MEDIUM: ssl: add bind-option "strict-sni"

This new option ensures that there is no possible fallback to a default
certificate if the client does not provide an SNI which is explicitly
handled by a certificate.
This commit is contained in:
Emmanuel Hocdet 2013-01-24 17:17:15 +01:00 committed by Willy Tarreau
parent cb2699a152
commit 656233715e
3 changed files with 33 additions and 7 deletions

View File

@ -7241,6 +7241,12 @@ ssl
appear in clear text, so that ACLs and HTTP processing will only have access
to deciphered contents.
strict-sni
This setting is only available when support for OpenSSL was built in. The
SSL/TLS negotiation is allow only if the client provided an SNI which match
a certificate. The default certificate is not used.
See the "crt" option for more information.
tfo
Is an optional keyword which is supported only on Linux kernels >= 3.6. It
enables TCP Fast Open on the listening socket, which means that clients which

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@ -127,6 +127,7 @@ struct bind_conf {
SSL_CTX *default_ctx; /* SSL context of first/default certificate */
char *npn_str; /* NPN protocol string */
int npn_len; /* NPN protocol string length */
int strict_sni; /* refuse negotiation if sni doesn't match a certificate */
struct eb_root sni_ctx; /* sni_ctx tree of all known certs full-names sorted by name */
struct eb_root sni_w_ctx; /* sni_ctx tree of all known certs wildcards sorted by name */
#endif

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@ -178,8 +178,12 @@ static int ssl_sock_switchctx_cbk(SSL *ssl, int *al, struct bind_conf *s)
(void)al; /* shut gcc stupid warning */
servername = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name);
if (!servername)
return SSL_TLSEXT_ERR_NOACK;
if (!servername) {
if (s->strict_sni)
return SSL_TLSEXT_ERR_ALERT_FATAL;
else
return SSL_TLSEXT_ERR_NOACK;
}
for (i = 0; i < trash.size; i++) {
if (!servername[i])
@ -193,13 +197,20 @@ static int ssl_sock_switchctx_cbk(SSL *ssl, int *al, struct bind_conf *s)
/* lookup in full qualified names */
node = ebst_lookup(&s->sni_ctx, trash.str);
if (!node) {
if (!wildp)
return SSL_TLSEXT_ERR_ALERT_WARNING;
if (!wildp) {
if (s->strict_sni)
return SSL_TLSEXT_ERR_ALERT_FATAL;
else
return SSL_TLSEXT_ERR_ALERT_WARNING;
}
/* lookup in full wildcards names */
node = ebst_lookup(&s->sni_w_ctx, wildp);
if (!node)
return SSL_TLSEXT_ERR_ALERT_WARNING;
if (!node) {
if (s->strict_sni)
return SSL_TLSEXT_ERR_ALERT_FATAL;
else
return SSL_TLSEXT_ERR_ALERT_WARNING;
}
}
/* switch ctx */
@ -2569,6 +2580,13 @@ static int bind_parse_ssl(char **args, int cur_arg, struct proxy *px, struct bin
return 0;
}
/* parse the "strict-sni" bind keyword */
static int bind_parse_strict_sni(char **args, int cur_arg, struct proxy *px, struct bind_conf *conf, char **err)
{
conf->strict_sni = 1;
return 0;
}
/* parse the "verify" bind keyword */
static int bind_parse_verify(char **args, int cur_arg, struct proxy *px, struct bind_conf *conf, char **err)
{
@ -2888,6 +2906,7 @@ static struct bind_kw_list bind_kws = { "SSL", { }, {
{ "no-tlsv12", bind_parse_no_tlsv12, 0 }, /* disable TLSv12 */
{ "no-tls-tickets", bind_parse_no_tls_tickets, 0 }, /* disable session resumption tickets */
{ "ssl", bind_parse_ssl, 0 }, /* enable SSL processing */
{ "strict-sni", bind_parse_strict_sni, 0 }, /* refuse negotiation if sni doesn't match a certificate */
{ "verify", bind_parse_verify, 1 }, /* set SSL verify method */
{ "npn", bind_parse_npn, 1 }, /* set NPN supported protocols */
{ NULL, NULL, 0 },