b4f9ae5126
- If the user set a legacy algorithm list (CURLOPT_SSL_CIPHER_LIST) then
use the SCHANNEL_CRED legacy structure to pass the list to Schannel.
- If the user set both a legacy algorithm list and a TLS 1.3 cipher list
then abort.
Although MS doesn't document it, Schannel will not negotiate TLS 1.3
when SCHANNEL_CRED is used. That means setting a legacy algorithm list
limits the user to earlier versions of TLS.
Prior to this change, since 8beff435 (precedes 7.85.0), libcurl would
ignore legacy algorithms in Windows 10 1809 and later.
Reported-by: zhihaoy@users.noreply.github.com
Fixes https://github.com/curl/curl/pull/10741
Closes https://github.com/curl/curl/pull/10746
89 lines
3.4 KiB
Groff
89 lines
3.4 KiB
Groff
.\" **************************************************************************
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.\" * _ _ ____ _
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.\" * Project ___| | | | _ \| |
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.\" * / __| | | | |_) | |
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.\" * | (__| |_| | _ <| |___
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.\" * \___|\___/|_| \_\_____|
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.\" *
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.\" * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
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.\" *
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.\" * This software is licensed as described in the file COPYING, which
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.\" * you should have received as part of this distribution. The terms
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.\" * are also available at https://curl.se/docs/copyright.html.
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.\" *
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.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
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.\" * copies of the Software, and permit persons to whom the Software is
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.\" * furnished to do so, under the terms of the COPYING file.
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.\" *
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.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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.\" * KIND, either express or implied.
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.\" *
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.\" * SPDX-License-Identifier: curl
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.\" *
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.\" **************************************************************************
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.\"
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.TH CURLOPT_SSL_CIPHER_LIST 3 "17 Jun 2014" libcurl libcurl
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.SH NAME
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CURLOPT_SSL_CIPHER_LIST \- ciphers to use for TLS
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.SH SYNOPSIS
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.nf
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#include <curl/curl.h>
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CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSL_CIPHER_LIST, char *list);
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.fi
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.SH DESCRIPTION
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Pass a char *, pointing to a null-terminated string holding the list of
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ciphers to use for the SSL connection. The list must be syntactically correct,
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it consists of one or more cipher strings separated by colons. Commas or
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spaces are also acceptable separators but colons are normally used, \&!, \&-
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and \&+ can be used as operators.
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For OpenSSL and GnuTLS valid examples of cipher lists include \fBRC4-SHA\fP,
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\fBSHA1+DES\fP, \fBTLSv1\fP and \fBDEFAULT\fP. The default list is normally
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set when you compile OpenSSL.
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For WolfSSL, valid examples of cipher lists include \fBECDHE-RSA-RC4-SHA\fP,
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\fBAES256-SHA:AES256-SHA256\fP, etc.
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For BearSSL, valid examples of cipher lists include
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\fBECDHE-RSA-CHACHA20-POLY1305:ECDHE-RSA-AES128-GCM-SHA256\fP, or when using IANA names
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\fBTLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256:TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256\fP,
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etc.
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With BearSSL you do not add/remove ciphers. If one uses this option then all
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known ciphers are disabled and only those passed in are enabled.
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For Schannel, you can use this option to set algorithms but not specific cipher
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suites. Refer to the ciphers lists document for algorithms.
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You will find more details about cipher lists on this URL:
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https://curl.se/docs/ssl-ciphers.html
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The application does not have to keep the string around after setting this
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option.
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.SH DEFAULT
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NULL, use internal default
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.SH PROTOCOLS
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All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.
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.SH EXAMPLE
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.nf
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CURL *curl = curl_easy_init();
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if(curl) {
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curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
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curl_easy_setopt(curl, CURLOPT_SSL_CIPHER_LIST, "TLSv1");
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ret = curl_easy_perform(curl);
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curl_easy_cleanup(curl);
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}
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.fi
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.SH AVAILABILITY
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Added in 7.9, in 7.83.0 for BearSSL
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If built TLS enabled.
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.SH RETURN VALUE
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Returns CURLE_OK if TLS is supported, CURLE_UNKNOWN_OPTION if not, or
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CURLE_OUT_OF_MEMORY if there was insufficient heap space.
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.SH "SEE ALSO"
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.BR CURLOPT_TLS13_CIPHERS "(3), " CURLOPT_SSLVERSION "(3), "
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.BR CURLOPT_PROXY_SSL_CIPHER_LIST "(3), " CURLOPT_PROXY_TLS13_CIPHERS "(3), "
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.BR CURLOPT_USE_SSL "(3), "
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