x509_vfy.c

开源的ssl算法openssl,版本0.9.8H

				ctx->error_depth = i;
				ctx->current_cert = x;
				ok=cb(0,ctx);
				if (!ok) goto end;
				}
			proxy_path_length++;
			must_be_ca = 0;
			}
		else
			must_be_ca = 1;
		}
	ok = 1;
 end:
	return ok;
#endif
}

static int check_trust(X509_STORE_CTX *ctx)
{
#ifdef OPENSSL_NO_CHAIN_VERIFY
	return 1;
#else
	int i, ok;
	X509 *x;
	int (*cb)(int xok,X509_STORE_CTX *xctx);
	cb=ctx->verify_cb;
/* For now just check the last certificate in the chain */
	i = sk_X509_num(ctx->chain) - 1;
	x = sk_X509_value(ctx->chain, i);
	ok = X509_check_trust(x, ctx->param->trust, 0);
	if (ok == X509_TRUST_TRUSTED)
		return 1;
	ctx->error_depth = i;
	ctx->current_cert = x;
	if (ok == X509_TRUST_REJECTED)
		ctx->error = X509_V_ERR_CERT_REJECTED;
	else
		ctx->error = X509_V_ERR_CERT_UNTRUSTED;
	ok = cb(0, ctx);
	return ok;
#endif
}

static int check_revocation(X509_STORE_CTX *ctx)
	{
	int i, last, ok;
	if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK))
		return 1;
	if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL)
		last = sk_X509_num(ctx->chain) - 1;
	else
		last = 0;
	for(i = 0; i <= last; i++)
		{
		ctx->error_depth = i;
		ok = check_cert(ctx);
		if (!ok) return ok;
		}
	return 1;
	}

static int check_cert(X509_STORE_CTX *ctx)
	{
	X509_CRL *crl = NULL;
	X509 *x;
	int ok, cnum;
	cnum = ctx->error_depth;
	x = sk_X509_value(ctx->chain, cnum);
	ctx->current_cert = x;
	/* Try to retrieve relevant CRL */
	ok = ctx->get_crl(ctx, &crl, x);
	/* If error looking up CRL, nothing we can do except
	 * notify callback
	 */
	if(!ok)
		{
		ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
		ok = ctx->verify_cb(0, ctx);
		goto err;
		}
	ctx->current_crl = crl;
	ok = ctx->check_crl(ctx, crl);
	if (!ok) goto err;
	ok = ctx->cert_crl(ctx, crl, x);
	err:
	ctx->current_crl = NULL;
	X509_CRL_free(crl);
	return ok;

	}

/* Check CRL times against values in X509_STORE_CTX */

static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
	{
	time_t *ptime;
	int i;
	ctx->current_crl = crl;
	if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
		ptime = &ctx->param->check_time;
	else
		ptime = NULL;

	i=X509_cmp_time(X509_CRL_get_lastUpdate(crl), ptime);
	if (i == 0)
		{
		ctx->error=X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD;
		if (!notify || !ctx->verify_cb(0, ctx))
			return 0;
		}

	if (i > 0)
		{
		ctx->error=X509_V_ERR_CRL_NOT_YET_VALID;
		if (!notify || !ctx->verify_cb(0, ctx))
			return 0;
		}

	if(X509_CRL_get_nextUpdate(crl))
		{
		i=X509_cmp_time(X509_CRL_get_nextUpdate(crl), ptime);

		if (i == 0)
			{
			ctx->error=X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD;
			if (!notify || !ctx->verify_cb(0, ctx))
				return 0;
			}

		if (i < 0)
			{
			ctx->error=X509_V_ERR_CRL_HAS_EXPIRED;
			if (!notify || !ctx->verify_cb(0, ctx))
				return 0;
			}
		}

	ctx->current_crl = NULL;

	return 1;
	}

/* Lookup CRLs from the supplied list. Look for matching isser name
 * and validity. If we can't find a valid CRL return the last one
 * with matching name. This gives more meaningful error codes. Otherwise
 * we'd get a CRL not found error if a CRL existed with matching name but
 * was invalid.
 */

static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
			X509_NAME *nm, STACK_OF(X509_CRL) *crls)
	{
	int i;
	X509_CRL *crl, *best_crl = NULL;
	for (i = 0; i < sk_X509_CRL_num(crls); i++)
		{
		crl = sk_X509_CRL_value(crls, i);
		if (X509_NAME_cmp(nm, X509_CRL_get_issuer(crl)))
			continue;
		if (check_crl_time(ctx, crl, 0))
			{
			*pcrl = crl;
			CRYPTO_add(&crl->references, 1, CRYPTO_LOCK_X509);
			return 1;
			}
		best_crl = crl;
		}
	if (best_crl)
		{
		*pcrl = best_crl;
		CRYPTO_add(&best_crl->references, 1, CRYPTO_LOCK_X509);
		}
		
