getSignature static method

String getSignature(
  1. String policyText
)

获取签名

Implementation

static String getSignature(String policyText) {
  //进行utf8编码
  List<int> policyUtf8 = utf8.encode(policyText);
  //进行base64编码
  String policyBase64 = base64.encode(policyUtf8);
  //再次进行utf8编码
  List<int> policy = utf8.encode(policyBase64);
  //进行utf8 编码
  List<int> key = utf8.encode(accessKeySecret);
  //通过hmac,使用sha1进行加密
  List<int> signaturePre = Hmac(sha1, key).convert(policy).bytes;
  //最后一步，将上述所得进行base64 编码
  String signature = base64.encode(signaturePre);
  return signature;
}