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 2.3 Unable to use PKCS12 certificate with Secure Transport 20 2.4 Secure Transport will not import PKCS#12 client certificates without a password 21 2.5 Client cert handling with Issuer DN differs between backends 22 2.7 Client cert (MTLS) issues with Schannel 23 2.11 Schannel TLS 1.2 handshake bug in old Windows versions 24 2.12 FTPS with Schannel times out file list operation 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 34 4. Command line 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 building for old macOS fails with gcc 40 5.5 cannot handle Unicode arguments in non-Unicode builds on Windows 41 5.6 cygwin: make install installs curl-config.1 twice 42 5.9 Utilize Requires.private directives in libcurl.pc 43 5.11 configure --with-gssapi with Heimdal is ignored on macOS 44 5.12 flaky CI builds 45 5.13 long paths are not fully supported on Windows 46 5.14 Windows Unicode builds use homedir in current locale 47 48 6. Authentication 49 6.1 NTLM authentication and unicode 50 6.2 MIT Kerberos for Windows build 51 6.3 NTLM in system context uses wrong name 52 6.5 NTLM does not support password with § character 53 6.6 libcurl can fail to try alternatives with --proxy-any 54 6.7 Do not clear digest for single realm 55 6.9 SHA-256 digest not supported in Windows SSPI builds 56 6.10 curl never completes Negotiate over HTTP 57 6.11 Negotiate on Windows fails 58 6.12 cannot use Secure Transport with Crypto Token Kit 59 6.13 Negotiate against Hadoop HDFS 60 61 7. FTP 62 7.3 FTP with NOBODY and FAILONERROR 63 7.4 FTP with ACCT 64 7.11 FTPS upload data loss with TLS 1.3 65 7.12 FTPS directory listing hangs on Windows with Schannel 66 67 9. SFTP and SCP 68 9.1 SFTP does not do CURLOPT_POSTQUOTE correct 69 9.2 wolfssh: publickey auth does not work 70 9.3 Remote recursive folder creation with SFTP 71 9.4 libssh blocking and infinite loop problem 72 9.5 cygwin: "WARNING: UNPROTECTED PRIVATE KEY FILE!" 73 74 10. SOCKS 75 10.3 FTPS over SOCKS 76 77 11. Internals 78 11.2 error buffer not set if connection to multiple addresses fails 79 11.4 HTTP test server 'connection-monitor' problems 80 11.5 Connection information when using TCP Fast Open 81 82 12. LDAP 83 12.1 OpenLDAP hangs after returning results 84 12.2 LDAP on Windows does authentication wrong? 85 12.3 LDAP on Windows does not work 86 12.4 LDAPS requests to ActiveDirectory server hang 87 88 13. TCP/IP 89 13.2 Trying local ports fails on Windows 90 91 15. CMake 92 15.1 cmake outputs: no version information available 93 15.2 support build with GnuTLS 94 15.3 unusable tool_hugehelp.c with MinGW 95 15.6 uses -lpthread instead of Threads::Threads 96 15.7 generated .pc file contains strange entries 97 15.8 libcurl.pc uses absolute library paths 98 15.11 ExternalProject_Add does not set CURL_CA_PATH 99 15.13 CMake build with MIT Kerberos does not work 100 101 16. aws-sigv4 102 16.1 aws-sigv4 does not sign requests with * correctly 103 16.6 aws-sigv4 does not behave well with AWS VPC Lattice 104 105 17. HTTP/2 106 17.2 HTTP/2 frames while in the connection pool kill reuse 107 17.3 ENHANCE_YOUR_CALM causes infinite retries 108 109 18. HTTP/3 110 18.1 connection migration does not work 111 112 19. RTSP 113 19.1 Some methods do not support response bodies 114 115============================================================================== 116 1171. HTTP 118 1191.2 hyper is slow 120 121 When curl is built to use hyper for HTTP, it is unnecessary slow. 122 123 https://github.com/curl/curl/issues/11203 124 1251.5 Expect-100 meets 417 126 127 If an upload using Expect: 100-continue receives an HTTP 417 response, it 128 ought to be automatically resent without the Expect:. A workaround is for 129 the client application to redo the transfer after disabling Expect:. 130 https://curl.se/mail/archive-2008-02/0043.html 131 1322. TLS 133 1342.3 Unable to use PKCS12 certificate with Secure Transport 135 136 See https://github.com/curl/curl/issues/5403 137 1382.4 Secure Transport will not import PKCS#12 client certificates without a password 139 140 libcurl calls SecPKCS12Import with the PKCS#12 client certificate, but that 141 function rejects certificates that do not have a password. 