The relevant ASN.1 definitions for a PKCS#8 encoded Elliptic Curve key are:
PrivateKeyInfo ::= SEQUENCE {
version Version,
privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
privateKey PrivateKey,
attributes [0] IMPLICIT Attributes OPTIONAL
}
AlgorithmIdentifier ::= SEQUENCE {
algorithm OBJECT IDENTIFIER,
parameters ANY DEFINED BY algorithm OPTIONAL
}
ECParameters ::= CHOICE {
namedCurve OBJECT IDENTIFIER
-- implicitCurve NULL
-- specifiedCurve SpecifiedECDomain
}
ECPrivateKey ::= SEQUENCE {
version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
privateKey OCTET STRING,
parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
publicKey [1] BIT STRING OPTIONAL
}
Because of the two optional fields, there are 4 possible variants that need to
be parsed: no optional fields, only parameters, only public key, and both
optional fields. Previously mbedTLS was unable to parse keys with "only
parameters". Also, only "only public key" was tested. There was a test for "no
optional fields", but it was labelled incorrectly as SEC.1 and not run because
of a great renaming mixup.
Change the script generate_errors.pl to call the grep function in Perl
instead of calling the external tool grep directly as this causes
problems when ANSI escape sequences are included in the grep output
string.
In mbedtls_ssl_derive_keys, don't call mbedtls_md_hmac_starts in
ciphersuites that don't use HMAC. This doesn't change the behavior of
the code, but avoids relying on an uncaught error when attempting to
start an HMAC operation that hadn't been initialized.
The 'critical' boolean can be set to false in two ways:
- by leaving it implicit (test data generated by openssl)
- by explicitly setting it to false (generated by hand)
This covers all lines added in the previous commit. Coverage was tested using:
make CFLAGS='--coverage -g3 -O0'
(cd tests && ./test_suite_x509parse)
make lcov
firefox Coverage/index.html # then visual check
Test data was generated by taking a copy of tests/data_files/crl-idp.pem,
encoding it as hex, and then manually changing the values of some bytes to
achieve the desired errors, using https://lapo.it/asn1js/ for help in locating
the desired bytes.
For library/certs.c the issue is resolved by aligning it with the version in
the 2.7 branch (which is currently the same as the version in the development
branch)