When writing a private EC key, use a constant size for the private
value, as specified in RFC 5915. Previously, the value was written
as an ASN.1 INTEGER, which caused the size of the key to leak
about 1 bit of information on average, and could cause the value to be
1 byte too large for the output buffer.
Add pk_write test cases where the ASN.1 INTEGER encoding of the
private value would not have the mandatory size for the OCTET STRING
that contains the value.
ec_256_long_prv.pem is a random secp256r1 private key, selected so
that the private value is >= 2^255, i.e. the top bit of the first byte
is set (which would cause the INTEGER encoding to have an extra
leading 0 byte).
ec_521_short_prv.pem is a random secp521r1 private key, selected so
that the private value is < 2^519, i.e. the first byte is 0 and the
top bit of the second byte is 0 (which would cause the INTEGER
encoding to have one less 0 byte at the start).
Previous commits attempted to use `gmtime_s()` for IAR systems; however,
this attempt depends on the use of C11 extensions which lead to incompatibility
with other pieces of the library, such as the use of `memset()` which is
being deprecated in favor of `memset_s()` in C11.
While these tests and the issue with it are pre-existing:
- we previously didn't understand that the issue was an openssl bug
- failures seem to have become more frequent since the recent changes
So let's disable these fragile tests in order to get a clean CI. We still have
the tests against gnutls-serv for interop testing.
While making the initial commit, I thought $OPENSSL_LEGACY was not affect by
this bug, but it turns out I was wrong. All versions of OpenSSL installed on
the CI are. Therefore, the corresponding tests are disabled for the same
reason as the gnutls-cli tests above it.
This commit is only about the tests that were added in the recent
fragmentation work. One of those two tests had a particularly
annoying mode of failure: it failed consistently with seed=1 (use in the
release version of all.sh), once #1951 was applied. This has nothing
particular to do with #1951, except that by changing retransmission behaviour
1951 made the proxy run into a path that triggered the OpenSSL bug with this
seed, while it previously did that only with other seeds.
Other 3d interop test are also susceptible to triggering this OpenSSL bug or
others (or bugs in GnuTLS), but they are left untouched by this commit as:
- they were pre-existing to the recent DTLS branches;
- they don't seem to have the particularly annoying seed=1 mode of failure.
However it's probably desirable to do something about them at some point in
the future.
previously a single function was used for most test cases (ctr_drbg_validate) making it harder to understand what the exact scenario is as a result it was split into easier to understand functions.