142 https://github.com/curl/curl/issues/1308 143 1442.5 Client cert handling with Issuer DN differs between backends 145 146 When the specified client certificate does not match any of the 147 server-specified DNs, the OpenSSL and GnuTLS backends behave differently. 148 The github discussion may contain a solution. 149 150 See https://github.com/curl/curl/issues/1411 151 1522.7 Client cert (MTLS) issues with Schannel 153 154 See https://github.com/curl/curl/issues/3145 155 1562.11 Schannel TLS 1.2 handshake bug in old Windows versions 157 158 In old versions of Windows such as 7 and 8.1 the Schannel TLS 1.2 handshake 159 implementation likely has a bug that can rarely cause the key exchange to 160 fail, resulting in error SEC_E_BUFFER_TOO_SMALL or SEC_E_MESSAGE_ALTERED. 161 162 https://github.com/curl/curl/issues/5488 163 1642.12 FTPS with Schannel times out file list operation 165 166 "Instead of the command completing, it just sits there until the timeout 167 expires." - the same command line seems to work with other TLS backends and 168 other operating systems. See https://github.com/curl/curl/issues/5284. 169 1702.13 CURLOPT_CERTINFO results in CURLE_OUT_OF_MEMORY with Schannel 171 172 https://github.com/curl/curl/issues/8741 173 1743. Email protocols 175 1763.1 IMAP SEARCH ALL truncated response 177 178 IMAP "SEARCH ALL" truncates output on large boxes. "A quick search of the 179 code reveals that pingpong.c contains some truncation code, at line 408, when 180 it deems the server response to be too large truncating it to 40 characters" 181 https://curl.se/bug/view.cgi?id=1366 182 1833.2 No disconnect command 184 185 The disconnect commands (LOGOUT and QUIT) may not be sent by IMAP, POP3 and 186 SMTP if a failure occurs during the authentication phase of a connection. 187 1883.3 POP3 expects "CRLF.CRLF" eob for some single-line responses 189 190 You have to tell libcurl not to expect a body, when dealing with one line 191 response commands. Please see the POP3 examples and test cases which show 192 this for the NOOP and DELE commands. https://curl.se/bug/?i=740 193 1943.4 AUTH PLAIN for SMTP is not working on all servers 195 196 Specifying "--login-options AUTH=PLAIN" on the command line does not seem to 197 work correctly. 198 199 See https://github.com/curl/curl/issues/4080 200 2013.5 APOP authentication fails on POP3 202 203 See https://github.com/curl/curl/issues/10073 204 2054. Command line 206 2075. Build and portability issues 208 2095.1 OS400 port requires deprecated IBM library 210 211 curl for OS400 requires QADRT to build, which provides ASCII wrappers for 212 libc/POSIX functions in the ILE, but IBM no longer supports or even offers 213 this library to download. 214 215 See https://github.com/curl/curl/issues/5176 216 2175.2 curl-config --libs contains private details 218 219 "curl-config --libs" will include details set in LDFLAGS when configure is 220 run that might be needed only for building libcurl. Further, curl-config 221 --cflags suffers from the same effects with CFLAGS/CPPFLAGS. 222 2235.3 building for old macOS fails with gcc 224 225 Building curl for certain old macOS versions fails when gcc is used. We 226 command using clang in those cases. 227 228 See https://github.com/curl/curl/issues/11441 229 2305.5 cannot handle Unicode arguments in non-Unicode builds on Windows 231 232 If a URL or filename cannot be encoded using the user's current codepage then 233 it can only be encoded properly in the Unicode character set. Windows uses 234 UTF-16 encoding for Unicode and stores it in wide characters, however curl 235 and libcurl are not equipped for that at the moment except when built with 236 _UNICODE and UNICODE defined. And, except for Cygwin, Windows cannot use UTF-8 237 as a locale. 238 239 https://curl.se/bug/?i=345 240 https://curl.se/bug/?i=731 241 https://curl.se/bug/?i=3747 242 2435.6 cygwin: make install installs curl-config.1 twice 244 245 https://github.com/curl/curl/issues/8839 246 2475.9 Utilize Requires.private directives in libcurl.pc 248 249 https://github.com/curl/curl/issues/864 250 2515.11 configure --with-gssapi with Heimdal is ignored on macOS 252 253 ... unless you also pass --with-gssapi-libs 254 255 https://github.com/curl/curl/issues/3841 256 2575.12 flaky CI builds 258 259 We run many CI builds for each commit and PR on github, and especially a 260 number of the Windows builds are flaky. This means that we rarely get all CI 261 builds go green and complete without errors. This is unfortunate as it makes 262 us sometimes miss actual build problems and it is surprising to newcomers to 263 the project who (rightfully) do not expect this. 264 265 See https://github.com/curl/curl/issues/6972 266 2675.13 long paths are not fully supported on Windows 268 269 curl on Windows cannot access long paths (paths longer than 260 characters). 