SSL: $ssl_curves (ticket #1088). The variable contains a list of curves as supported by the client. Known curves are listed by their names, unknown ones are shown in hex, e.g., "0x001d:prime256v1:secp521r1:secp384r1". Note that OpenSSL uses session data for SSL_get1_curves(), and it doesn't store full list of curves supported by the client when serializing a session. As a result $ssl_curves is only available for new sessions (and will be empty for reused ones). The variable is only meaningful when using OpenSSL 1.0.2 and above. With older versions the variable is empty.

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_MD5_H_INCLUDED_
#define _NGX_MD5_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


typedef struct {
    uint64_t  bytes;
    uint32_t  a, b, c, d;
    u_char    buffer[64];
} ngx_md5_t;


void ngx_md5_init(ngx_md5_t *ctx);
void ngx_md5_update(ngx_md5_t *ctx, const void *data, size_t size);
void ngx_md5_final(u_char result[16], ngx_md5_t *ctx);


#endif /* _NGX_MD5_H_INCLUDED_ */