756 lines
28 KiB
Plaintext
756 lines
28 KiB
Plaintext
_ _ ____ _
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/ __| | | | |_) | |
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| (__| |_| | _ <| |___
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\___|\___/|_| \_\_____|
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Known Bugs
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These are problems and bugs known to exist at the time of this release. Feel
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free to join in and help us correct one or more of these! Also be sure to
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check the changelog of the current development status, as one or more of these
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problems may have been fixed or changed somewhat since this was written!
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1. HTTP
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1.1 CURLFORM_CONTENTLEN in an array
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1.2 Disabling HTTP Pipelining
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1.3 STARTTRANSFER time is wrong for HTTP POSTs
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1.4 multipart formposts file name encoding
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1.5 Expect-100 meets 417
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1.6 Unnecessary close when 401 received waiting for 100
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1.7 Deflate error after all content was received
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1.9 HTTP/2 frames while in the connection pool kill reuse
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1.10 Strips trailing dot from host name
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1.11 CURLOPT_SEEKFUNCTION not called with CURLFORM_STREAM
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2. TLS
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2.1 CURLINFO_SSL_VERIFYRESULT has limited support
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2.2 DER in keychain
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2.3 GnuTLS backend skips really long certificate fields
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2.4 DarwinSSL won't import PKCS#12 client certificates without a password
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2.5 Client cert handling with Issuer DN differs between backends
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2.6 CURL_GLOBAL_SSL
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2.7 Client cert (MTLS) issues with Schannel
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3. Email protocols
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3.1 IMAP SEARCH ALL truncated response
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3.2 No disconnect command
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3.3 SMTP to multiple recipients
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3.4 POP3 expects "CRLF.CRLF" eob for some single-line responses
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4. Command line
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4.1 -J and -O with %-encoded file names
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4.2 -J with -C - fails
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4.3 --retry and transfer timeouts
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4.4 --upload-file . hang if delay in STDIN
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4.5 Improve --data-urlencode space encoding
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5. Build and portability issues
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5.1 tests not compatible with python3
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5.2 curl-config --libs contains private details
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5.3 curl compiled on OSX 10.13 failed to run on OSX 10.10
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5.4 Cannot compile against a static build of OpenLDAP
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5.5 can't handle Unicode arguments in Windows
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5.6 cmake support gaps
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5.7 Visual Studio project gaps
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5.8 configure finding libs in wrong directory
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5.9 Utilize Requires.private directives in libcurl.pc
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6. Authentication
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6.1 NTLM authentication and unicode
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6.2 MIT Kerberos for Windows build
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6.3 NTLM in system context uses wrong name
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6.4 Negotiate and Kerberos V5 need a fake user name
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6.5 NTLM doesn't support password with § character
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6.6 libcurl can fail to try alternatives with --proxy-any
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7. FTP
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7.1 FTP without or slow 220 response
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7.2 FTP with CONNECT and slow server
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7.3 FTP with NOBODY and FAILONERROR
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7.4 FTP with ACCT
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7.5 ASCII FTP
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7.6 FTP with NULs in URL parts
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7.7 FTP and empty path parts in the URL
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7.8 Premature transfer end but healthy control channel
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7.9 Passive transfer tries only one IP address
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7.10 Stick to same family over SOCKS proxy
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8. TELNET
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8.1 TELNET and time limitations don't work
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8.2 Microsoft telnet server
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9. SFTP and SCP
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9.1 SFTP doesn't do CURLOPT_POSTQUOTE correct
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10. SOCKS
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10.1 SOCKS proxy connections are done blocking
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10.2 SOCKS don't support timeouts
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10.3 FTPS over SOCKS
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10.4 active FTP over a SOCKS
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11. Internals
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11.1 Curl leaks .onion hostnames in DNS
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11.2 error buffer not set if connection to multiple addresses fails
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11.3 c-ares deviates from stock resolver on http://1346569778
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11.4 HTTP test server 'connection-monitor' problems
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11.5 Connection information when using TCP Fast Open
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11.6 slow connect to localhost on Windows
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12. LDAP and OpenLDAP
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12.1 OpenLDAP hangs after returning results
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13. TCP/IP
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13.1 --interface for ipv6 binds to unusable IP address
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14 DICT
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14.1 DICT responses show the underlying protocol
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==============================================================================
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1. HTTP
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1.1 CURLFORM_CONTENTLEN in an array
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It is not possible to pass a 64-bit value using CURLFORM_CONTENTLEN with
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CURLFORM_ARRAY, when compiled on 32-bit platforms that support 64-bit
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integers. This is because the underlying structure 'curl_forms' uses a dual
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purpose char* for storing these values in via casting. For more information
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see the now closed related issue:
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https://github.com/curl/curl/issues/608
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1.2 Disabling HTTP Pipelining
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Disabling HTTP Pipelining when there are ongoing transfers can lead to
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heap corruption and crash. https://curl.haxx.se/bug/view.cgi?id=1411
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Similarly, removing a handle when pipelining corrupts data:
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https://github.com/curl/curl/issues/2101
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1.3 STARTTRANSFER time is wrong for HTTP POSTs
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Wrong STARTTRANSFER timer accounting for POST requests Timer works fine with
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GET requests, but while using POST the time for CURLINFO_STARTTRANSFER_TIME
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is wrong. While using POST CURLINFO_STARTTRANSFER_TIME minus
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CURLINFO_PRETRANSFER_TIME is near to zero every time.
