chainhash

var (
	// TagBIP0340Challenge is the BIP-0340 tag for challenges.
	TagBIP0340Challenge = []byte("BIP0340/challenge")

	// TagBIP0340Aux is the BIP-0340 tag for aux data.
	TagBIP0340Aux = []byte("BIP0340/aux")

	// TagBIP0340Nonce is the BIP-0340 tag for nonces.
	TagBIP0340Nonce = []byte("BIP0340/nonce")

	// TagTapSighash is the tag used by BIP 341 to generate the sighash
	// flags.
	TagTapSighash = []byte("TapSighash")

	// TagTagTapLeaf is the message tag prefix used to compute the hash
	// digest of a tapscript leaf.
	TagTapLeaf = []byte("TapLeaf")

	// TagTapBranch is the message tag prefix used to compute the
	// hash digest of two tap leaves into a taproot branch node.
	TagTapBranch = []byte("TapBranch")

	// TagTapTweak is the message tag prefix used to compute the hash tweak
	// used to enable a public key to commit to the taproot branch root
	// for the witness program.
	TagTapTweak = []byte("TapTweak")

	// TagUtreexoV1 is the tag used by utreexo v1 serialized hashes to
	// generate the leaf hashes to be committed into the accumulator.
	TagUtreexoV1 = []byte("UtreexoV1")

	// UTREEXO_TAG_V1 is the version tag to be prepended to the leafhash. It's just the sha512 hash of the string
	// `UtreexoV1` represented as a vector of [u8] ([85 116 114 101 101 120 111 86 49]).
	// The same tag is "5574726565786f5631" as a hex string.
	UTREEXO_TAG_V1 = [64]byte{
		0x5b, 0x83, 0x2d, 0xb8, 0xca, 0x26, 0xc2, 0x5b, 0xe1, 0xc5, 0x42, 0xd6, 0xcc, 0xed, 0xdd, 0xa8,
		0xc1, 0x45, 0x61, 0x5c, 0xff, 0x5c, 0x35, 0x72, 0x7f, 0xb3, 0x46, 0x26, 0x10, 0x80, 0x7e, 0x20,
		0xae, 0x53, 0x4d, 0xc3, 0xf6, 0x42, 0x99, 0x19, 0x99, 0x31, 0x77, 0x2e, 0x03, 0x78, 0x7d, 0x18,
		0x15, 0x6e, 0xb3, 0x15, 0x1e, 0x0e, 0xd1, 0xb3, 0x09, 0x8b, 0xdc, 0x84, 0x45, 0x86, 0x18, 0x85,
	}

	// UTREEXO_TAG_V1_APPEND is just UTREEXO_TAG_V1 doubled so it can be appeneded directly to a hash digest.
	UTREEXO_TAG_V1_APPEND = [128]byte{}/* 128 elements not displayed */

)

var ErrHashStrSize = fmt.Errorf("max hash string length is %v bytes", MaxHashStringSize)