Commit 0a597075 authored by Paul Bakker's avatar Paul Bakker

- Added simple SSL session cache implementation

 - Revamped session resumption handling
parent 1a0f5520
......@@ -26,6 +26,7 @@ Features
* Added PKCS#5 PBKDF2 key derivation function
* Added Secure Renegotiation (RFC 5746)
* Added predefined DHM groups from RFC 5114
* Added simple SSL session cache implementation
Changes
* Removed redundant POLARSSL_DEBUG_MSG define
......@@ -38,6 +39,7 @@ Changes
* Cipher layer cipher_mode_t POLARSSL_MODE_CFB128 is renamed to
POLARSSL_MODE_CFB, to also handle different block size CFB modes.
* Removed handling for SSLv2 Client Hello (as per RFC 5246 recommendation)
* Revamped session resumption handling
Bugfix
* Fixed handling error in mpi_cmp_mpi() on longer B values (found by
......
......@@ -3,7 +3,7 @@
*
* \brief Configuration options (set of defines)
*
* Copyright (C) 2006-2011, Brainspark B.V.
* Copyright (C) 2006-2012, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
......@@ -683,6 +683,18 @@
*/
#define POLARSSL_SHA4_C
/**
* \def POLARSSL_SSL_CACHE_C
*
* Enable simple SSL cache implementation.
*
* Module: library/ssl_cache.c
* Caller:
*
* Requires: POLARSSL_SSL_CACHE_C
*/
#define POLARSSL_SSL_CACHE_C
/**
* \def POLARSSL_SSL_CLI_C
*
......
......@@ -284,7 +284,7 @@ typedef struct _ssl_transform ssl_transform;
typedef struct _ssl_handshake_params ssl_handshake_params;
/*
* This structure is used for session resuming.
* This structure is used for storing current session data.
*/
struct _ssl_session
{
......@@ -295,7 +295,6 @@ struct _ssl_session
unsigned char id[32]; /*!< session identifier */
unsigned char master[48]; /*!< the master secret */
x509_cert *peer_cert; /*!< peer X.509 cert chain */
ssl_session *next; /*!< next session entry */
};
/*
......@@ -362,6 +361,8 @@ struct _ssl_handshake_params
unsigned char randbytes[64]; /*!< random bytes */
unsigned char premaster[256]; /*!< premaster secret */
int resume; /*!< session resume indicator*/
};
struct _ssl_context
......@@ -386,24 +387,24 @@ struct _ssl_context
int (*f_recv)(void *, unsigned char *, size_t);
int (*f_send)(void *, const unsigned char *, size_t);
int (*f_vrfy)(void *, x509_cert *, int, int);
int (*f_get_cache)(void *, ssl_session *);
int (*f_set_cache)(void *, const ssl_session *);
void *p_rng; /*!< context for the RNG function */
void *p_dbg; /*!< context for the debug function */
void *p_recv; /*!< context for reading operations */
void *p_send; /*!< context for writing operations */
void *p_vrfy; /*!< context for verification */
void *p_vrfy; /*!< context for verification */
void *p_get_cache; /*!< context for cache retrieval */
void *p_set_cache; /*!< context for cache store */
/*
* Session layer
*/
int resume; /*!< session resuming flag */
int timeout; /*!< sess. expiration time */
ssl_session *session_in; /*!< current session data (in) */
ssl_session *session_out; /*!< current session data (out) */
ssl_session *session; /*!< negotiated session data */
ssl_session *session_negotiate; /*!< session data in negotiation */
int (*s_get)(ssl_context *); /*!< (server) get callback */
int (*s_set)(ssl_context *); /*!< (server) set callback */
ssl_handshake_params *handshake; /*!< params required only during
the handshake process */
......@@ -636,26 +637,59 @@ void ssl_set_bio( ssl_context *ssl,
int (*f_send)(void *, const unsigned char *, size_t), void *p_send );
/**
* \brief Set the session callbacks (server-side only)
* \brief Set the session cache callbacks (server-side only)
* If not set, no session resuming is done.
*
* \param ssl SSL context
* \param s_get session get callback
* \param s_set session set callback
* The session cache has the responsibility to check for stale
* entries based on timeout. See RFC 5246 for recommendations.
*
* Warning: session.peer_cert is cleared by the SSL/TLS layer on
* connection shutdown, so do not cache the pointer! Either set
* it to NULL or make a full copy of the certificate.
*
* The get callback is called once during the initial handshake
* to enable session resuming. The get function has the
* following parameters: (void *parameter, ssl_session *session)
* If a valid entry is found, it should fill the master of
* the session object with the cached values and return 0,
* return 1 otherwise. Optionally peer_cert can be set as well
* if it is properly present in cache entry.
