SEARCH ALL truncated response 170 171 IMAP "SEARCH ALL" truncates output on large boxes. "A quick search of the 172 code reveals that pingpong.c contains some truncation code, at line 408, when 173 it deems the server response to be too large truncating it to 40 characters" 174 https://curl.se/bug/view.cgi?id=1366 175 1763.2 No disconnect command 177 178 The disconnect commands (LOGOUT and QUIT) may not be sent by IMAP, POP3 and 179 SMTP if a failure occurs during the authentication phase of a connection. 180 1813.4 AUTH PLAIN for SMTP is not working on all servers 182 183 Specifying "--login-options AUTH=PLAIN" on the command line does not seem to 184 work correctly. 185 186 See https://github.com/curl/curl/issues/4080 187 1883.5 APOP authentication fails on POP3 189 190 See https://github.com/curl/curl/issues/10073 191 1923.6 POP3 issue when reading small chunks 193 194 CURL_DBG_SOCK_RMAX=4 ./runtests.pl -v 982 195 196 See https://github.com/curl/curl/issues/12063 197 1984. Command line 199 2004.1 -T /dev/stdin may upload with an incorrect content length 201 202 -T stats the path to figure out its size in bytes to use it as Content-Length 203 if it is a regular file. 204 205 The problem with that is that, on BSDs and some other UNIXes (not Linux), 206 open(path) may not give you a file descriptor with a 0 offset from the start 207 of the file. 208 209 See https://github.com/curl/curl/issues/12177 210 2114.2 -T - always uploads chunked 212 213 When the `<` shell operator is used. curl should realise that stdin is a 214 regular file in this case, and that it can do a non-chunked upload, like it 215 would do if you used -T file. 216 217 See https://github.com/curl/curl/issues/12171 218 2195. Build and portability issues 220 2215.1 OS400 port requires deprecated IBM library 222 223 curl for OS400 requires QADRT to build, which provides ASCII wrappers for 224 libc/POSIX functions in the ILE, but IBM no longer supports or even offers 225 this library to download. 226 227 See https://github.com/curl/curl/issues/5176 228 2295.2 curl-config --libs contains private details 230 231 "curl-config --libs" include details set in LDFLAGS when configure is run 232 that might be needed only for building libcurl. Further, curl-config --cflags 233 suffers from the same effects with CFLAGS/CPPFLAGS. 234 2355.3 LDFLAGS passed too late making libs linked incorrectly 236 237 Compiling latest curl on HP-UX and linking against a custom OpenSSL (which is 238 on the default loader/linker path), fails because the generated Makefile has 239 LDFLAGS passed on after LIBS. 240 241 See https://github.com/curl/curl/issues/14893 242 2435.6 Cygwin: make install installs curl-config.1 twice 244 245 https://github.com/curl/curl/issues/8839 246 2475.11 configure --with-gssapi with Heimdal is ignored on macOS 248 249 ... unless you also pass --with-gssapi-libs 250 251 https://github.com/curl/curl/issues/3841 252 2535.12 flaky CI builds 254 255 We run many CI builds for each commit and PR on github, and especially a 256 number of the Windows builds are flaky. This means that we rarely get all CI 257 builds go green and complete without errors. This is unfortunate as it makes 258 us sometimes miss actual build problems and it is surprising to newcomers to 259 the project who (rightfully) do not expect this. 260 261 See https://github.com/curl/curl/issues/6972 262 2635.13 long paths are not fully supported on Windows 264 265 curl on Windows cannot access long paths (paths longer than 260 characters). 266 However, as a workaround, the Windows path prefix \\?\ which disables all 267 path interpretation may work to allow curl to access the path. For example: 268 \\?\c:\longpath. 269 270 See https://github.com/curl/curl/issues/8361 271 2725.15 Unicode on Windows 273 274 Passing in a Unicode filename with -o: 275 276 https://github.com/curl/curl/issues/11461 277 278 Passing in Unicode character with -d: 279 280 https://github.com/curl/curl/issues/12231 281 282 Windows Unicode builds use homedir in current locale 283 284 The Windows Unicode builds of curl use the current locale, but expect Unicode 285 UTF-8 encoded paths for internal use such as open, access and stat. The 286 user's home directory is retrieved via curl_getenv in the current locale and 287 not as UTF-8 encoded Unicode. 