77 lines
2.2 KiB
Go
77 lines
2.2 KiB
Go
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package shachain
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import (
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"github.com/roasbeef/btcd/chaincfg/chainhash"
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)
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// Producer is an interface which serves as an abstraction over data
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// structure responsible for efficient generating the secrets by given index.
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// The generation of secrets should be made in such way that secret store
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// might efficiently store and retrieve the secrets.
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type Producer interface {
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// AtIndex produce secret by given index.
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AtIndex(uint64) (*chainhash.Hash, error)
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// ToBytes convert producer to the binary representation.
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ToBytes() ([]byte, error)
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}
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// RevocationProducer implementation of Producer. This version of shachain
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// slightly changed in terms of method naming. Initial concept might be found
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// here:
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// https://github.com/rustyrussell/ccan/blob/master/ccan/crypto/shachain/design.txt
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type RevocationProducer struct {
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// root is the element from which we may generate all hashes which
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// corresponds to the index domain [281474976710655,0].
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root *element
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}
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// A compile time check to ensure RevocationProducer implements the Producer
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// interface.
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var _ Producer = (*RevocationProducer)(nil)
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// NewRevocationProducer create new instance of shachain producer.
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func NewRevocationProducer(root *chainhash.Hash) *RevocationProducer {
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return &RevocationProducer{
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root: &element{
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index: rootIndex,
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hash: *root,
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}}
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}
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// NewRevocationProducerFromBytes deserialize an instance of a RevocationProducer
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// encoded in the passed byte slice, returning a fully initialize instance of a
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// RevocationProducer.
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func NewRevocationProducerFromBytes(data []byte) (*RevocationProducer, error) {
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root, err := chainhash.NewHash(data)
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if err != nil {
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return nil, err
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}
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return &RevocationProducer{
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root: &element{
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index: rootIndex,
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hash: *root,
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},
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}, nil
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}
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// AtIndex produce secret by given index.
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// NOTE: Part of the Producer interface.
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func (p *RevocationProducer) AtIndex(v uint64) (*chainhash.Hash, error) {
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ind := newIndex(v)
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element, err := p.root.derive(ind)
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if err != nil {
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return nil, err
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}
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return &element.hash, nil
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}
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// ToBytes convert producer to the binary representation.
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// NOTE: Part of the Producer interface.
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func (p *RevocationProducer) ToBytes() ([]byte, error) {
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return p.root.hash.CloneBytes(), nil
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}
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