Package org.wildfly.security.asn1

Class DERDecoder

java.lang.Object

org.wildfly.security.asn1.DERDecoder

All Implemented Interfaces:

ASN1Decoder

public class DERDecoder
extends Object
implements ASN1Decoder

A class used to decode ASN.1 values that have been encoded using the Distinguished Encoding Rules (DER).

Author:

Farah Juma

Constructor Summary

Constructors

Constructor	Description
DERDecoder(byte[] buf)	Create a DER decoder that will decode values from the given byte array.
DERDecoder(byte[] buf, int offset, int length)	Create a DER decoder that will decode values from the given byte array.

Method Summary

Modifier and Type	Method	Description
byte[]	decodeBitString()	Decode the next ASN.1 element as a bit string.
BigInteger	decodeBitStringAsInteger()	Decode the next ASN.1 element as a bit string where the value is a ASN.1 INTEGER.
String	decodeBitStringAsString()	Decode the next ASN.1 element as a bit string.
String	decodeBMPString()	Decode the next ASN.1 element as an BMPString.
byte[]	decodeBMPStringAsBytes()	Decode the next ASN.1 element as an BMPString.
boolean	decodeBoolean()	Decode the next ASN.1 element as a boolean value.
String	decodeIA5String()	Decode the next ASN.1 element as an IA5 string.
byte[]	decodeIA5StringAsBytes()	Decode the next ASN.1 element as an IA5 string.
void	decodeImplicit(int number)	Indicate that the next ASN.1 element has the given implicit, context-specific tag.
void	decodeImplicit(int clazz, int number)	Indicate that the next ASN.1 element has the given implicit tag.
BigInteger	decodeInteger()	Decode the next ASN.1 element as an integer.
void	decodeNull()	Decode the next ASN.1 element as a null element.
String	decodeObjectIdentifier()	Decode the next ASN.1 element as an object identifier.
String	decodeObjectIdentifierAsKeyAlgorithm()	Decodes an OID and resolve its corresponding key algorithm.
byte[]	decodeOctetString()	Decode the next ASN.1 element as an octet string.
String	decodeOctetStringAsString()	Decode the next ASN.1 element as an octet string.
String	decodeOctetStringAsString(String charSet)	Decode the next ASN.1 element as an octet string.
String	decodePrintableString()	Decode the next ASN.1 element as a PrintableString.
byte[]	decodePrintableStringAsBytes()	Decode the next ASN.1 element as a PrintableString.
String	decodeUniversalString()	Decode the next ASN.1 element as an UniversalString.
byte[]	decodeUniversalStringAsBytes()	Decode the next ASN.1 element as an UniversalString.
String	decodeUtf8String()	Decode the next ASN.1 element as an UTF8String.
byte[]	decodeUtf8StringAsBytes()	Decode the next ASN.1 element as an UTF8String.
byte[]	drain()	Drain all of the remaining bytes from the input stream.
byte[]	drainElement()	Drain all of the bytes from the next ASN.1 element.
byte[]	drainElementValue()	Drain the value bytes from the next ASN.1 element.
void	endExplicit()	Advance to the end of an explicitly tagged element.
void	endSequence()	Advance to the end of a sequence.
void	endSet()	Advance to the end of a set.
void	endSetOf()	Advance to the end of a "set of" element.
boolean	hasNextElement()	Determine if there is at least one more ASN.1 element that can be read.
boolean	isNextType(int clazz, int number, boolean isConstructed)	Determine if the type of the next ASN.1 element matches the given type without actually decoding the next element.
int	peekType()	Retrieve the type of the next ASN.1 element without actually decoding the next element.
void	skipElement()	Skip over the next ASN.1 element.
void	startExplicit(int number)	Start decoding an ASN.1 explicitly tagged element.
void	startExplicit(int clazz, int number)	Start decoding an ASN.1 explicitly tagged element.
void	startSequence()	Start decoding an ASN.1 sequence.
void	startSet()	Start decoding an ASN.1 set.
void	startSetOf()	Start decoding an ASN.1 "set of" element.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DERDecoder

public DERDecoder(byte[] buf)

Create a DER decoder that will decode values from the given byte array.

Parameters:

buf - the byte array to decode

DERDecoder

public DERDecoder(byte[] buf,
                  int offset,
                  int length)

Create a DER decoder that will decode values from the given byte array.

