Function Decode

src/bech32.cpp:374–400

Decode a Bech32 or Bech32m string. */

/** Decode a Bech32 or Bech32m string. */
DecodeResult Decode(const std::string& str, CharLimit limit) {
    std::vector<int> errors;
    if (!CheckCharacters(str, errors)) return {};
    size_t pos = str.rfind(SEPARATOR);
    if (str.size() > limit) return {};
    if (pos == str.npos || pos == 0 || pos + CHECKSUM_SIZE >= str.size()) {
        return {};
    }
    data values(str.size() - 1 - pos);
    for (size_t i = 0; i < str.size() - 1 - pos; ++i) {
        unsigned char c = str[i + pos + 1];
        int8_t rev = CHARSET_REV[c];

        if (rev == -1) {
            return {};
        }
        values[i] = rev;
    }
    std::string hrp;
    hrp.reserve(pos);
    for (size_t i = 0; i < pos; ++i) {
        hrp += LowerCase(str[i]);
    }
    Encoding result = VerifyChecksum(hrp, values);
    if (result == Encoding::INVALID) return {};
    return {result, std::move(hrp), data(values.begin(), values.end() - CHECKSUM_SIZE)};
}

/** Find index of an incorrect character in a Bech32 string. */
std::pair<std::string, std::vector<int>> LocateErrors(const std::string& str, CharLimit limit) {