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https://github.com/curl/curl/issues/218
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https://curl.haxx.se/bug/view.cgi?id=1213
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1.4 multipart formposts file name encoding
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When creating multipart formposts. The file name part can be encoded with
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something beyond ascii but currently libcurl will only pass in the verbatim
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string the app provides. There are several browsers that already do this
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encoding. The key seems to be the updated draft to RFC2231:
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https://tools.ietf.org/html/draft-reschke-rfc2231-in-http-02
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1.5 Expect-100 meets 417
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If an upload using Expect: 100-continue receives an HTTP 417 response, it
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ought to be automatically resent without the Expect:. A workaround is for
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the client application to redo the transfer after disabling Expect:.
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https://curl.haxx.se/mail/archive-2008-02/0043.html
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1.6 Unnecessary close when 401 received waiting for 100
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libcurl closes the connection if an HTTP 401 reply is received while it is
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waiting for the the 100-continue response.
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https://curl.haxx.se/mail/lib-2008-08/0462.html
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1.7 Deflate error after all content was received
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There's a situation where we can get an error in a HTTP response that is
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compressed, when that error is detected after all the actual body contents
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have been received and delivered to the appliction. This is tricky, but is
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ultimately a broken server.
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See https://github.com/curl/curl/issues/2719
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1.9 HTTP/2 frames while in the connection pool kill reuse
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If the server sends HTTP/2 frames (like for example an HTTP/2 PING frame) to
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curl while the connection is held in curl's connection pool, the socket will
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be found readable when considered for reuse and that makes curl think it is
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dead and then it will be closed and a new connection gets created instead.
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This is *best* fixed by adding monitoring to connections while they are kept
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in the pool so that pings can be responded to appropriately.
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1.10 Strips trailing dot from host name
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When given a URL with a trailing dot for the host name part:
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"https://example.com./", libcurl will strip off the dot and use the name
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without a dot internally and send it dot-less in HTTP Host: headers and in
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the TLS SNI field. For the purpose of resolving the name to an address
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the hostname is used as is without any change.
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The HTTP part violates RFC 7230 section 5.4 but the SNI part is accordance
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with RFC 6066 section 3.
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URLs using these trailing dots are very rare in the wild and we have not seen
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or gotten any real-world problems with such URLs reported. The popular
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browsers seem to have stayed with not stripping the dot for both uses (thus
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they violate RFC 6066 instead of RFC 7230).
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Daniel took the discussion to the HTTPbis mailing list in March 2016:
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https://lists.w3.org/Archives/Public/ietf-http-wg/2016JanMar/0430.html but
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there was not major rush or interest to fix this. The impression I get is
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that most HTTP people rather not rock the boat now and instead prioritize web
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compatibility rather than to strictly adhere to these RFCs.
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Our current approach allows a knowing client to send a custom HTTP header
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with the dot added.
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In a few cases there is a difference in name resolving to IP addresses with
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a trailing dot, but it can be noted that many HTTP servers will not happily
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accept the trailing dot there unless that has been specifically configured
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to be a fine virtual host.
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If URLs with trailing dots for host names become more popular or even just
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used more than for just plain fun experiments, I'm sure we will have reason
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to go back and reconsider.
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See https://github.com/curl/curl/issues/716 for the discussion.
