decode method Null safety

RsaPublicKey decode(
  1. String encodedKey
)

Implementation

static RsaPublicKey decode(String encodedKey) {
  ASN1Parser topLevelParser = ASN1Parser(base64.decode(encodedKey));
  ASN1Sequence topLevelSeq = topLevelParser.nextObject() as ASN1Sequence;

  ASN1BitString publicKeyBitString =
      topLevelSeq.elements![1] as ASN1BitString;
  ASN1Sequence publicKeySeq =
      ASN1Sequence.fromBytes(publicKeyBitString.stringValues as Uint8List);

  ASN1Integer modulus = publicKeySeq.elements![0] as ASN1Integer;
  ASN1Integer exponent = publicKeySeq.elements![1] as ASN1Integer;
  return RsaPublicKey(modulus.integer!, exponent.integer!);
}