diff options
Diffstat (limited to 'libjava/classpath/gnu/java/security/der/DERReader.java')
| -rw-r--r-- | libjava/classpath/gnu/java/security/der/DERReader.java | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/java/security/der/DERReader.java b/libjava/classpath/gnu/java/security/der/DERReader.java new file mode 100644 index 000000000..cd552c8be --- /dev/null +++ b/libjava/classpath/gnu/java/security/der/DERReader.java @@ -0,0 +1,439 @@ +/* DERReader.java -- parses ASN.1 DER sequences + Copyright (C) 2003 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package gnu.java.security.der; + +import gnu.java.lang.CPStringBuilder; + +import gnu.java.security.OID; + +import java.io.BufferedInputStream; +import java.io.ByteArrayInputStream; +import java.io.ByteArrayOutputStream; +import java.io.EOFException; +import java.io.IOException; +import java.io.InputStream; +import java.math.BigInteger; +import java.util.Calendar; +import java.util.Date; +import java.util.TimeZone; + +/** + * This class decodes DER sequences into Java objects. The methods of + * this class do not have knowledge of higher-levels of structure in the + * DER stream -- such as ASN.1 constructions -- and it is therefore up + * to the calling application to determine if the data are structured + * properly by inspecting the {@link DERValue} that is returned. + * + * @author Casey Marshall (csm@gnu.org) + */ +public class DERReader implements DER +{ + + // Fields. + // ------------------------------------------------------------------------ + + protected InputStream in; + + protected final ByteArrayOutputStream encBuf; + + // Constructor. + // ------------------------------------------------------------------------ + + /** + * Create a new DER reader from a byte array. + * + * @param in The encoded bytes. + */ + public DERReader(byte[] in) + { + this(new ByteArrayInputStream(in)); + } + + public DERReader (byte[] in, int off, int len) + { + this (new ByteArrayInputStream (in, off, len)); + } + + /** + * Create a new DER readed from an input stream. + * + * @param in The encoded bytes. + */ + public DERReader(InputStream in) + { + if (!in.markSupported()) + this.in = new BufferedInputStream(in, 16384); + else + this.in = in; + encBuf = new ByteArrayOutputStream(2048); + } + + // Class methods. + // ------------------------------------------------------------------------ + + /** + * Convenience method for reading a single primitive value from the + * given byte array. + * + * @param encoded The encoded bytes. + * @throws IOException If the bytes do not represent an encoded + * object. + */ + public static DERValue read(byte[] encoded) throws IOException + { + return new DERReader(encoded).read(); + } + + // Instance methods. + // ------------------------------------------------------------------------ + + public void skip (int bytes) throws IOException + { + in.skip (bytes); + } + + /** + * Decode a single value from the input stream, returning it in a new + * {@link DERValue}. By "single value" we mean any single type in its + * entirety -- including constructed types such as SEQUENCE and all + * the values they contain. Usually it is sufficient to call this + * method once to parse and return the top-level structure, then to + * inspect the returned value for the proper contents. + * + * @return The parsed DER structure. + * @throws IOException If an error occurs reading from the input + * stream. + * @throws DEREncodingException If the input does not represent a + * valid DER stream. + */ + public DERValue read() throws IOException + { + int tag = in.read(); + if (tag == -1) + throw new EOFException(); + encBuf.write(tag); + int len = readLength(); + DERValue value = null; + if ((tag & CONSTRUCTED) == CONSTRUCTED) + { + in.mark(2048); + byte[] encoded = new byte[len]; + in.read(encoded); + encBuf.write(encoded); + value = new DERValue(tag, len, CONSTRUCTED_VALUE, encBuf.toByteArray()); + in.reset(); + encBuf.reset(); + return value; + } + switch (tag & 0xC0) + { + case UNIVERSAL: + value = new DERValue(tag, len, readUniversal(tag, len), + encBuf.toByteArray()); + encBuf.reset(); + break; + case CONTEXT: + byte[] encoded = new byte[len]; + in.read(encoded); + encBuf.write(encoded); + value = new DERValue(tag, len, encoded, encBuf.toByteArray()); + encBuf.reset(); + break; + case APPLICATION: + // This should not be reached, since (I think) APPLICATION is + // always constructed. + throw new DEREncodingException("non-constructed APPLICATION data"); + default: + throw new DEREncodingException("PRIVATE class not supported"); + } + return value; + } + + protected int readLength() throws IOException + { + int i = in.read(); + if (i == -1) + throw new EOFException(); + encBuf.write(i); + if ((i & ~0x7F) == 0) + { + return i; + } + else if (i < 0xFF) + { + byte[] octets = new byte[i & 0x7F]; + in.read(octets); + encBuf.write(octets); + return new BigInteger(1, octets).intValue(); + } + throw new DEREncodingException(); + } + + // Own methods. + // ------------------------------------------------------------------------ + + private Object readUniversal(int tag, int len) throws IOException + { + byte[] value = new byte[len]; + in.read(value); + encBuf.write(value); + switch (tag & 0x1F) + { + case BOOLEAN: + if (value.length != 1) + throw new DEREncodingException(); + return Boolean.valueOf(value[0] != 0); + case NULL: + if (len != 0) + throw new DEREncodingException(); + return null; + case INTEGER: + case ENUMERATED: + return new BigInteger(value); + case BIT_STRING: + byte[] bits = new byte[len - 1]; + System.arraycopy(value, 1, bits, 0, bits.length); + return new BitString(bits, value[0] & 0xFF); + case OCTET_STRING: + return value; + case NUMERIC_STRING: + case PRINTABLE_STRING: + case T61_STRING: + case VIDEOTEX_STRING: + case IA5_STRING: + case GRAPHIC_STRING: + case ISO646_STRING: + case GENERAL_STRING: + case UNIVERSAL_STRING: + case BMP_STRING: + case UTF8_STRING: + return makeString(tag, value); + case UTC_TIME: + case GENERALIZED_TIME: + return makeTime(tag, value); + case OBJECT_IDENTIFIER: + return new OID(value); + case RELATIVE_OID: + return new OID(value, true); + default: + throw new DEREncodingException("unknown tag " + tag); + } + } + + private static String makeString(int tag, byte[] value) + throws IOException + { + switch (tag & 0x1F) + { + case NUMERIC_STRING: + case PRINTABLE_STRING: + case T61_STRING: + case VIDEOTEX_STRING: + case IA5_STRING: + case GRAPHIC_STRING: + case ISO646_STRING: + case GENERAL_STRING: + return fromIso88591(value); + + case UNIVERSAL_STRING: + // XXX The docs say UniversalString is encoded in four bytes + // per character, but Java has no support (yet) for UTF-32. + //return new String(buf, "UTF-32"); + case BMP_STRING: + return fromUtf16Be(value); + + case UTF8_STRING: + return fromUtf8(value); + + default: + throw new DEREncodingException("unknown string tag"); + } + } + + private static String fromIso88591(byte[] bytes) + { + CPStringBuilder str = new CPStringBuilder(bytes.length); + for (int i = 0; i < bytes.length; i++) + str.append((char) (bytes[i] & 0xFF)); + return str.toString(); + } + + private static String fromUtf16Be(byte[] bytes) throws IOException + { + if ((bytes.length & 0x01) != 0) + throw new IOException("UTF-16 bytes are odd in length"); + CPStringBuilder str = new CPStringBuilder(bytes.length / 2); + for (int i = 0; i < bytes.length; i += 2) + { + char