Parameters:

buf - the byte array to decode

offset - the offset in the byte array of the first byte to read

length - the maximum number of bytes to read from the byte array

Method Detail

startSequence

public void startSequence()
                   throws ASN1Exception

Description copied from interface: ASN1Decoder

Start decoding an ASN.1 sequence. All subsequent decode operations will decode elements from this sequence until ASN1Decoder.endSequence() is called.

Specified by:

startSequence in interface ASN1Decoder

Throws:

ASN1Exception - if the next element is not a sequence

endSequence

public void endSequence()
                 throws ASN1Exception

Description copied from interface: ASN1Decoder

Advance to the end of a sequence. If there are any elements in the sequence that have not yet been decoded, they will be discarded.

Specified by:

endSequence in interface ASN1Decoder

Throws:

ASN1Exception - if an error occurs while advancing to the end of the sequence

startSet

public void startSet()
              throws ASN1Exception

Description copied from interface: ASN1Decoder

Start decoding an ASN.1 set. All subsequent decode operations will decode elements from this set until ASN1Decoder.endSet() is called.

Specified by:

startSet in interface ASN1Decoder

Throws:

ASN1Exception - if the next element is not a set

endSet

public void endSet()
            throws ASN1Exception

Description copied from interface: ASN1Decoder

Advance to the end of a set. If there are any elements in the set that have not yet been decoded, they will be discarded.

Specified by:

endSet in interface ASN1Decoder

Throws:

ASN1Exception - if an error occurs while advancing to the end of the set

startSetOf

public void startSetOf()
                throws ASN1Exception

Description copied from interface: ASN1Decoder

Start decoding an ASN.1 "set of" element. All subsequent decode operations will decode elements from this set until ASN1Decoder.endSetOf() is called.

Specified by:

startSetOf in interface ASN1Decoder

Throws:

ASN1Exception - if the next element is not a set

endSetOf

public void endSetOf()
              throws ASN1Exception

Description copied from interface: ASN1Decoder

Advance to the end of a "set of" element. If there are any elements in the set that have not yet been decoded, they will be discarded.

Specified by:

endSetOf in interface ASN1Decoder

Throws:

ASN1Exception - if an error occurs while advancing to the end of the set

startExplicit

public void startExplicit(int number)
                   throws ASN1Exception

Description copied from interface: ASN1Decoder

Start decoding an ASN.1 explicitly tagged element. All subsequent decode operations will decode elements from this explicitly tagged element until ASN1Decoder.endExplicit() is called.

Specified by:

startExplicit in interface ASN1Decoder

Parameters:

number - the tag number for the explicit, context-specific tag

Throws:

ASN1Exception - if the next element's type does not match the given type

startExplicit

public void startExplicit(int clazz,
                          int number)
                   throws ASN1Exception

Description copied from interface: ASN1Decoder

Start decoding an ASN.1 explicitly tagged element. All subsequent decode operations will decode elements from this explicitly tagged element until ASN1Decoder.endExplicit() is called.

Specified by:

startExplicit in interface ASN1Decoder

Parameters:

clazz - the class for the explicit tag

number - the tag number for the explicit tag

Throws:

ASN1Exception - if the next element's type does not match the given type

endExplicit

public void endExplicit()
                 throws ASN1Exception

Description copied from interface: ASN1Decoder

Advance to the end of an explicitly tagged element. If there are any elements within the explicitly tagged element that have not yet been decoded, they will be discarded.

Specified by:

endExplicit in interface ASN1Decoder

Throws:

ASN1Exception - if an error occurs while advancing to the end of the explicitly tagged element

decodeOctetString

public byte[] decodeOctetString()
                         throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an octet string.

Specified by:

decodeOctetString in interface ASN1Decoder

Returns:

the decoded octet string, as a byte array

Throws:

ASN1Exception - if the next element is not an octet string

decodeOctetStringAsString

public String decodeOctetStringAsString()
                                 throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an octet string.

Specified by:

decodeOctetStringAsString in interface ASN1Decoder

Returns:

the decoded octet string, as a UTF-8 string

Throws:

ASN1Exception - if the next element is not an octet string

decodeOctetStringAsString

public String decodeOctetStringAsString(String charSet)
                                 throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an octet string.

