LDAP KrbKey encoder and decoder fixes #129
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In the LDAP KDB module, ensure that every krb5_key_data we pass to asn1_encode_sequence_of_keys includes a salt type, for compatibility with the decoder in unpatched krb5 1.11 and 1.12. This is not a behavior change by itself; since 1.7 the encoder has always included a KrbKey salt field because it erroneously treats that field as non-optional. (Luckily, the encoded salt always happens to have salt type 0 because krb5_key_data constructors start with zeroed memory.) The next commit will fix the encoder and decoder to properly treat the KrbKey salt field as optional, so we need this change to ensure that our encodings remain compatible. Also fix the ASN.1 tests to set key_data_ver correctly for the sample test key data. ticket: 7919
Per the ASN.1 definition, the KrbKey salt field is optional. Since 1.7, we have been treating it as mandatory in the encoder; since 1.11, we have been treating it as mandatory in the decoder. Mostly by luck, we have been encoding a salt type of 0 when key_data_ver is 1, but we really should not be looking at key_data_type[1] or key_data_length[1] in this situation. Treat the salt field as optional in the encoder and decoder. Although the previous commit ensures that we continue to always encode a salt (without any dangerous assumptions about krb5_key_data constructors), this change will allow us to decode key data encoded by 1.6 without salt fields. This also fixes issue #7918, by properly setting key_data_ver to 2 if a salt type but no salt value is present. It is difficult to get the decoder to actually assign 2 to key_data_ver just because the salt field is there, so take care of that in asn1_decode_sequence_of_keys. Adjust kdbtest.c to match the new behavior by setting key_data_ver to 2 in both test keys. ticket: 7919 target_version: 1.12.2 tags: pullup
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These commits fix RT issues #7918 and #7919 while remaining compatible with unpatched code.