Skip to content

bpo-32185: Don't send IP in SNI TLS extension #5865

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Feb 25, 2018
Merged

bpo-32185: Don't send IP in SNI TLS extension #5865

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Library/2017-12-20-09-25-10.bpo-32185.IL0cMt.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
The SSL module no longer sends IP addresses in SNI TLS extension on
platforms with OpenSSL 1.0.2+ or inet_pton.
42 changes: 40 additions & 2 deletions Modules/_ssl.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -55,6 +55,11 @@ static PySocketModule_APIObject PySocketModule;
#include <sys/poll.h>
#endif

#ifndef MS_WINDOWS
/* inet_pton */
#include <arpa/inet.h>
#endif

/* Don't warn about deprecated functions */
#ifdef __GNUC__
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
Expand Down Expand Up @@ -667,8 +672,41 @@ newPySSLSocket(PySSLContext *sslctx, PySocketSockObject *sock,
SSL_set_mode(self->ssl, mode);

#if HAVE_SNI
if (server_hostname != NULL)
SSL_set_tlsext_host_name(self->ssl, server_hostname);
if (server_hostname != NULL) {
/* Don't send SNI for IP addresses. We cannot simply use inet_aton() and
* inet_pton() here. inet_aton() may be linked weakly and inet_pton() isn't
* available on all platforms. Use OpenSSL's IP address parser. It's
* available since 1.0.2 and LibreSSL since at least 2.3.0. */
int send_sni = 1;
#if OPENSSL_VERSION_NUMBER >= 0x10200000L
ASN1_OCTET_STRING *ip = a2i_IPADDRESS(server_hostname);
if (ip == NULL) {
send_sni = 1;
ERR_clear_error();
} else {
send_sni = 0;
ASN1_OCTET_STRING_free(ip);
}
#elif defined(HAVE_INET_PTON)
#ifdef ENABLE_IPV6
char packed[Py_MAX(sizeof(struct in_addr), sizeof(struct in6_addr))];
#else
char packed[sizeof(struct in_addr)];
#endif /* ENABLE_IPV6 */
if (inet_pton(AF_INET, server_hostname, packed)) {
send_sni = 0;
#ifdef ENABLE_IPV6
} else if(inet_pton(AF_INET6, server_hostname, packed)) {
send_sni = 0;
#endif /* ENABLE_IPV6 */
} else {
send_sni = 1;
}
#endif /* HAVE_INET_PTON */
if (send_sni) {
SSL_set_tlsext_host_name(self->ssl, server_hostname);
}
}
#endif

/* If the socket is in non-blocking mode or timeout mode, set the BIO
Expand Down