288 289 See https://github.com/curl/curl/pull/7252 and 290 https://github.com/curl/curl/pull/7281 291 292 Cannot handle Unicode arguments in non-Unicode builds on Windows 293 294 If a URL or filename cannot be encoded using the user's current codepage then 295 it can only be encoded properly in the Unicode character set. Windows uses 296 UTF-16 encoding for Unicode and stores it in wide characters, however curl 297 and libcurl are not equipped for that at the moment except when built with 298 _UNICODE and UNICODE defined. Except for Cygwin, Windows cannot use UTF-8 as 299 a locale. 300 301 https://curl.se/bug/?i=345 302 https://curl.se/bug/?i=731 303 https://curl.se/bug/?i=3747 304 305 NTLM authentication and Unicode 306 307 NTLM authentication involving Unicode username or password only works 308 properly if built with UNICODE defined together with the Schannel backend. 309 The original problem was mentioned in: 310 https://curl.se/mail/lib-2009-10/0024.html 311 https://curl.se/bug/view.cgi?id=896 312 313 The Schannel version verified to work as mentioned in 314 https://curl.se/mail/lib-2012-07/0073.html 315 3166. Authentication 317 3186.2 MIT Kerberos for Windows build 319 320 libcurl fails to build with MIT Kerberos for Windows (KfW) due to KfW's 321 library header files exporting symbols/macros that should be kept private to 322 the KfW library. See ticket #5601 at https://krbdev.mit.edu/rt/ 323 3246.3 NTLM in system context uses wrong name 325 326 NTLM authentication using SSPI (on Windows) when (lib)curl is running in 327 "system context" makes it use wrong(?) username - at least when compared to 328 what winhttp does. See https://curl.se/bug/view.cgi?id=535 329 3306.5 NTLM does not support password with § character 331 332 https://github.com/curl/curl/issues/2120 333 3346.6 libcurl can fail to try alternatives with --proxy-any 335 336 When connecting via a proxy using --proxy-any, a failure to establish an 337 authentication causes libcurl to abort trying other options if the failed 338 method has a higher preference than the alternatives. As an example, 339 --proxy-any against a proxy which advertise Negotiate and NTLM, but which 340 fails to set up Kerberos authentication does not proceed to try 341 authentication using NTLM. 342 343 https://github.com/curl/curl/issues/876 344 3456.7 Do not clear digest for single realm 346 347 https://github.com/curl/curl/issues/3267 348 3496.8 Heimdal memory leaks 350 351 Running test 2077 and 2078 with curl built to do GSS with Heimdal causes 352 valgrind errors (memory leak). 353 354 https://github.com/curl/curl/issues/14446 355 3566.9 SHA-256 digest not supported in Windows SSPI builds 357 358 Windows builds of curl that have SSPI enabled use the native Windows API calls 359 to create authentication strings. The call to InitializeSecurityContext fails 360 with SEC_E_QOP_NOT_SUPPORTED which causes curl to fail with CURLE_AUTH_ERROR. 361 362 Microsoft does not document supported digest algorithms and that SEC_E error 363 code is not a documented error for InitializeSecurityContext (digest). 364 365 https://github.com/curl/curl/issues/6302 366 3676.10 curl never completes Negotiate over HTTP 368 369 Apparently it is not working correctly...? 370 371 See https://github.com/curl/curl/issues/5235 372 3736.11 Negotiate on Windows fails 374 375 When using --negotiate (or NTLM) with curl on Windows, SSL/TLS handshake 376 fails despite having a valid kerberos ticket cached. Works without any issue 377 in Unix/Linux. 378 379 https://github.com/curl/curl/issues/5881 380 3816.12 cannot use Secure Transport with Crypto Token Kit 382 383 https://github.com/curl/curl/issues/7048 384 3856.13 Negotiate authentication against Hadoop HDFS 386 387 https://github.com/curl/curl/issues/8264 388 3897. FTP 390 3917.4 FTP with ACCT 392 393 When doing an operation over FTP that requires the ACCT command (but not when 394 logging in), the operation fails since libcurl does not detect this and thus 395 fails to issue the correct command: https://curl.se/bug/view.cgi?id=635 396 3977.12 FTPS server compatibility on Windows with Schannel 398 399 FTPS is not widely used with the Schannel TLS backend and so there may be 400 more bugs compared to other TLS backends such as OpenSSL. In the past users 401 have reported hanging and failed connections. It is likely some changes to 402 curl since then fixed the issues. None of the reported issues can be 403 reproduced any longer. 