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1.11 CURLOPT_SEEKFUNCTION not called with CURLFORM_STREAM
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I'm using libcurl to POST form data using a FILE* with the CURLFORM_STREAM
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option of curl_formadd(). I've noticed that if the connection drops at just
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the right time, the POST is reattempted without the data from the file. It
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seems like the file stream position isn't getting reset to the beginning of
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the file. I found the CURLOPT_SEEKFUNCTION option and set that with a
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function that performs an fseek() on the FILE*. However, setting that didn't
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seem to fix the issue or even get called. See
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https://github.com/curl/curl/issues/768
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2. TLS
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2.1 CURLINFO_SSL_VERIFYRESULT has limited support
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CURLINFO_SSL_VERIFYRESULT is only implemented for the OpenSSL and NSS
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backends, so relying on this information in a generic app is flaky.
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2.2 DER in keychain
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Curl doesn't recognize certificates in DER format in keychain, but it works
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with PEM. https://curl.haxx.se/bug/view.cgi?id=1065
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2.3 GnuTLS backend skips really long certificate fields
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libcurl calls gnutls_x509_crt_get_dn() with a fixed buffer size and if the
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field is too long in the cert, it'll just return an error and the field will
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be displayed blank.
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2.4 DarwinSSL won't import PKCS#12 client certificates without a password
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libcurl calls SecPKCS12Import with the PKCS#12 client certificate, but that
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function rejects certificates that do not have a password.
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https://github.com/curl/curl/issues/1308
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2.5 Client cert handling with Issuer DN differs between backends
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When the specified client certificate doesn't match any of the
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server-specified DNs, the OpenSSL and GnuTLS backends behave differently.
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The github discussion may contain a solution.
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See https://github.com/curl/curl/issues/1411
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2.6 CURL_GLOBAL_SSL
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Since libcurl 7.57.0, the flag CURL_GLOBAL_SSL is a no-op. The change was
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merged in https://github.com/curl/curl/commit/d661b0afb571a
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It was removed since it was
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A) never clear for applications on how to deal with init in the light of
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different SSL backends (the option was added back in the days when life
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was simpler)
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B) multissl introduced dynamic switching between SSL backends which
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emphasized (A) even more
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C) libcurl uses some TLS backend functionality even for non-TLS functions (to
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get "good" random) so applications trying to avoid the init for
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performance reasons would do wrong anyway
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D) never very carefully documented so all this mostly just happened to work
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for some users
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However, in spite of the problems with the feature, there were some users who
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apparently depended on this feature and who now claim libcurl is broken for
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them. The fix for this situation is not obvious as a downright revert of the
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patch is totally ruled out due to those reasons above.
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https://github.com/curl/curl/issues/2276
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2.7 Client cert (MTLS) issues with Schannel
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See https://github.com/curl/curl/issues/3145
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3. Email protocols
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3.1 IMAP SEARCH ALL truncated response
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IMAP "SEARCH ALL" truncates output on large boxes. "A quick search of the
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code reveals that pingpong.c contains some truncation code, at line 408, when
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it deems the server response to be too large truncating it to 40 characters"
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https://curl.haxx.se/bug/view.cgi?id=1366
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3.2 No disconnect command
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The disconnect commands (LOGOUT and QUIT) may not be sent by IMAP, POP3 and
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SMTP if a failure occurs during the authentication phase of a connection.
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3.3 SMTP to multiple recipients
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When sending data to multiple recipients, curl will abort and return failure
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if one of the recipients indicate failure (on the "RCPT TO"
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command). Ordinary mail programs would proceed and still send to the ones
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that can receive data. This is subject for change in the future.
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https://curl.haxx.se/bug/view.cgi?id=1116
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3.4 POP3 expects "CRLF.CRLF" eob for some single-line responses
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You have to tell libcurl not to expect a body, when dealing with one line
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response commands. Please see the POP3 examples and test cases which show
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this for the NOOP and DELE commands. https://curl.haxx.se/bug/?i=740
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4. Command line
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4.1 -J and -O with %-encoded file names
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-J/--remote-header-name doesn't decode %-encoded file names. RFC6266 details
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how it should be done. The can of worm is basically that we have no charset
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handling in curl and ascii >=128 is a challenge for us. Not to mention that
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decoding also means that we need to check for nastiness that is attempted,
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like "../" sequences and the like. Probably everything to the left of any
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embedded slashes should be cut off.
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https://curl.haxx.se/bug/view.cgi?id=1294
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-O also doesn't decode %-encoded names, and while it has even less
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information about the charset involved the process is similar to the -J case.
