x509_vfy.c

openssl是ssl的开源项目

/* crypto/x509/x509_vfy.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.]
 */

#include <stdio.h>
#include <time.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>

#include "crypto.h"
#include "cryptlib.h"
#include "lhash.h"
#include "buffer.h"
#include "evp.h"
#include "asn1.h"
#include "x509.h"
#include "objects.h"
#include "pem.h"

#ifndef NOPROTO
static int null_callback(int ok,X509_STORE_CTX *e);
static int internal_verify(X509_STORE_CTX *ctx);
#else
static int null_callback();
static int internal_verify();
#endif

char *X509_version="X.509 part of OpenSSL 0.9.1c 23-Dec-1998";
static STACK *x509_store_ctx_method=NULL;
static int x509_store_ctx_num=0;
#if 0
static int x509_store_num=1;
static STACK *x509_store_method=NULL;
#endif

static int null_callback(ok,e)
int ok;
X509_STORE_CTX *e;
	{
	return(ok);
	}

#if 0
static int x509_subject_cmp(a,b)
X509 **a,**b;
	{
	return(X509_subject_name_cmp(*a,*b));
	}
#endif

int X509_verify_cert(ctx)
X509_STORE_CTX *ctx;
	{
	X509 *x,*xtmp,*chain_ss=NULL;
	X509_NAME *xn;
	X509_OBJECT obj;
	int depth,i,ok=0;
	int num;
	int (*cb)();
	STACK *sktmp=NULL;

	if (ctx->cert == NULL)
		{
		X509err(X509_F_X509_VERIFY_CERT,X509_R_NO_CERT_SET_FOR_US_TO_VERIFY);
		return(-1);
		}

	cb=ctx->ctx->verify_cb;
	if (cb == NULL) cb=null_callback;

	/* first we make sure the chain we are going to build is
	 * present and that the first entry is in place */
	if (ctx->chain == NULL)
		{
		if (	((ctx->chain=sk_new_null()) == NULL) ||
			(!sk_push(ctx->chain,(char *)ctx->cert)))
			{
			X509err(X509_F_X509_VERIFY_CERT,ERR_R_MALLOC_FAILURE);
			goto end;
			}
		CRYPTO_add(&ctx->cert->references,1,CRYPTO_LOCK_X509);
		ctx->last_untrusted=1;
		}

	/* We use a temporary so we can chop and hack at it */
	if ((ctx->untrusted != NULL) && (sktmp=sk_dup(ctx->untrusted)) == NULL)
		{
		X509err(X509_F_X509_VERIFY_CERT,ERR_R_MALLOC_FAILURE);
		goto end;
		}

	num=sk_num(ctx->chain);
	x=(X509 *)sk_value(ctx->chain,num-1);
	depth=ctx->depth;


	for (;;)
		{
		/* If we have enough, we break */
		if (depth <= num) break;

		/* If we are self signed, we break */
		xn=X509_get_issuer_name(x);
		if (X509_NAME_cmp(X509_get_subject_name(x),xn) == 0)
			break;

		/* If we were passed a cert chain, use it first */
		if (ctx->untrusted != NULL)
			{
			xtmp=X509_find_by_subject(sktmp,xn);
			if (xtmp != NULL)
				{
				if (!sk_push(ctx->chain,(char *)xtmp))
					{
					X509err(X509_F_X509_VERIFY_CERT,ERR_R_MALLOC_FAILURE);
					goto end;
					}
				CRYPTO_add(&xtmp->references,1,CRYPTO_LOCK_X509);
				sk_delete_ptr(sktmp,(char *)xtmp);
				ctx->last_untrusted++;
				x=xtmp;
				num++;
				/* reparse the full chain for
				 * the next one */
				continue;
				}
			}
		break;
		}

