From 61ec58a9bed5ec0cae60c3f3b8d46382beecc5c6 Mon Sep 17 00:00:00 2001 From: Maxim Dounin Date: Thu, 19 May 2016 14:46:32 +0300 Subject: [PATCH] SSL: removed default DH parameters. Using the same DH parameters on multiple servers is believed to be subject to precomputation attacks, see http://weakdh.org/. Additionally, 1024 bits are not enough in the modern world as well. Let users provide their own DH parameters with the ssl_dhparam directive if they want to use EDH ciphers. Note that SSL_CTX_set_dh_auto() as provided by OpenSSL 1.1.0 uses fixed DH parameters from RFC 5114 and RFC 3526, and therefore subject to the same precomputation attacks. We avoid using it as well. This change also fixes compilation with OpenSSL 1.1.0-pre5 (aka Beta 2), as OpenSSL developers changed their policy after releasing Beta 1 and broke API once again by making the DH struct opaque (see ticket #860). --- src/event/ngx_event_openssl.c | 45 ----------------------------------- 1 file changed, 45 deletions(-) diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c index 96c059be9..810c46995 100644 --- a/src/event/ngx_event_openssl.c +++ b/src/event/ngx_event_openssl.c @@ -981,52 +981,7 @@ ngx_ssl_dhparam(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *file) DH *dh; BIO *bio; - /* - * -----BEGIN DH PARAMETERS----- - * MIGHAoGBALu8LcrYRnSQfEP89YDpz9vZWKP1aLQtSwju1OsPs1BMbAMCducQgAxc - * y7qokiYUxb7spWWl/fHSh6K8BJvmd4Bg6RqSp1fjBI9osHb302zI8pul34HcLKcl - * 7OZicMyaUDXYzs7vnqAnSmOrHlj6/UmI0PZdFGdX2gcd8EXP4WubAgEC - * -----END DH PARAMETERS----- - */ - - static unsigned char dh1024_p[] = { - 0xBB, 0xBC, 0x2D, 0xCA, 0xD8, 0x46, 0x74, 0x90, 0x7C, 0x43, 0xFC, 0xF5, - 0x80, 0xE9, 0xCF, 0xDB, 0xD9, 0x58, 0xA3, 0xF5, 0x68, 0xB4, 0x2D, 0x4B, - 0x08, 0xEE, 0xD4, 0xEB, 0x0F, 0xB3, 0x50, 0x4C, 0x6C, 0x03, 0x02, 0x76, - 0xE7, 0x10, 0x80, 0x0C, 0x5C, 0xCB, 0xBA, 0xA8, 0x92, 0x26, 0x14, 0xC5, - 0xBE, 0xEC, 0xA5, 0x65, 0xA5, 0xFD, 0xF1, 0xD2, 0x87, 0xA2, 0xBC, 0x04, - 0x9B, 0xE6, 0x77, 0x80, 0x60, 0xE9, 0x1A, 0x92, 0xA7, 0x57, 0xE3, 0x04, - 0x8F, 0x68, 0xB0, 0x76, 0xF7, 0xD3, 0x6C, 0xC8, 0xF2, 0x9B, 0xA5, 0xDF, - 0x81, 0xDC, 0x2C, 0xA7, 0x25, 0xEC, 0xE6, 0x62, 0x70, 0xCC, 0x9A, 0x50, - 0x35, 0xD8, 0xCE, 0xCE, 0xEF, 0x9E, 0xA0, 0x27, 0x4A, 0x63, 0xAB, 0x1E, - 0x58, 0xFA, 0xFD, 0x49, 0x88, 0xD0, 0xF6, 0x5D, 0x14, 0x67, 0x57, 0xDA, - 0x07, 0x1D, 0xF0, 0x45, 0xCF, 0xE1, 0x6B, 0x9B - }; - - static unsigned char dh1024_g[] = { 0x02 }; - - if (file->len == 0) { - - dh = DH_new(); - if (dh == NULL) { - ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0, "DH_new() failed"); - return NGX_ERROR; - } - - dh->p = BN_bin2bn(dh1024_p, sizeof(dh1024_p), NULL); - dh->g = BN_bin2bn(dh1024_g, sizeof(dh1024_g), NULL); - - if (dh->p == NULL || dh->g == NULL) { - ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0, "BN_bin2bn() failed"); - DH_free(dh); - return NGX_ERROR; - } - - SSL_CTX_set_tmp_dh(ssl->ctx, dh); - - DH_free(dh); - return NGX_OK; }