404 405 If you encounter an issue connecting to your server via FTPS with the latest 406 curl and Schannel then please search for open issues or file a new issue. 407 4089. SFTP and SCP 409 4109.1 SFTP does not do CURLOPT_POSTQUOTE correct 411 412 When libcurl sends CURLOPT_POSTQUOTE commands when connected to a SFTP server 413 using the multi interface, the commands are not being sent correctly and 414 instead the connection is "cancelled" (the operation is considered done) 415 prematurely. There is a half-baked (busy-looping) patch provided in the bug 416 report but it cannot be accepted as-is. See 417 https://curl.se/bug/view.cgi?id=748 418 4199.2 wolfssh: publickey auth does not work 420 421 When building curl to use the wolfSSH backend for SFTP, the publickey 422 authentication does not work. This is simply functionality not written for curl 423 yet, the necessary API for make this work is provided by wolfSSH. 424 425 See https://github.com/curl/curl/issues/4820 426 4279.3 Remote recursive folder creation with SFTP 428 429 On this servers, the curl fails to create directories on the remote server 430 even when the CURLOPT_FTP_CREATE_MISSING_DIRS option is set. 431 432 See https://github.com/curl/curl/issues/5204 433 4349.4 libssh blocking and infinite loop problem 435 436 In the SSH_SFTP_INIT state for libssh, the ssh session working mode is set to 437 blocking mode. If the network is suddenly disconnected during sftp 438 transmission, curl is stuck, even if curl is configured with a timeout. 439 440 https://github.com/curl/curl/issues/8632 441 4429.5 Cygwin: "WARNING: UNPROTECTED PRIVATE KEY FILE!" 443 444 Running SCP and SFTP tests on Cygwin makes this warning message appear. 445 446 https://github.com/curl/curl/issues/11244 447 44810. SOCKS 449 45011. Internals 451 45211.1 gssapi library name + version is missing in curl_version_info() 453 454 The struct needs to be expanded and code added to store this info. 455 456 See https://github.com/curl/curl/issues/13492 457 45811.2 error buffer not set if connection to multiple addresses fails 459 460 If you ask libcurl to resolve a hostname like example.com to IPv6 addresses 461 when you only have IPv4 connectivity. libcurl fails with 462 CURLE_COULDNT_CONNECT, but the error buffer set by CURLOPT_ERRORBUFFER 463 remains empty. Issue: https://github.com/curl/curl/issues/544 464 46511.3 TFTP tests fail on OpenBSD 466 467 When adding an OpenBSD job with tests to GHA, some tests consistently fail 468 to run. 469 470 See https://github.com/curl/curl/issues/13623 471 47211.4 HTTP test server 'connection-monitor' problems 473 474 The 'connection-monitor' feature of the sws HTTP test server does not work 475 properly if some tests are run in unexpected order. Like 1509 and then 1525. 476 477 See https://github.com/curl/curl/issues/868 478 47911.5 Connection information when using TCP Fast Open 480 481 CURLINFO_LOCAL_PORT (and possibly a few other) fails when TCP Fast Open is 482 enabled. 483 484 See https://github.com/curl/curl/issues/1332 and 485 https://github.com/curl/curl/issues/4296 486 48711.6 test cases sometimes timeout 488 489 Occasionally, one of the tests timeouts. Inexplicably. 490 491 See https://github.com/curl/curl/issues/13350 492 49311.7 CURLOPT_CONNECT_TO does not work for HTTPS proxy 494 495 It is unclear if the same option should even cover the proxy connection or if 496 if requires a separate option. 497 498 See https://github.com/curl/curl/issues/14481 499 50011.8 WinIDN test failures 501 502 Test 165 disabled when built with WinIDN. 503 50411.9 setting a disabled option should return CURLE_NOT_BUILT_IN 505 506 When curl has been built with specific features or protocols disabled, 507 setting such options with curl_easy_setopt() should rather return 508 CURLE_NOT_BUILT_IN instead of CURLE_UNKNOWN_OPTION to signal the difference 509 to the application 510 511 See https://github.com/curl/curl/issues/15472 512 51312. LDAP 514 51512.1 OpenLDAP hangs after returning results 516 517 By configuration defaults, OpenLDAP automatically chase referrals on 518 secondary socket descriptors. The OpenLDAP backend is asynchronous and thus 519 should monitor all socket descriptors involved. Currently, these secondary 520 descriptors are not monitored, causing OpenLDAP library to never receive 521 data from them. 522 523 As a temporary workaround, disable referrals chasing by configuration. 