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Note that we won't add decoding to -O without the user asking for it with
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some other means as well, since -O has always been documented to use the name
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exactly as specified in the URL.
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4.2 -J with -C - fails
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When using -J (with -O), automatically resumed downloading together with "-C
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-" fails. Without -J the same command line works! This happens because the
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resume logic is worked out before the target file name (and thus its
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pre-transfer size) has been figured out!
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https://curl.haxx.se/bug/view.cgi?id=1169
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4.3 --retry and transfer timeouts
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If using --retry and the transfer timeouts (possibly due to using -m or
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-y/-Y) the next attempt doesn't resume the transfer properly from what was
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downloaded in the previous attempt but will truncate and restart at the
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original position where it was at before the previous failed attempt. See
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https://curl.haxx.se/mail/lib-2008-01/0080.html and Mandriva bug report
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https://qa.mandriva.com/show_bug.cgi?id=22565
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4.4 --upload-file . hangs if delay in STDIN
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"(echo start; sleep 1; echo end) | curl --upload-file . http://mywebsite -vv"
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... causes a hang when it shouldn't.
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See https://github.com/curl/curl/issues/2051
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4.5 Improve --data-urlencode space encoding
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ASCII space characters in --data-urlencode are currently encoded as %20
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rather than +, which RFC 1866 says should be used.
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See https://github.com/curl/curl/issues/3229
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5. Build and portability issues
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5.1 tests not compatible with python3
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The smb test server still needs python2.
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See https://github.com/curl/curl/issues/3289
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5.2 curl-config --libs contains private details
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"curl-config --libs" will include details set in LDFLAGS when configure is
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run that might be needed only for building libcurl. Further, curl-config
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--cflags suffers from the same effects with CFLAGS/CPPFLAGS.
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5.3 curl compiled on OSX 10.13 failed to run on OSX 10.10
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See https://github.com/curl/curl/issues/2905
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5.4 Cannot compile against a static build of OpenLDAP
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See https://github.com/curl/curl/issues/2367
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5.5 can't handle Unicode arguments in Windows
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If a URL or filename can't be encoded using the user's current codepage then
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it can only be encoded properly in the Unicode character set. Windows uses
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UTF-16 encoding for Unicode and stores it in wide characters, however curl
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and libcurl are not equipped for that at the moment. And, except for Cygwin,
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Windows can't use UTF-8 as a locale.
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https://curl.haxx.se/bug/?i=345
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https://curl.haxx.se/bug/?i=731
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5.6 cmake support gaps
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The cmake build setup lacks several features that the autoconf build
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offers. This includes:
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- use of correct soname for the shared library build
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- support for several TLS backends are missing
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- the unit tests cause link failures in regular non-static builds
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- no nghttp2 check
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- unusable tool_hugehelp.c with MinGW, see
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https://github.com/curl/curl/issues/3125
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5.7 Visual Studio project gaps
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The Visual Studio projects lack some features that the autoconf and nmake
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builds offer, such as the following:
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- support for zlib and nghttp2
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- use of static runtime libraries
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- add the test suite components
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In addition to this the following could be implemented:
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- support for other development IDEs
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- add PATH environment variables for third-party DLLs
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5.8 configure finding libs in wrong directory
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When the configure script checks for third-party libraries, it adds those
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directories to the LDFLAGS variable and then tries linking to see if it
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works. When successful, the found directory is kept in the LDFLAGS variable
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when the script continues to execute and do more tests and possibly check for
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more libraries.
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This can make subsequent checks for libraries wrongly detect another
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installation in a directory that was previously added to LDFLAGS by another
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library check!
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A possibly better way to do these checks would be to keep the pristine LDFLAGS
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even after successful checks and instead add those verified paths to a
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separate variable that only after all library checks have been performed gets
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appended to LDFLAGS.
