code: func prf10(result, secret, label, seed []byte) {
  	hashSHA1 := sha1.New
  	hashMD5 := md5.New
  
  	labelAndSeed := make([]byte, len(label)+len(seed))
  	copy(labelAndSeed, label)
  	copy(labelAndSeed[len(label):], seed)
  
  	s1, s2 := splitPreMasterSecret(secret)
  	pHash(result, s1, labelAndSeed, hashMD5)
  	result2 := make([]byte, len(result))
  	pHash(result2, s2, labelAndSeed, hashSHA1)
  
  	for i, b := range result2 {
  		result[i] ^= b
  	}
  }
docs: // prf10 implements the TLS 1.0 pseudo-random function, as defined in RFC 2246, section 5.