Commit cb22d2ae authored Jun 24, 2015 by Matt Caswell

Fix alt chains bug



This is a follow up to the alternate chains certificate forgery issue
(CVE-2015-1793). That issue is exacerbated in 1.0.1 by a related bug which
means that we *always* check for an alternative chain, even if we have
already found a chain. The code is supposed to stop as soon as it has found
one (and does do in master and 1.0.2).

Reviewed-by: Stephen Henson <steve@openssl.org>

parent b3b1eb57

crypto/x509/verify_extra_test.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -168,7 +168,8 @@ static int test_alt_chains_cert_forgery(void)

		i = X509_verify_cert(sctx);

		if(i == 0 && X509_STORE_CTX_get_error(sctx) == X509_V_ERR_INVALID_CA) {
		if(i == 0 && X509_STORE_CTX_get_error(sctx)
		== X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT) {
		/* This is the result we were expecting: Test passed */
		ret = 1;
		}

crypto/x509/x509_vfy.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -312,7 +312,7 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
		* if the user hasn't switched off alternate chain checking
		*/
		retry = 0;
		if (j == ctx->last_untrusted &&
		if (num == ctx->last_untrusted &&
		!(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS)) {
		while (j-- > 1) {
		xtmp2 = sk_X509_value(ctx->chain, j - 1);