c = (char) ((bytes[i] << 8) & 0xFF); + c |= (char) (bytes[i+1] & 0xFF); + str.append(c); + } + return str.toString(); + } + + private static String fromUtf8(byte[] bytes) throws IOException + { + CPStringBuilder str = new CPStringBuilder((int)(bytes.length / 1.5)); + for (int i = 0; i < bytes.length; ) + { + char c = 0; + if ((bytes[i] & 0xE0) == 0xE0) + { + if ((i + 2) >= bytes.length) + throw new IOException("short UTF-8 input"); + c = (char) ((bytes[i++] & 0x0F) << 12); + if ((bytes[i] & 0x80) != 0x80) + throw new IOException("malformed UTF-8 input"); + c |= (char) ((bytes[i++] & 0x3F) << 6); + if ((bytes[i] & 0x80) != 0x80) + throw new IOException("malformed UTF-8 input"); + c |= (char) (bytes[i++] & 0x3F); + } + else if ((bytes[i] & 0xC0) == 0xC0) + { + if ((i + 1) >= bytes.length) + throw new IOException("short input"); + c = (char) ((bytes[i++] & 0x1F) << 6); + if ((bytes[i] & 0x80) != 0x80) + throw new IOException("malformed UTF-8 input"); + c |= (char) (bytes[i++] & 0x3F); + } + else if ((bytes[i] & 0xFF) < 0x80) + { + c = (char) (bytes[i++] & 0xFF); + } + else + throw new IOException("badly formed UTF-8 sequence"); + str.append(c); + } + return str.toString(); + } + + private Date makeTime(int tag, byte[] value) throws IOException + { + Calendar calendar = Calendar.getInstance(); + String str = makeString(PRINTABLE_STRING, value); + + // Classpath's SimpleDateFormat does not work for parsing these + // types of times, so we do this by hand. + String date = str; + String tz = ""; + if (str.indexOf("+") > 0) + { + date = str.substring(0, str.indexOf("+")); + tz = str.substring(str.indexOf("+")); + } + else if (str.indexOf("-") > 0) + { + date = str.substring(0, str.indexOf("-")); + tz = str.substring(str.indexOf("-")); + } + else if (str.endsWith("Z")) + { + date = str.substring(0, str.length()-2); + tz = "Z"; + } + if (!tz.equals("Z") && tz.length() > 0) + calendar.setTimeZone(TimeZone.getTimeZone(tz)); + else + calendar.setTimeZone(TimeZone.getTimeZone("UTC")); + if ((tag & 0x1F) == UTC_TIME) + { + if (date.length() < 10) // must be at least 10 chars long + throw new DEREncodingException("cannot parse date"); + // UTCTime is of the form "yyMMddHHmm[ss](Z|(+|-)hhmm)" + try + { + int year = Integer.parseInt(str.substring(0, 2)); + if (year < 50) + year += 2000; + else + year += 1900; + calendar.set(year, + Integer.parseInt(str.substring( 2, 4))-1, // month + Integer.parseInt(str.substring( 4, 6)), // day + Integer.parseInt(str.substring( 6, 8)), // hour + Integer.parseInt(str.substring( 8, 10))); // minute + if (date.length() == 12) + calendar.set(Calendar.SECOND, + Integer.parseInt(str.substring(10, 12))); + } + catch (NumberFormatException nfe) + { + throw new DEREncodingException("cannot parse date"); + } + } + else + { + if (date.length() < 10) // must be at least 10 chars long + throw new DEREncodingException("cannot parse date"); + // GeneralTime is of the form "yyyyMMddHH[mm[ss[(.|,)SSSS]]]" + // followed by "Z" or "(+|-)hh[mm]" + try + { + calendar.set( + Integer.parseInt(date.substring(0, 4)), // year + Integer.parseInt(date.substring(4, 6))-1, // month + Integer.parseInt(date.substring(6, 8)), // day + Integer.parseInt(date.substring(8, 10)), 0); // hour, min + switch (date.length()) + { + case 19: + case 18: + case 17: + case 16: + calendar.set(Calendar.MILLISECOND, + Integer.parseInt(date.substring(15))); + case 14: + calendar.set(Calendar.SECOND, + Integer.parseInt(date.substring(12, 14))); + case 12: + calendar.set(Calendar.MINUTE, + Integer.parseInt(date.substring(10, 12))); + } + } + catch (NumberFormatException nfe) + { + throw new DEREncodingException("cannot parse date"); + } + } + return calendar.getTime(); + } +} |