aergoio/aergo

/**
 *  @file
 *  @copyright defined in aergo/LICENSE.txt
 */

package key

import (
    "bytes"
    "crypto/ecdsa"
    "encoding/binary"

    "github.com/aergoio/aergo/v2/types"
)

// GenerateAddress calculates the raw (not-encoded) address for a private key.
// Address is the raw, internally used identifier of an account
// In Aergo, the address is synonymous with the compressed public key (33 bytes).
func GenerateAddress(pubkey *ecdsa.PublicKey) []byte {
    if pubkey == nil {
        return nil
    }
    addr := new(bytes.Buffer)
    // Calculate compressed pubkey
    binary.Write(addr, binary.LittleEndian, uint8(0x2+pubkey.Y.Bit(0))) // 0x2 for even, 0x3 for odd Y
    keyLength := len(pubkey.X.Bytes())
    if keyLength < 32 { // Add padding
        for i := 1; i < types.AddressLength-keyLength; i++ {
            binary.Write(addr, binary.LittleEndian, uint8(0))
        }
    }
    binary.Write(addr, binary.LittleEndian, pubkey.X.Bytes())
    return addr.Bytes() // 33 bytes
}