Specified by:

decodeOctetStringAsString in interface ASN1Decoder

Parameters:

charSet - the character set to use when decoding

Returns:

the decoded octet string

Throws:

ASN1Exception - if the next element is not an octet string

decodeIA5String

public String decodeIA5String()
                       throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an IA5 string.

Specified by:

decodeIA5String in interface ASN1Decoder

Returns:

the decoded IA5 string

Throws:

ASN1Exception - if the next element is not an IA5 string

decodeIA5StringAsBytes

public byte[] decodeIA5StringAsBytes()
                              throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an IA5 string.

Specified by:

decodeIA5StringAsBytes in interface ASN1Decoder

Returns:

the decoded IA5 string, as a byte array

Throws:

ASN1Exception - if the next element is not an IA5 string

decodeBitString

public byte[] decodeBitString()
                       throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as a bit string.

Specified by:

decodeBitString in interface ASN1Decoder

Returns:

the decoded bit string as a byte array, with any unused bits removed

Throws:

ASN1Exception - if the next element is not a bit string

decodeBitStringAsInteger

public BigInteger decodeBitStringAsInteger()

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as a bit string where the value is a ASN.1 INTEGER.

Specified by:

decodeBitStringAsInteger in interface ASN1Decoder

Returns:

a BigInteger decoded from the bit string

decodeBitStringAsString

public String decodeBitStringAsString()
                               throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as a bit string.

Specified by:

decodeBitStringAsString in interface ASN1Decoder

Returns:

the decoded bit string as a binary string, with any unused bits removed

Throws:

ASN1Exception - if the next element is not a bit string

decodePrintableString

public String decodePrintableString()
                             throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as a PrintableString.

Specified by:

decodePrintableString in interface ASN1Decoder

Returns:

the decoded PrintableString as a string

Throws:

ASN1Exception - if the next element is not a PrintableString

decodePrintableStringAsBytes

public byte[] decodePrintableStringAsBytes()
                                    throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as a PrintableString.

Specified by:

decodePrintableStringAsBytes in interface ASN1Decoder

Returns:

the decoded PrintableString as a byte array

Throws:

ASN1Exception - if the next element is not a PrintableString

decodeUniversalString

public String decodeUniversalString()
                             throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an UniversalString.

Specified by:

decodeUniversalString in interface ASN1Decoder

Returns:

the decoded UniversalString as a string

Throws:

ASN1Exception - if the next element is not a UniversalString

decodeUniversalStringAsBytes

public byte[] decodeUniversalStringAsBytes()
                                    throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an UniversalString.

Specified by:

decodeUniversalStringAsBytes in interface ASN1Decoder

Returns:

the decoded UniversalString as a byte array

Throws:

ASN1Exception - if the next element is not a UniversalString

decodeUtf8String

public String decodeUtf8String()
                        throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an UTF8String.

Specified by:

decodeUtf8String in interface ASN1Decoder

Returns:

the decoded UTF8String as a string

Throws:

ASN1Exception - if the next element is not a UTF8String

decodeUtf8StringAsBytes

public byte[] decodeUtf8StringAsBytes()
                               throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an UTF8String.

Specified by:

decodeUtf8StringAsBytes in interface ASN1Decoder

Returns:

the decoded UTF8String as a byte array

Throws:

ASN1Exception - if the next element is not a UTF8String

decodeBMPString

public String decodeBMPString()
                       throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an BMPString.

Specified by:

decodeBMPString in interface ASN1Decoder

Returns:

the decoded BMPString as a string

Throws:

ASN1Exception - if the next element is not a BMPString

decodeBMPStringAsBytes

public byte[] decodeBMPStringAsBytes()
                              throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an BMPString.

Specified by:

decodeBMPStringAsBytes in interface ASN1Decoder

Returns:

the decoded BMPString as a byte array

Throws:

ASN1Exception - if the next element is not a BMPString

decodeObjectIdentifier

public String decodeObjectIdentifier()
                              throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an object identifier.

Specified by:

decodeObjectIdentifier in interface ASN1Decoder

Returns:

the object identifier as a string

Throws:

ASN1Exception - if the next element is not a bit string

decodeInteger

public BigInteger decodeInteger()
                         throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as an integer.

