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package model.asn1;
import model.asn1.exceptions.ParseException;
import model.asn1.parsing.BytesReader;
import ui.Utils;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
/**
* Represents an ASN.1 IA5String type. It is a string that is restricted to ISO 646 / T.50 characters.
*/
public class IA5String extends ASN1String {
/**
* The X.680 universal class tag assignment.
*/
public static final Tag TAG = new Tag(TagClass.UNIVERSAL, false, 0x16);
/**
* EFFECTS: Constructs an IA5String with the given tag and string.
* Throws {@link ParseException} if the string is invalid. It must only contain T.50 chars.
* REQUIRES: For the requirements of tag and parentTag, consult {@link ASN1Object}.
*/
public IA5String(Tag tag, Tag parentTag, String string) throws ParseException {
super(tag, parentTag, string);
}
/**
* EFFECTS: Parse from user input. Tags are parsed as-per {@link ASN1Object}. The value will be parsed as UTF-8 big
* endian.
* Throws {@link ParseException} if the encoded data is invalid:
* - Illegal string (containing non-T.50 chars)
* - Early EOF
* - Other cases in {@link ASN1Object}
* MODIFIES: this, encoded
*/
public IA5String(BytesReader encoded, boolean hasParentTag) throws ParseException {
super(encoded, hasParentTag);
setString(new String(Utils.byteToByte(encoded.require(getLength(), true)),
StandardCharsets.UTF_8));
}
/**
* EFFECTS: Checks whether the given string only contains ISO 646 / T.50 chars.
*/
@Override
protected boolean validate(String newString) {
// Java doesn't have unsigned bytes - that is, bytes greater than 0x7F will
// overflow and become < 0. Thus, just compare b >= 0 will suffice.
return Arrays.stream(Utils.byteToByte(newString.getBytes(StandardCharsets.UTF_8)))
.noneMatch(b -> b < 0);
}
}
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