ssl_ciph.c

mediastreamer2是开源的网络传输媒体流的库

/* ssl/ssl_ciph.c */
/* Copyright (C) 1995-1998 Eric Young ([e-mail])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([e-mail]).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson ([e-mail]).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * 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 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young ([e-mail])"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson ([e-mail])"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 AUTHOR 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.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 * ECC cipher suite support in OpenSSL originally developed by 
 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
 */
#include <stdio.h>
#include <openssl/objects.h>
#include <openssl/comp.h>
#include "ssl_locl.h"

#define SSL_ENC_DES_IDX		0
#define SSL_ENC_3DES_IDX	1
#define SSL_ENC_RC4_IDX		2
#define SSL_ENC_RC2_IDX		3
#define SSL_ENC_IDEA_IDX	4
#define SSL_ENC_eFZA_IDX	5
#define SSL_ENC_NULL_IDX	6
#define SSL_ENC_AES128_IDX	7
#define SSL_ENC_AES256_IDX	8
#define SSL_ENC_NUM_IDX		9

static const EVP_CIPHER *ssl_cipher_methods[SSL_ENC_NUM_IDX]={
	NULL,NULL,NULL,NULL,NULL,NULL,
	};

#define SSL_COMP_NULL_IDX	0
#define SSL_COMP_ZLIB_IDX	1
#define SSL_COMP_NUM_IDX	2

static STACK_OF(SSL_COMP) *ssl_comp_methods=NULL;

#define SSL_MD_MD5_IDX	0
#define SSL_MD_SHA1_IDX	1
#define SSL_MD_NUM_IDX	2
static const EVP_MD *ssl_digest_methods[SSL_MD_NUM_IDX]={
	NULL,NULL,
	};

#define CIPHER_ADD	1
#define CIPHER_KILL	2
#define CIPHER_DEL	3
#define CIPHER_ORD	4
#define CIPHER_SPECIAL	5

typedef struct cipher_order_st
	{
	SSL_CIPHER *cipher;
	int active;
	int dead;
	struct cipher_order_st *next,*prev;
	} CIPHER_ORDER;

static const SSL_CIPHER cipher_aliases[]={
	/* Don't include eNULL unless specifically enabled. */
	/* Don't include ECC in ALL because these ciphers are not yet official. */
	{0,SSL_TXT_ALL, 0,SSL_ALL & ~SSL_eNULL & ~SSL_kECDH & ~SSL_kECDHE, SSL_ALL ,0,0,0,SSL_ALL,SSL_ALL}, /* must be first */
	/* TODO: COMPLEMENT OF ALL and COMPLEMENT OF DEFAULT do not have ECC cipher suites handled properly. */
	{0,SSL_TXT_CMPALL,0,SSL_eNULL,0,0,0,0,SSL_ENC_MASK,0},  /* COMPLEMENT OF ALL */
	{0,SSL_TXT_CMPDEF,0,SSL_ADH, 0,0,0,0,SSL_AUTH_MASK,0},
	{0,SSL_TXT_kKRB5,0,SSL_kKRB5,0,0,0,0,SSL_MKEY_MASK,0},  /* VRS Kerberos5 */
	{0,SSL_TXT_kRSA,0,SSL_kRSA,  0,0,0,0,SSL_MKEY_MASK,0},
	{0,SSL_TXT_kDHr,0,SSL_kDHr,  0,0,0,0,SSL_MKEY_MASK,0},
	{0,SSL_TXT_kDHd,0,SSL_kDHd,  0,0,0,0,SSL_MKEY_MASK,0},
	{0,SSL_TXT_kEDH,0,SSL_kEDH,  0,0,0,0,SSL_MKEY_MASK,0},
	{0,SSL_TXT_kFZA,0,SSL_kFZA,  0,0,0,0,SSL_MKEY_MASK,0},
	{0,SSL_TXT_DH,	0,SSL_DH,    0,0,0,0,SSL_MKEY_MASK,0},
	{0,SSL_TXT_ECC,	0,(SSL_kECDH|SSL_kECDHE), 0,0,0,0,SSL_MKEY_MASK,0},
	{0,SSL_TXT_EDH,	0,SSL_EDH,   0,0,0,0,SSL_MKEY_MASK|SSL_AUTH_MASK,0},
	{0,SSL_TXT_aKRB5,0,SSL_aKRB5,0,0,0,0,SSL_AUTH_MASK,0},  /* VRS Kerberos5 */
	{0,SSL_TXT_aRSA,0,SSL_aRSA,  0,0,0,0,SSL_AUTH_MASK,0},
	{0,SSL_TXT_aDSS,0,SSL_aDSS,  0,0,0,0,SSL_AUTH_MASK,0},
	{0,SSL_TXT_aFZA,0,SSL_aFZA,  0,0,0,0,SSL_AUTH_MASK,0},
	{0,SSL_TXT_aNULL,0,SSL_aNULL,0,0,0,0,SSL_AUTH_MASK,0},
	{0,SSL_TXT_aDH, 0,SSL_aDH,   0,0,0,0,SSL_AUTH_MASK,0},
	{0,SSL_TXT_DSS,	0,SSL_DSS,   0,0,0,0,SSL_AUTH_MASK,0},

