diff options
Diffstat (limited to 'src/main/java/com/lowagie/bc/asn1/DERInputStream.java')
| -rw-r--r-- | src/main/java/com/lowagie/bc/asn1/DERInputStream.java | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/src/main/java/com/lowagie/bc/asn1/DERInputStream.java b/src/main/java/com/lowagie/bc/asn1/DERInputStream.java new file mode 100644 index 0000000..3148a3f --- /dev/null +++ b/src/main/java/com/lowagie/bc/asn1/DERInputStream.java @@ -0,0 +1,258 @@ +package com.lowagie.bc.asn1;
+
+import java.io.ByteArrayInputStream;
+import java.io.EOFException;
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Don't use this class. It will eventually disappear, use ASN1InputStream.
+ * <br>
+ * This class is scheduled for removal.
+ */
+public class DERInputStream
+ extends FilterInputStream implements DERTags
+{
+ public DERInputStream(
+ InputStream is)
+ {
+ super(is);
+ }
+
+ protected int readLength()
+ throws IOException
+ {
+ int length = read();
+ if (length < 0)
+ {
+ throw new IOException("EOF found when length expected");
+ }
+
+ if (length == 0x80)
+ {
+ return -1; // indefinite-length encoding
+ }
+
+ if (length > 127)
+ {
+ int size = length & 0x7f;
+
+ length = 0;
+ for (int i = 0; i < size; i++)
+ {
+ int next = read();
+
+ if (next < 0)
+ {
+ throw new IOException("EOF found reading length");
+ }
+
+ length = (length << 8) + next;
+ }
+ }
+
+ return length;
+ }
+
+ protected void readFully(
+ byte[] bytes)
+ throws IOException
+ {
+ int left = bytes.length;
+
+ if (left == 0)
+ {
+ return;
+ }
+
+ while (left > 0)
+ {
+ int l = read(bytes, bytes.length - left, left);
+
+ if (l < 0)
+ {
+ throw new EOFException("unexpected end of stream");
+ }
+
+ left -= l;
+ }
+ }
+
+ /**
+ * build an object given its tag and a byte stream to construct it
+ * from.
+ */
+ protected DERObject buildObject(
+ int tag,
+ byte[] bytes)
+ throws IOException
+ {
+ switch (tag)
+ {
+ case NULL:
+ return null;
+ case SEQUENCE | CONSTRUCTED:
+ ByteArrayInputStream bIn = new ByteArrayInputStream(bytes);
+ BERInputStream dIn = new BERInputStream(bIn);
+ DERConstructedSequence seq = new DERConstructedSequence();
+
+ try
+ {
+ for (;;)
+ {
+ DERObject obj = dIn.readObject();
+
+ seq.addObject(obj);
+ }
+ }
+ catch (EOFException ex)
+ {
+ return seq;
+ }
+ case SET | CONSTRUCTED:
+ bIn = new ByteArrayInputStream(bytes);
+ dIn = new BERInputStream(bIn);
+
+ ASN1EncodableVector v = new ASN1EncodableVector();
+
+ try
+ {
+ for (;;)
+ {
+ DERObject obj = dIn.readObject();
+
+ v.add(obj);
+ }
+ }
+ catch (EOFException ex)
+ {
+ return new DERConstructedSet(v);
+ }
+ case BOOLEAN:
+ return new DERBoolean(bytes);
+ case INTEGER:
+ return new DERInteger(bytes);
+ case ENUMERATED:
+ return new DEREnumerated(bytes);
+ case OBJECT_IDENTIFIER:
+ return new DERObjectIdentifier(bytes);
+ case BIT_STRING:
+ int padBits = bytes[0];
+ byte[] data = new byte[bytes.length - 1];
+
+ System.arraycopy(bytes, 1, data, 0, bytes.length - 1);
+
+ return new DERBitString(data, padBits);
+ case UTF8_STRING:
+ return new DERUTF8String(bytes);
+ case PRINTABLE_STRING:
+ return new DERPrintableString(bytes);
+ case IA5_STRING:
+ return new DERIA5String(bytes);
+ case T61_STRING:
+ return new DERT61String(bytes);
+ case VISIBLE_STRING:
+ return new DERVisibleString(bytes);
+ case UNIVERSAL_STRING:
+ return new DERUniversalString(bytes);
+ case GENERAL_STRING:
+ return new DERGeneralString(bytes);
+ case BMP_STRING:
+ return new DERBMPString(bytes);
+ case OCTET_STRING:
+ return new DEROctetString(bytes);
+ case UTC_TIME:
+ return new DERUTCTime(bytes);
+ case GENERALIZED_TIME:
+ return new DERGeneralizedTime(bytes);
+ default:
+ //
+ // with tagged object tag number is bottom 5 bits
+ //
+ if ((tag & TAGGED) != 0)
+ {
+ if ((tag & 0x1f) == 0x1f)
+ {
+ throw new IOException("unsupported high tag encountered");
+ }
+
+ if (bytes.length == 0) // empty tag!
+ {
+ if ((tag & CONSTRUCTED) == 0)
+ {
+ return new DERTaggedObject(false, tag & 0x1f, new DERNull());
+ }
+ else
+ {
+ return new DERTaggedObject(false, tag & 0x1f, new DERConstructedSequence());
+ }
+ }
+
+ //
+ // simple type - implicit... return an octet string
+ //
+ if ((tag & CONSTRUCTED) == 0)
+ {
+ return new DERTaggedObject(false, tag & 0x1f, new DEROctetString(bytes));
+ }
+
+ bIn = new ByteArrayInputStream(bytes);
+ dIn = new BERInputStream(bIn);
+
+ DEREncodable dObj = dIn.readObject();
+
+ //
+ // explicitly tagged (probably!) - if it isn't we'd have to
+ // tell from the context
+ //
+ if (dIn.available() == 0)
+ {
+ return new DERTaggedObject(tag & 0x1f, dObj);
+ }
+
+ //
+ // another implicit object, we'll create a sequence...
+ //
+ seq = new DERConstructedSequence();
+
+ seq.addObject(dObj);
+
+ try
+ {
+ for (;;)
+ {
+ dObj = dIn.readObject();
+
+ seq.addObject(dObj);
+ }
+ }
+ catch (EOFException ex)
+ {
+ // ignore --
+ }
+
+ return new DERTaggedObject(false, tag & 0x1f, seq);
+ }
+
+ return new DERUnknownTag(tag, bytes);
+ }
+ }
+
+ public DERObject readObject()
+ throws IOException
+ {
+ int tag = read();
+ if (tag == -1)
+ {
+ throw new EOFException();
+ }
+
+ int length = readLength();
+ byte[] bytes = new byte[length];
+
+ readFully(bytes);
+
+ return buildObject(tag, bytes);
+ }
+}
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