tree 71f8e4c54865695671c0278b8ef41c7cc5e7dcd0
parent 1df70cea5daa391e10f5df9057c60fd740b912ab
author David Benjamin <davidben@google.com> 1670287429 -0500
committer Boringssl LUCI CQ <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com> 1675274380 +0000

Unexport and remove support for implicit tagging on ASN1_ITYPE_EXTERN.

Currently, the only EXTERN type is X509_NAME. Implicitly tagging an
X509_NAME didn't work anyway because of the cached encoding. Moreover,
even if it did work, it'd be invalid. Name in RFC 5280 is actually a
one-element CHOICE type, and CHOICE types can never be implicitly
tagged. So just remove support.

One thing of note: I'm thinking EXTERN can be used later to retain
ASN1_ITEM compatibility, once X509 and friends no longer use the
template machinery. That means we're not only assuming X509_NAME is
never implicitly tagged, but also that external callers using
<openssl/asn1t.h> won't implicitly tag a built-in type.

This removes a case we need to handle in the rewritten tasn_enc.c. (In
particular, crypto/asn1 and crypto/bytestring use a different tag
representation and I'd like to minimum the number of conversions we
need.)

Update-Note: IMPLEMENT_EXTERN_ASN1 can no longer be used outside the
library. I found no callers using this machinery, and we're better off
gradually migrating every <openssl/asn1t.h> user to CBS/CBB anyway.

Bug: 548
Change-Id: I0aab531077d25960dd3f16183656f318d78a0806
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/56186
Reviewed-by: Bob Beck <bbe@google.com>
Commit-Queue: David Benjamin <davidben@google.com>