270 However, as a workaround, the Windows path prefix \\?\ which disables all path 271 interpretation may work to allow curl to access the path. For example: 272 \\?\c:\longpath. 273 274 See https://github.com/curl/curl/issues/8361 275 2765.14 Windows Unicode builds use homedir in current locale 277 278 The Windows Unicode builds of curl use the current locale, but expect Unicode 279 UTF-8 encoded paths for internal use such as open, access and stat. The user's 280 home directory is retrieved via curl_getenv in the current locale and not as 281 UTF-8 encoded Unicode. 282 283 See https://github.com/curl/curl/pull/7252 and 284 https://github.com/curl/curl/pull/7281 285 2866. Authentication 287 2886.1 NTLM authentication and unicode 289 290 NTLM authentication involving unicode user name or password only works 291 properly if built with UNICODE defined together with the Schannel 292 backend. The original problem was mentioned in: 293 https://curl.se/mail/lib-2009-10/0024.html 294 https://curl.se/bug/view.cgi?id=896 295 296 The Schannel version verified to work as mentioned in 297 https://curl.se/mail/lib-2012-07/0073.html 298 2996.2 MIT Kerberos for Windows build 300 301 libcurl fails to build with MIT Kerberos for Windows (KfW) due to KfW's 302 library header files exporting symbols/macros that should be kept private to 303 the KfW library. See ticket #5601 at https://krbdev.mit.edu/rt/ 304 3056.3 NTLM in system context uses wrong name 306 307 NTLM authentication using SSPI (on Windows) when (lib)curl is running in 308 "system context" will make it use wrong(?) user name - at least when compared 309 to what winhttp does. See https://curl.se/bug/view.cgi?id=535 310 3116.5 NTLM does not support password with § character 312 313 https://github.com/curl/curl/issues/2120 314 3156.6 libcurl can fail to try alternatives with --proxy-any 316 317 When connecting via a proxy using --proxy-any, a failure to establish an 318 authentication will cause libcurl to abort trying other options if the 319 failed method has a higher preference than the alternatives. As an example, 320 --proxy-any against a proxy which advertise Negotiate and NTLM, but which 321 fails to set up Kerberos authentication will not proceed to try authentication 322 using NTLM. 323 324 https://github.com/curl/curl/issues/876 325 3266.7 Do not clear digest for single realm 327 328 https://github.com/curl/curl/issues/3267 329 3306.9 SHA-256 digest not supported in Windows SSPI builds 331 332 Windows builds of curl that have SSPI enabled use the native Windows API calls 333 to create authentication strings. The call to InitializeSecurityContext fails 334 with SEC_E_QOP_NOT_SUPPORTED which causes curl to fail with CURLE_AUTH_ERROR. 335 336 Microsoft does not document supported digest algorithms and that SEC_E error 337 code is not a documented error for InitializeSecurityContext (digest). 338 339 https://github.com/curl/curl/issues/6302 340 3416.10 curl never completes Negotiate over HTTP 342 343 Apparently it is not working correctly...? 344 345 See https://github.com/curl/curl/issues/5235 346 3476.11 Negotiate on Windows fails 348 349 When using --negotiate (or NTLM) with curl on Windows, SSL/TLS handshake 350 fails despite having a valid kerberos ticket cached. Works without any issue 351 in Unix/Linux. 