From 0966ab5bd4ad547c74e1032899c87f7214bc5b73 Mon Sep 17 00:00:00 2001 From: JDepooter Date: Thu, 2 Feb 2017 13:40:16 -0800 Subject: darwinssl: Warn that disabling host verify also disables SNI In DarwinSSL the SSLSetPeerDomainName function is used to enable both sending SNI and verifying the host. When host verification is disabled the function cannot be called, therefore SNI is disabled as well. Closes https://github.com/curl/curl/pull/1240 --- docs/libcurl/opts/CURLOPT_SSL_VERIFYHOST.3 | 13 ++++++++++--- lib/vtls/darwinssl.c | 3 +++ 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/docs/libcurl/opts/CURLOPT_SSL_VERIFYHOST.3 b/docs/libcurl/opts/CURLOPT_SSL_VERIFYHOST.3 index 159147327..acadd0774 100644 --- a/docs/libcurl/opts/CURLOPT_SSL_VERIFYHOST.3 +++ b/docs/libcurl/opts/CURLOPT_SSL_VERIFYHOST.3 @@ -58,9 +58,16 @@ The default value for this option is 2. This option controls checking the server's certificate's claimed identity. The server could be lying. To control lying, see -\fICURLOPT_SSL_VERIFYPEER(3)\fP. If libcurl is built against NSS and -\fICURLOPT_SSL_VERIFYPEER(3)\fP is zero, \fICURLOPT_SSL_VERIFYHOST(3)\fP is -also set to zero and cannot be overridden. +\fICURLOPT_SSL_VERIFYPEER(3)\fP. +.SH LIMITATIONS +DarwinSSL: If \fIverify\fP value is 0, then SNI is also disabled. SNI is a TLS +extension that sends the hostname to the server. The server may use that +information to do such things as sending back a specific certificate for the +hostname, or forwarding the request to a specific origin server. Some hostnames +may be inaccessible if SNI is not sent. + +NSS: If \fICURLOPT_SSL_VERIFYPEER(3)\fP is zero, +\fICURLOPT_SSL_VERIFYHOST(3)\fP is also set to zero and cannot be overridden. .SH DEFAULT 2 .SH PROTOCOLS diff --git a/lib/vtls/darwinssl.c b/lib/vtls/darwinssl.c index 050bf960b..25a8ab8b6 100644 --- a/lib/vtls/darwinssl.c +++ b/lib/vtls/darwinssl.c @@ -1425,6 +1425,9 @@ static CURLcode darwinssl_connect_step1(struct connectdata *conn, "the OS.\n"); } } + else { + infof(data, "WARNING: disabling hostname validation also disables SNI.\n"); + } /* Disable cipher suites that ST supports but are not safe. These ciphers are unlikely to be used in any case since ST gives other ciphers a much -- cgit v1.2.3