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Diffstat (limited to 'src/main/model/asn1/IA5String.java')
-rw-r--r-- | src/main/model/asn1/IA5String.java | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/src/main/model/asn1/IA5String.java b/src/main/model/asn1/IA5String.java new file mode 100644 index 0000000..ea5cf91 --- /dev/null +++ b/src/main/model/asn1/IA5String.java @@ -0,0 +1,53 @@ +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); + } +} |