static int check_chain_extensions(X509_STORE_CTX *ctx)
{
#ifdef OPENSSL_NO_CHAIN_VERIFY
	return 1;
#else
	int i, ok=0, must_be_ca;
	X509 *x;
	int (*cb)();
	cb=ctx->verify_cb;

	/* must_be_ca can have 1 of 3 values:
	   -1: we accept both CA and non-CA certificates, to allow direct
	       use of self-signed certificates (which are marked as CA).
	   0:  we only accept non-CA certificates.  This is currently not
	       used, but the possibility is present for future extensions.
	   1:  we only accept CA certificates.  This is currently used for
	       all certificates in the chain except the leaf certificate.
	*/
	must_be_ca = -1;
	/* Check all untrusted certificates */
	for (i = 0; i < ctx->last_untrusted; i++)
		{
		int ret;
		x = sk_X509_value(ctx->chain, i);
		if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
			&& (x->ex_flags & EXFLAG_CRITICAL))
			{
			ctx->error = X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION;
			ctx->error_depth = i;
			ctx->current_cert = x;
			ok=cb(0,ctx);
			if (!ok) goto end;
			}
		ret = X509_check_ca(x);
		switch(must_be_ca)
			{
		case -1:
			if ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
				&& (ret != 1) && (ret != 0))
				{
				ret = 0;
				ctx->error = X509_V_ERR_INVALID_CA;
				}
			else
				ret = 1;
			break;
		case 0:
			if (ret != 0)
				{
				ret = 0;
				ctx->error = X509_V_ERR_INVALID_NON_CA;
				}
			else
				ret = 1;
			break;
		default:
			if ((ret == 0)
				|| ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
					&& (ret != 1)))
				{
				ret = 0;
				ctx->error = X509_V_ERR_INVALID_CA;
				}
			else
				ret = 1;
			break;
			}
		if (ret == 0)
			{
			ctx->error_depth = i;
			ctx->current_cert = x;
			ok=cb(0,ctx);
			if (!ok) goto end;
			}
		if (ctx->param->purpose > 0)
			{
			ret = X509_check_purpose(x, ctx->param->purpose,
				must_be_ca > 0);
			if ((ret == 0)
				|| ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
					&& (ret != 1)))
				{
				ctx->error = X509_V_ERR_INVALID_PURPOSE;
				ctx->error_depth = i;
				ctx->current_cert = x;
				ok=cb(0,ctx);
				if (!ok) goto end;
				}
			}
		/* Check pathlen */
		if ((i > 1) && (x->ex_pathlen != -1)
			   && (i > (x->ex_pathlen + 1)))
			{
			ctx->error = X509_V_ERR_PATH_LENGTH_EXCEEDED;
			ctx->error_depth = i;
			ctx->current_cert = x;
			ok=cb(0,ctx);
			if (!ok) goto end;
			}
		/* The next certificate must be a CA */
		must_be_ca = 1;
		}
	ok = 1;
 end:
	return ok;
#endif
}