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5.9 Utilize Requires.private directives in libcurl.pc
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https://github.com/curl/curl/issues/864
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6. Authentication
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6.1 NTLM authentication and unicode
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NTLM authentication involving unicode user name or password only works
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properly if built with UNICODE defined together with the WinSSL/Schannel
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backend. The original problem was mentioned in:
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https://curl.haxx.se/mail/lib-2009-10/0024.html
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https://curl.haxx.se/bug/view.cgi?id=896
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The WinSSL/Schannel version verified to work as mentioned in
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https://curl.haxx.se/mail/lib-2012-07/0073.html
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6.2 MIT Kerberos for Windows build
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libcurl fails to build with MIT Kerberos for Windows (KfW) due to KfW's
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library header files exporting symbols/macros that should be kept private to
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the KfW library. See ticket #5601 at https://krbdev.mit.edu/rt/
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6.3 NTLM in system context uses wrong name
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NTLM authentication using SSPI (on Windows) when (lib)curl is running in
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"system context" will make it use wrong(?) user name - at least when compared
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to what winhttp does. See https://curl.haxx.se/bug/view.cgi?id=535
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6.4 Negotiate and Kerberos V5 need a fake user name
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In order to get Negotiate (SPNEGO) authentication to work in HTTP or Kerberos
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V5 in the e-mail protocols, you need to provide a (fake) user name (this
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concerns both curl and the lib) because the code wrongly only considers
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authentication if there's a user name provided by setting
|
|
conn->bits.user_passwd in url.c https://curl.haxx.se/bug/view.cgi?id=440 How?
|
|
https://curl.haxx.se/mail/lib-2004-08/0182.html A possible solution is to
|
|
either modify this variable to be set or introduce a variable such as
|
|
new conn->bits.want_authentication which is set when any of the authentication
|
|
options are set.
|
|
|
|
6.5 NTLM doesn't support password with § character
|
|
|
|
https://github.com/curl/curl/issues/2120
|
|
|
|
6.6 libcurl can fail to try alternatives with --proxy-any
|
|
|
|
When connecting via a proxy using --proxy-any, a failure to establish an
|
|
authentication will cause libcurl to abort trying other options if the
|
|
failed method has a higher preference than the alternatives. As an example,
|
|
--proxy-any against a proxy which advertise Negotiate and NTLM, but which
|
|
fails to set up Kerberos authentication won't proceed to try authentication
|
|
using NTLM.
|
|
|
|
https://github.com/curl/curl/issues/876
|
|
|
|
7. FTP
|
|
|
|
7.1 FTP without or slow 220 response
|
|
|
|
If a connection is made to a FTP server but the server then just never sends
|
|
the 220 response or otherwise is dead slow, libcurl will not acknowledge the
|
|
connection timeout during that phase but only the "real" timeout - which may
|
|
surprise users as it is probably considered to be the connect phase to most
|
|
people. Brought up (and is being misunderstood) in:
|
|
https://curl.haxx.se/bug/view.cgi?id=856
|
|
|
|
7.2 FTP with CONNECT and slow server
|
|
|
|
When doing FTP over a socks proxy or CONNECT through HTTP proxy and the multi
|
|
interface is used, libcurl will fail if the (passive) TCP connection for the
|
|
data transfer isn't more or less instant as the code does not properly wait
|
|
for the connect to be confirmed. See test case 564 for a first shot at a test
|
|
case.
|
|
|
|
7.3 FTP with NOBODY and FAILONERROR
|
|
|
|
It seems sensible to be able to use CURLOPT_NOBODY and CURLOPT_FAILONERROR
|
|
with FTP to detect if a file exists or not, but it is not working:
|
|
https://curl.haxx.se/mail/lib-2008-07/0295.html
|
|
|
|
7.4 FTP with ACCT
|
|
|
|
When doing an operation over FTP that requires the ACCT command (but not when
|
|
logging in), the operation will fail since libcurl doesn't detect this and
|
|
thus fails to issue the correct command:
|
|
https://curl.haxx.se/bug/view.cgi?id=635
|
|
|
|
7.5 ASCII FTP
|
|
|
|
FTP ASCII transfers do not follow RFC959. They don't convert the data
|
|
accordingly (not for sending nor for receiving). RFC 959 section 3.1.1.1
|
|
clearly describes how this should be done:
|
|
|
|
The sender converts the data from an internal character representation to
|
|
the standard 8-bit NVT-ASCII representation (see the Telnet
|
|
specification). The receiver will convert the data from the standard
|
|
form to his own internal form.
|
|
|
|
Since 7.15.4 at least line endings are converted.
|
|
|
|
7.6 FTP with NULs in URL parts
|
|
|
|
FTP URLs passed to curl may contain NUL (0x00) in the RFC 1738 <user>,
|
|
<password>, and <fpath> components, encoded as "%00". The problem is that
|
|
curl_unescape does not detect this, but instead returns a shortened C string.
