Only check the CN against DNS name contraints if the
`X509_CHECK_FLAG_NEVER_CHECK_SUBJECT` flag is not set, and either the
certificate has no DNS subject alternative names or the
`X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT` flag is set.
Add pertinent documentation, and touch up some stale text about
name checks and DANE.
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
Don't apply DNS name constraints to the subject CN when there's a
least one DNS-ID subjectAlternativeName.
Don't apply DNS name constraints to subject CN's that are sufficiently
unlike DNS names. Checked name must have at least two labels, with
all labels non-empty, no trailing '.' and all hyphens must be
internal in each label. In addition to the usual LDH characters,
we also allow "_", since some sites use these for hostnames despite
all the standards.
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
The functions strcasecmp() and strncasecmp() will use locale specific rules
when performing comparison. This could cause some problems in certain
locales. For example in the Turkish locale an 'I' character is not the
uppercase version of 'i'. However IA5 strings should not use locale specific
rules, i.e. for an IA5 string 'I' is uppercase 'i' even if using the
Turkish locale.
This fixes a bug in name constraints checking reported by Thomas Pornin
(NCCGroup).
This is not considered a security issue because it would require both a
Turkish locale (or other locale with similar issues) and malfeasance by
a trusted name-constrained CA for a certificate to pass name constraints
in error. The constraints also have to be for excluded sub-trees which are
extremely rare. Failure to match permitted subtrees is a bug, not a
vulnerability.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4569)
This guards against the name constraints check consuming large amounts
of CPU time when certificates in the presented chain contain an
excessive number of names (specifically subject email names or subject
alternative DNS names) and/or name constraints.
Name constraints checking compares the names presented in a certificate
against the name constraints included in a certificate higher up in the
chain using two nested for loops.
Move the name constraints check so that it happens after signature
verification so peers cannot exploit this using a chain with invalid
signatures. Also impose a hard limit on the number of name constraints
check loop iterations to further mitigate the issue.
Thanks to NCC for finding this issue. Fix written by Martin Kreichgauer.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4393)
cryptilib.h is the second.
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4188)
Removed e_os.h from all bar three headers (apps/apps.h crypto/bio/bio_lcl.h and
ssl/ssl_locl.h).
Added e_os.h into the files that need it now.
Directly reference internal/nelem.h when required.
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4188)
New hostname checking function asn1_valid_host()
Check commonName entries against nameConstraints: any CN components in
EE certificate which look like hostnames are checked against
nameConstraints.
Note that RFC5280 et al only require checking subject alt name against
DNS name constraints.
Reviewed-by: Richard Levitte <levitte@openssl.org>
This was done by the following
find . -name '*.[ch]' | /tmp/pl
where /tmp/pl is the following three-line script:
print unless $. == 1 && m@/\* .*\.[ch] \*/@;
close ARGV if eof; # Close file to reset $.
And then some hand-editing of other files.
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
There are header files in crypto/ that are used by a number of crypto/
submodules. Move those to crypto/include/internal and adapt the
affected source code and Makefiles.
The header files that got moved are:
crypto/cryptolib.h
crypto/md32_common.h
Reviewed-by: Rich Salz <rsalz@openssl.org>
For the various string-compare routines (strcmp, strcasecmp, str.*cmp)
use "strcmp()==0" instead of "!strcmp()"
Reviewed-by: Tim Hudson <tjh@openssl.org>
subjectAltName field. The Name Contraint example in x509v3_config(5) even use IP
as an example:
nameConstraints=permitted;IP:192.168.0.0/255.255.0.0
However, until now, the verify code for IP name contraints did not exist. Any
check with a IP Address Name Constraint results in a "unsupported name constraint
type" error.
This patch implements support for IP Address Name Constraint (v4 and v6). This code
validaded correcly certificates with multiple IPv4/IPv6 address checking against
a CA certificate with these constraints:
permitted;IP.1=10.9.0.0/255.255.0.0
permitted;IP.2=10.48.0.0/255.255.0.0
permitted;IP.3=10.148.0.0/255.255.0.0
permitted;IP.4=fdc8:123f:e31f::/ffff:ffff:ffff::
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
