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

Nested Class Summary

Nested Classes
Modifier and Type Class Description

(package private) static class DERDecoder.DecoderState
A class used to maintain state information during DER decoding.

Field Summary

Fields
Modifier and Type	Field	Description
`private org.wildfly.common.iteration.ByteIterator`	`bi`
`private static int`	`BOOLEAN_FALSE`
`private int`	`implicitTag`
`private ArrayDeque<DERDecoder.DecoderState>`	`states`
`private static Charset`	`UTF_32BE`

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.
`DERDecoder(org.wildfly.common.iteration.ByteIterator bi)`	Create a DER decoder that will decode values from the given `ByteIterator`.

Method Summary

All Methods Instance Methods Concrete Methods
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.
`private byte[]`	`decodeUncheckedStringAsBytes()`
`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.
`private void`	`endConstructedElement(long nextElementIndex)`
`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.
`private boolean`	`hasCompleteElement()`
`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.
`private int`	`readLength()`
`private int`	`readTag()`
`private void`	`readTag(int expectedTag)`
`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

- Field Detail
  - BOOLEAN_FALSE
```
private static final int BOOLEAN_FALSE
```
    See Also:
    
    Constant Field Values
  - UTF_32BE
```
private static final Charset UTF_32BE
```
  - bi
```
private final org.wildfly.common.iteration.ByteIterator bi
```
  - states
```
private final ArrayDeque<DERDecoder.DecoderState> states
```
  - implicitTag
```
private int implicitTag
```
- 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
  - DERDecoder
```
DERDecoder(org.wildfly.common.iteration.ByteIterator bi)
```
    Create a DER decoder that will decode values from the given ByteIterator.
    
    Parameters:
    
    bi - the ByteIterator from which DER encoded values will be decoded
- 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
  - endConstructedElement
```
private void endConstructedElement(long nextElementIndex)
                            throws ASN1Exception
```
    Throws:
    
    ASN1Exception
  - 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
  - decodeUncheckedStringAsBytes
```
private byte[] decodeUncheckedStringAsBytes()
                                     throws ASN1Exception
```
    Throws:
    
    ASN1Exception
  - 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
  - hasCompleteElement
```
private boolean hasCompleteElement()
```
  - 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
  - readTag
```
private int readTag()
             throws ASN1Exception
```
    Throws:
    
    ASN1Exception
  - readTag
```
private void readTag(int expectedTag)
              throws ASN1Exception
```
    Throws:
    
    ASN1Exception
  - readLength
```
private int readLength()
                throws ASN1Exception
```
    Throws:
    
    ASN1Exception
  - 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

Class DERDecoder

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

BOOLEAN_FALSE

UTF_32BE

bi

states

implicitTag

Constructor Detail

DERDecoder

DERDecoder

DERDecoder

Method Detail

startSequence

endSequence

startSet

endSet

startSetOf

endSetOf

startExplicit

startExplicit

endExplicit

endConstructedElement

decodeOctetString

decodeOctetStringAsString

decodeOctetStringAsString

decodeIA5String

decodeIA5StringAsBytes

decodeBitString

decodeBitStringAsInteger

decodeBitStringAsString

decodePrintableString

decodePrintableStringAsBytes

decodeUniversalString

decodeUniversalStringAsBytes

decodeUtf8String

decodeUtf8StringAsBytes

decodeBMPString

decodeBMPStringAsBytes

decodeUncheckedStringAsBytes

decodeObjectIdentifier

decodeInteger

decodeNull

decodeImplicit

decodeImplicit

decodeBoolean

isNextType

peekType

skipElement

hasNextElement

hasCompleteElement

drainElementValue

drainElement

drain

readTag

readTag

readLength

decodeObjectIdentifierAsKeyAlgorithm