|
|
From a strict FTP protocol standpoint, NUL is a valid character within RFC
|
|
959 <string>, so the way to handle this correctly in curl would be to use a
|
|
data structure other than a plain C string, one that can handle embedded NUL
|
|
characters. From a practical standpoint, most FTP servers would not
|
|
meaningfully support NUL characters within RFC 959 <string>, anyway (e.g.,
|
|
Unix pathnames may not contain NUL).
|
|
|
|
7.7 FTP and empty path parts in the URL
|
|
|
|
libcurl ignores empty path parts in FTP URLs, whereas RFC1738 states that
|
|
such parts should be sent to the server as 'CWD ' (without an argument). The
|
|
only exception to this rule, is that we knowingly break this if the empty
|
|
part is first in the path, as then we use the double slashes to indicate that
|
|
the user wants to reach the root dir (this exception SHALL remain even when
|
|
this bug is fixed).
|
|
|
|
7.8 Premature transfer end but healthy control channel
|
|
|
|
When 'multi_done' is called before the transfer has been completed the normal
|
|
way, it is considered a "premature" transfer end. In this situation, libcurl
|
|
closes the connection assuming it doesn't know the state of the connection so
|
|
it can't be reused for subsequent requests.
|
|
|
|
With FTP however, this isn't necessarily true but there are a bunch of
|
|
situations (listed in the ftp_done code) where it *could* keep the connection
|
|
alive even in this situation - but the current code doesn't. Fixing this would
|
|
allow libcurl to reuse FTP connections better.
|
|
|
|
7.9 Passive transfer tries only one IP address
|
|
|
|
When doing FTP operations through a proxy at localhost, the reported spotted
|
|
that curl only tried to connect once to the proxy, while it had multiple
|
|
addresses and a failed connect on one address should make it try the next.
|
|
|
|
After switching to passive mode (EPSV), curl should try all IP addresses for
|
|
"localhost". Currently it tries ::1, but it should also try 127.0.0.1.
|
|
|
|
See https://github.com/curl/curl/issues/1508
|
|
|
|
7.10 Stick to same family over SOCKS proxy
|
|
|
|
When asked to do FTP over a SOCKS proxy, it might connect to the proxy (and
|
|
then subsequently to the remote server) using for example IPv4. When doing
|
|
the second connection, curl should make sure that the second connection is
|
|
using the same IP protocol version as the first connection did and not try
|
|
others, since the remote server will only accept the same.
|
|
|
|
See https://curl.haxx.se/mail/archive-2018-07/0000.html
|
|
|
|
8. TELNET
|
|
|
|
8.1 TELNET and time limitations don't work
|
|
|
|
When using telnet, the time limitation options don't work.
|
|
https://curl.haxx.se/bug/view.cgi?id=846
|
|
|
|
8.2 Microsoft telnet server
|
|
|
|
There seems to be a problem when connecting to the Microsoft telnet server.
|
|
https://curl.haxx.se/bug/view.cgi?id=649
|
|
|
|
|
|
9. SFTP and SCP
|
|
|
|
9.1 SFTP doesn't do CURLOPT_POSTQUOTE correct
|
|
|
|
When libcurl sends CURLOPT_POSTQUOTE commands when connected to a SFTP server
|
|
using the multi interface, the commands are not being sent correctly and
|
|
instead the connection is "cancelled" (the operation is considered done)
|
|
prematurely. There is a half-baked (busy-looping) patch provided in the bug
|
|
report but it cannot be accepted as-is. See
|
|
https://curl.haxx.se/bug/view.cgi?id=748
|
|
|
|
|
|
10. SOCKS
|
|
|
|
10.1 SOCKS proxy connections are done blocking
|
|
|
|
Both SOCKS5 and SOCKS4 proxy connections are done blocking, which is very bad
|
|
when used with the multi interface.
|
|
|
|
10.2 SOCKS don't support timeouts
|
|
|
|
The SOCKS4 connection codes don't properly acknowledge (connect) timeouts.
|
|
According to bug #1556528, even the SOCKS5 connect code does not do it right:
|
|
https://curl.haxx.se/bug/view.cgi?id=604
|
|
|
|
When connecting to a SOCK proxy, the (connect) timeout is not properly
|
|
acknowledged after the actual TCP connect (during the SOCKS "negotiate"
|
|
phase).
|
|
|
|
10.3 FTPS over SOCKS
|
|
|
|
libcurl doesn't support FTPS over a SOCKS proxy.
