public static ECDSASignature decodeFromDER(byte[] bytes) {
ASN1InputStream decoder = null;
try {
decoder = new ASN1InputStream(bytes);
DLSequence seq = (DLSequence) decoder.readObject();
if (seq == null) throw new RuntimeException("Reached past end of ASN.1 stream.");
ASN1Integer r, s;
try {
r = (ASN1Integer) seq.getObjectAt(0);
s = (ASN1Integer) seq.getObjectAt(1);
} catch (ClassCastException e) {
throw new IllegalArgumentException(e);
}
// OpenSSL deviates from the DER spec by interpreting these values as unsigned, though they
// should not be
// Thus, we always use the positive versions. See: http://r6.ca/blog/20111119T211504Z.html
return new ECDSASignature(r.getPositiveValue(), s.getPositiveValue());
} catch (IOException e) {
throw new RuntimeException(e);
} finally {
if (decoder != null)
try {
decoder.close();
} catch (IOException x) {
}
}
}
/**
* Create a base ASN.1 object from a byte stream.
*
* @param data the byte stream to parse.
* @return the base ASN.1 object represented by the byte stream.
* @exception IOException if there is a problem parsing the data.
*/
public static ASN1Object fromByteArray(byte[] data) throws IOException {
ASN1InputStream aIn = new ASN1InputStream(data);
try {
return (ASN1Object) aIn.readObject();
} catch (ClassCastException e) {
throw new IOException("cannot recognise object in stream");
}
}
/**
* Create a base ASN.1 object from a byte stream.
*
* @param data the byte stream to parse.
* @return the base ASN.1 object represented by the byte stream.
* @exception IOException if there is a problem parsing the data.
*/
public static ASN1Object fromByteArray(byte[] data) throws IOException {
ASN1InputStream aIn = new ASN1InputStream(data);
return (ASN1Object) aIn.readObject();
}