	{0,SSL_TXT_DES,	0,SSL_DES,   0,0,0,0,SSL_ENC_MASK,0},
	{0,SSL_TXT_3DES,0,SSL_3DES,  0,0,0,0,SSL_ENC_MASK,0},
	{0,SSL_TXT_RC4,	0,SSL_RC4,   0,0,0,0,SSL_ENC_MASK,0},
	{0,SSL_TXT_RC2,	0,SSL_RC2,   0,0,0,0,SSL_ENC_MASK,0},
#ifndef OPENSSL_NO_IDEA
	{0,SSL_TXT_IDEA,0,SSL_IDEA,  0,0,0,0,SSL_ENC_MASK,0},
#endif
	{0,SSL_TXT_eNULL,0,SSL_eNULL,0,0,0,0,SSL_ENC_MASK,0},
	{0,SSL_TXT_eFZA,0,SSL_eFZA,  0,0,0,0,SSL_ENC_MASK,0},
	{0,SSL_TXT_AES,	0,SSL_AES,   0,0,0,0,SSL_ENC_MASK,0},

	{0,SSL_TXT_MD5,	0,SSL_MD5,   0,0,0,0,SSL_MAC_MASK,0},
	{0,SSL_TXT_SHA1,0,SSL_SHA1,  0,0,0,0,SSL_MAC_MASK,0},
	{0,SSL_TXT_SHA,	0,SSL_SHA,   0,0,0,0,SSL_MAC_MASK,0},

	{0,SSL_TXT_NULL,0,SSL_NULL,  0,0,0,0,SSL_ENC_MASK,0},
	{0,SSL_TXT_KRB5,0,SSL_KRB5,  0,0,0,0,SSL_AUTH_MASK|SSL_MKEY_MASK,0},
	{0,SSL_TXT_RSA,	0,SSL_RSA,   0,0,0,0,SSL_AUTH_MASK|SSL_MKEY_MASK,0},
	{0,SSL_TXT_ADH,	0,SSL_ADH,   0,0,0,0,SSL_AUTH_MASK|SSL_MKEY_MASK,0},
	{0,SSL_TXT_FZA,	0,SSL_FZA,   0,0,0,0,SSL_AUTH_MASK|SSL_MKEY_MASK|SSL_ENC_MASK,0},

	{0,SSL_TXT_SSLV2, 0,SSL_SSLV2, 0,0,0,0,SSL_SSL_MASK,0},
	{0,SSL_TXT_SSLV3, 0,SSL_SSLV3, 0,0,0,0,SSL_SSL_MASK,0},
	{0,SSL_TXT_TLSV1, 0,SSL_TLSV1, 0,0,0,0,SSL_SSL_MASK,0},

	{0,SSL_TXT_EXP   ,0, 0,SSL_EXPORT, 0,0,0,0,SSL_EXP_MASK},
	{0,SSL_TXT_EXPORT,0, 0,SSL_EXPORT, 0,0,0,0,SSL_EXP_MASK},
	{0,SSL_TXT_EXP40, 0, 0, SSL_EXP40, 0,0,0,0,SSL_STRONG_MASK},
	{0,SSL_TXT_EXP56, 0, 0, SSL_EXP56, 0,0,0,0,SSL_STRONG_MASK},
	{0,SSL_TXT_LOW,   0, 0,   SSL_LOW, 0,0,0,0,SSL_STRONG_MASK},
	{0,SSL_TXT_MEDIUM,0, 0,SSL_MEDIUM, 0,0,0,0,SSL_STRONG_MASK},
	{0,SSL_TXT_HIGH,  0, 0,  SSL_HIGH, 0,0,0,0,SSL_STRONG_MASK},
	};

