* At this time, this class supports only a subset of the types of DER data encodings which are defined. That subset is * sufficient for generating most X.509 certificates. * * @version 1.32 * * @author David Brownell * @author Amit Kapoor * @author Hemma Prafullchandra */ public class DerOutputStream extends ByteArrayOutputStream implements DerEncoder { /** * Construct an DER output stream. * * @param size how large a buffer to preallocate. */ public DerOutputStream(int size) { super(size); } /** * Construct an DER output stream. */ public DerOutputStream() { } /** * Writes tagged, pre-marshaled data. This calcuates and encodes * the length, so that the output data is the standard triple of * { tag, length, data } used by all DER values. * * @param tag the DER value tag for the data, such as DerValue.tag_Sequence * @param buf buffered data, which must be DER-encoded */ public void write(byte tag, byte[] buf) throws IOException { write(tag); putLength(buf.length); write(buf, 0, buf.length); } /** * Writes tagged data using buffer-to-buffer copy. As above, * this writes a standard DER record. This is often used when * efficiently encapsulating values in sequences. * * @param tag the DER value tag for the data, such as DerValue.tag_Sequence * @param out buffered data */ public void write(byte tag, DerOutputStream out) throws IOException { write(tag); putLength(out.count); write(out.buf, 0, out.count); } /** * Writes implicitly tagged data using buffer-to-buffer copy. As above, * this writes a standard DER record. This is often used when * efficiently encapsulating implicitly tagged values. * * @param tag the DER value of the context-specific tag that replaces * original tag of the value in the output , such as in * *
* [N] IMPLICIT
*
*
* For example, FooLength [1] IMPLICIT INTEGER, with value=4;
* would be encoded as "81 01 04" whereas in explicit
* tagging it would be encoded as "A1 03 02 01 04".
* Notice that the tag is A1 and not 81, this is because with
* explicit tagging the form is always constructed.
* @param value original value being implicitly tagged
*/
public void writeImplicit(byte tag, DerOutputStream value)
throws IOException {
write(tag);
write(value.buf, 1, value.count - 1);
}
/**
* Marshals pre-encoded DER value onto the output stream.
*/
public void putDerValue(DerValue val) throws IOException {
val.encode(this);
}
/*
* PRIMITIVES -- these are "universal" ASN.1 simple types.
*
* BOOLEAN, INTEGER, BIT STRING, OCTET STRING, NULL
* OBJECT IDENTIFIER, SEQUENCE(OF), SET(OF)
* PrintableString, T61String, IA5String, UTCTime
*/
/**
* Marshals a DER boolean on the output stream.
*/
public void putBoolean(boolean val) throws IOException {
write(DerValue.tag_Boolean);
putLength(1);
if (val) {
write(0xff);
} else {
write(0);
}
}
/**
* Marshals a DER unsigned integer on the output stream.
*/
public void putInteger(BigInt i) throws IOException {
putUnsignedInteger(i.toByteArray());
}
/**
* Marshals a DER unsigned integer on the output stream.
*/
public void putUnsignedInteger(byte[] integerBytes) throws IOException {
write(DerValue.tag_Integer);
if ((integerBytes[0] & 0x080) != 0) {
/*
* prepend zero so it's not read as a negative number
*/
putLength(integerBytes.length + 1);
write(0);
} else
putLength(integerBytes.length);
write(integerBytes, 0, integerBytes.length);
}
/**
* Marshals a DER enumerated value on the output stream.
*/
public void putEnumerated(int i) throws IOException {
write(DerValue.tag_Enumerated);
int bytemask = 0xff000000;
int signmask = 0x80000000;
int length;
if ((i & 0x80000000) != 0) {
// negative case
for (length = 4; length > 1; --length) {
if ((i & bytemask) != bytemask)
break;
bytemask = bytemask >>> 8;
signmask = signmask >>> 8;
}
if ((i & signmask) == 0) {
// ensure negative case
putLength(length + 1);
write(0xff);
} else {
putLength(length);
}
// unrolled loop
switch (length) {
case 4:
write((byte) (i >>> 24));
case 3:
write((byte) (i >>> 16));
case 2:
write((byte) (i >>> 8));
case 1:
write((byte) i);
}
} else {
// positive case
for (length = 4; length > 0; --length) {
if ((i & bytemask) != 0)
break;
bytemask = bytemask >>> 8;
signmask = signmask >>> 8;
}
if ((i & signmask) != 0) {
// ensure posititive case
putLength(length + 1);
write(0x00);
} else {
putLength(length);
}
// unrolled loop
switch (length) {
case 4:
write((byte) (i >>> 24));
case 3:
write((byte) (i >>> 16));
case 2:
write((byte) (i >>> 8));
case 1:
write((byte) i);
}
}
}
/**
* Marshals a DER bit string on the output stream. The bit
* string must be byte-aligned.
