This change fixes a regression introduced by an earlier commit that
modified x509_crt_verify_top() to ensure that valid certificates
that are after past or future valid in the chain are processed. However
the change introduced a change in behaviour that caused the
verification flags MBEDTLS_X509_BADCERT_EXPIRED and
MBEDTLS_BADCERT_FUTURE to always be set whenever there is a failure in
the verification regardless of the cause.
The fix maintains both behaviours:
* Ensure that valid certificates after future and past are verified
* Ensure that the correct verification flags are set.
To do so, a temporary pointer to the first future or past valid
certificate is maintained while traversing the chain. If a truly valid
certificate is found then that one is used, otherwise if no valid
certificate is found and the end of the chain is reached, the program
reverts back to using the future or past valid certificate.
Fix an issue that caused valid certificates being rejected whenever an
expired or not yet valid version of the trusted certificate was before the
valid version in the trusted certificate list.
Remove check on the pathLenConstraint value when looking for a parent to the
EE cert, as the constraint is on the number of intermediate certs below the
parent, and that number is always 0 at that point, so the constraint is always
satisfied.
The check was actually off-by-one, which caused valid chains to be rejected
under the following conditions:
- the parent certificate is not a trusted root, and
- it has pathLenConstraint == 0 (max_pathlen == 1 in our representation)
fixes#280
This helps in the case where an intermediate certificate is directly trusted.
In that case we want to ignore what comes after it in the chain, not only for
performance but also to avoid false negatives (eg an old root being no longer
trusted while the newer intermediate is directly trusted).
closes#220
Assume we have two trusted CAs with the same name, the first uses ECDSA 256
bits, the second RSA 2048; cert is signed by the second. If we do the keysize
check before we checked the key types match, we'll raise the badkey flags when
checking the EC-256 CA and it will remain up even when we finally find the
correct CA. So, move the check for the key size after signature verification,
which implicitly checks the key type.
Just applying rename.pl with this file:
mbedtls_cipher_get_key_size mbedtls_cipher_get_key_bitlen
mbedtls_pk_get_size mbedtls_pk_get_bitlen
MBEDTLS_BLOWFISH_MIN_KEY MBEDTLS_BLOWFISH_MIN_KEY_BITS
MBEDTLS_BLOWFISH_MAX_KEY MBEDTLS_BLOWFISH_MAX_KEY_BITS
- allows to express 'none' or 'all' more easily than lists
- more compact and easier to declare statically
- easier to check too
Only drawback: if we ever have more than 32 curves, we'll need an ABI change to
make that field a uint64_t.
* mbedtls-1.3:
Mark unused constant as such
Update ChangeLog for recent external bugfix
Serious bug fix in entropy.c
Fix memleak with repeated [gc]cm_setkey()
fix minor bug in path_cnt checks
Conflicts:
include/mbedtls/cipher.h
library/ccm.c
library/entropy.c
library/gcm.c
library/x509_crt.c
If the top certificate occurs twice in trust_ca (for example) it would
not be good for the second instance to be checked with check_path_cnt
reduced twice!
- more freedom for us to change it in the future
- enforces hygiene
- performance impact of making accessors no longer inline should really be
negligible