void ssl_load_ciphers(void)
	{
	ssl_cipher_methods[SSL_ENC_DES_IDX]= 
		EVP_get_cipherbyname(SN_des_cbc);
	ssl_cipher_methods[SSL_ENC_3DES_IDX]=
		EVP_get_cipherbyname(SN_des_ede3_cbc);
	ssl_cipher_methods[SSL_ENC_RC4_IDX]=
		EVP_get_cipherbyname(SN_rc4);
	ssl_cipher_methods[SSL_ENC_RC2_IDX]= 
		EVP_get_cipherbyname(SN_rc2_cbc);
#ifndef OPENSSL_NO_IDEA
	ssl_cipher_methods[SSL_ENC_IDEA_IDX]= 
		EVP_get_cipherbyname(SN_idea_cbc);
#else
	ssl_cipher_methods[SSL_ENC_IDEA_IDX]= NULL;
#endif
	ssl_cipher_methods[SSL_ENC_AES128_IDX]=
	  EVP_get_cipherbyname(SN_aes_128_cbc);
	ssl_cipher_methods[SSL_ENC_AES256_IDX]=
	  EVP_get_cipherbyname(SN_aes_256_cbc);

	ssl_digest_methods[SSL_MD_MD5_IDX]=
		EVP_get_digestbyname(SN_md5);
	ssl_digest_methods[SSL_MD_SHA1_IDX]=
		EVP_get_digestbyname(SN_sha1);
	}


#ifndef OPENSSL_NO_COMP

static int sk_comp_cmp(const SSL_COMP * const *a,
			const SSL_COMP * const *b)
	{
	return((*a)->id-(*b)->id);
	}

static void load_builtin_compressions(void)
	{
	if (ssl_comp_methods != NULL)
		return;

	CRYPTO_w_lock(CRYPTO_LOCK_SSL);
	if (ssl_comp_methods == NULL)
		{
		SSL_COMP *comp = NULL;

		MemCheck_off();
		ssl_comp_methods=sk_SSL_COMP_new(sk_comp_cmp);
		if (ssl_comp_methods != NULL)
			{
			comp=(SSL_COMP *)OPENSSL_malloc(sizeof(SSL_COMP));
			if (comp != NULL)
				{
				comp->method=COMP_zlib();
				if (comp->method
					&& comp->method->type == NID_undef)
					OPENSSL_free(comp);
				else
					{
					comp->id=SSL_COMP_ZLIB_IDX;
					comp->name=comp->method->name;
					sk_SSL_COMP_push(ssl_comp_methods,comp);
					}
				}
			}
		MemCheck_on();
		}
	CRYPTO_w_unlock(CRYPTO_LOCK_SSL);
	}
#endif

int ssl_cipher_get_evp(const SSL_SESSION *s, const EVP_CIPHER **enc,
	     const EVP_MD **md, SSL_COMP **comp)
	{
	int i;
	SSL_CIPHER *c;

	c=s->cipher;
	if (c == NULL) return(0);
	if (comp != NULL)
		{
		SSL_COMP ctmp;
#ifndef OPENSSL_NO_COMP
		load_builtin_compressions();
#endif

		*comp=NULL;
		ctmp.id=s->compress_meth;
		if (ssl_comp_methods != NULL)
			{
			i=sk_SSL_COMP_find(ssl_comp_methods,&ctmp);
			if (i >= 0)
				*comp=sk_SSL_COMP_value(ssl_comp_methods,i);
			else
				*comp=NULL;
			}
		}

	if ((enc == NULL) || (md == NULL)) return(0);

	switch (c->algorithms & SSL_ENC_MASK)
		{
	case SSL_DES:
		i=SSL_ENC_DES_IDX;
		break;
	case SSL_3DES:
		i=SSL_ENC_3DES_IDX;
		break;
	case SSL_RC4:
		i=SSL_ENC_RC4_IDX;
		break;
	case SSL_RC2:
		i=SSL_ENC_RC2_IDX;
		break;
	case SSL_IDEA:
		i=SSL_ENC_IDEA_IDX;
		break;
	case SSL_eNULL:
		i=SSL_ENC_NULL_IDX;
		break;
	case SSL_AES:
		switch(c->alg_bits)
			{
		case 128: i=SSL_ENC_AES128_IDX; break;
		case 256: i=SSL_ENC_AES256_IDX; break;
		default: i=-1; break;
			}
		break;
	default:
		i= -1;
		break;
		}