*
* @param bits the bit string, MSB first
*/
public void putBitString(byte[] bits) throws IOException {
write(DerValue.tag_BitString);
putLength(bits.length + 1);
write(0); // all of last octet is used
write(bits);
}
/**
* Converts a boolean array to a BitArray. Trims trailing 0 bits
* in accordance with DER encoding standard. We assume the input is not
* null.
*/
private static BitArray toBitArray(boolean[] bitString) {
if (bitString.length == 0) {
return new BitArray(bitString);
}
// find index of last 1 bit. -1 if there aren't any
int i;
for (i = bitString.length - 1; i >= 0; i--) {
if (bitString[i]) {
break;
}
}
int length = i + 1;
// if length changed, copy to new appropriately-sized array
if (length != bitString.length) {
boolean[] newBitString = new boolean[length];
System.arraycopy(bitString, 0, newBitString, 0, length);
bitString = newBitString;
}
return new BitArray(bitString);
}
/**
* Converts bit string to a BitArray, stripping off trailing 0 bits.
* We assume that the bit string is not null.
*/
private static BitArray toBitArray(byte[] bitString) {
// compute length in bits of bit string
int length, i;
int maxIndex = 0;
if (bitString.length == 0) {
return new BitArray(0, bitString);
}
// find the index of the last byte with a 1 bit
for (i = 0; i < bitString.length; i++) {
if (bitString[i] != 0) {
maxIndex = i;
}
}
byte lastByte = bitString[maxIndex];
length = (maxIndex + 1) * 8; // maximum, might reduce in next step
// now find the last 1 bit in this last byte
for (i = 1; i <= 0x80; i <<= 1) {
if ((lastByte & i) == 0) {
length--;
} else {
break;
}
}
return new BitArray(length, bitString);
}
/**
* Marshals a DER bit string on the output stream.
* The bit strings need not be byte-aligned.
*
* @param bits the bit string, MSB first
*/
public void putUnalignedBitString(BitArray ba) throws IOException {
byte[] bits = ba.toByteArray();
write(DerValue.tag_BitString);
putLength(bits.length + 1);
write(bits.length * 8 - ba.length()); // excess bits in last octet
write(bits);
}
/**
* Marshals a DER bit string on the output stream.
* All trailing 0 bits will be stripped off in accordance with DER
* encoding.
*
* @param bits the bit string, MSB first
*/
public void putUnalignedBitString(byte[] bitString) throws IOException {
putUnalignedBitString(toBitArray(bitString));
}
/**
* Marshals a DER bit string on the output stream.
* All trailing 0 bits will be stripped off in accordance with DER
* encoding.
*
* @param bits the bit string as an array of booleans.
*/
public void putUnalignedBitString(boolean[] bitString) throws IOException {
putUnalignedBitString(toBitArray(bitString));
}
/**
* DER-encodes an ASN.1 OCTET STRING value on the output stream.
*
* @param octets the octet string
*/
public void putOctetString(byte[] octets) throws IOException {
write(DerValue.tag_OctetString, octets);
}
/**
* Marshals a DER "null" value on the output stream. These are
* often used to indicate optional values which have been omitted.
*/
public void putNull() throws IOException {
write(DerValue.tag_Null);
putLength(0);
}
/**
* Marshals an object identifier (OID) on the output stream.
* Corresponds to the ASN.1 "OBJECT IDENTIFIER" construct.
*/
public void putOID(ObjectIdentifier oid) throws IOException {
oid.encode(this);
}
/**
* Marshals a sequence on the output stream. This supports both
* the ASN.1 "SEQUENCE" (zero to N values) and "SEQUENCE OF"
* (one to N values) constructs.
*/
public void putSequence(DerValue[] seq) throws IOException {
DerOutputStream bytes = new DerOutputStream();
int i;
for (i = 0; i < seq.length; i++)
seq[i].encode(bytes);
write(DerValue.tag_Sequence, bytes);
}
/**
* Marshals the contents of a set on the output stream without
* ordering the elements. Ok for BER encoding, but not for DER
* encoding.
*
* For DER encoding, use orderedPutSet() or orderedPutSetOf().
*/
public void putSet(DerValue[] set) throws IOException {
DerOutputStream bytes = new DerOutputStream();
int i;
for (i = 0; i < set.length; i++)
set[i].encode(bytes);
write(DerValue.tag_Set, bytes);
}
/**
* NSCP :
* Like putOrderSetOf, except not sorted.
