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 25 3. Email protocols 26 3.1 IMAP SEARCH ALL truncated response 27 3.2 No disconnect command 28 3.4 AUTH PLAIN for SMTP is not working on all servers 29 3.5 APOP authentication fails on POP3 30 3.6 POP3 issue when reading small chunks 31 32 4. Command line 33 4.1 -T /dev/stdin may upload with an incorrect content length 34 4.2 -T - always uploads chunked 35 36 5. Build and portability issues 37 5.1 OS400 port requires deprecated IBM library 38 5.2 curl-config --libs contains private details 39 5.3 LDFLAGS passed too late making libs linked incorrectly 40 5.6 Cygwin: make install installs curl-config.1 twice 41 5.11 configure --with-gssapi with Heimdal is ignored on macOS 42 5.12 flaky CI builds 43 5.13 long paths are not fully supported on Windows 44 5.15 Unicode on Windows 45 46 6. Authentication 47 6.2 MIT Kerberos for Windows build 48 6.3 NTLM in system context uses wrong name 49 6.5 NTLM does not support password with § character 50 6.6 libcurl can fail to try alternatives with --proxy-any 51 6.7 Do not clear digest for single realm 52 6.8 Heimdal memory leaks 53 6.9 SHA-256 digest not supported in Windows SSPI builds 54 6.10 curl never completes Negotiate over HTTP 55 6.11 Negotiate on Windows fails 56 6.12 cannot use Secure Transport with Crypto Token Kit 57 6.13 Negotiate against Hadoop HDFS 58 59 7. FTP 60 7.4 FTP with ACCT 61 7.12 FTPS directory listing hangs on Windows with Schannel 62 63 9. SFTP and SCP 64 9.1 SFTP does not do CURLOPT_POSTQUOTE correct 65 9.2 wolfssh: publickey auth does not work 66 9.3 Remote recursive folder creation with SFTP 67 9.4 libssh blocking and infinite loop problem 68 9.5 Cygwin: "WARNING: UNPROTECTED PRIVATE KEY FILE!" 69 70 10. SOCKS 71 72 11. Internals 73 11.1 gssapi library name + version is missing in curl_version_info() 74 11.2 error buffer not set if connection to multiple addresses fails 75 11.3 TFTP tests fail on OpenBSD 76 11.4 HTTP test server 'connection-monitor' problems 77 11.5 Connection information when using TCP Fast Open 78 11.6 test cases sometimes timeout 79 11.7 CURLOPT_CONNECT_TO does not work for HTTPS proxy 80 11.8 WinIDN test failures 81 11.9 setting a disabled option should return CURLE_NOT_BUILT_IN 82 83 12. LDAP 84 12.1 OpenLDAP hangs after returning results 85 12.2 LDAP on Windows does authentication wrong? 86 12.3 LDAP on Windows does not work 87 12.4 LDAPS requests to ActiveDirectory server hang 88 89 13. TCP/IP 90 13.2 Trying local ports fails on Windows 91 92 15. CMake 93 15.1 cmake outputs: no version information available 94 15.2 support build with GnuTLS 95 15.3 unusable tool_hugehelp.c with MinGW 96 15.6 uses -lpthread instead of Threads::Threads 97 15.7 generated .pc file contains strange entries 98 15.13 CMake build with MIT Kerberos does not work 99 100 16. aws-sigv4 101 16.2 aws-sigv4 does not handle multipart/form-data correctly 102 16.3 aws-sigv4 has problems with particular URLs 103 16.6 aws-sigv4 does not behave well with AWS VPC Lattice 104 105 17. HTTP/2 106 17.1 HTTP/2 prior knowledge over proxy 107 17.2 HTTP/2 frames while in the connection pool kill reuse 108 17.3 ENHANCE_YOUR_CALM causes infinite retries 109 17.4 HTTP/2 + TLS spends a lot of time in recv 110 111 18. HTTP/3 112 18.1 connection migration does not work 113 18.2 quiche: QUIC connection is draining 114 115 19. RTSP 116 19.1 Some methods do not support response bodies 117 118============================================================================== 119 1201. HTTP 121 1222. TLS 123 1242.1 IMAPS connection fails with Rustls error 125 126 https://github.com/curl/curl/issues/10457 127 1282.3 Unable to use PKCS12 certificate with Secure Transport 129 130 See https://github.com/curl/curl/issues/5403 131 1322.4 Secure Transport does not import PKCS#12 client certificates without a password 133 134 libcurl calls SecPKCS12Import with the PKCS#12 client certificate, but that 135 function rejects certificates that do not have a password. 