	/* at this point, chain should contain a list of untrusted
	 * certificates.  We now need to add at least one trusted one,
	 * if possible, otherwise we complain. */

	i=sk_num(ctx->chain);
	x=(X509 *)sk_value(ctx->chain,i-1);
	if (X509_NAME_cmp(X509_get_subject_name(x),X509_get_issuer_name(x))
		== 0)
		{
		/* we have a self signed certificate */
		if (sk_num(ctx->chain) == 1)
			{
			ctx->error=X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT;
			ctx->current_cert=x;
			ctx->error_depth=i-1;
			ok=cb(0,ctx);
			if (!ok) goto end;
			}
		else
			{
			/* worry more about this one elsewhere */
			chain_ss=(X509 *)sk_pop(ctx->chain);
			ctx->last_untrusted--;
			num--;
			x=(X509 *)sk_value(ctx->chain,num-1);
			}
		}

	/* We now lookup certs from the certificate store */
	for (;;)
		{
		/* If we have enough, we break */
		if (depth <= num) break;

		/* If we are self signed, we break */
		xn=X509_get_issuer_name(x);
		if (X509_NAME_cmp(X509_get_subject_name(x),xn) == 0)
			break;

		ok=X509_STORE_get_by_subject(ctx,X509_LU_X509,xn,&obj);
		if (ok != X509_LU_X509)
			{
			if (ok == X509_LU_RETRY)
				{
				X509_OBJECT_free_contents(&obj);
				X509err(X509_F_X509_VERIFY_CERT,X509_R_SHOULD_RETRY);
				return(ok);
				}
			else if (ok != X509_LU_FAIL)
				{
				X509_OBJECT_free_contents(&obj);
				/* not good :-(, break anyway */
				return(ok);
				}
			break;
			}
		x=obj.data.x509;
		if (!sk_push(ctx->chain,(char *)obj.data.x509))
			{
			X509_OBJECT_free_contents(&obj);
			X509err(X509_F_X509_VERIFY_CERT,ERR_R_MALLOC_FAILURE);
			return(0);
			}
		num++;
		}

	/* we now have our chain, lets check it... */
	xn=X509_get_issuer_name(x);
	if (X509_NAME_cmp(X509_get_subject_name(x),xn) != 0)
		{
		if ((chain_ss == NULL) || (X509_NAME_cmp(X509_get_subject_name(chain_ss),xn) != 0))
			{
			if (ctx->last_untrusted >= num)
				ctx->error=X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY;
			else
				ctx->error=X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT;
			ctx->current_cert=x;
			}
		else
			{

			sk_push(ctx->chain,(char *)chain_ss);
			num++;
			ctx->last_untrusted=num;
			ctx->current_cert=chain_ss;
			ctx->error=X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN;
			chain_ss=NULL;
			}

		ctx->error_depth=num-1;
		ok=cb(0,ctx);
		if (!ok) goto end;
		}

	/* We may as well copy down any DSA parameters that are required */
	X509_get_pubkey_parameters(NULL,ctx->chain);

	/* At this point, we have a chain and just need to verify it */
	if (ctx->ctx->verify != NULL)
		ok=ctx->ctx->verify(ctx);
	else
		ok=internal_verify(ctx);
	if (0)
		{
end:
		X509_get_pubkey_parameters(NULL,ctx->chain);
		}
	if (sktmp != NULL) sk_free(sktmp);
	if (chain_ss != NULL) X509_free(chain_ss);
	return(ok);
	}

static int internal_verify(ctx)
X509_STORE_CTX *ctx;
	{
	int i,ok=0,n;
	X509 *xs,*xi;
	EVP_PKEY *pkey=NULL;
	int (*cb)();

	cb=ctx->ctx->verify_cb;
	if (cb == NULL) cb=null_callback;

	n=sk_num(ctx->chain);
	ctx->error_depth=n-1;
	n--;
	xi=(X509 *)sk_value(ctx->chain,n);
	if (X509_NAME_cmp(X509_get_subject_name(xi),
		X509_get_issuer_name(xi)) == 0)
		xs=xi;
	else
		{
		if (n <= 0)
			{
			ctx->error=X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE;
			ctx->current_cert=xi;
			ok=cb(0,ctx);
			goto end;
			}
		else
			{
			n--;
			ctx->error_depth=n;
			xs=(X509 *)sk_value(ctx->chain,n);
			}
		}