[nginx] SSL: the $ssl_client_escaped_cert variable (ticket #857).

[Maxim Dounin]

details:   http://hg.nginx.org/nginx/rev/82f0b8dcca27
branches:  
changeset: 7091:82f0b8dcca27
user:      Maxim Dounin <mdounin at mdounin.ru>
date:      Tue Aug 22 15:18:10 2017 +0300
description:
SSL: the $ssl_client_escaped_cert variable (ticket #857).

This variable contains URL-encoded client SSL certificate.  In contrast
to $ssl_client_cert, it doesn't depend on deprecated header continuation.
The NGX_ESCAPE_URI_COMPONENT variant of encoding is used, so the resulting
variable can be safely used not only in headers, but also as a request
argument.

The $ssl_client_cert variable should be considered deprecated now.
The $ssl_client_raw_cert variable will be eventually renambed back
to $ssl_client_cert.

diffstat:

 src/event/ngx_event_openssl.c          |  30 ++++++++++++++++++++++++++++++
 src/event/ngx_event_openssl.h          |   2 ++
 src/http/modules/ngx_http_ssl_module.c |   4 ++++
 src/stream/ngx_stream_ssl_module.c     |   4 ++++
 4 files changed, 40 insertions(+), 0 deletions(-)

diffs (80 lines):

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -3663,6 +3663,36 @@ ngx_ssl_get_certificate(ngx_connection_t
 
 
 ngx_int_t
+ngx_ssl_get_escaped_certificate(ngx_connection_t *c, ngx_pool_t *pool,
+    ngx_str_t *s)
+{
+    ngx_str_t  cert;
+    uintptr_t  n;
+
+    if (ngx_ssl_get_raw_certificate(c, pool, &cert) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+    if (cert.len == 0) {
+        s->len = 0;
+        return NGX_OK;
+    }
+
+    n = ngx_escape_uri(NULL, cert.data, cert.len, NGX_ESCAPE_URI_COMPONENT);
+
+    s->len = cert.len + n * 2;
+    s->data = ngx_pnalloc(pool, s->len);
+    if (s->data == NULL) {
+        return NGX_ERROR;
+    }
+
+    ngx_escape_uri(s->data, cert.data, cert.len, NGX_ESCAPE_URI_COMPONENT);
+
+    return NGX_OK;
+}
+
+
+ngx_int_t
 ngx_ssl_get_subject_dn(ngx_connection_t *c, ngx_pool_t *pool, ngx_str_t *s)
 {
     BIO        *bio;
diff --git a/src/event/ngx_event_openssl.h b/src/event/ngx_event_openssl.h
--- a/src/event/ngx_event_openssl.h
+++ b/src/event/ngx_event_openssl.h
@@ -212,6 +212,8 @@ ngx_int_t ngx_ssl_get_raw_certificate(ng
     ngx_str_t *s);
 ngx_int_t ngx_ssl_get_certificate(ngx_connection_t *c, ngx_pool_t *pool,
     ngx_str_t *s);
+ngx_int_t ngx_ssl_get_escaped_certificate(ngx_connection_t *c, ngx_pool_t *pool,
+    ngx_str_t *s);
 ngx_int_t ngx_ssl_get_subject_dn(ngx_connection_t *c, ngx_pool_t *pool,
     ngx_str_t *s);
 ngx_int_t ngx_ssl_get_issuer_dn(ngx_connection_t *c, ngx_pool_t *pool,
diff --git a/src/http/modules/ngx_http_ssl_module.c b/src/http/modules/ngx_http_ssl_module.c
--- a/src/http/modules/ngx_http_ssl_module.c
+++ b/src/http/modules/ngx_http_ssl_module.c
@@ -299,6 +299,10 @@ static ngx_http_variable_t  ngx_http_ssl
       (uintptr_t) ngx_ssl_get_raw_certificate,
       NGX_HTTP_VAR_CHANGEABLE, 0 },
 
+    { ngx_string("ssl_client_escaped_cert"), NULL, ngx_http_ssl_variable,
+      (uintptr_t) ngx_ssl_get_escaped_certificate,
+      NGX_HTTP_VAR_CHANGEABLE, 0 },
+
     { ngx_string("ssl_client_s_dn"), NULL, ngx_http_ssl_variable,
       (uintptr_t) ngx_ssl_get_subject_dn, NGX_HTTP_VAR_CHANGEABLE, 0 },
 
diff --git a/src/stream/ngx_stream_ssl_module.c b/src/stream/ngx_stream_ssl_module.c
--- a/src/stream/ngx_stream_ssl_module.c
+++ b/src/stream/ngx_stream_ssl_module.c
@@ -249,6 +249,10 @@ static ngx_stream_variable_t  ngx_stream
       (uintptr_t) ngx_ssl_get_raw_certificate,
       NGX_STREAM_VAR_CHANGEABLE, 0 },
 
+    { ngx_string("ssl_client_escaped_cert"), NULL, ngx_stream_ssl_variable,
+      (uintptr_t) ngx_ssl_get_escaped_certificate,
+      NGX_STREAM_VAR_CHANGEABLE, 0 },
+
     { ngx_string("ssl_client_s_dn"), NULL, ngx_stream_ssl_variable,
       (uintptr_t) ngx_ssl_get_subject_dn, NGX_STREAM_VAR_CHANGEABLE, 0 },