352 353 https://github.com/curl/curl/issues/5881 354 3556.12 cannot use Secure Transport with Crypto Token Kit 356 357 https://github.com/curl/curl/issues/7048 358 3596.13 Negotiate authentication against Hadoop HDFS 360 361 https://github.com/curl/curl/issues/8264 362 3637. FTP 364 3657.3 FTP with NOBODY and FAILONERROR 366 367 It seems sensible to be able to use CURLOPT_NOBODY and CURLOPT_FAILONERROR 368 with FTP to detect if a file exists or not, but it is not working: 369 https://curl.se/mail/lib-2008-07/0295.html 370 3717.4 FTP with ACCT 372 373 When doing an operation over FTP that requires the ACCT command (but not when 374 logging in), the operation will fail since libcurl does not detect this and 375 thus fails to issue the correct command: 376 https://curl.se/bug/view.cgi?id=635 377 3787.11 FTPS upload data loss with TLS 1.3 379 380 During FTPS upload curl does not attempt to read TLS handshake messages sent 381 after the initial handshake. OpenSSL servers running TLS 1.3 may send such a 382 message. When curl closes the upload connection if unread data has been 383 received (such as a TLS handshake message) then the TCP protocol sends an 384 RST to the server, which may cause the server to discard or truncate the 385 upload if it has not read all sent data yet, and then return an error to curl 386 on the control channel connection. 387 388 Since 7.78.0 this is mostly fixed. curl will do a single read before closing 389 TLS connections (which causes the TLS library to read handshake messages), 390 however there is still possibility of an RST if more messages need to be read 391 or a message arrives after the read but before close (network race condition). 392 393 https://github.com/curl/curl/issues/6149 394 3957.12 FTPS directory listing hangs on Windows with Schannel 396 397 https://github.com/curl/curl/issues/9161 398 3999. SFTP and SCP 400 4019.1 SFTP does not do CURLOPT_POSTQUOTE correct 402 403 When libcurl sends CURLOPT_POSTQUOTE commands when connected to a SFTP server 404 using the multi interface, the commands are not being sent correctly and 405 instead the connection is "cancelled" (the operation is considered done) 406 prematurely. There is a half-baked (busy-looping) patch provided in the bug 407 report but it cannot be accepted as-is. See 408 https://curl.se/bug/view.cgi?id=748 409 4109.2 wolfssh: publickey auth does not work 411 412 When building curl to use the wolfSSH backend for SFTP, the publickey 413 authentication does not work. This is simply functionality not written for curl 414 yet, the necessary API for make this work is provided by wolfSSH. 415 416 See https://github.com/curl/curl/issues/4820 417 4189.3 Remote recursive folder creation with SFTP 419 420 On this servers, the curl fails to create directories on the remote server 421 even when the CURLOPT_FTP_CREATE_MISSING_DIRS option is set. 422 423 See https://github.com/curl/curl/issues/5204 424 4259.4 libssh blocking and infinite loop problem 426 427 In the SSH_SFTP_INIT state for libssh, the ssh session working mode is set to 428 blocking mode. If the network is suddenly disconnected during sftp 429 transmission, curl will be stuck, even if curl is configured with a timeout. 430 431 https://github.com/curl/curl/issues/8632 432 4339.5 cygwin: "WARNING: UNPROTECTED PRIVATE KEY FILE!" 434 435 Running SCP and SFTP tests on cygwin makes this warning message appear. 436 437 https://github.com/curl/curl/issues/11244 438 43910. SOCKS 440 44110.3 FTPS over SOCKS 442 443 libcurl does not support FTPS over a SOCKS proxy. 444 445 44611. Internals 447 44811.2 error buffer not set if connection to multiple addresses fails 449 450 If you ask libcurl to resolve a hostname like example.com to IPv6 addresses 451 only. But you only have IPv4 connectivity. libcurl will correctly fail with 452 CURLE_COULDNT_CONNECT. But the error buffer set by CURLOPT_ERRORBUFFER 453 remains empty. Issue: https://github.com/curl/curl/issues/544 454 45511.4 HTTP test server 'connection-monitor' problems 456 457 The 'connection-monitor' feature of the sws HTTP test server does not work 458 properly if some tests are run in unexpected order. Like 1509 and then 1525. 459 460 See https://github.com/curl/curl/issues/868 461 46211.5 Connection information when using TCP Fast Open 463 464 CURLINFO_LOCAL_PORT (and possibly a few other) fails when TCP Fast Open is 465 enabled. 466 467 See https://github.com/curl/curl/issues/1332 and 468 https://github.com/curl/curl/issues/4296 469 47012. LDAP 471 47212.1 OpenLDAP hangs after returning results 473 474 By configuration defaults, OpenLDAP automatically chase referrals on 475 secondary socket descriptors. The OpenLDAP backend is asynchronous and thus 476 should monitor all socket descriptors involved. Currently, these secondary 477 descriptors are not monitored, causing OpenLDAP library to never receive 478 data from them. 479 480 As a temporary workaround, disable referrals chasing by configuration. 