136 https://github.com/curl/curl/issues/1308 137 1382.5 Client cert handling with Issuer DN differs between backends 139 140 When the specified client certificate does not match any of the 141 server-specified DNs, the OpenSSL and GnuTLS backends behave differently. 142 The github discussion may contain a solution. 143 144 See https://github.com/curl/curl/issues/1411 145 1462.7 Client cert (MTLS) issues with Schannel 147 148 See https://github.com/curl/curl/issues/3145 149 1502.11 Schannel TLS 1.2 handshake bug in old Windows versions 151 152 In old versions of Windows such as 7 and 8.1 the Schannel TLS 1.2 handshake 153 implementation likely has a bug that can rarely cause the key exchange to 154 fail, resulting in error SEC_E_BUFFER_TOO_SMALL or SEC_E_MESSAGE_ALTERED. 155 156 https://github.com/curl/curl/issues/5488 157 1582.13 CURLOPT_CERTINFO results in CURLE_OUT_OF_MEMORY with Schannel 159 160 https://github.com/curl/curl/issues/8741 161 1623. Email protocols 163 1643.1 IMAP SEARCH ALL truncated response 165 166 IMAP "SEARCH ALL" truncates output on large boxes. "A quick search of the 167 code reveals that pingpong.c contains some truncation code, at line 408, when 168 it deems the server response to be too large truncating it to 40 characters" 169 https://curl.se/bug/view.cgi?id=1366 170 1713.2 No disconnect command 172 173 The disconnect commands (LOGOUT and QUIT) may not be sent by IMAP, POP3 and 174 SMTP if a failure occurs during the authentication phase of a connection. 175 1763.4 AUTH PLAIN for SMTP is not working on all servers 177 178 Specifying "--login-options AUTH=PLAIN" on the command line does not seem to 179 work correctly. 180 181 See https://github.com/curl/curl/issues/4080 182 1833.5 APOP authentication fails on POP3 184 185 See https://github.com/curl/curl/issues/10073 186 1873.6 POP3 issue when reading small chunks 188 189 CURL_DBG_SOCK_RMAX=4 ./runtests.pl -v 982 190 191 See https://github.com/curl/curl/issues/12063 192 1934. Command line 194 1954.1 -T /dev/stdin may upload with an incorrect content length 196 197 -T stats the path to figure out its size in bytes to use it as Content-Length 198 if it is a regular file. 199 200 The problem with that is that, on BSDs and some other UNIXes (not Linux), 201 open(path) may not give you a file descriptor with a 0 offset from the start 202 of the file. 203 204 See https://github.com/curl/curl/issues/12177 205 2064.2 -T - always uploads chunked 207 208 When the `<` shell operator is used. curl should realise that stdin is a 209 regular file in this case, and that it can do a non-chunked upload, like it 210 would do if you used -T file. 211 212 See https://github.com/curl/curl/issues/12171 213 2145. Build and portability issues 215 2165.1 OS400 port requires deprecated IBM library 217 218 curl for OS400 requires QADRT to build, which provides ASCII wrappers for 219 libc/POSIX functions in the ILE, but IBM no longer supports or even offers 220 this library to download. 221 222 See https://github.com/curl/curl/issues/5176 223 2245.2 curl-config --libs contains private details 225 226 "curl-config --libs" include details set in LDFLAGS when configure is run 227 that might be needed only for building libcurl. Further, curl-config --cflags 228 suffers from the same effects with CFLAGS/CPPFLAGS. 