By using non-DER or invalid encodings outside the signed portion of a
certificate the fingerprint can be changed without breaking the signature.
Although no details of the signed portion of the certificate can be changed
this can cause problems with some applications: e.g. those using the
certificate fingerprint for blacklists.
1. Reject signatures with non zero unused bits.
If the BIT STRING containing the signature has non zero unused bits reject
the signature. All current signature algorithms require zero unused bits.
2. Check certificate algorithm consistency.
Check the AlgorithmIdentifier inside TBS matches the one in the
certificate signature. NB: this will result in signature failure
errors for some broken certificates.
3. Check DSA/ECDSA signatures use DER.
Reencode DSA/ECDSA signatures and compare with the original received
signature. Return an error if there is a mismatch.
This will reject various cases including garbage after signature
(thanks to Antti Karjalainen and Tuomo Untinen from the Codenomicon CROSS
program for discovering this case) and use of BER or invalid ASN.1 INTEGERs
(negative or with leading zeroes).
CVE-2014-8275
Reviewed-by: Emilia Käsper <emilia@openssl.org>
(cherry picked from commit 684400ce19)
Conflicts:
CHANGES
crypto/dsa/dsa_asn1.c
Submitted by: "Andrzej Chmielowiec" <achmielowiec@enigma.com.pl>, steve@openssl.org
Approved by: steve@openssl.org
Truncate hash if it is too large: as required by FIPS 186-3.
knock-on work than expected - they've been extracted into a patch
series that can be completed elsewhere, or in a different branch,
before merging back to HEAD.
deprecate the original (numeric-only) scheme, and replace with the
CRYPTO_THREADID object. This hides the platform-specifics and should reduce
the possibility for programming errors (where failing to explicitly check
both thread ID forms could create subtle, platform-specific bugs).
Thanks to Bodo, for invaluable review and feedback.
to 'unsigned long' (ie. odd platforms/compilers), so a pointer-typed
version was added but it required portable code to check *both* modes to
determine equality. This commit maintains the availability of both thread
ID types, but deprecates the type-specific accessor APIs that invoke the
callbacks - instead a single type-independent API is used. This simplifies
software that calls into this interface, and should also make it less
error-prone - as forgetting to call and compare *both* thread ID accessors
could have led to hard-to-debug/infrequent bugs (that might only affect
certain platforms or thread implementations). As the CHANGES note says,
there were corresponding deprecations and replacements in the
thread-related functions for BN_BLINDING and ERR too.
- hide the EC_KEY structure definition in ec_lcl.c + add
some functions to use/access the EC_KEY fields
- change the way how method specific data (ecdsa/ecdh) is
attached to a EC_KEY
- add ECDSA_sign_ex and ECDSA_do_sign_ex functions with
additional parameters for pre-computed values
- rebuild libeay.num from 0.9.7
during "make errors" and thus during "make update".
Fix lots of bugs that util/ck_errf.pl can detect automatically.
Various others of these are still left to fix; that's why
"make update" will complain loudly when run now.
