openpgp: Rework streaming encryptor.

  - Instead of giving a set of TPKs to the encryptor, hand in a set of
    recipients, which are (keyid, key)-tuples, conveniently created
    from key queries over TPKs.  This simplifies the encryptor, and
    makes the key selection explicit.

  - Drop the EncryptionMode type.

  - As a nice side effect, we can now generate encrypted messages with
    wildcard recipient addresses.

1 files changed, 40 insertions, 0 deletions

diff --git a/openpgp-ffi/include/sequoia/openpgp/serialize.h b/openpgp-ffi/include/sequoia/openpgp/serialize.h
new file mode 100644
index 00000000..7d41d9b0
--- /dev/null
+++ b/openpgp-ffi/include/sequoia/openpgp/serialize.h
@@ -0,0 +1,40 @@
+#ifndef SEQUOIA_OPENPGP_SERIALIZE_H
+#define SEQUOIA_OPENPGP_SERIALIZE_H
+
+/*/
+/// Creates a new recipient with an explicit recipient keyid.
+///
+/// Consumes `keyid`, references `key`.
+/*/
+pgp_recipient_t pgp_recipient_new (pgp_keyid_t keyid, pgp_key_t key);
+
+/*/
+/// Frees this object.
+/*/
+void pgp_recipient_free (pgp_recipient_t);
+
+/*/
+/// Returns a human readable description of this object suitable for
+/// debugging.
+/*/
+char *pgp_recipient_debug (const pgp_recipient_t);
+
+/*/
+/// Gets the KeyID.
+/*/
+pgp_keyid_t pgp_recipient_keyid (const pgp_recipient_t);
+
+/*/
+/// Sets the KeyID.
+/*/
+void pgp_recipient_set_keyid (pgp_recipient_t, pgp_keyid_t);
+
+/*/
+/// Collects recipients from a `pgp_tpk_key_iter_t`.
+///
+/// Consumes the iterator.  The returned buffer must be freed using
+/// libc's allocator.
+/*/
+pgp_recipient_t *pgp_recipients_from_key_iter (pgp_tpk_key_iter_t, size_t *);
+
+#endif