Hi,

I was able to add support for elliptic curve cryptography. Nginx has to be compiled with Openssl 1.0.0 libraries, though. The patch against nginx-0.8.54 is here (sorry I do not know how to add attachment). Basicly, it ads extra configuration parameter ssl_eccurve with which one can specify the elliptic curve. If this parameter is missing then the default secp224r1 curve is used.

[code]
diff -rupN nginx-0.8.54/src/event/ngx_event_openssl.c nginx-0.8.54p/src/event/ngx_event_openssl.c
--- nginx-0.8.54/src/event/ngx_event_openssl.c 2010-07-29 12:30:15.000000000 +0300
+++ nginx-0.8.54p/src/event/ngx_event_openssl.c 2011-01-04 17:11:08.000000000 +0200
@@ -479,6 +479,60 @@ ngx_ssl_dhparam(ngx_conf_t *cf, ngx_ssl_
return NGX_OK;
}

+ngx_int_t
+ngx_ssl_eccurve(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *named_curve)
+{
+ /*
+ * Elliptic-Curve Diffie-Hellman parameters are either "named curves"
+ * from RFC 4492 section 5.1.1, or explicitly described curves over
+ * binary fields. OpenSSL only supports the "named curves", which provide
+ * maximum interoperability.
+ */
+
+ EC_KEY *ecdh=NULL;
+ int nid;
+
+ if (named_curve->len) {
+ nid = OBJ_sn2nid( (const char *) named_curve->data);
+
+ if (nid == 0) {
+ ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0, "Unknown curve name (%s)\n", named_curve->data);
+
+ EC_KEY_free(ecdh);
+ return NGX_ERROR;
+ }
+
+ ecdh = EC_KEY_new_by_curve_name(nid);
+
+ if (ecdh == NULL) {
+ ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0, "Unable to create curve (%s)\n", named_curve->data);
+
+ EC_KEY_free(ecdh);
+ return NGX_ERROR;
+ }
+
+ SSL_CTX_set_tmp_ecdh(ssl->ctx, ecdh);
+
+ EC_KEY_free(ecdh);
+
+ return NGX_OK;
+ }
+
+ ecdh = EC_KEY_new_by_curve_name(NID_secp224r1);
+
+ if (ecdh == NULL) {
+ ngx_ssl_error(NGX_LOG_EMERG, ssl->log, 0, "Unable to create curve (%s)\n", named_curve->data);
+
+ EC_KEY_free(ecdh);
+ return NGX_ERROR;
+ }
+
+ SSL_CTX_set_tmp_ecdh(ssl->ctx, ecdh);
+
+ EC_KEY_free(ecdh);
+
+ return NGX_OK;
+}

ngx_int_t
ngx_ssl_create_connection(ngx_ssl_t *ssl, ngx_connection_t *c, ngx_uint_t flags)
diff -rupN nginx-0.8.54/src/event/ngx_event_openssl.h nginx-0.8.54p/src/event/ngx_event_openssl.h
--- nginx-0.8.54/src/event/ngx_event_openssl.h 2010-03-03 18:23:14.000000000 +0200
+++ nginx-0.8.54p/src/event/ngx_event_openssl.h 2011-01-04 14:57:00.000000000 +0200
@@ -101,6 +101,7 @@ ngx_int_t ngx_ssl_client_certificate(ngx
ngx_int_t ngx_ssl_crl(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *crl);
ngx_int_t ngx_ssl_generate_rsa512_key(ngx_ssl_t *ssl);
ngx_int_t ngx_ssl_dhparam(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *file);
+ngx_int_t ngx_ssl_eccurve(ngx_conf_t *cf, ngx_ssl_t *ssl, ngx_str_t *named_curve);
ngx_int_t ngx_ssl_session_cache(ngx_ssl_t *ssl, ngx_str_t *sess_ctx,
ssize_t builtin_session_cache, ngx_shm_zone_t *shm_zone, time_t timeout);
ngx_int_t ngx_ssl_create_connection(ngx_ssl_t *ssl, ngx_connection_t *c,
diff -rupN nginx-0.8.54/src/http/modules/ngx_http_ssl_module.c nginx-0.8.54p/src/http/modules/ngx_http_ssl_module.c
--- nginx-0.8.54/src/http/modules/ngx_http_ssl_module.c 2010-05-14 12:56:37.000000000 +0300
+++ nginx-0.8.54p/src/http/modules/ngx_http_ssl_module.c 2011-01-04 16:06:10.000000000 +0200
@@ -77,7 +77,14 @@ static ngx_command_t ngx_http_ssl_comma
NGX_HTTP_SRV_CONF_OFFSET,
offsetof(ngx_http_ssl_srv_conf_t, dhparam),
NULL },
-
+
+ { ngx_string("ssl_eccurve"),
+ NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
+ ngx_conf_set_str_slot,
+ NGX_HTTP_SRV_CONF_OFFSET,
+ offsetof(ngx_http_ssl_srv_conf_t, eccurve),
+ NULL },
+
{ ngx_string("ssl_protocols"),
NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_1MORE,
ngx_conf_set_bitmask_slot,
@@ -312,6 +319,7 @@ ngx_http_ssl_create_srv_conf(ngx_conf_t
* sscf->certificate = { 0, NULL };
* sscf->certificate_key = { 0, NULL };
* sscf->dhparam = { 0, NULL };
+ * sscf->eccurve = { 0, NULL };
* sscf->client_certificate = { 0, NULL };
* sscf->crl = { 0, NULL };
* sscf->ciphers = { 0, NULL };
@@ -356,6 +364,8 @@ ngx_http_ssl_merge_srv_conf(ngx_conf_t *

ngx_conf_merge_str_value(conf->dhparam, prev->dhparam, "");

