Documentation
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Overview ¶
Package bech32 decodes a Bech32 / Bech32m string — the encoding modern Bitcoin uses for SegWit addresses (bc1…/tb1…), and which Nostr (npub/nsec/note), Lightning (lnbc…), and Cosmos-family chains also use — into its human-readable prefix (HRP), data payload, and checksum variant, and interprets SegWit addresses (witness version + program + type). It is the Bech32 companion to base58check_decode, closing out Bitcoin-address coverage for crypto-forensics / IR / pentest loot. Pure offline transform; no network or device.
Wrap-vs-native judgement ¶
Native. Bech32 is a public spec (BIP-173 / BIP-350): a base-32 charset, a BCH checksum over the polynomial defined there (constant 1 for Bech32, 0x2bc830a3 for Bech32m), and a 5-bit↔8-bit regrouping — pure integer maths, stdlib only, nothing to wrap.
What this covers / defers ¶
- General Bech32 and Bech32m decode: HRP, the 5→8-bit data payload, and the checksum variant — works for any HRP (Bitcoin, Nostr, Lightning, Cosmos…).
- SegWit address interpretation for the bc/tb/bcrt HRPs: witness version, witness program, and the address type (P2WPKH / P2WSH / P2TR), with the BIP-173/350 variant rule enforced (v0 ⇒ Bech32, v1+ ⇒ Bech32m).
- Nostr (npub/nsec/note) and Lightning (lnbc…) HRPs are labelled; their inner TLV / invoice structure is left to the caller (a separate surface).
- Base58Check (legacy 1…/3… addresses, WIF) is the other encoding — see base58check_decode.
Verifiable / no confidently-wrong output ¶
Anchored to the BIP-173 / BIP-350 test vectors — A12UEL5L (Bech32, HRP "a"), A1LQFN3A (Bech32m, HRP "a"), and the P2WPKH address bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4 → witness v0, program 751e76e8199196d454941c45d1b3a323f1433bd6. A string whose checksum does not validate, or a SegWit address whose variant does not match its witness version, is reported as such rather than asserted valid; mixed-case input, a missing separator, or an out-of-charset character is rejected.
Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Result ¶
type Result struct {
Input string `json:"input"`
HRP string `json:"hrp"`
Variant string `json:"variant"` // "bech32" / "bech32m" / "invalid"
ChecksumValid bool `json:"checksum_valid"`
// DataHex is the data payload regrouped from 5-bit to 8-bit (when it is
// byte-aligned). Empty for an empty or non-byte-aligned payload.
DataHex string `json:"data_hex,omitempty"`
// Type labels a recognised artifact (SegWit address class, Nostr, Lightning).
Type string `json:"type,omitempty"`
// SegWit fields (set when the HRP is a SegWit network).
WitnessVersion *int `json:"witness_version,omitempty"`
WitnessProgramHex string `json:"witness_program_hex,omitempty"`
Note string `json:"note,omitempty"`
}
Result is the decoded view of a Bech32/Bech32m string.
Source Files