	return 0;
	}

/* Retrieve CRL corresponding to certificate: currently just a
 * subject lookup: maybe use AKID later...
 */
static int get_crl(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509 *x)
	{
	int ok;
	X509_CRL *crl = NULL;
	X509_OBJECT xobj;
	X509_NAME *nm;
	nm = X509_get_issuer_name(x);
	ok = get_crl_sk(ctx, &crl, nm, ctx->crls);
	if (ok)
		{
		*pcrl = crl;
		return 1;
		}

	ok = X509_STORE_get_by_subject(ctx, X509_LU_CRL, nm, &xobj);

	if (!ok)
		{
		/* If we got a near match from get_crl_sk use that */
		if (crl)
			{
			*pcrl = crl;
			return 1;
			}
		return 0;
		}

	*pcrl = xobj.data.crl;
	if (crl)
		X509_CRL_free(crl);
	return 1;
	}

/* Check CRL validity */
static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
	{
	X509 *issuer = NULL;
	EVP_PKEY *ikey = NULL;
	int ok = 0, chnum, cnum;
	cnum = ctx->error_depth;
	chnum = sk_X509_num(ctx->chain) - 1;
	/* Find CRL issuer: if not last certificate then issuer
	 * is next certificate in chain.
	 */
	if(cnum < chnum)
		issuer = sk_X509_value(ctx->chain, cnum + 1);
	else
		{
		issuer = sk_X509_value(ctx->chain, chnum);
		/* If not self signed, can't check signature */
		if(!ctx->check_issued(ctx, issuer, issuer))
			{
			ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER;
			ok = ctx->verify_cb(0, ctx);
			if(!ok) goto err;
			}
		}

	if(issuer)
		{
		/* Check for cRLSign bit if keyUsage present */
		if ((issuer->ex_flags & EXFLAG_KUSAGE) &&
			!(issuer->ex_kusage & KU_CRL_SIGN))
			{
			ctx->error = X509_V_ERR_KEYUSAGE_NO_CRL_SIGN;
			ok = ctx->verify_cb(0, ctx);
			if(!ok) goto err;
			}

		/* Attempt to get issuer certificate public key */
		ikey = X509_get_pubkey(issuer);

		if(!ikey)
			{
			ctx->error=X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
			ok = ctx->verify_cb(0, ctx);
			if (!ok) goto err;
			}
		else
			{
			/* Verify CRL signature */
			if(X509_CRL_verify(crl, ikey) <= 0)
				{
				ctx->error=X509_V_ERR_CRL_SIGNATURE_FAILURE;
				ok = ctx->verify_cb(0, ctx);
				if (!ok) goto err;
				}
			}
		}

	ok = check_crl_time(ctx, crl, 1);
	if (!ok)
		goto err;

	ok = 1;

	err:
	EVP_PKEY_free(ikey);
	return ok;
	}

/* Check certificate against CRL */
static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
	{
	int idx, ok;
	X509_REVOKED rtmp;
	STACK_OF(X509_EXTENSION) *exts;
	X509_EXTENSION *ext;
	/* Look for serial number of certificate in CRL */
	rtmp.serialNumber = X509_get_serialNumber(x);
	/* Sort revoked into serial number order if not already sorted.
	 * Do this under a lock to avoid race condition.
 	 */
	if (!sk_X509_REVOKED_is_sorted(crl->crl->revoked))
		{
		CRYPTO_w_lock(CRYPTO_LOCK_X509_CRL);
		sk_X509_REVOKED_sort(crl->crl->revoked);
		CRYPTO_w_unlock(CRYPTO_LOCK_X509_CRL);
		}
	idx = sk_X509_REVOKED_find(crl->crl->revoked, &rtmp);
	/* If found assume revoked: want something cleverer than
	 * this to handle entry extensions in V2 CRLs.
	 */
	if(idx >= 0)
		{
		ctx->error = X509_V_ERR_CERT_REVOKED;
		ok = ctx->verify_cb(0, ctx);
		if (!ok) return 0;
		}

	if (ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
		return 1;

