Checking the error code of decoding a blob as an hdb_entry or
hdb_entry_alias to determine which of those the blob is depends on a
detail of the Heimdal ASN.1 compiler and library that shouldn't be
depended on. Using a CHOICE adds no octets to the encoding:
HDB-EntryOrAlias ::= CHOICE {
entry hdb_entry,
alias hdb_entry_alias
}
since we're adding no additional tags and the two arms of the CHOICE
already differ in tag (hdb_entry's tag is a [UNIVERSAL Sequence] tag,
while hdb_entry_alias's is an [APPLICATION 0] tag).
6aeab13f06