* This may defy DER encoding but is needed for compatibility
* with communicator.
*/
public void putSet(byte tag, DerEncoder[] set) throws IOException {
putOrderedSet(tag, set, null);
}
/**
* Marshals the contents of a set on the output stream. Sets
* are semantically unordered, but DER requires that encodings of
* set elements be sorted into ascending lexicographical order
* before being output. Hence sets with the same tags and
* elements have the same DER encoding.
*
* This method supports the ASN.1 "SET OF" construct, but not
* "SET", which uses a different order.
*/
public void putOrderedSetOf(byte tag, DerEncoder[] set) throws IOException {
putOrderedSet(tag, set, lexOrder);
}
/**
* Marshals the contents of a set on the output stream. Sets
* are semantically unordered, but DER requires that encodings of
* set elements be sorted into ascending tag order
* before being output. Hence sets with the same tags and
* elements have the same DER encoding.
*
* This method supports the ASN.1 "SET" construct, but not
* "SET OF", which uses a different order.
*/
public void putOrderedSet(byte tag, DerEncoder[] set) throws IOException {
putOrderedSet(tag, set, tagOrder);
}
/**
* Lexicographical order comparison on byte arrays, for ordering
* elements of a SET OF objects in DER encoding.
*/
private static ByteArrayLexOrder lexOrder = new ByteArrayLexOrder();
/**
* Tag order comparison on byte arrays, for ordering elements of
* SET objects in DER encoding.
*/
private static ByteArrayTagOrder tagOrder = new ByteArrayTagOrder();
/**
* Marshals a the contents of a set on the output stream with the
* encodings of its sorted in increasing order.
*
* @param order the order to use when sorting encodings of components.
*/
private void putOrderedSet(byte tag, DerEncoder[] set,
Comparator* YYMMDDhhmmss{Z|+hhmm|-hhmm} ... emits only using Zulu time and with seconds (even if seconds=0) as per IETF-PKIX * partI. */ public void putUTCTime(Date d) throws IOException { /* * Format the date. */ // This was the old code. Way too slow to be usable (stevep) // String pattern = "yyMMddHHmmss'Z'"; // SimpleDateFormat sdf = new SimpleDateFormat(pattern); // TimeZone tz = TimeZone.getTimeZone("GMT"); // sdf.setTimeZone(tz); // byte[] utc = (sdf.format(d)).getBytes(); byte[] datebytes = getDateBytes(d, true); // UTC = true /* * Write the formatted date. */ write(DerValue.tag_UtcTime); putLength(datebytes.length); write(datebytes); } /** * Marshals a DER Generalized Time/date value. * *
* YYYYMMDDhhmmss{Z|+hhmm|-hhmm} ... emits only using Zulu time and with seconds (even if seconds=0) as per
* IETF-PKIX partI.
*/
public void putGeneralizedTime(Date d) throws IOException {
/*
* Format the date.
*/
TimeZone tz = TimeZone.getTimeZone("GMT");
// This is way too slow to be usable (stevep)
String pattern = "yyyyMMddHHmmss'Z'";
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
sdf.setTimeZone(tz);
byte[] gt = (sdf.format(d)).getBytes();
/*
* Write the formatted date.
*/
write(DerValue.tag_GeneralizedTime);
putLength(gt.length);
write(gt);
}
/**
* Put the encoding of the length in the stream.
*
* @param len the length of the attribute.
* @exception IOException on writing errors.
*/
public void putLength(int len) throws IOException {
if (len < 128) {
write((byte) len);
} else if (len < (1 << 8)) {
write((byte) 0x081);
write((byte) len);
} else if (len < (1 << 16)) {
write((byte) 0x082);
write((byte) (len >> 8));
write((byte) len);
} else if (len < (1 << 24)) {
write((byte) 0x083);
write((byte) (len >> 16));
write((byte) (len >> 8));
write((byte) len);
} else {
write((byte) 0x084);
write((byte) (len >> 24));
write((byte) (len >> 16));
write((byte) (len >> 8));
write((byte) len);
}
}
/**
* Put the tag of the attribute in the stream.
*
* @param class the tag class type, one of UNIVERSAL, CONTEXT,
* APPLICATION or PRIVATE
* @param form if true, the value is constructed, otherwise it is
* primitive.
* @param val the tag value
*/
public void putTag(byte tagClass, boolean form, byte val) {
byte tag = (byte) (tagClass | val);
if (form) {
tag |= (byte) 0x20;
}
write(tag);
}
/**
* Write the current contents of this DerOutputStream to an OutputStream.
*
* @exception IOException on output error.
*/
public void derEncode(OutputStream out) throws IOException {
out.write(toByteArray());
}
}