481 482 The fix is not easy: proper automatic referrals chasing requires a 483 synchronous bind callback and monitoring an arbitrary number of socket 484 descriptors for a single easy handle (currently limited to 5). 485 486 Generic LDAP is synchronous: OK. 487 488 See https://github.com/curl/curl/issues/622 and 489 https://curl.se/mail/lib-2016-01/0101.html 490 49112.2 LDAP on Windows does authentication wrong? 492 493 https://github.com/curl/curl/issues/3116 494 49512.3 LDAP on Windows does not work 496 497 A simple curl command line getting "ldap://ldap.forumsys.com" returns an 498 error that says "no memory" ! 499 500 https://github.com/curl/curl/issues/4261 501 50212.4 LDAPS requests to ActiveDirectory server hang 503 504 https://github.com/curl/curl/issues/9580 505 50613. TCP/IP 507 50813.2 Trying local ports fails on Windows 509 510 This makes '--local-port [range]' to not work since curl cannot properly 511 detect if a port is already in use, so it will try the first port, use that and 512 then subsequently fail anyway if that was actually in use. 513 514 https://github.com/curl/curl/issues/8112 515 51615. CMake 517 51815.1 cmake outputs: no version information available 519 520 Something in the SONAME generation seems to be wrong in the cmake build. 521 522 https://github.com/curl/curl/issues/11158 523 52415.2 support build with GnuTLS 525 52615.3 unusable tool_hugehelp.c with MinGW 527 528 see https://github.com/curl/curl/issues/3125 529 53015.6 uses -lpthread instead of Threads::Threads 531 532 See https://github.com/curl/curl/issues/6166 533 53415.7 generated .pc file contains strange entries 535 536 The Libs.private field of the generated .pc file contains -lgcc -lgcc_s -lc 537 -lgcc -lgcc_s 538 539 See https://github.com/curl/curl/issues/6167 540 54115.8 libcurl.pc uses absolute library paths 542 543 The libcurl.pc file generated by cmake contains things like Libs.private: 544 /usr/lib64/libssl.so /usr/lib64/libcrypto.so /usr/lib64/libz.so. The 545 autotools equivalent would say Libs.private: -lssl -lcrypto -lz 546 547 See https://github.com/curl/curl/issues/6169 548 54915.11 ExternalProject_Add does not set CURL_CA_PATH 550 551 CURL_CA_BUNDLE and CURL_CA_PATH are not set properly when cmake's 552 ExternalProject_Add is used to build curl as a dependency. 553 554 See https://github.com/curl/curl/issues/6313 555 55615.13 CMake build with MIT Kerberos does not work 557 558 Minimum CMake version was bumped in curl 7.71.0 (#5358) Since CMake 3.2 559 try_compile started respecting the CMAKE_EXE_FLAGS. The code dealing with 560 MIT Kerberos detection sets few variables to potentially weird mix of space, 561 and ;-separated flags. It had to blow up at some point. All the CMake checks 562 that involve compilation are doomed from that point, the configured tree 563 cannot be built. 564 565 https://github.com/curl/curl/issues/6904 566 56716. aws-sigv4 568 56916.1 aws-sigv4 does not sign requests with * correctly 570 571 https://github.com/curl/curl/issues/7559 572 57316.6 aws-sigv4 does not behave well with AWS VPC Lattice 574 575 https://github.com/curl/curl/issues/11007 576 57717. HTTP/2 578 57917.2 HTTP/2 frames while in the connection pool kill reuse 580 581 If the server sends HTTP/2 frames (like for example an HTTP/2 PING frame) to 582 curl while the connection is held in curl's connection pool, the socket will 583 be found readable when considered for reuse and that makes curl think it is 584 dead and then it will be closed and a new connection gets created instead. 585 586 This is *best* fixed by adding monitoring to connections while they are kept 587 in the pool so that pings can be responded to appropriately. 588 58917.3 ENHANCE_YOUR_CALM causes infinite retries 590 591 Infinite retries with 2 parallel requests on one connection receiving GOAWAY 592 with ENHANCE_YOUR_CALM error code. 593 594 See https://github.com/curl/curl/issues/5119 595 59618. HTTP/3 597 59818.1 connection migration does not work 599 600 https://github.com/curl/curl/issues/7695 601 60219. RTSP 603 60419.1 Some methods do not support response bodies 605 606 The RTSP implementation is written to assume that a number of RTSP methods 607 will always get responses without bodies, even though there seems to be no 608 indication in the RFC that this is always the case. 609 610 https://github.com/curl/curl/issues/12414 611