*
* The set callback is called once during the initial handshake
* to enable session resuming after the entire handshake has
* been finished. The set function has the following parameters:
* (void *parameter, const ssl_session *session). The function
* should create a cache entry for future retrieval based on
* the data in the session structure and should keep in mind
* that the ssl_session object presented (and all its referenced
* data) is cleared by the SSL/TLS layer when the connection is
* terminated. It is recommended to add metadata to determine if
* an entry is still valid in the future. Return 0 if
* successfully cached, return 0 otherwise.
*
* \param ssl SSL context
* \param f_get_cache session get callback
* \param p_get_cache session get parameter
* \param f_set_cache session set callback
* \param p_set_cache session set parameter
*/
void ssl_set_scb( ssl_context *ssl,
int (*s_get)(ssl_context *),
int (*s_set)(ssl_context *) );
void ssl_set_session_cache( ssl_context *ssl,
int (*f_get_cache)(void *, ssl_session *), void *p_get_cache,
int (*f_set_cache)(void *, const ssl_session *), void *p_set_cache );
/**
* \brief Set the session resuming flag, timeout and data
* \brief Request resumption of session (client-side only)
* Session data is copied from presented session structure.
*
* Warning: session.peer_cert is cleared by the SSL/TLS layer on
* connection shutdown, so do not cache the pointer! Either set
* it to NULL or make a full copy of the certificate when
* storing the session for use in this function.
*
* \param ssl SSL context
* \param resume if 0 (default), the session will not be resumed
* \param timeout session timeout in seconds, or 0 (no timeout)
* \param session session context
*/
void ssl_set_session( ssl_context *ssl, int resume, int timeout,
ssl_session *session );
void ssl_set_session( ssl_context *ssl, const ssl_session *session );
/**
* \brief Set the list of allowed ciphersuites
......@@ -900,8 +934,8 @@ int ssl_close_notify( ssl_context *ssl );
void ssl_free( ssl_context *ssl );
/**
* \brief Free referenced items in an SSL session and free all
* sessions in the chain. Memory is cleared
* \brief Free referenced items in an SSL session including the
* peer certificate and clear memory
*
* \param session SSL session
*/
......
/**
* \file ssl_cache.h
*
* \brief SSL session cache implementation
*
* Copyright (C) 2006-2012, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef POLARSSL_SSL_CACHE_H
#define POLARSSL_SSL_CACHE_H
#include "ssl.h"
#define SSL_CACHE_DEFAULT_TIMEOUT 86400 /*!< 1 day */
#ifdef __cplusplus
extern "C" {
#endif
typedef struct _ssl_cache_context ssl_cache_context;
typedef struct _ssl_cache_entry ssl_cache_entry;
/**
* \brief This structure is used for storing cache entries
*/
struct _ssl_cache_entry
{
time_t timestamp; /*!< entry timestamp */
ssl_session session; /*!< entry session */
ssl_cache_entry *next; /*!< chain pointer */
};
/**
* \brief Cache context
*/
struct _ssl_cache_context
{
ssl_cache_entry *chain; /*!< start of the chain */
int timeout; /*!< cache timeout */
};
/**
* \brief Initialize an SSL cache context
*
* \param cache SSL cache context
*/
void ssl_cache_init( ssl_cache_context *cache );
/**
* \brief Cache get callback implementation
*
* \param data SSL cache context
* \param session session to retrieve entry for
*/
int ssl_cache_get( void *data, ssl_session *session );
/**
* \brief Cache set callback implementation
*
* \param data SSL cache context
* \param session session to store entry for
*/
int ssl_cache_set( void *data, const ssl_session *session );
/**
* \brief Set the cache timeout
* (Default: SSL_CACHE_DEFAULT_TIMEOUT (1 day))
*
* A timeout of 0 indicates no timeout.
*
* \param cache SSL cache context
* \param timeout cache entry timeout
*/
void ssl_cache_set_timeout( ssl_cache_context *cache, int timeout );
/**
* \brief Free referenced items in a cache context and clear memory
*
* \param cache SSL cache context
*/
void ssl_cache_free( ssl_cache_context *cache );
#ifdef __cplusplus
}
#endif
#endif /* ssl_cache.h */
......@@ -35,6 +35,7 @@ set(src
sha1.c
sha2.c
sha4.c
ssl_cache.c
ssl_cli.c
ssl_srv.c
ssl_tls.c
......
