text: /*-
   * SSLsplit - transparent SSL/TLS interception
   * https://www.roe.ch/SSLsplit
   *
   * Copyright (c) 2009-2019, Daniel Roethlisberger <daniel@roe.ch>.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   * 1. Redistributions of source code must retain the above copyright notice,
   *    this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS ``AS IS''
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "cachessess.h"
  
  #include "dynbuf.h"
  #include "ssl.h"
  #include "khash.h"
  
  /*
   * Cache for incoming src connection SSL sessions.
   *
   * key: dynbuf_t *  SSL session ID
   * val: dynbuf_t *  ASN.1 serialized SSL_SESSION
   */
  
  static inline khint_t
  kh_dynbuf_hash_func(dynbuf_t *b)
  {
  	khint_t *p = (khint_t *)b->buf;
  	khint_t h = 0;
  	int rem;
  
  	if ((rem = b->sz % sizeof(khint_t))) {
  		memcpy(&h, b->buf + b->sz - rem, rem);
  	}
  
  	while (p < (khint_t*)(b->buf + b->sz - rem)) {
  		h ^= *p++;
  	}
  
  	return h;
  }
  
  #define kh_dynbuf_hash_equal(a, b) \
          (((a)->sz == (b)->sz) && \
           (memcmp((a)->buf, (b)->buf, (a)->sz) == 0))
  
  KHASH_INIT(dynbufmap_t, dynbuf_t*, dynbuf_t*, 1, kh_dynbuf_hash_func,
             kh_dynbuf_hash_equal)
  
  static khash_t(dynbufmap_t) *srcsessmap;
  
  static cache_iter_t
  cachessess_begin_cb(void)
  {
  	return kh_begin(srcsessmap);
  }
  
  static cache_iter_t
  cachessess_end_cb(void)
  {
  	return kh_end(srcsessmap);
  }
  
  static int
  cachessess_exist_cb(cache_iter_t it)
  {
  	return kh_exist(srcsessmap, it);
  }
  
  static void
  cachessess_del_cb(cache_iter_t it)
  {
  	kh_del(dynbufmap_t, srcsessmap, it);
  }
  
  static cache_iter_t
  cachessess_get_cb(cache_key_t key)
  {
  	return kh_get(dynbufmap_t, srcsessmap, key);
  }
  
  static cache_iter_t
  cachessess_put_cb(cache_key_t key, int *ret)
  {
  	return kh_put(dynbufmap_t, srcsessmap, key, ret);
  }
  
  static void
  cachessess_free_key_cb(cache_key_t key)
  {
  	dynbuf_free(key);
  }
  
  static void
  cachessess_free_val_cb(cache_val_t val)
  {
  	dynbuf_free(val);
  }
  
  static cache_key_t
  cachessess_get_key_cb(cache_iter_t it)
  {
  	return kh_key(srcsessmap, it);
  }
  
  static cache_val_t
  cachessess_get_val_cb(cache_iter_t it)
  {
  	return kh_val(srcsessmap, it);
  }
  
  static void
  cachessess_set_val_cb(cache_iter_t it, cache_val_t val)
  {
  	kh_val(srcsessmap, it) = val;
  }
  
  static cache_val_t
  cachessess_unpackverify_val_cb(cache_val_t val, int copy)
  {
  	dynbuf_t *valbuf = val;
  	SSL_SESSION *sess;
  	const unsigned char *p;
  
  	p = (const unsigned char *)valbuf->buf;
  	sess = d2i_SSL_SESSION(NULL, &p, valbuf->sz); /* increments p */
  	if (!sess)
  		return NULL;
  	if (!ssl_session_is_valid(sess)) {
  		SSL_SESSION_free(sess);
  		return NULL;
  	}
  	if (copy)
  		return sess;
  	SSL_SESSION_free(sess);
  	return ((void*)-1);
  }
  
  static void
  cachessess_fini_cb(void)
  {
  	kh_destroy(dynbufmap_t, srcsessmap);
  }
  
  void
  cachessess_init_cb(cache_t *cache)
  {
  	srcsessmap = kh_init(dynbufmap_t);
  
  	cache->begin_cb                 = cachessess_begin_cb;
  	cache->end_cb                   = cachessess_end_cb;
  	cache->exist_cb                 = cachessess_exist_cb;
  	cache->del_cb                   = cachessess_del_cb;
  	cache->get_cb                   = cachessess_get_cb;
  	cache->put_cb                   = cachessess_put_cb;
  	cache->free_key_cb              = cachessess_free_key_cb;
  	cache->free_val_cb              = cachessess_free_val_cb;
  	cache->get_key_cb               = cachessess_get_key_cb;
  	cache->get_val_cb               = cachessess_get_val_cb;
  	cache->set_val_cb               = cachessess_set_val_cb;
  	cache->unpackverify_val_cb      = cachessess_unpackverify_val_cb;
  	cache->fini_cb                  = cachessess_fini_cb;
  }
  
  cache_key_t
  cachessess_mkkey(const unsigned char *id, const size_t idlen)
  {
  	return dynbuf_new_copy(id, idlen);
  }
  
  cache_val_t
  cachessess_mkval(SSL_SESSION *sess)
  {
  	dynbuf_t *db;
  	unsigned char *p;
  	size_t asn1sz;
  
  	asn1sz = i2d_SSL_SESSION(sess, NULL);
  	if (!asn1sz || !(db = dynbuf_new_alloc(asn1sz))) {
  		return NULL;
  	}
  	p = db->buf;
  	i2d_SSL_SESSION(sess, &p); /* updates p */
  	return db;
  }
  
  /* vim: set noet ft=c: */
  