524 525 The fix is not easy: proper automatic referrals chasing requires a 526 synchronous bind callback and monitoring an arbitrary number of socket 527 descriptors for a single easy handle (currently limited to 5). 528 529 Generic LDAP is synchronous: OK. 530 531 See https://github.com/curl/curl/issues/622 and 532 https://curl.se/mail/lib-2016-01/0101.html 533 53412.2 LDAP on Windows does authentication wrong? 535 536 https://github.com/curl/curl/issues/3116 537 53812.3 LDAP on Windows does not work 539 540 A simple curl command line getting "ldap://ldap.forumsys.com" returns an 541 error that says "no memory" ! 542 543 https://github.com/curl/curl/issues/4261 544 54512.4 LDAPS requests to ActiveDirectory server hang 546 547 https://github.com/curl/curl/issues/9580 548 54913. TCP/IP 550 55113.2 Trying local ports fails on Windows 552 553 This makes '--local-port [range]' to not work since curl cannot properly 554 detect if a port is already in use, so it tries the first port, uses that and 555 then subsequently fails anyway if that was actually in use. 556 557 https://github.com/curl/curl/issues/8112 558 55915. CMake 560 56115.1 cmake outputs: no version information available 562 563 Something in the SONAME generation seems to be wrong in the cmake build. 564 565 https://github.com/curl/curl/issues/11158 566 56715.6 uses -lpthread instead of Threads::Threads 568 569 See https://github.com/curl/curl/issues/6166 570 57115.7 generated .pc file contains strange entries 572 573 The Libs.private field of the generated .pc file contains -lgcc -lgcc_s -lc 574 -lgcc -lgcc_s 575 576 See https://github.com/curl/curl/issues/6167 577 57815.13 CMake build with MIT Kerberos does not work 579 580 Minimum CMake version was bumped in curl 7.71.0 (#5358) Since CMake 3.2 581 try_compile started respecting the CMAKE_EXE_FLAGS. The code dealing with 582 MIT Kerberos detection sets few variables to potentially weird mix of space, 583 and ;-separated flags. It had to blow up at some point. All the CMake checks 584 that involve compilation are doomed from that point, the configured tree 585 cannot be built. 586 587 https://github.com/curl/curl/issues/6904 588 58916. aws-sigv4 590 59116.2 aws-sigv4 does not handle multipart/form-data correctly 592 593 https://github.com/curl/curl/issues/13351 594 59516.3 aws-sigv4 has problems with particular URLs 596 597 https://github.com/curl/curl/issues/13058 598 59916.6 aws-sigv4 does not behave well with AWS VPC Lattice 600 601 https://github.com/curl/curl/issues/11007 602 60317. HTTP/2 604 60517.1 HTTP/2 prior knowledge over proxy 606 607 https://github.com/curl/curl/issues/12641 608 60917.2 HTTP/2 frames while in the connection pool kill reuse 610 611 If the server sends HTTP/2 frames (like for example an HTTP/2 PING frame) to 612 curl while the connection is held in curl's connection pool, the socket is 613 found readable when considered for reuse and that makes curl think it is dead 614 and then it is closed and a new connection gets created instead. 615 616 This is *best* fixed by adding monitoring to connections while they are kept 617 in the pool so that pings can be responded to appropriately. 618 61917.3 ENHANCE_YOUR_CALM causes infinite retries 620 621 Infinite retries with 2 parallel requests on one connection receiving GOAWAY 622 with ENHANCE_YOUR_CALM error code. 623 624 See https://github.com/curl/curl/issues/5119 625 62617.4 HTTP/2 + TLS spends a lot of time in recv 627 628 It has been observered that by making the speed limit less accurate we could 629 improve this performance. (by reverting 630 https://github.com/curl/curl/commit/db5c9f4f9e0779b49624752b135281a0717b277b) 631 Can we find a golden middle ground? 632 633 See https://curl.se/mail/lib-2024-05/0026.html and 634 https://github.com/curl/curl/issues/13416 635 63618. HTTP/3 637 63818.1 connection migration does not work 639 640 https://github.com/curl/curl/issues/7695 641 64218.2 quiche: QUIC connection is draining 643 644 The transfer ends with error "QUIC connection is draining". 645 646 https://github.com/curl/curl/issues/12037 647 64819. RTSP 649 65019.1 Some methods do not support response bodies 651 652 The RTSP implementation is written to assume that a number of RTSP methods 653 always get responses without bodies, even though there seems to be no 654 indication in the RFC that this is always the case. 655 656 https://github.com/curl/curl/issues/12414 657