229 2305.3 LDFLAGS passed too late making libs linked incorrectly 231 232 Compiling latest curl on HP-UX and linking against a custom OpenSSL (which is 233 on the default loader/linker path), fails because the generated Makefile has 234 LDFLAGS passed on after LIBS. 235 236 See https://github.com/curl/curl/issues/14893 237 2385.6 Cygwin: make install installs curl-config.1 twice 239 240 https://github.com/curl/curl/issues/8839 241 2425.11 configure --with-gssapi with Heimdal is ignored on macOS 243 244 ... unless you also pass --with-gssapi-libs 245 246 https://github.com/curl/curl/issues/3841 247 2485.12 flaky CI builds 249 250 We run many CI builds for each commit and PR on github, and especially a 251 number of the Windows builds are flaky. This means that we rarely get all CI 252 builds go green and complete without errors. This is unfortunate as it makes 253 us sometimes miss actual build problems and it is surprising to newcomers to 254 the project who (rightfully) do not expect this. 255 256 See https://github.com/curl/curl/issues/6972 257 2585.13 long paths are not fully supported on Windows 259 260 curl on Windows cannot access long paths (paths longer than 260 characters). 261 However, as a workaround, the Windows path prefix \\?\ which disables all 262 path interpretation may work to allow curl to access the path. For example: 263 \\?\c:\longpath. 264 265 See https://github.com/curl/curl/issues/8361 266 2675.15 Unicode on Windows 268 269 Passing in a Unicode filename with -o: 270 271 https://github.com/curl/curl/issues/11461 272 273 Passing in Unicode character with -d: 274 275 https://github.com/curl/curl/issues/12231 276 277 Windows Unicode builds use homedir in current locale 278 279 The Windows Unicode builds of curl use the current locale, but expect Unicode 280 UTF-8 encoded paths for internal use such as open, access and stat. The 281 user's home directory is retrieved via curl_getenv in the current locale and 282 not as UTF-8 encoded Unicode. 283 284 See https://github.com/curl/curl/pull/7252 and 285 https://github.com/curl/curl/pull/7281 286 287 Cannot handle Unicode arguments in non-Unicode builds on Windows 288 289 If a URL or filename cannot be encoded using the user's current codepage then 290 it can only be encoded properly in the Unicode character set. Windows uses 291 UTF-16 encoding for Unicode and stores it in wide characters, however curl 292 and libcurl are not equipped for that at the moment except when built with 293 _UNICODE and UNICODE defined. Except for Cygwin, Windows cannot use UTF-8 as 294 a locale. 295 296 https://curl.se/bug/?i=345 297 https://curl.se/bug/?i=731 298 https://curl.se/bug/?i=3747 299 300 NTLM authentication and Unicode 301 302 NTLM authentication involving Unicode username or password only works 303 properly if built with UNICODE defined together with the Schannel backend. 304 The original problem was mentioned in: 305 https://curl.se/mail/lib-2009-10/0024.html 306 https://curl.se/bug/view.cgi?id=896 307 308 The Schannel version verified to work as mentioned in 309 https://curl.se/mail/lib-2012-07/0073.html 310 3116. Authentication 312 3136.2 MIT Kerberos for Windows build 314 315 libcurl fails to build with MIT Kerberos for Windows (KfW) due to KfW's 316 library header files exporting symbols/macros that should be kept private to 317 the KfW library. See ticket #5601 at https://krbdev.mit.edu/rt/ 318 3196.3 NTLM in system context uses wrong name 320 321 NTLM authentication using SSPI (on Windows) when (lib)curl is running in 322 "system context" makes it use wrong(?) username - at least when compared to 323 what winhttp does. See https://curl.se/bug/view.cgi?id=535 324 3256.5 NTLM does not support password with § character 326 327 https://github.com/curl/curl/issues/2120 328 3296.6 libcurl can fail to try alternatives with --proxy-any 330 331 When connecting via a proxy using --proxy-any, a failure to establish an 332 authentication causes libcurl to abort trying other options if the failed 333 method has a higher preference than the alternatives. As an example, 334 --proxy-any against a proxy which advertise Negotiate and NTLM, but which 335 fails to set up Kerberos authentication does not proceed to try 336 authentication using NTLM. 337 338 https://github.com/curl/curl/issues/876 339 3406.7 Do not clear digest for single realm 341 342 https://github.com/curl/curl/issues/3267 343 3446.8 Heimdal memory leaks 345 346 Running test 2077 and 2078 with curl built to do GSS with Heimdal causes 347 valgrind errors (memory leak). 