diff options
Diffstat (limited to 'vendor/go.mau.fi/util/base58')
-rw-r--r-- | vendor/go.mau.fi/util/base58/README.md | 9 | ||||
-rw-r--r-- | vendor/go.mau.fi/util/base58/alphabet.go | 49 | ||||
-rw-r--r-- | vendor/go.mau.fi/util/base58/base58.go | 138 | ||||
-rw-r--r-- | vendor/go.mau.fi/util/base58/base58check.go | 52 | ||||
-rw-r--r-- | vendor/go.mau.fi/util/base58/doc.go | 29 |
5 files changed, 277 insertions, 0 deletions
diff --git a/vendor/go.mau.fi/util/base58/README.md b/vendor/go.mau.fi/util/base58/README.md new file mode 100644 index 0000000..5095450 --- /dev/null +++ b/vendor/go.mau.fi/util/base58/README.md @@ -0,0 +1,9 @@ +base58 +========== + +This is a copy of <https://github.com/btcsuite/btcd/tree/master/btcutil/base58>. + +## License + +Package base58 is licensed under the [copyfree](http://copyfree.org) ISC +License. diff --git a/vendor/go.mau.fi/util/base58/alphabet.go b/vendor/go.mau.fi/util/base58/alphabet.go new file mode 100644 index 0000000..6bb39fe --- /dev/null +++ b/vendor/go.mau.fi/util/base58/alphabet.go @@ -0,0 +1,49 @@ +// Copyright (c) 2015 The btcsuite developers +// Use of this source code is governed by an ISC +// license that can be found in the LICENSE file. + +// AUTOGENERATED by genalphabet.go; do not edit. + +package base58 + +const ( + // alphabet is the modified base58 alphabet used by Bitcoin. + alphabet = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz" + + alphabetIdx0 = '1' +) + +var b58 = [256]byte{ + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 0, 1, 2, 3, 4, 5, 6, + 7, 8, 255, 255, 255, 255, 255, 255, + 255, 9, 10, 11, 12, 13, 14, 15, + 16, 255, 17, 18, 19, 20, 21, 255, + 22, 23, 24, 25, 26, 27, 28, 29, + 30, 31, 32, 255, 255, 255, 255, 255, + 255, 33, 34, 35, 36, 37, 38, 39, + 40, 41, 42, 43, 255, 44, 45, 46, + 47, 48, 49, 50, 51, 52, 53, 54, + 55, 56, 57, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, +} diff --git a/vendor/go.mau.fi/util/base58/base58.go b/vendor/go.mau.fi/util/base58/base58.go new file mode 100644 index 0000000..8ee5956 --- /dev/null +++ b/vendor/go.mau.fi/util/base58/base58.go @@ -0,0 +1,138 @@ +// Copyright (c) 2013-2015 The btcsuite developers +// Use of this source code is governed by an ISC +// license that can be found in the LICENSE file. + +package base58 + +import ( + "math/big" +) + +//go:generate go run genalphabet.go + +var bigRadix = [...]*big.Int{ + big.NewInt(0), + big.NewInt(58), + big.NewInt(58 * 58), + big.NewInt(58 * 58 * 58), + big.NewInt(58 * 58 * 58 * 58), + big.NewInt(58 * 58 * 58 * 58 * 58), + big.NewInt(58 * 58 * 58 * 58 * 58 * 58), + big.NewInt(58 * 58 * 58 * 58 * 58 * 58 * 58), + big.NewInt(58 * 58 * 58 * 58 * 58 * 58 * 58 * 58), + big.NewInt(58 * 58 * 58 * 58 * 58 * 58 * 58 * 58 * 58), + bigRadix10, +} + +var bigRadix10 = big.NewInt(58 * 58 * 58 * 58 * 58 * 58 * 58 * 58 * 58 * 58) // 58^10 + +// Decode decodes a modified base58 string to a byte slice. +func Decode(b string) []byte { + answer := big.NewInt(0) + scratch := new(big.Int) + + // Calculating with big.Int is slow for each iteration. + // x += b58[b[i]] * j + // j *= 58 + // + // Instead we can try to do as much calculations on int64. + // We can represent a 10 digit base58 number using an int64. + // + // Hence we'll try to convert 10, base58 digits at a time. + // The rough idea is to calculate `t`, such that: + // + // t := b58[b[i+9]] * 58^9 ... + b58[b[i+1]] * 58^1 + b58[b[i]] * 58^0 + // x *= 58^10 + // x += t + // + // Of course, in addition, we'll need to handle boundary condition when `b` is not multiple of 58^10. + // In that case we'll use the bigRadix[n] lookup for the appropriate power. + for t := b; len(t) > 0; { + n := len(t) + if n > 10 { + n = 10 + } + + total := uint64(0) + for _, v := range t[:n] { + tmp := b58[v] + if tmp == 255 { + return []byte("") + } + total = total*58 + uint64(tmp) + } + + answer.Mul(answer, bigRadix[n]) + scratch.SetUint64(total) + answer.Add(answer, scratch) + + t = t[n:] + } + + tmpval := answer.Bytes() + + var numZeros int + for numZeros = 0; numZeros < len(b); numZeros++ { + if b[numZeros] != alphabetIdx0 { + break + } + } + flen := numZeros + len(tmpval) + val := make([]byte, flen) + copy(val[numZeros:], tmpval) + + return val +} + +// Encode encodes a byte slice to a modified base58 string. +func Encode(b []byte) string { + x := new(big.Int) + x.SetBytes(b) + + // maximum length of