......@@ -44,10 +44,10 @@ OBJS= aes.o arc4.o asn1parse.o \
padlock.o pbkdf2.o pem.o \
pkcs11.o \
rsa.o sha1.o sha2.o \
sha4.o ssl_cli.o ssl_srv.o \
sha4.o ssl_cache.o ssl_cli.o \
ssl_srv.o \
ssl_tls.o timing.o version.o \
x509parse.o x509write.o xtea.o
.SILENT:
......
/*
* SSL session cache implementation
*
* Copyright (C) 2006-2012, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/*
* These session callbacks use a simple chained list
* to store and retrieve the session information.
*/
#include "polarssl/config.h"
#if defined(POLARSSL_SSL_CACHE_C)
#include "polarssl/ssl_cache.h"
#include <stdlib.h>
void ssl_cache_init( ssl_cache_context *cache )
{
memset( cache, 0, sizeof( ssl_cache_context ) );
cache->timeout = SSL_CACHE_DEFAULT_TIMEOUT;
}
int ssl_cache_get( void *data, ssl_session *session )
{
time_t t = time( NULL );
ssl_cache_context *cache = (ssl_cache_context *) data;
ssl_cache_entry *cur, *entry;
cur = cache->chain;
entry = NULL;
while( cur != NULL )
{
entry = cur;
cur = cur->next;
if( cache->timeout != 0 &&
(int) ( t - entry->timestamp ) > cache->timeout )
continue;
if( session->ciphersuite != entry->session.ciphersuite ||
session->compression != entry->session.compression ||
session->length != entry->session.length )
continue;
if( memcmp( session->id, entry->session.id,
entry->session.length ) != 0 )
continue;
memcpy( session->master, entry->session.master, 48 );
return( 0 );
}
return( 1 );
}
int ssl_cache_set( void *data, const ssl_session *session )
{
time_t t = time( NULL );
ssl_cache_context *cache = (ssl_cache_context *) data;
ssl_cache_entry *cur, *prv;
cur = cache->chain;
prv = NULL;
while( cur != NULL )
{
if( cache->timeout != 0 &&
(int) ( t - cur->timestamp ) > cache->timeout )
{
cur->timestamp = t;
break; /* expired, reuse this slot, update timestamp */
}
if( memcmp( session->id, cur->session.id, cur->session.length ) == 0 )
break; /* client reconnected, keep timestamp for session id */
prv = cur;
cur = cur->next;
}
if( cur == NULL )
{
cur = (ssl_cache_entry *) malloc( sizeof( ssl_cache_entry ) );
if( cur == NULL )
return( 1 );
memset( cur, 0, sizeof( ssl_cache_entry ) );
if( prv == NULL )
cache->chain = cur;
else
prv->next = cur;
cur->timestamp = t;
}
memcpy( &cur->session, session, sizeof( ssl_session ) );
// Do not include peer_cert in cache entry
//
cur->session.peer_cert = NULL;
return( 0 );
}
void ssl_cache_set_timeout( ssl_cache_context *cache, int timeout )
{
if( timeout < 0 ) timeout = 0;
cache->timeout = timeout;
}
void ssl_cache_free( ssl_cache_context *cache )
{
ssl_cache_entry *cur, *prv;
cur = cache->chain;
while( cur != NULL )
{
prv = cur;
cur = cur->next;
ssl_session_free( &prv->session );
free( prv );
}
}
#endif /* POLARSSL_SSL_CACHE_C */
......@@ -111,9 +111,8 @@ static int ssl_write_client_hello( ssl_context *ssl )
*/
n = ssl->session_negotiate->length;
if( n < 16 || n > 32 || ssl->resume == 0 ||
( ssl->timeout != 0 &&
t - ssl->session_negotiate->start > ssl->timeout ) )
if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE || n < 16 || n > 32 ||
ssl->handshake->resume == 0 )
n = 0;
*p++ = (unsigned char) n;
......@@ -473,14 +472,15 @@ static int ssl_parse_server_hello( ssl_context *ssl )
/*
* Check if the session can be resumed
*/
if( ssl->resume == 0 || n == 0 ||
if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE ||
ssl->handshake->resume == 0 || n == 0 ||
ssl->session_negotiate->ciphersuite != i ||
ssl->session_negotiate->compression != comp ||
ssl->session_negotiate->length != n ||
memcmp( ssl->session_negotiate->id, buf + 39, n ) != 0 )
{
ssl->state++;
ssl->resume = 0;
ssl->handshake->resume = 0;
ssl->session_negotiate->start = time( NULL );
ssl->session_negotiate->ciphersuite = i;
ssl->session_negotiate->compression = comp;
......@@ -499,7 +499,7 @@ static int ssl_parse_server_hello( ssl_context *ssl )
}
SSL_DEBUG_MSG( 3, ( "%s session has been resumed",
ssl->resume ? "a" : "no" ) );
ssl->handshake->resume ? "a" : "no" ) );
SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %d", i ) );
SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: %d", buf[41 + n] ) );
......