348 349 https://github.com/curl/curl/issues/14446 350 3516.9 SHA-256 digest not supported in Windows SSPI builds 352 353 Windows builds of curl that have SSPI enabled use the native Windows API calls 354 to create authentication strings. The call to InitializeSecurityContext fails 355 with SEC_E_QOP_NOT_SUPPORTED which causes curl to fail with CURLE_AUTH_ERROR. 356 357 Microsoft does not document supported digest algorithms and that SEC_E error 358 code is not a documented error for InitializeSecurityContext (digest). 359 360 https://github.com/curl/curl/issues/6302 361 3626.10 curl never completes Negotiate over HTTP 363 364 Apparently it is not working correctly...? 365 366 See https://github.com/curl/curl/issues/5235 367 3686.11 Negotiate on Windows fails 369 370 When using --negotiate (or NTLM) with curl on Windows, SSL/TLS handshake 371 fails despite having a valid kerberos ticket cached. Works without any issue 372 in Unix/Linux. 373 374 https://github.com/curl/curl/issues/5881 375 3766.12 cannot use Secure Transport with Crypto Token Kit 377 378 https://github.com/curl/curl/issues/7048 379 3806.13 Negotiate authentication against Hadoop HDFS 381 382 https://github.com/curl/curl/issues/8264 383 3847. FTP 385 3867.4 FTP with ACCT 387 388 When doing an operation over FTP that requires the ACCT command (but not when 389 logging in), the operation fails since libcurl does not detect this and thus 390 fails to issue the correct command: https://curl.se/bug/view.cgi?id=635 391 3927.12 FTPS server compatibility on Windows with Schannel 393 394 FTPS is not widely used with the Schannel TLS backend and so there may be 395 more bugs compared to other TLS backends such as OpenSSL. In the past users 396 have reported hanging and failed connections. It is likely some changes to 397 curl since then fixed the issues. None of the reported issues can be 398 reproduced any longer. 399 400 If you encounter an issue connecting to your server via FTPS with the latest 401 curl and Schannel then please search for open issues or file a new issue. 402 4039. SFTP and SCP 404 4059.1 SFTP does not do CURLOPT_POSTQUOTE correct 406 407 When libcurl sends CURLOPT_POSTQUOTE commands when connected to a SFTP server 408 using the multi interface, the commands are not being sent correctly and 409 instead the connection is "cancelled" (the operation is considered done) 410 prematurely. There is a half-baked (busy-looping) patch provided in the bug 411 report but it cannot be accepted as-is. See 412 https://curl.se/bug/view.cgi?id=748 413 4149.2 wolfssh: publickey auth does not work 415 416 When building curl to use the wolfSSH backend for SFTP, the publickey 417 authentication does not work. This is simply functionality not written for curl 418 yet, the necessary API for make this work is provided by wolfSSH. 419 420 See https://github.com/curl/curl/issues/4820 421 4229.3 Remote recursive folder creation with SFTP 423 424 On this servers, the curl fails to create directories on the remote server 425 even when the CURLOPT_FTP_CREATE_MISSING_DIRS option is set. 426 427 See https://github.com/curl/curl/issues/5204 428 4299.4 libssh blocking and infinite loop problem 430 431 In the SSH_SFTP_INIT state for libssh, the ssh session working mode is set to 432 blocking mode. If the network is suddenly disconnected during sftp 433 transmission, curl is stuck, even if curl is configured with a timeout. 