search for: ssl_op_cipher_server_preference

...cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-3389 "The internet" has some workarounds for this problem. For example, in Apache webserver, you need to set SSLHonorCipherOrder On in apache config. This results in the following C-Code being executed: SSL_CTX_set_options(ctx, SSL_OP_CIPHER_SERVER_PREFERENCE); This setting tells OpenSSL not to honor the Ciper Order sent from the client, but prefer it's own configured set of CipherSuites. According to Qualis SSL Labs ( https://www.ssllabs.com/ssldb/index.html ), a webserver configured with this setting is not affected by that BEAST security leak....

RedHat released sendmail-8.13.8-10.el5_11.src.rpm which includes sendmail-8.13.8-ssl-opts.patch which adds support for disabling SSLv3 and SSLv2 in sendmail.cf But as far as I can see there is no support in sendmail.mc - I can't see how to compile sendmail.mc to get the required line ServerSSLOptions in sendmail.cf Does anyone know how to do this ? -- Andrew Daviel, TRIUMF, Canada

...ssl docs https://www.openssl.org/docs/man1.1.1/man3/SSL_CONF_cmd.html BOTH are valid 'Options', ... ServerPreference: use server and not client preference order when determining which cipher suite, signature algorithm or elliptic curve to use for an incoming connection. Equivalent to SSL_OP_CIPHER_SERVER_PREFERENCE. Only used by servers. PrioritizeChaCha: prioritizes ChaCha ciphers when the client has a ChaCha20 cipher at the top of its preference list. This usually indicates a mobile client is in use. Equivalent to SSL_OP_PRIORITIZE_CHACHA. Only used by servers. ... The mere presence of that option in a...

...quired line > ServerSSLOptions in sendmail.cf > > > Does anyone know how to do this ? At the end of sendmail.mc, after the MAILER macros, add a LOCAL_CONFIG, e.g,, LOCAL_CONFIG O ClientSSLOptions=+SSL_OP_NO_SSLv2 +SSL_OP_NO_SSLv3 O ServerSSLOptions=+SSL_OP_NO_SSLv2 +SSL_OP_NO_SSLv3 +SSL_OP_CIPHER_SERVER_PREFERENCE -- Paul Heinlein heinlein at madboa.com 45?38' N, 122?6' W

...penssl.org/docs/man1.1.1/man3/SSL_CONF_cmd.html > > BOTH are valid 'Options', > > ... > ServerPreference: use server and not client preference order when determining which cipher suite, signature algorithm or elliptic curve to use for an incoming connection. Equivalent to SSL_OP_CIPHER_SERVER_PREFERENCE. Only used by servers. > > PrioritizeChaCha: prioritizes ChaCha ciphers when the client has a ChaCha20 cipher at the top of its preference list. This usually indicates a mobile client is in use. Equivalent to SSL_OP_PRIORITIZE_CHACHA. Only used by servers. > ... > > > The mer...

Hi Is there known advices on how to favor PFS with dovecot? In Apache, I use the following directives, with cause all modern browsers to adopt 256 bit PFS ciphers, while keeping backward compatibility with older browsers and avoiding BEAST attack: SSLProtocol all -SSLv2 SSLHonorCipherOrder On SSLCipherSuite ECDHE at STRENGTH:ECDH at STRENGTH:DH at STRENGTH:HIGH:-SSLv3-SHA1:-TLSv10

...ar *ssl_lowest_version; bool ssl_verify_client_cert; bool ssl_require_crl; --- a/src/login-common/ssl-proxy-openssl.c +++ b/src/login-common/ssl-proxy-openssl.c @@ -1302,7 +1302,20 @@ ssl_server_context_init(const struct log if (ctx->prefer_server_ciphers) SSL_CTX_set_options(ssl_ctx, SSL_OP_CIPHER_SERVER_PREFERENCE); SSL_CTX_set_options(ssl_ctx, openssl_get_protocol_options(ctx->protocols)); - +#if OPENSSL_VERSION_NUMBER >= 0x10100000 + if (ssl_set->ssl_lowest_version) { + if (!strcmp(ssl_set->ssl_lowest_version, "TLS1.0")) + SSL_CTX_set_min_proto_version(ssl_ctx, TLS1_VERSION);...

Am 04.07.2015 um 15:34 schrieb Gregory P. Ennis <PoMec at PoMec.Net>: > On Sat, 2015-07-04 at 08:07 -0500, Gregory P. Ennis wrote: >> Everyone, >> >> Looks like the new version of oppenssl has broken my sendmail's use >> of >> tls. Has anyone else had this problem or seen a fix? >> >> Greg Ennis >>

...man3/SSL_CONF_cmd.html > > > > BOTH are valid 'Options', > > > > ... > > ServerPreference: use server and not client preference order when determining which cipher suite, signature algorithm or elliptic curve to use for an incoming connection. Equivalent to SSL_OP_CIPHER_SERVER_PREFERENCE. Only used by servers. > > > > PrioritizeChaCha: prioritizes ChaCha ciphers when the client has a ChaCha20 cipher at the top of its preference list. This usually indicates a mobile client is in use. Equivalent to SSL_OP_PRIORITIZE_CHACHA. Only used by servers. > > ... > >...

Hi, I came up with the following patch while trying to figure out a good solution for the situation described in Debian bug #871987[1]. In short, OpenSSL in Debian unstable has disabled TLSv1.0 and TLSv1.1 *by default*. That means that unless an application requests otherwise, only TLSv1.2 is supported. In the world of e-mail this is seemingly an issue, as there are still way too many old clients