	/* See if we have any critical CRL extensions: since we
	 * currently don't handle any CRL extensions the CRL must be
	 * rejected. 
	 * This code accesses the X509_CRL structure directly: applications
	 * shouldn't do this.
	 */

	exts = crl->crl->extensions;

	for (idx = 0; idx < sk_X509_EXTENSION_num(exts); idx++)
		{
		ext = sk_X509_EXTENSION_value(exts, idx);
		if (ext->critical > 0)
			{
			ctx->error =
				X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION;
			ok = ctx->verify_cb(0, ctx);
			if(!ok) return 0;
			break;
			}
		}
	return 1;
	}

static int check_policy(X509_STORE_CTX *ctx)
	{
	int ret;
	ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain,
				ctx->param->policies, ctx->param->flags);
	if (ret == 0)
		{
		X509err(X509_F_CHECK_POLICY,ERR_R_MALLOC_FAILURE);
		return 0;
		}
	/* Invalid or inconsistent extensions */
	if (ret == -1)
		{
		/* Locate certificates with bad extensions and notify
		 * callback.
		 */
		X509 *x;
		int i;
		for (i = 1; i < sk_X509_num(ctx->chain); i++)
			{
			x = sk_X509_value(ctx->chain, i);
			if (!(x->ex_flags & EXFLAG_INVALID_POLICY))
				continue;
			ctx->current_cert = x;
			ctx->error = X509_V_ERR_INVALID_POLICY_EXTENSION;
			ret = ctx->verify_cb(0, ctx);
			}
		return 1;
		}
	if (ret == -2)
		{
		ctx->current_cert = NULL;
		ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY;
		return ctx->verify_cb(0, ctx);
		}

	if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY)
		{
		ctx->current_cert = NULL;
		ctx->error = X509_V_OK;
		if (!ctx->verify_cb(2, ctx))
			return 0;
		}

	return 1;
	}

static int check_cert_time(X509_STORE_CTX *ctx, X509 *x)
	{
	time_t *ptime;
	int i;

	if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
		ptime = &ctx->param->check_time;
	else
		ptime = NULL;

	i=X509_cmp_time(X509_get_notBefore(x), ptime);
	if (i == 0)
		{
		ctx->error=X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD;
		ctx->current_cert=x;
		if (!ctx->verify_cb(0, ctx))
			return 0;
		}

	if (i > 0)
		{
		ctx->error=X509_V_ERR_CERT_NOT_YET_VALID;
		ctx->current_cert=x;
		if (!ctx->verify_cb(0, ctx))
			return 0;
		}

	i=X509_cmp_time(X509_get_notAfter(x), ptime);
	if (i == 0)
		{
		ctx->error=X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD;
		ctx->current_cert=x;
		if (!ctx->verify_cb(0, ctx))
			return 0;
		}

	if (i < 0)
		{
		ctx->error=X509_V_ERR_CERT_HAS_EXPIRED;
		ctx->current_cert=x;
		if (!ctx->verify_cb(0, ctx))
			return 0;
		}

	return 1;
	}

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

	cb=ctx->verify_cb;

	n=sk_X509_num(ctx->chain);
	ctx->error_depth=n-1;
	n--;
	xi=sk_X509_value(ctx->chain,n);

	if (ctx->check_issued(ctx, xi, xi))
		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=sk_X509_value(ctx->chain,n);
			}
		}

/*	ctx->error=0;  not needed */
	while (n >= 0)
		{
		ctx->error_depth=n;
		if (!xs->valid)
			{
			if ((pkey=X509_get_pubkey(xi)) == NULL)
				{
				ctx->error=X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
				ctx->current_cert=xi;
				ok=(*cb)(0,ctx);
				if (!ok) goto end;
				}
			else if (X509_verify(xs,pkey) <= 0)
				/* XXX  For the final trusted self-signed cert,
				 * this is a waste of time.  That check should
				 * optional so that e.g. 'openssl x509' can be
				 * used to detect invalid self-signatures, but
				 * we don't verify again and again in SSL
				 * handshakes and the like once the cert has
				 * been declared trusted. */
				{
				ctx->error=X509_V_ERR_CERT_SIGNATURE_FAILURE;
				ctx->current_cert=xs;
				ok=(*cb)(0,ctx);
				if (!ok)
					{
					EVP_PKEY_free(pkey);
					goto end;
					}
				}
			EVP_PKEY_free(pkey);
			pkey=NULL;
			}

		xs->valid = 1;

		ok = check_cert_time(ctx, xs);
		if (!ok)
			goto end;

		/* The last error (if any) is still in the error value */
		ctx->current_issuer=xi;
		ctx->current_cert=xs;
		ok=(*cb)(1,ctx);
		if (!ok) goto end;

		n--;
		if (n >= 0)
			{
			xi=xs;
			xs=sk_X509_value(ctx->chain,n);
			}
		}