434 435 https://github.com/curl/curl/issues/8632 436 4379.5 Cygwin: "WARNING: UNPROTECTED PRIVATE KEY FILE!" 438 439 Running SCP and SFTP tests on Cygwin makes this warning message appear. 440 441 https://github.com/curl/curl/issues/11244 442 44310. SOCKS 444 44511. Internals 446 44711.1 gssapi library name + version is missing in curl_version_info() 448 449 The struct needs to be expanded and code added to store this info. 450 451 See https://github.com/curl/curl/issues/13492 452 45311.2 error buffer not set if connection to multiple addresses fails 454 455 If you ask libcurl to resolve a hostname like example.com to IPv6 addresses 456 when you only have IPv4 connectivity. libcurl fails with 457 CURLE_COULDNT_CONNECT, but the error buffer set by CURLOPT_ERRORBUFFER 458 remains empty. Issue: https://github.com/curl/curl/issues/544 459 46011.3 TFTP tests fail on OpenBSD 461 462 When adding an OpenBSD job with tests to GHA, some tests consistently fail 463 to run. 464 465 See https://github.com/curl/curl/issues/13623 466 46711.4 HTTP test server 'connection-monitor' problems 468 469 The 'connection-monitor' feature of the sws HTTP test server does not work 470 properly if some tests are run in unexpected order. Like 1509 and then 1525. 471 472 See https://github.com/curl/curl/issues/868 473 47411.5 Connection information when using TCP Fast Open 475 476 CURLINFO_LOCAL_PORT (and possibly a few other) fails when TCP Fast Open is 477 enabled. 478 479 See https://github.com/curl/curl/issues/1332 and 480 https://github.com/curl/curl/issues/4296 481 48211.6 test cases sometimes timeout 483 484 Occasionally, one of the tests timeouts. Inexplicably. 485 486 See https://github.com/curl/curl/issues/13350 487 48811.7 CURLOPT_CONNECT_TO does not work for HTTPS proxy 489 490 It is unclear if the same option should even cover the proxy connection or if 491 if requires a separate option. 492 493 See https://github.com/curl/curl/issues/14481 494 49511.8 WinIDN test failures 496 497 Test 165 disabled when built with WinIDN. 498 49911.9 setting a disabled option should return CURLE_NOT_BUILT_IN 500 501 When curl has been built with specific features or protocols disabled, 502 setting such options with curl_easy_setopt() should rather return 503 CURLE_NOT_BUILT_IN instead of CURLE_UNKNOWN_OPTION to signal the difference 504 to the application 505 506 See https://github.com/curl/curl/issues/15472 507 50812. LDAP 509 51012.1 OpenLDAP hangs after returning results 511 512 By configuration defaults, OpenLDAP automatically chase referrals on 513 secondary socket descriptors. The OpenLDAP backend is asynchronous and thus 514 should monitor all socket descriptors involved. Currently, these secondary 515 descriptors are not monitored, causing OpenLDAP library to never receive 516 data from them. 517 518 As a temporary workaround, disable referrals chasing by configuration. 519 520 The fix is not easy: proper automatic referrals chasing requires a 521 synchronous bind callback and monitoring an arbitrary number of socket 522 descriptors for a single easy handle (currently limited to 5). 523 524 Generic LDAP is synchronous: OK. 525 526 See https://github.com/curl/curl/issues/622 and 527 https://curl.se/mail/lib-2016-01/0101.html 528 52912.2 LDAP on Windows does authentication wrong? 530 531 https://github.com/curl/curl/issues/3116 532 53312.3 LDAP on Windows does not work 534 535 A simple curl command line getting "ldap://ldap.forumsys.com" returns an 536 error that says "no memory" ! 