	if ((i < 0) || (i > SSL_ENC_NUM_IDX))
		*enc=NULL;
	else
		{
		if (i == SSL_ENC_NULL_IDX)
			*enc=EVP_enc_null();
		else
			*enc=ssl_cipher_methods[i];
		}

	switch (c->algorithms & SSL_MAC_MASK)
		{
	case SSL_MD5:
		i=SSL_MD_MD5_IDX;
		break;
	case SSL_SHA1:
		i=SSL_MD_SHA1_IDX;
		break;
	default:
		i= -1;
		break;
		}
	if ((i < 0) || (i > SSL_MD_NUM_IDX))
		*md=NULL;
	else
		*md=ssl_digest_methods[i];

	if ((*enc != NULL) && (*md != NULL))
		return(1);
	else
		return(0);
	}

#define ITEM_SEP(a) \
	(((a) == ':') || ((a) == ' ') || ((a) == ';') || ((a) == ','))

static void ll_append_tail(CIPHER_ORDER **head, CIPHER_ORDER *curr,
	     CIPHER_ORDER **tail)
	{
	if (curr == *tail) return;
	if (curr == *head)
		*head=curr->next;
	if (curr->prev != NULL)
		curr->prev->next=curr->next;
	if (curr->next != NULL) /* should always be true */
		curr->next->prev=curr->prev;
	(*tail)->next=curr;
	curr->prev= *tail;
	curr->next=NULL;
	*tail=curr;
	}

static unsigned long ssl_cipher_get_disabled(void)
	{
	unsigned long mask;

	mask = SSL_kFZA;
#ifdef OPENSSL_NO_RSA
	mask |= SSL_aRSA|SSL_kRSA;
#endif
#ifdef OPENSSL_NO_DSA
	mask |= SSL_aDSS;
#endif
#ifdef OPENSSL_NO_DH
	mask |= SSL_kDHr|SSL_kDHd|SSL_kEDH|SSL_aDH;
#endif
#ifdef OPENSSL_NO_KRB5
	mask |= SSL_kKRB5|SSL_aKRB5;
#endif
#ifdef OPENSSL_NO_ECDH
	mask |= SSL_kECDH|SSL_kECDHE;
#endif
#ifdef SSL_FORBID_ENULL
	mask |= SSL_eNULL;
#endif

	mask |= (ssl_cipher_methods[SSL_ENC_DES_IDX ] == NULL) ? SSL_DES :0;
	mask |= (ssl_cipher_methods[SSL_ENC_3DES_IDX] == NULL) ? SSL_3DES:0;
	mask |= (ssl_cipher_methods[SSL_ENC_RC4_IDX ] == NULL) ? SSL_RC4 :0;
	mask |= (ssl_cipher_methods[SSL_ENC_RC2_IDX ] == NULL) ? SSL_RC2 :0;
	mask |= (ssl_cipher_methods[SSL_ENC_IDEA_IDX] == NULL) ? SSL_IDEA:0;
	mask |= (ssl_cipher_methods[SSL_ENC_eFZA_IDX] == NULL) ? SSL_eFZA:0;
	mask |= (ssl_cipher_methods[SSL_ENC_AES128_IDX] == NULL) ? SSL_AES:0;

	mask |= (ssl_digest_methods[SSL_MD_MD5_IDX ] == NULL) ? SSL_MD5 :0;
	mask |= (ssl_digest_methods[SSL_MD_SHA1_IDX] == NULL) ? SSL_SHA1:0;

	return(mask);
	}

static void ssl_cipher_collect_ciphers(const SSL_METHOD *ssl_method,
		int num_of_ciphers, unsigned long mask, CIPHER_ORDER *co_list,
		CIPHER_ORDER **head_p, CIPHER_ORDER **tail_p)
	{
	int i, co_list_num;
	SSL_CIPHER *c;

	/*
	 * We have num_of_ciphers descriptions compiled in, depending on the
	 * method selected (SSLv2 and/or SSLv3, TLSv1 etc).
	 * These will later be sorted in a linked list with at most num
	 * entries.
	 */

	/* Get the initial list of ciphers */