mbc

This Rust crate provides ergonomic types for working with strings that are multibase-encoded multicodec-encoded byte sequences. Versions of each type are provided that are analogous to the String and str types, with analogous semantics.

Codec Categories

A "codec" refers to an entry in the multicodec registry.

This crate provides a CodecCategory enum that represents a categorization of relevant codecs. Note that this is not a standard categorization, doesn't guarantee to be complete, but it does accurately categorize the most common codecs.

Available Types

Multibase-encoded Multicodec-encoded types

These types are newtype wrappers around String and str, respectively, where the string content is a multibase-encoded multicodec-encoded byte sequence. The anatomy of the string is as follows. Given a base-encoding B, a codec C, and data bytes D, the string is of the form:

PrefixCharFor(B) MultibaseEncoded(B, MulticodecEncoded(UnsignedVarintEncoded(C), D))

The types are:

• MBC and MBCStr : a multibase-encoded multicodec-encoded byte sequence, with no restriction on the codec category. Analogous to the String and str types respectively.
• MBX and MBXStr : a multibase-encoded multicodec-encoded byte sequence, restricted to a specified codec category. Analogous to the String and str types respectively.

Examples:

• z6MkiTBz1ymuepAQ4HEHYSF1H8quG5GLVVQR3djdX3mDooWp : An ed25519 public key in base58btc encoding.

Fixed-base-encoded Multicodec-encoded types

These types are newtype wrappers around String and str, respectively, where the string content is a fixed-base-encoded multicodec-encoded byte sequence. The anatomy of the string is as follows. Given a base-encoding B, a codec C, and data bytes D, the string is of the form:

MultibaseEncoded(B, MulticodecEncoded(UnsignedVarintEncoded(C), D))

The difference between this an the multibase-encoded types is the lack of the prefix char. The base-encoding is specified in the type itself via generic parameter. Consumption of a string of this form requires knowledge of the specific base-encoding used. For example, there could be a schema in which base64url is always used. In these situations, there's no need for the base-encoding prefix character.

The types are:

• FBC and FBCStr : a fixed-base-encoded multicodec-encoded byte sequence, with no restriction on the codec category. Analogous to the String and str types respectively.
• FBX and FBXStr : a fixed-base-encoded multicodec-encoded byte sequence, restricted to a specified codec category. Analogous to the String and str types respectively.

Examples:

• 6MkiTBz1ymuepAQ4HEHYSF1H8quG5GLVVQR3djdX3mDooWp : An ed25519 public key known to be use base58btc encoding. Note that this is identical to the example in the above section but without the prefix char.

License

MIT License.