[openssl-commits] [openssl] OpenSSL_1_1_0-stable update
Viktor Dukhovni
viktor at openssl.org
Thu Oct 18 04:12:27 UTC 2018
The branch OpenSSL_1_1_0-stable has been updated
via d46f9173bbd62ffa7ae0b20bf05c600e14722cc6 (commit)
via cc54a2a0f5a2455205ee236bb44458cc39366065 (commit)
from a76a41655e57b72b30a373aae6e75afedf920076 (commit)
- Log -----------------------------------------------------------------
commit d46f9173bbd62ffa7ae0b20bf05c600e14722cc6
Author: Viktor Dukhovni <openssl-users at dukhovni.org>
Date: Mon Oct 8 12:05:14 2018 -0400
Apply self-imposed path length also to root CAs
Also, some readers of the code find starting the count at 1 for EE
cert confusing (since RFC5280 counts only non-self-issued intermediate
CAs, but we also counted the leaf). Therefore, never count the EE
cert, and adjust the path length comparison accordinly. This may
be more clear to the reader.
Reviewed-by: Matt Caswell <matt at openssl.org>
(cherry picked from commit dc5831da59e9bfad61ba425d886a0b06ac160cd6)
commit cc54a2a0f5a2455205ee236bb44458cc39366065
Author: Viktor Dukhovni <openssl-users at dukhovni.org>
Date: Thu Oct 4 23:53:01 2018 -0400
Only CA certificates can be self-issued
At the bottom of https://tools.ietf.org/html/rfc5280#page-12 and
top of https://tools.ietf.org/html/rfc5280#page-13 (last paragraph
of above https://tools.ietf.org/html/rfc5280#section-3.3), we see:
This specification covers two classes of certificates: CA
certificates and end entity certificates. CA certificates may be
further divided into three classes: cross-certificates, self-issued
certificates, and self-signed certificates. Cross-certificates are
CA certificates in which the issuer and subject are different
entities. Cross-certificates describe a trust relationship between
the two CAs. Self-issued certificates are CA certificates in which
the issuer and subject are the same entity. Self-issued certificates
are generated to support changes in policy or operations. Self-
signed certificates are self-issued certificates where the digital
signature may be verified by the public key bound into the
certificate. Self-signed certificates are used to convey a public
key for use to begin certification paths. End entity certificates
are issued to subjects that are not authorized to issue certificates.
that the term "self-issued" is only applicable to CAs, not end-entity
certificates. In https://tools.ietf.org/html/rfc5280#section-4.2.1.9
the description of path length constraints says:
The pathLenConstraint field is meaningful only if the cA boolean is
asserted and the key usage extension, if present, asserts the
keyCertSign bit (Section 4.2.1.3). In this case, it gives the
maximum number of non-self-issued intermediate certificates that may
follow this certificate in a valid certification path. (Note: The
last certificate in the certification path is not an intermediate
certificate, and is not included in this limit. Usually, the last
certificate is an end entity certificate, but it can be a CA
certificate.)
This makes it clear that exclusion of self-issued certificates from
the path length count applies only to some *intermediate* CA
certificates. A leaf certificate whether it has identical issuer
and subject or whether it is a CA or not is never part of the
intermediate certificate count. The handling of all leaf certificates
must be the same, in the case of our code to post-increment the
path count by 1, so that we ultimately reach a non-self-issued
intermediate it will be the first one (not zeroth) in the chain
of intermediates.
Reviewed-by: Matt Caswell <matt at openssl.org>
(cherry picked from commit ed422a2d0196ada0f5c1b6e296f4a4e5ed69577f)
-----------------------------------------------------------------------
Summary of changes:
crypto/x509/x509_vfy.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/crypto/x509/x509_vfy.c b/crypto/x509/x509_vfy.c
index f86871f..ba186d3 100644
--- a/crypto/x509/x509_vfy.c
+++ b/crypto/x509/x509_vfy.c
@@ -515,15 +515,14 @@ static int check_chain_extensions(X509_STORE_CTX *ctx)
/* check_purpose() makes the callback as needed */
if (purpose > 0 && !check_purpose(ctx, x, purpose, i, must_be_ca))
return 0;
- /* Check pathlen if not self issued */
- if ((i > 1) && !(x->ex_flags & EXFLAG_SI)
- && (x->ex_pathlen != -1)
- && (plen > (x->ex_pathlen + proxy_path_length + 1))) {
+ /* Check pathlen */
+ if ((i > 1) && (x->ex_pathlen != -1)
+ && (plen > (x->ex_pathlen + proxy_path_length))) {
if (!verify_cb_cert(ctx, x, i, X509_V_ERR_PATH_LENGTH_EXCEEDED))
return 0;
}
- /* Increment path length if not self issued */
- if (!(x->ex_flags & EXFLAG_SI))
+ /* Increment path length if not a self issued intermediate CA */
+ if (i > 0 && (x->ex_flags & EXFLAG_SI) == 0)
plen++;
/*
* If this certificate is a proxy certificate, the next certificate
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