63 lines
1.6 KiB
Go
63 lines
1.6 KiB
Go
package crypto
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import (
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"bytes"
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"crypto/ecdsa"
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"crypto/sha256"
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"fmt"
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"git.frostfs.info/TrueCloudLab/frostfs-crypto/internal"
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"github.com/mr-tron/base58"
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)
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const (
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// WIFLength constant length of WIF string.
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WIFLength = 38
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// ErrBadWIF when passed WIF-string could not be decoded from base58.
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ErrBadWIF = internal.Error("bad wif")
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// ErrBadChecksum when passed WIF-string could not be verified
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// by last 4 bytes signature.
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ErrBadChecksum = internal.Error("bad checksum")
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// ErrEmptyPrivateKey when PK passed into WIFEncode method is nil.
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ErrEmptyPrivateKey = internal.Error("empty private key")
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)
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func wifCheckSum(data []byte) []byte {
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sum := sha256.Sum256(data)
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sum = sha256.Sum256(sum[:])
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return sum[:4]
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}
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// WIFEncode encodes the given private key into a WIF string.
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func WIFEncode(key *ecdsa.PrivateKey) (string, error) {
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if key == nil || key.D == nil {
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return "", ErrEmptyPrivateKey
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}
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data := make([]byte, WIFLength)
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data[0] = 0x80
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data[33] = 0x01
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copy(data[1:33], key.D.Bytes())
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copy(data[34:], wifCheckSum(data[:34]))
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return base58.Encode(data), nil
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}
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// WIFDecode decoded the given WIF string into a private key.
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func WIFDecode(wif string) (*ecdsa.PrivateKey, error) {
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data, err := base58.Decode(wif)
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if err != nil {
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return nil, fmt.Errorf("%w: %v", ErrBadWIF, err)
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} else if actual := len(data); actual != WIFLength {
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return nil, fmt.Errorf("%w: expect: %d, actual: %d", ErrBadWIF, WIFLength, actual)
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} else if sum := wifCheckSum(data[:34]); !bytes.Equal(data[34:], sum) {
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return nil, ErrBadChecksum
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}
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return UnmarshalPrivateKey(data[1:33])
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}
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