44 lines
1.1 KiB
Go
44 lines
1.1 KiB
Go
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package typeddata
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import (
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"crypto/ecdsa"
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"math/big"
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"github.com/ethereum/go-ethereum/common"
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"github.com/ethereum/go-ethereum/crypto"
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)
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var (
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// x19 to avoid collision with rlp encode. x01 version byte defined in EIP-191
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messagePadding = []byte{0x19, 0x01}
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)
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func encodeData(typed TypedData) (rst common.Hash, err error) {
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domainSeparator, err := hashStruct(eip712Domain, typed.Domain, typed.Types)
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if err != nil {
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return rst, err
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}
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primary, err := hashStruct(typed.PrimaryType, typed.Message, typed.Types)
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if err != nil {
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return rst, err
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}
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return crypto.Keccak256Hash(messagePadding, domainSeparator[:], primary[:]), nil
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}
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// Sign TypedData with a given private key. Verify that chainId in the typed data matches currently selected chain.
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func Sign(typed TypedData, prv *ecdsa.PrivateKey, chain *big.Int) ([]byte, error) {
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if err := typed.ValidateChainID(chain); err != nil {
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return nil, err
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}
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hash, err := encodeData(typed)
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if err != nil {
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return nil, err
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}
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sig, err := crypto.Sign(hash[:], prv)
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if err != nil {
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return nil, err
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}
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sig[64] += 27
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return sig, nil
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}
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