output is log58(2^(8*len(b))) == len(b) * 8 / log(58) + maxlen := int(float64(len(b))*1.365658237309761) + 1 + answer := make([]byte, 0, maxlen) + mod := new(big.Int) + for x.Sign() > 0 { + // Calculating with big.Int is slow for each iteration. + // x, mod = x / 58, x % 58 + // + // Instead we can try to do as much calculations on int64. + // x, mod = x / 58^10, x % 58^10 + // + // Which will give us mod, which is 10 digit base58 number. + // We'll loop that 10 times to convert to the answer. + + x.DivMod(x, bigRadix10, mod) + if x.Sign() == 0 { + // When x = 0, we need to ensure we don't add any extra zeros. + m := mod.Int64() + for m > 0 { + answer = append(answer, alphabet[m%58]) + m /= 58 + } + } else { + m := mod.Int64() + for i := 0; i < 10; i++ { + answer = append(answer, alphabet[m%58]) + m /= 58 + } + } + } + + // leading zero bytes + for _, i := range b { + if i != 0 { + break + } + answer = append(answer, alphabetIdx0) + } + + // reverse + alen := len(answer) + for i := 0; i < alen/2; i++ { + answer[i], answer[alen-1-i] = answer[alen-1-i], answer[i] + } + + return string(answer) +} diff --git a/vendor/go.mau.fi/util/base58/base58check.go b/vendor/go.mau.fi/util/base58/base58check.go new file mode 100644 index 0000000..402c323 --- /dev/null +++ b/vendor/go.mau.fi/util/base58/base58check.go @@ -0,0 +1,52 @@ +// Copyright (c) 2013-2014 The btcsuite developers +// Use of this source code is governed by an ISC +// license that can be found in the LICENSE file. + +package base58 + +import ( + "crypto/sha256" + "errors" +) + +// ErrChecksum indicates that the checksum of a check-encoded string does not verify against +// the checksum. +var ErrChecksum = errors.New("checksum error") + +// ErrInvalidFormat indicates that the check-encoded string has an invalid format. +var ErrInvalidFormat = errors.New("invalid format: version and/or checksum bytes missing") + +// checksum: first four bytes of sha256^2 +func checksum(input []byte) (cksum [4]byte) { + h := sha256.Sum256(input) + h2 := sha256.Sum256(h[:]) + copy(cksum[:], h2[:4]) + return +} + +// CheckEncode prepends a version byte and appends a four byte checksum. +func CheckEncode(input []byte, version byte) string { + b := make([]byte, 0, 1+len(input)+4) + b = append(b, version) + b = append(b, input...) + cksum := checksum(b) + b = append(b, cksum[:]...) + return Encode(b) +} + +// CheckDecode decodes a string that was encoded with CheckEncode and verifies the checksum. +func CheckDecode(input string) (result []byte, version byte, err error) { + decoded := Decode(input) + if len(decoded) < 5 { + return nil, 0, ErrInvalidFormat + } + version = decoded[0] + var cksum [4]byte + copy(cksum[:], decoded[len(decoded)-4:]) + if checksum(decoded[:len(decoded)-4]) != cksum { + return nil, 0, ErrChecksum + } + payload := decoded[1 : len(decoded)-4] + result = append(result, payload...) + return +} diff --git a/vendor/go.mau.fi/util/base58/doc.go b/vendor/go.mau.fi/util/base58/doc.go new file mode 100644 index 0000000..d657f05 --- /dev/null +++ b/vendor/go.mau.fi/util/base58/doc.go @@ -0,0 +1,29 @@ +// Copyright (c) 2014 The btcsuite developers +// Use of this source code is governed by an ISC +// license that can be found in the LICENSE file. + +/* +Package base58 provides an API for working with modified base58 and Base58Check +encodings. + +# Modified Base58 Encoding + +Standard base58 encoding is similar to standard base64 encoding except, as the +name implies, it uses a 58 character alphabet which results in an alphanumeric +string and allows some characters which are problematic for humans to be +excluded. Due to this, there can be various base58 alphabets. + +The modified base58 alphabet used by Bitcoin, and hence this package, omits the +0, O, I, and l characters that look the same in many fonts and are therefore +hard to humans to distinguish. + +# Base58Check Encoding Scheme + +The Base58Check encoding scheme is primarily used for Bitcoin addresses at the +time of this writing, however it can be used to generically encode arbitrary +byte arrays into human-readable strings along with a version byte that can be +used to differentiate the same payload. For Bitcoin addresses, the extra +version is used to differentiate the network of otherwise identical public keys +which helps prevent using an address intended for one network on another. +*/ +package base58 |