aergoio/aergo

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

package key

import (
    "crypto/aes"
    "crypto/cipher"
    "errors"

    sha256 "github.com/minio/sha256-simd"
)

func hashBytes(b1 []byte, b2 []byte) []byte {
    h := sha256.New()
    h.Write(b1)
    h.Write(b2)
    return h.Sum(nil)
}

func encrypt(base, key, data []byte) ([]byte, error) {
    block, err := aes.NewCipher(key)
    if err != nil {
        return nil, err
    }
    // Never use more than 2^32 random nonces with a given key because of the risk of a repeat.
    if len(base) < 16 {
        return nil, errors.New("too short address length")
    }
    nonce := base[4:16]

    aesgcm, err := cipher.NewGCM(block)
    if err != nil {
        return nil, err
    }

    cipherbytes := aesgcm.Seal(nil, nonce, data, nil)
    return cipherbytes, nil
}

func decrypt(base, key, data []byte) ([]byte, error) {
    if len(base) < 16 {
        return nil, errors.New("too short address length")
    }
    nonce := base[4:16]

    block, err := aes.NewCipher(key)
    if err != nil {
        return nil, err
    }

    aesgcm, err := cipher.NewGCM(block)
    if err != nil {
        return nil, err
    }

    plainbytes, err := aesgcm.Open(nil, nonce, data, nil)

    if err != nil {
        return nil, err
    }
    return plainbytes, nil
}