|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: INNER | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Object | +--com.ibm.security12.sun.security.util.DerInputStream
A DER input stream, used for parsing ASN.1 DER-encoded data such as that found in X.509 certificates. DER is a subset of BER/1, which has the advantage that it allows only a single encoding of primitive data. (High level data such as dates still support many encodings.) That is, it uses the "Definite" Encoding Rules (DER) not the "Basic" ones (BER).
Note that, like BER/1, DER streams are streams of explicitly tagged data values. Accordingly, this programming interface does not expose any variant of the java.io.InputStream interface, since that kind of input stream holds untagged data values and using that I/O model could prevent correct parsing of the DER data.
At this time, this class supports only a subset of the types of DER data encodings which are defined. That subset is sufficient for parsing most X.509 certificates.
Constructor Summary | |
DerInputStream(byte[] data)
Create a DER input stream from a data buffer. |
|
DerInputStream(byte[] data,
int offset,
int len)
Create a DER input stream from part of a data buffer. |
Method Summary | |
int |
available()
Returns the number of bytes available for reading. |
byte[] |
getBitString()
Get a bit string from the input stream. |
void |
getBytes(byte[] val)
Returns the asked number of bytes from the input stream. |
DerValue |
getDerValue()
Get a single DER-encoded value from the input stream. |
BigInt |
getEnumerated()
Get an enumerated from the input stream. |
Date |
getGeneralizedTime()
Get a Generalized encoded time value from the input stream. |
BigInt |
getInteger()
Get an (unsigned) integer from the input stream. |
void |
getNull()
Reads an encoded null value from the input stream. |
byte[] |
getOctetString()
Returns an ASN.1 OCTET STRING from the input stream. |
ObjectIdentifier |
getOID()
Reads an X.200 style Object Identifier from the stream. |
DerValue[] |
getSequence(int startLen)
Return a sequence of encoded entities. |
DerValue[] |
getSet(int startLen)
Return a set of encoded entities. |
DerValue[] |
getSet(int startLen,
boolean implicit)
Return a set of encoded entities. |
BitArray |
getUnalignedBitString()
Get a bit string from the input stream. |
Date |
getUTCTime()
Get a UTC encoded time value from the input stream. |
void |
mark(int value)
Mark the current position in the buffer, so that a later call to reset will return here. |
int |
peekByte()
|
protected DerValue[] |
readVector(int startLen)
|
void |
reset()
Return to the position of the last mark
call. |
DerInputStream |
subStream(int len,
boolean do_skip)
Creates a new DER input stream from part of this input stream. |
byte[] |
toByteArray()
Return what has been written to this DerInputStream as a byte array. |
Methods inherited from class java.lang.Object |
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait |
Constructor Detail |
public DerInputStream(byte[] data)
data
- the buffer from which to create the string (CONSUMED)public DerInputStream(byte[] data, int offset, int len)
data
- the buffer from which to create the string (CONSUMED)offset
- the first index of data which will
be read as DER input in the new streamlen
- how long a chunk of the buffer to use,
starting at "offset"Method Detail |
public DerInputStream subStream(int len, boolean do_skip) throws IOException
len
- how long a chunk of the current input stream to use,
starting at the current position.do_skip
- true if the existing data in the input stream should
be skipped. If this value is false, the next data read
on this stream and the newly created stream will be the
same.public byte[] toByteArray()
public BigInt getInteger() throws IOException
public BigInt getEnumerated() throws IOException
public byte[] getBitString() throws IOException
public BitArray getUnalignedBitString() throws IOException
public byte[] getOctetString() throws IOException
public void getBytes(byte[] val) throws IOException
public void getNull() throws IOException
public ObjectIdentifier getOID() throws IOException
public DerValue[] getSequence(int startLen) throws IOException
startLen
- guess about how long the sequence will be
(used to initialize an auto-growing data structure)public DerValue[] getSet(int startLen) throws IOException
startLen
- guess about how large the set will be
(used to initialize an auto-growing data structure)public DerValue[] getSet(int startLen, boolean implicit) throws IOException
startLen
- guess about how large the set will be
(used to initialize an auto-growing data structure)implicit
- if true tag is assumed implicit.protected DerValue[] readVector(int startLen) throws IOException
public DerValue getDerValue() throws IOException
public Date getUTCTime() throws IOException
public Date getGeneralizedTime() throws IOException
public int peekByte() throws IOException
public void mark(int value)
reset
will return here.public void reset()
mark
call. A mark is implicitly set at the beginning of
the stream when it is created.public int available()
|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: INNER | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |