fromBase64toSha256 method
Implementation
String fromBase64toSha256(final String value) {
final List<int> bytes = base64.decode(value);
final String hexForm = hex.encode(bytes);
if (!isValidSha256Format(hexForm)) {
throw const FormatException('Value is not SHA-256');
}
final String sha256Form = _formatSha(hexForm);
return sha256Form;
}