......@@ -456,21 +456,16 @@ static int ssl_write_server_hello( ssl_context *ssl )
ssl->session_negotiate->length = n = 32;
*p++ = (unsigned char) ssl->session_negotiate->length;
if( ssl->s_get == NULL ||
ssl->s_get( ssl ) != 0 )
if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE ||
ssl->f_get_cache == NULL ||
ssl->f_get_cache( ssl->p_get_cache, ssl->session_negotiate ) != 0 )
{
/*
* Not found, create a new session id
*/
ssl->resume = 0;
ssl->handshake->resume = 0;
ssl->state++;
if( ssl->session_negotiate == NULL )
{
SSL_DEBUG_MSG( 1, ( "No session struct set" ) );
return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
}
if( ( ret = ssl->f_rng( ssl->p_rng, ssl->session_negotiate->id,
n ) ) != 0 )
return( ret );
......@@ -478,9 +473,9 @@ static int ssl_write_server_hello( ssl_context *ssl )
else
{
/*
* Found a matching session, resume it
* Found a matching session, resuming it
*/
ssl->resume = 1;
ssl->handshake->resume = 1;
ssl->state = SSL_SERVER_CHANGE_CIPHER_SPEC;
if( ( ret = ssl_derive_keys( ssl ) ) != 0 )
......@@ -496,7 +491,7 @@ static int ssl_write_server_hello( ssl_context *ssl )
SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) );
SSL_DEBUG_BUF( 3, "server hello, session id", buf + 39, n );
SSL_DEBUG_MSG( 3, ( "%s session has been resumed",
ssl->resume ? "a" : "no" ) );
ssl->handshake->resume ? "a" : "no" ) );
*p++ = (unsigned char)( ssl->session_negotiate->ciphersuite >> 8 );
*p++ = (unsigned char)( ssl->session_negotiate->ciphersuite );
......@@ -987,9 +982,6 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
return( ret );
}
if( ssl->s_set != NULL )
ssl->s_set( ssl );
ssl->state++;
SSL_DEBUG_MSG( 2, ( "<= parse client key exchange" ) );
......
......@@ -317,7 +317,7 @@ int ssl_derive_keys( ssl_context *ssl )
* TLSv1:
* master = PRF( premaster, "master secret", randbytes )[0..47]
*/
if( ssl->resume == 0 )
if( handshake->resume == 0 )
{
SSL_DEBUG_BUF( 3, "premaster secret", handshake->premaster,
handshake->pmslen );
......@@ -2641,24 +2641,20 @@ void ssl_handshake_wrapup( ssl_context *ssl )
ssl->transform = ssl->transform_negotiate;
ssl->transform_negotiate = NULL;
if( ssl->session )
{
ssl_session_free( ssl->session );
free( ssl->session );
}
ssl->session = ssl->session_negotiate;
ssl->session_negotiate = NULL;
/*
* Migrate data to existing session structure (in chain)
* Step 1. Clear existing data (but not the rest of the chain)
* Step 2. Migrate data to existing object in chain
* Step 3. Remove negotiation session object without removing items pointed
* to
* Add cache entry
*/
ssl->session_negotiate->next = ssl->session->next;
ssl->session->next = NULL;
ssl_session_free( ssl->session );
memcpy( ssl->session, ssl->session_negotiate, sizeof(ssl_session) );
ssl->session_in = ssl->session;
ssl->session_out = ssl->session;
memset( ssl->session_negotiate, 0, sizeof(ssl_session) );
free( ssl->session_negotiate );
ssl->session_negotiate = NULL;
if( ssl->f_set_cache != NULL )
if( ssl->f_set_cache( ssl->p_set_cache, ssl->session ) != 0 )
SSL_DEBUG_MSG( 1, ( "cache did not store session" ) );
ssl->state++;
......@@ -2687,7 +2683,7 @@ int ssl_write_finished( ssl_context *ssl )
* In case of session resuming, invert the client and server
* ChangeCipherSpec messages order.
