SSL: single allocation in session cache on 32-bit platforms. Given the present typical SSL session sizes, on 32-bit platforms it is now beneficial to store all data in a single allocation, since rbtree node + session id + ASN1 representation of a session takes 256 bytes of shared memory (36 + 32 + 150 = about 218 bytes plus SNI server name). Storing all data in a single allocation is beneficial for SNI names up to about 40 characters long and makes it possible to store about 4000 sessions in one megabyte (instead of about 3000 sessions now). This also slightly simplifies the code.

/*
 * 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_ */