|
|
|
|
10.4 active FTP over a SOCKS
|
|
|
|
libcurl doesn't support active FTP over a SOCKS proxy
|
|
|
|
|
|
11. Internals
|
|
|
|
11.1 Curl leaks .onion hostnames in DNS
|
|
|
|
Curl sends DNS requests for hostnames with a .onion TLD. This leaks
|
|
information about what the user is attempting to access, and violates this
|
|
requirement of RFC7686: https://tools.ietf.org/html/rfc7686
|
|
|
|
Issue: https://github.com/curl/curl/issues/543
|
|
|
|
11.2 error buffer not set if connection to multiple addresses fails
|
|
|
|
If you ask libcurl to resolve a hostname like example.com to IPv6 addresses
|
|
only. But you only have IPv4 connectivity. libcurl will correctly fail with
|
|
CURLE_COULDNT_CONNECT. But the error buffer set by CURLOPT_ERRORBUFFER
|
|
remains empty. Issue: https://github.com/curl/curl/issues/544
|
|
|
|
11.3 c-ares deviates from stock resolver on http://1346569778
|
|
|
|
When using the socket resolvers, that URL becomes:
|
|
|
|
* Rebuilt URL to: http://1346569778/
|
|
* Trying 80.67.6.50...
|
|
|
|
but with c-ares it instead says "Could not resolve: 1346569778 (Domain name
|
|
not found)"
|
|
|
|
See https://github.com/curl/curl/issues/893
|
|
|
|
11.4 HTTP test server 'connection-monitor' problems
|
|
|
|
The 'connection-monitor' feature of the sws HTTP test server doesn't work
|
|
properly if some tests are run in unexpected order. Like 1509 and then 1525.
|
|
|
|
See https://github.com/curl/curl/issues/868
|
|
|
|
11.5 Connection information when using TCP Fast Open
|
|
|
|
CURLINFO_LOCAL_PORT (and possibly a few other) fails when TCP Fast Open is
|
|
enabled.
|
|
|
|
See https://github.com/curl/curl/issues/1332
|
|
|
|
11.6 slow connect to localhost on Windows
|
|
|
|
When connecting to "localhost" on Windows, curl will resolve the name for
|
|
both ipv4 and ipv6 and try to connect to both happy eyeballs-style. Something
|
|
in there does however make it take 200 milliseconds to succeed - which is the
|
|
HAPPY_EYEBALLS_TIMEOUT define exactly. Lowering that define speeds up the
|
|
connection, suggesting a problem in the HE handling.
|
|
|
|
If we can *know* that we're talking to a local host, we should lower the
|
|
happy eyeballs delay timeout for IPv6 (related: hardcode the "localhost"
|
|
addresses, mentioned in TODO). Possibly we should reduce that delay for all.
|
|
|
|
https://github.com/curl/curl/issues/2281
|
|
|
|
12. LDAP and OpenLDAP
|
|
|
|
12.1 OpenLDAP hangs after returning results
|
|
|
|
By configuration defaults, openldap automatically chase referrals on
|
|
secondary socket descriptors. The OpenLDAP backend is asynchronous and thus
|
|
should monitor all socket descriptors involved. Currently, these secondary
|
|
descriptors are not monitored, causing openldap library to never receive
|
|
data from them.
|
|
|
|
As a temporary workaround, disable referrals chasing by configuration.
|
|
|
|
The fix is not easy: proper automatic referrals chasing requires a
|
|
synchronous bind callback and monitoring an arbitrary number of socket
|
|
descriptors for a single easy handle (currently limited to 5).
|
|
|
|
Generic LDAP is synchronous: OK.
|
|
|
|
See https://github.com/curl/curl/issues/622 and
|
|
https://curl.haxx.se/mail/lib-2016-01/0101.html
|
|
|
|
|
|
13. TCP/IP
|
|
|
|
13.1 --interface for ipv6 binds to unusable IP address
|
|
|
|
Since IPv6 provides a lot of addresses with different scope, binding to an
|
|
IPv6 address needs to take the proper care so that it doesn't bind to a
|
|
locally scoped address as that is bound to fail.
|
|
|
|
https://github.com/curl/curl/issues/686
|
|
|
|
14. DICT
|
|
|
|
14.1 DICT responses show the underlying protocol
|
|
|
|
When getting a DICT response, the protocol parts of DICT aren't stripped off
|
|
from the output.
|
|
|
|
https://github.com/curl/curl/issues/1809
|