*/
if( ssl->resume != 0 )
if( ssl->handshake->resume != 0 )
{
if( ssl->endpoint == SSL_IS_CLIENT )
ssl->state = SSL_HANDSHAKE_WRAPUP;
......@@ -2765,7 +2761,7 @@ int ssl_parse_finished( ssl_context *ssl )
ssl->verify_data_len = hash_len;
memcpy( ssl->peer_verify_data, buf, hash_len );
if( ssl->resume != 0 )
if( ssl->handshake->resume != 0 )
{
if( ssl->endpoint == SSL_IS_CLIENT )
ssl->state = SSL_CLIENT_CHANGE_CIPHER_SPEC;
......@@ -2970,20 +2966,20 @@ void ssl_set_bio( ssl_context *ssl,
ssl->p_send = p_send;
}
void ssl_set_scb( ssl_context *ssl,
int (*s_get)(ssl_context *),
int (*s_set)(ssl_context *) )
void ssl_set_session_cache( ssl_context *ssl,
int (*f_get_cache)(void *, ssl_session *), void *p_get_cache,
int (*f_set_cache)(void *, const ssl_session *), void *p_set_cache )
{
ssl->s_get = s_get;
ssl->s_set = s_set;
ssl->f_get_cache = f_get_cache;
ssl->p_get_cache = p_get_cache;
ssl->f_set_cache = f_set_cache;
ssl->p_set_cache = p_set_cache;
}
void ssl_set_session( ssl_context *ssl, int resume, int timeout,
ssl_session *session )
void ssl_set_session( ssl_context *ssl, const ssl_session *session )
{
ssl->resume = resume;
ssl->timeout = timeout;
ssl->session = session;
memcpy( ssl->session_negotiate, session, sizeof(ssl_session) );
ssl->handshake->resume = 1;
}
void ssl_set_ciphersuites( ssl_context *ssl, const int *ciphersuites )
......@@ -3687,23 +3683,13 @@ void ssl_handshake_free( ssl_handshake_params *handshake )
void ssl_session_free( ssl_session *session )
{
ssl_session *cur = session, *prv;
while( cur != NULL )
if( session->peer_cert != NULL )
{
prv = cur;
cur = cur->next;
if( prv->peer_cert != NULL )
{
x509_free( prv->peer_cert );
free( prv->peer_cert );
}
memset( prv, 0, sizeof( ssl_session ) );
if( prv != session )
free( prv );
x509_free( session->peer_cert );
free( session->peer_cert );
}
memset( session, 0, sizeof( ssl_session ) );
}
/*
......
......@@ -78,7 +78,6 @@ int main( int argc, char *argv[] )
entropy_context entropy;
ctr_drbg_context ctr_drbg;
ssl_context ssl;
ssl_session ssn;
((void) argc);
((void) argv);
......@@ -86,7 +85,6 @@ int main( int argc, char *argv[] )
/*
* 0. Initialize the RNG and the session data
*/
memset( &ssn, 0, sizeof( ssl_session ) );
memset( &ssl, 0, sizeof( ssl_context ) );
printf( "\n . Seeding the random number generator..." );
......@@ -141,7 +139,6 @@ int main( int argc, char *argv[] )
net_send, &server_fd );
ssl_set_ciphersuites( &ssl, ssl_default_ciphersuites );
ssl_set_session( &ssl, 1, 600, &ssn );
/*
* 3. Write the GET request
......
......@@ -131,7 +131,6 @@ int main( int argc, char *argv[] )
entropy_context entropy;
ctr_drbg_context ctr_drbg;
ssl_context ssl;
ssl_session ssn;
x509_cert cacert;
x509_cert clicert;
rsa_context rsa;
......@@ -144,7 +143,6 @@ int main( int argc, char *argv[] )
* Make sure memory references are valid.
*/
server_fd = 0;
memset( &ssn, 0, sizeof( ssl_session ) );
memset( &ssl, 0, sizeof( ssl_context ) );
memset( &cacert, 0, sizeof( x509_cert ) );
memset( &clicert, 0, sizeof( x509_cert ) );
......@@ -389,8 +387,6 @@ int main( int argc, char *argv[] )
ssl_set_renegotiation( &ssl, opt.renegotiation );
ssl_legacy_renegotiation( &ssl, opt.allow_legacy );
ssl_set_session( &ssl, 1, 600, &ssn );
ssl_set_ca_chain( &ssl, &cacert, NULL, opt.server_name );
ssl_set_own_cert( &ssl, &clicert, &rsa );
......@@ -518,7 +514,6 @@ exit:
x509_free( &clicert );
x509_free( &cacert );
rsa_free( &rsa );
ssl_session_free( &ssn );
ssl_free( &ssl );
memset( &ssl, 0, sizeof( ssl ) );
......
......@@ -126,80 +126,6 @@ void my_debug( void *ctx, int level, const char *str )
}
}
/*
* These session callbacks use a simple chained list
* to store and retrieve the session information.
*/