Add a builder for creating invoice requests for an offer given a
payer_id. Other settings may be optional depending on the offer and
duplicative settings will override previous settings. Building produces
a semantically valid `invoice_request` message for the offer, which then
can be signed for the payer_id.
When reading an offer, an `invoice_request` message is sent over the
wire. Implement Writeable for encoding the message and TryFrom for
decoding it by defining in terms of TLV streams. These streams represent
content for the payer metadata (0), reflected `offer` (1-79),
`invoice_request` (80-159), and signature (240).
Offers uses a merkle root hash construction for signature calculation
and verification. Add a submodule implementing this so that it can be
used when parsing and signing invoice_request and invoice messages.
Define an interface for BOLT 12 `invoice_request` messages. The
underlying format consists of the original bytes and the parsed
contents.
The bytes are later needed when constructing an `invoice` message. This
is because it must mirror all the `offer` and `invoice_request` TLV
records, including unknown ones, which aren't represented in the
contents.
The contents will be used in `invoice` messages to avoid duplication.
Some fields while required in a typical user-pays-merchant flow may not
be necessary in the merchant-pays-user flow (e.g., refund, ATM).
BOLT 12 messages are limited to a range of TLV record types. Refactor
decode_tlv_stream into a decode_tlv_stream_range macro for limiting
which types are parsed. Requires a SeekReadable trait for rewinding when
a type outside of the range is seen. This allows for composing TLV
streams of different ranges.
Updates offer parsing accordingly and adds a test demonstrating failure
if a type outside of the range is included.
Add common bech32 parsing for BOLT 12 messages. The encoding is similar
to bech32 only without a checksum and with support for continuing
messages across multiple parts.
Messages implementing Bech32Encode are parsed into a TLV stream, which
is converted to the desired message content while performing semantic
checks. Checking after conversion allows for more elaborate checks of
data composed of multiple TLV records and for more meaningful error
messages.
The parsed bytes are also saved to allow creating messages with mirrored
data, even if TLV records are unknown.
Add a builder for creating offers given a required description and
node_id. Other settings are optional and duplicative settings will
override previous settings for non-Vec fields.
Define an interface for BOLT 12 `offer` messages. The underlying format
consists of the original bytes and the parsed contents.
The bytes are later needed when constructing an `invoice_request`
message. This is because it must mirror all the `offer` TLV records,
including unknown ones, which aren't represented in the contents.
The contents will be used in `invoice_request` messages to avoid
duplication. Some fields while required in a typical user-pays-merchant
flow may not be necessary in the merchant-pays-user flow (i.e., refund).