537 538 https://github.com/curl/curl/issues/4261 539 54012.4 LDAPS requests to ActiveDirectory server hang 541 542 https://github.com/curl/curl/issues/9580 543 54413. TCP/IP 545 54613.2 Trying local ports fails on Windows 547 548 This makes '--local-port [range]' to not work since curl cannot properly 549 detect if a port is already in use, so it tries the first port, uses that and 550 then subsequently fails anyway if that was actually in use. 551 552 https://github.com/curl/curl/issues/8112 553 55415. CMake 555 55615.1 cmake outputs: no version information available 557 558 Something in the SONAME generation seems to be wrong in the cmake build. 559 560 https://github.com/curl/curl/issues/11158 561 56215.6 uses -lpthread instead of Threads::Threads 563 564 See https://github.com/curl/curl/issues/6166 565 56615.7 generated .pc file contains strange entries 567 568 The Libs.private field of the generated .pc file contains -lgcc -lgcc_s -lc 569 -lgcc -lgcc_s 570 571 See https://github.com/curl/curl/issues/6167 572 57315.13 CMake build with MIT Kerberos does not work 574 575 Minimum CMake version was bumped in curl 7.71.0 (#5358) Since CMake 3.2 576 try_compile started respecting the CMAKE_EXE_FLAGS. The code dealing with 577 MIT Kerberos detection sets few variables to potentially weird mix of space, 578 and ;-separated flags. It had to blow up at some point. All the CMake checks 579 that involve compilation are doomed from that point, the configured tree 580 cannot be built. 581 582 https://github.com/curl/curl/issues/6904 583 58416. aws-sigv4 585 58616.2 aws-sigv4 does not handle multipart/form-data correctly 587 588 https://github.com/curl/curl/issues/13351 589 59016.3 aws-sigv4 has problems with particular URLs 591 592 https://github.com/curl/curl/issues/13058 593 59416.6 aws-sigv4 does not behave well with AWS VPC Lattice 595 596 https://github.com/curl/curl/issues/11007 597 59817. HTTP/2 599 60017.1 HTTP/2 prior knowledge over proxy 601 602 https://github.com/curl/curl/issues/12641 603 60417.2 HTTP/2 frames while in the connection pool kill reuse 605 606 If the server sends HTTP/2 frames (like for example an HTTP/2 PING frame) to 607 curl while the connection is held in curl's connection pool, the socket is 608 found readable when considered for reuse and that makes curl think it is dead 609 and then it is closed and a new connection gets created instead. 610 611 This is *best* fixed by adding monitoring to connections while they are kept 612 in the pool so that pings can be responded to appropriately. 613 61417.3 ENHANCE_YOUR_CALM causes infinite retries 615 616 Infinite retries with 2 parallel requests on one connection receiving GOAWAY 617 with ENHANCE_YOUR_CALM error code. 618 619 See https://github.com/curl/curl/issues/5119 620 62117.4 HTTP/2 + TLS spends a lot of time in recv 622 623 It has been observered that by making the speed limit less accurate we could 624 improve this performance. (by reverting 625 https://github.com/curl/curl/commit/db5c9f4f9e0779b49624752b135281a0717b277b) 626 Can we find a golden middle ground? 627 628 See https://curl.se/mail/lib-2024-05/0026.html and 629 https://github.com/curl/curl/issues/13416 630 63118. HTTP/3 632 63318.1 connection migration does not work 634 635 https://github.com/curl/curl/issues/7695 636 63718.2 quiche: QUIC connection is draining 638 639 The transfer ends with error "QUIC connection is draining". 640 641 https://github.com/curl/curl/issues/12037 642 64319. RTSP 644 64519.1 Some methods do not support response bodies 646 647 The RTSP implementation is written to assume that a number of RTSP methods 648 always get responses without bodies, even though there seems to be no 649 indication in the RFC that this is always the case. 650 651 https://github.com/curl/curl/issues/12414 652
