diff options
Diffstat (limited to 'src/cz/crcs/ectester/reader/ECParams.java')
| -rw-r--r-- | src/cz/crcs/ectester/reader/ECParams.java | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/src/cz/crcs/ectester/reader/ECParams.java b/src/cz/crcs/ectester/reader/ECParams.java new file mode 100644 index 0000000..c19640e --- /dev/null +++ b/src/cz/crcs/ectester/reader/ECParams.java @@ -0,0 +1,202 @@ +package cz.crcs.ectester.reader; + +import cz.crcs.ectester.applet.EC_Consts; + +import java.io.*; +import java.util.ArrayList; +import java.util.LinkedList; +import java.util.List; +import java.util.Scanner; +import java.util.regex.Pattern; + +/** + * @author Jan Jancar johny@neuromancer.sk + */ +public class ECParams { + private static final Pattern hex = Pattern.compile("[a-fA-F\\d]+"); + + /** + * Flattens params read from String[] data into a byte[] with their lengths prepended as short entries. + * + * @param params (EC_Consts.PARAMETER_* | ...) + * @param data data read by readString, readFile, readResource + * @return byte[] with params flattened, or null + */ + public static byte[] flatten(short params, String[] data) { + if (!validate(data)) { + return null; + } + + ByteArrayOutputStream out = new ByteArrayOutputStream(); + short paramMask = EC_Consts.PARAMETER_FP; + int i = 0; + while (paramMask <= EC_Consts.PARAMETER_S) { + short masked = (short) (params & paramMask); + if (masked != 0) { + byte[] param = parse(data[i]); + if (masked == EC_Consts.PARAMETER_F2M && data.length == 9) { + //read and pad and append e_2, e_3 + param = Util.concatenate(param, parse(data[i + 1]), parse(data[i + 2])); + i += 2; + if (param.length != 6) + throw new RuntimeException("PARAMETER_F2M length is not 6.(should be)"); + } + if (masked == EC_Consts.PARAMETER_G || masked == EC_Consts.PARAMETER_W) { + //read another param (the y coord) and put into X962 format. + byte[] y = parse(data[i + 1]); + param = Util.concatenate(new byte[]{4}, param, y); //<- ugly but works! + i++; + } + if (param.length == 0) + throw new RuntimeException("Empty parameter read?"); + + //write length + byte[] length = new byte[2]; + Util.setShort(length, 0, (short) param.length); + out.write(length, 0, 2); + //write data + out.write(param, 0, param.length); + i++; + } + paramMask = (short) (paramMask << 1); + } + + return (out.size() == 0) ? null : out.toByteArray(); + } + + /** + * @param data + * @param params + * @return + */ + public static String[] expand(byte[][] data, short params) { + List<String> out = new ArrayList<>(); + + short paramMask = EC_Consts.PARAMETER_FP; + int index = 0; + while (paramMask <= EC_Consts.PARAMETER_S) { + short masked = (short) (params & paramMask); + if (masked != 0) { + byte[] param = data[index]; + + if (masked == EC_Consts.PARAMETER_F2M) { + //split into three shorts + if (param.length != 6) { + throw new RuntimeException("PARAMETER_F2M length is not 6.(should be)"); + } + for (int i = 0; i < 3; ++i) { + out.add(String.format("%04x", Util.getShort(param, i*2))); + } + + } else if (masked == EC_Consts.PARAMETER_G || masked == EC_Consts.PARAMETER_W) { + //split from X962 format into X and Y + //disregard the first 04 and then split into half(uncompress) + int half = (param.length - 1) / 2; + out.add(Util.bytesToHex(param, 1, half, false)); + out.add(Util.bytesToHex(param, half + 1, half, false)); + } else { + //read raw + out.add(Util.bytesToHex(data[index], false)); + } + index++; + } + paramMask = (short) (paramMask << 1); + } + return out.toArray(new String[out.size()]); + } + + /** + * @param filePath + * @param data + * @throws IOException + */ + public static void writeFile(String filePath, String[] data) throws IOException { + FileOutputStream out = new FileOutputStream(filePath); + write(out, data); + out.close(); + } + + /** + * Reads hex params from a CSV String data. + * + * @param data String containing CSV data(hex) + * @return String array containing the CSV entries + */ + public static String[] readString(String data) { + return read(new ByteArrayInputStream(data.getBytes())); + } + + /** + * Reads hex params from a CSV Resource (inside jar). + * + * @param resourcePath path to the resourse + * @return String array containing the CSV entries + */ + public static String[] readResource(String resourcePath) { + return read(ECParams.class.getResourceAsStream(resourcePath)); + } + + /** + * Reads hex params from a CSV file. + * + * @param filePath path to the file + * @return String array containing the CSV entries + * @throws FileNotFoundException if the file cannot be opened + */ + public static String[] readFile(String filePath) throws FileNotFoundException { + return read(new FileInputStream(filePath)); + } + + private static String[] read(InputStream in) { + Scanner s = new Scanner(in); + + s.useDelimiter(",|;"); + List<String> data = new LinkedList<String>(); + while (s.hasNext()) { + String field = s.next(); + data.add(field.replaceAll("\\s+", "")); + } + return data.toArray(new String[data.size()]); + } + + private static boolean validate(String[] data) { + if (data == null || data.length == 0) { + return false; + } + for (String param : data) { + if (!hex.matcher(param).matches()) { + return false; + } + } + return true; + } + + private static byte[] parse(String hex) { + byte[] data = Util.hexToBytes(hex); + if (data == null) + return new byte[0]; + if (data.length < 2) + return pad(data); + return data; + } + + private static byte[] pad(byte[] data) { + if (data.length == 1) { + return new byte[]{(byte) 0, data[0]}; + } else if (data.length == 0 || data.length > 2) { + return data; + } + return null; + } + + private static void write(OutputStream out, String[] data) throws IOException { + Writer w = new OutputStreamWriter(out); + for (int i = 0; i < data.length; ++i) { + w.write(data[i]); + if (i < data.length - 1) { + w.write(","); + } + } + w.flush(); + } +} |