Specified by:

decodeInteger in interface ASN1Decoder

Returns:

an integer decoded from the next element

Throws:

ASN1Exception - if the next element is not an integer

decodeNull

public void decodeNull()
                throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as a null element.

Specified by:

decodeNull in interface ASN1Decoder

Throws:

ASN1Exception - if the next element is not null

decodeImplicit

public void decodeImplicit(int number)

Description copied from interface: ASN1Decoder

Indicate that the next ASN.1 element has the given implicit, context-specific tag.

Specified by:

decodeImplicit in interface ASN1Decoder

Parameters:

number - the tag number for the implicit tag

decodeImplicit

public void decodeImplicit(int clazz,
                           int number)

Description copied from interface: ASN1Decoder

Indicate that the next ASN.1 element has the given implicit tag.

Specified by:

decodeImplicit in interface ASN1Decoder

Parameters:

clazz - the class for the implicit tag

number - the tag number for the implicit tag

decodeBoolean

public boolean decodeBoolean()
                      throws ASN1Exception

Description copied from interface: ASN1Decoder

Decode the next ASN.1 element as a boolean value.

Specified by:

decodeBoolean in interface ASN1Decoder

Returns:

the decoded boolean value

Throws:

ASN1Exception - if the next element is not a boolean value

isNextType

public boolean isNextType(int clazz,
                          int number,
                          boolean isConstructed)

Description copied from interface: ASN1Decoder

Determine if the type of the next ASN.1 element matches the given type without actually decoding the next element. This method can be used to determine if an optional ASN.1 value has been included in the encoding or not.

Specified by:

isNextType in interface ASN1Decoder

Parameters:

clazz - the tag class to match against

number - the tag number to match against

isConstructed - whether or not the next element should be constructed

Returns:

true if the type of the next ASN.1 element matches the given type and false otherwise

peekType

public int peekType()
             throws ASN1Exception

Description copied from interface: ASN1Decoder

Retrieve the type of the next ASN.1 element without actually decoding the next element.

Specified by:

peekType in interface ASN1Decoder

Returns:

the type of the next ASN.1 element

Throws:

ASN1Exception - if an error occurs while determining the type of the next element

skipElement

public void skipElement()
                 throws ASN1Exception

Description copied from interface: ASN1Decoder

Skip over the next ASN.1 element.

Specified by:

skipElement in interface ASN1Decoder

Throws:

ASN1Exception - if the next element cannot be skipped

hasNextElement

public boolean hasNextElement()

Description copied from interface: ASN1Decoder

Determine if there is at least one more ASN.1 element that can be read. If called while decoding a constructed element (i.e., while decoding a sequence, set, or explicitly tagged element), this method will return whether the constructed element has at least one more ASN.1 element that can be read. Otherwise, this method will return whether at least one more ASN.1 element can be read from the input stream.

Specified by:

hasNextElement in interface ASN1Decoder

Returns:

true if there is at least one more ASN.1 element that can be read and false otherwise

drainElementValue

public byte[] drainElementValue()
                         throws ASN1Exception

Description copied from interface: ASN1Decoder

Drain the value bytes from the next ASN.1 element.

Specified by:

drainElementValue in interface ASN1Decoder

Returns:

the value bytes from the next ASN.1 element, as a byte array

Throws:

ASN1Exception - if the value bytes from the next ASN.1 element cannot be obtained

drainElement

public byte[] drainElement()
                    throws ASN1Exception

Description copied from interface: ASN1Decoder

Drain all of the bytes from the next ASN.1 element.

Specified by:

drainElement in interface ASN1Decoder

Returns:

all of the bytes from the next ASN.1 element

Throws:

ASN1Exception - if the bytes from the next ASN.1 element cannot be obtained

drain

public byte[] drain()

Description copied from interface: ASN1Decoder

Drain all of the remaining bytes from the input stream.

Specified by:

drain in interface ASN1Decoder

Returns:

all of the remaining bytes from the input stream

decodeObjectIdentifierAsKeyAlgorithm

public String decodeObjectIdentifierAsKeyAlgorithm()

Decodes an OID and resolve its corresponding key algorithm.

Returns:

the key algorithm associated with the OID or null if no algorithm could be resolved