+ ngx_conf_merge_str_value(conf->eccurve, prev->eccurve, "");
+
ngx_conf_merge_str_value(conf->client_certificate, prev->client_certificate,
"");
ngx_conf_merge_str_value(conf->crl, prev->crl, "");
@@ -473,6 +483,10 @@ ngx_http_ssl_merge_srv_conf(ngx_conf_t *
return NGX_CONF_ERROR;
}

+ if (ngx_ssl_eccurve(cf, &conf->ssl, &conf->eccurve) != NGX_OK) {
+ return NGX_CONF_ERROR;
+ }
+
ngx_conf_merge_value(conf->builtin_session_cache,
prev->builtin_session_cache, NGX_SSL_NONE_SCACHE);

diff -rupN nginx-0.8.54/src/http/modules/ngx_http_ssl_module.h nginx-0.8.54p/src/http/modules/ngx_http_ssl_module.h
--- nginx-0.8.54/src/http/modules/ngx_http_ssl_module.h 2009-07-23 15:21:26.000000000 +0300
+++ nginx-0.8.54p/src/http/modules/ngx_http_ssl_module.h 2011-01-04 15:41:00.000000000 +0200
@@ -32,6 +32,7 @@ typedef struct {
ngx_str_t certificate;
ngx_str_t certificate_key;
ngx_str_t dhparam;
+ ngx_str_t eccurve;
ngx_str_t client_certificate;
ngx_str_t crl;

diff -rupN nginx-0.8.54/src/mail/ngx_mail_ssl_module.c nginx-0.8.54p/src/mail/ngx_mail_ssl_module.c
--- nginx-0.8.54/src/mail/ngx_mail_ssl_module.c 2010-05-14 12:56:37.000000000 +0300
+++ nginx-0.8.54p/src/mail/ngx_mail_ssl_module.c 2011-01-04 14:55:00.000000000 +0200
@@ -77,6 +77,13 @@ static ngx_command_t ngx_mail_ssl_comma
offsetof(ngx_mail_ssl_conf_t, dhparam),
NULL },

+ { ngx_string("ssl_eccurve"),
+ NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
+ ngx_conf_set_str_slot,
+ NGX_MAIL_SRV_CONF_OFFSET,
+ offsetof(ngx_mail_ssl_conf_t, eccurve),
+ NULL },
+
{ ngx_string("ssl_protocols"),
NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE,
ngx_conf_set_bitmask_slot,
@@ -163,6 +170,7 @@ ngx_mail_ssl_create_conf(ngx_conf_t *cf)
* scf->certificate = { 0, NULL };
* scf->certificate_key = { 0, NULL };
* scf->dhparam = { 0, NULL };
+ * scf->eccurve = { 0, NULL };
* scf->ciphers = { 0, NULL };
* scf->shm_zone = NULL;
*/
@@ -204,6 +212,8 @@ ngx_mail_ssl_merge_conf(ngx_conf_t *cf,

ngx_conf_merge_str_value(conf->dhparam, prev->dhparam, "");

+ ngx_conf_merge_str_value(conf->eccurve, prev->eccurve, "");
+
ngx_conf_merge_str_value(conf->ciphers, prev->ciphers, NGX_DEFAULT_CIPHERS);


@@ -294,6 +304,10 @@ ngx_mail_ssl_merge_conf(ngx_conf_t *cf,
return NGX_CONF_ERROR;
}

+ if (ngx_ssl_eccurve(cf, &conf->ssl, &conf->eccurve) != NGX_OK) {
+ return NGX_CONF_ERROR;
+ }
+
ngx_conf_merge_value(conf->builtin_session_cache,
prev->builtin_session_cache, NGX_SSL_NONE_SCACHE);

diff -rupN nginx-0.8.54/src/mail/ngx_mail_ssl_module.h nginx-0.8.54p/src/mail/ngx_mail_ssl_module.h
--- nginx-0.8.54/src/mail/ngx_mail_ssl_module.h 2008-09-01 17:19:01.000000000 +0300
+++ nginx-0.8.54p/src/mail/ngx_mail_ssl_module.h 2011-01-04 14:49:00.000000000 +0200
@@ -34,6 +34,7 @@ typedef struct {
ngx_str_t certificate;
ngx_str_t certificate_key;
ngx_str_t dhparam;
+ ngx_str_t eccurve;

ngx_str_t ciphers;

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