ASN1Decoder (Red Hat JBoss Enterprise Application Platform 7.2.0.Beta public API)

All Known Implementing Classes:

DERDecoder
```
public interface ASN1Decoder
```
An interface for decoding ASN.1 encoded values from an input stream.

Author:

Farah Juma

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and 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.
`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.
`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 printable string.
`byte[]`	`decodePrintableStringAsBytes()` Decode the next ASN.1 element as a printable string.
`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.

- Method Detail
  - startSequence
```
void startSequence()
            throws ASN1Exception
```
    Start decoding an ASN.1 sequence. All subsequent decode operations will decode elements from this sequence until endSequence() is called.
    
    Throws:
    
    ASN1Exception - if the next element is not a sequence
  - endSequence
```
void endSequence()
          throws ASN1Exception
```
    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.
    
    Throws:
    
    ASN1Exception - if an error occurs while advancing to the end of the sequence
  - startSet
```
void startSet()
       throws ASN1Exception
```
    Start decoding an ASN.1 set. All subsequent decode operations will decode elements from this set until endSet() is called.
    
    Throws:
    
    ASN1Exception - if the next element is not a set
  - endSet
```
void endSet()
     throws ASN1Exception
```
    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.
    
    Throws:
    
    ASN1Exception - if an error occurs while advancing to the end of the set
  - startSetOf
```
void startSetOf()
         throws ASN1Exception
```
    Start decoding an ASN.1 "set of" element. All subsequent decode operations will decode elements from this set until endSetOf() is called.
    
    Throws:
    
    ASN1Exception - if the next element is not a set
  - endSetOf
```
void endSetOf()
       throws ASN1Exception
```
    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.
    
    Throws:
    
    ASN1Exception - if an error occurs while advancing to the end of the set
  - startExplicit
```
void startExplicit(int number)
            throws ASN1Exception
```
    Start decoding an ASN.1 explicitly tagged element. All subsequent decode operations will decode elements from this explicitly tagged element until endExplicit() is called.
    
    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
```
void startExplicit(int clazz,
                   int number)
            throws ASN1Exception
```
    Start decoding an ASN.1 explicitly tagged element. All subsequent decode operations will decode elements from this explicitly tagged element until endExplicit() is called.
    
    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
```
void endExplicit()
          throws ASN1Exception
```
    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.
    
    Throws:
    
    ASN1Exception - if an error occurs while advancing to the end of the explicitly tagged element
  - decodeOctetString
```
byte[] decodeOctetString()
                  throws ASN1Exception
```
    Decode the next ASN.1 element as an octet string.
    
    Returns:
    
    the decoded octet string, as a byte array
    
    Throws:
    
    ASN1Exception - if the next element is not an octet string
  - decodeOctetStringAsString
```
String decodeOctetStringAsString()
                          throws ASN1Exception
```
    Decode the next ASN.1 element as an octet string.
    
    Returns:
    
    the decoded octet string, as a UTF-8 string
    
    Throws:
    
    ASN1Exception - if the next element is not an octet string
  - decodeOctetStringAsString
```
String decodeOctetStringAsString(String charSet)
                          throws ASN1Exception
```
    Decode the next ASN.1 element as an octet string.
    
    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
```
String decodeIA5String()
                throws ASN1Exception
```
    Decode the next ASN.1 element as an IA5 string.
    
    Returns:
    
    the decoded IA5 string
    
    Throws:
    
    ASN1Exception - if the next element is not an IA5 string
  - decodeIA5StringAsBytes
```
byte[] decodeIA5StringAsBytes()
                       throws ASN1Exception
```
    Decode the next ASN.1 element as an IA5 string.
    
    Returns:
    
    the decoded IA5 string, as a byte array
    
    Throws:
    
    ASN1Exception - if the next element is not an IA5 string
  - decodeBitString
```
byte[] decodeBitString()
                throws ASN1Exception
```
    Decode the next ASN.1 element as a bit string.
    
    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
```
BigInteger decodeBitStringAsInteger()
```
    Decode the next ASN.1 element as a bit string where the value is a ASN.1 INTEGER.
    
    Returns:
    
    a BigInteger decoded from the bit string
    
    Throws:
    
    ASN1Exception - if the next element is not a bit string or its value is not an integer
  - decodeBitStringAsString
```
String decodeBitStringAsString()
                        throws ASN1Exception
```
    Decode the next ASN.1 element as a bit string.
    
    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
```
String decodePrintableString()
                      throws ASN1Exception
```
    Decode the next ASN.1 element as a printable string.
    
    Returns:
    
    the decoded printable string as a string
    
    Throws:
    
    ASN1Exception - if the next element is not a printable string
  - decodePrintableStringAsBytes
```
byte[] decodePrintableStringAsBytes()
                             throws ASN1Exception
```
    Decode the next ASN.1 element as a printable string.
    
    Returns:
    
    the decoded printable string as a byte array
    
    Throws:
    
    ASN1Exception - if the next element is not a printable string
  - decodeObjectIdentifier
```
String decodeObjectIdentifier()
                       throws ASN1Exception
```
    Decode the next ASN.1 element as an object identifier.
    
    Returns:
    
    the object identifier as a string
    
    Throws:
    
    ASN1Exception - if the next element is not a bit string
  - decodeInteger
```
BigInteger decodeInteger()
```
    Decode the next ASN.1 element as an integer.
    
    Returns:
    
    an integer decoded from the next element
    
    Throws:
    
    ASN1Exception - if the next element is not an integer
  - decodeNull
```
void decodeNull()
         throws ASN1Exception
```
    Decode the next ASN.1 element as a null element.
    
    Throws:
    
    ASN1Exception - if the next element is not null
  - decodeImplicit
```
void decodeImplicit(int number)
```
    Indicate that the next ASN.1 element has the given implicit, context-specific tag.
    
    Parameters:
    
    number - the tag number for the implicit tag
  - decodeImplicit
```
void decodeImplicit(int clazz,
                    int number)
```
    Indicate that the next ASN.1 element has the given implicit tag.
    
    Parameters:
    
    clazz - the class for the implicit tag
    
    number - the tag number for the implicit tag
  - decodeBoolean
```
boolean decodeBoolean()
               throws ASN1Exception
```
    Decode the next ASN.1 element as a boolean value.
    
    Returns:
    
    the decoded boolean value
    
    Throws:
    
    ASN1Exception - if the next element is not a boolean value
    
    Since:
    
    1.2.0
  - isNextType
```
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. This method can be used to determine if an optional ASN.1 value has been included in the encoding or not.
    
    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
```
int peekType()
      throws ASN1Exception
```
    Retrieve the type of the next ASN.1 element without actually decoding the next element.
    
    Returns:
    
    the type of the next ASN.1 element
    
    Throws:
    
    ASN1Exception - if an error occurs while determining the type of the next element
  - skipElement
```
void skipElement()
          throws ASN1Exception
```
    Skip over the next ASN.1 element.
    
    Throws:
    
    ASN1Exception - if the next element cannot be skipped
  - hasNextElement
```
boolean hasNextElement()
```
    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.
    
    Returns:
    
    true if there is at least one more ASN.1 element that can be read and false otherwise
  - drainElementValue
```
byte[] drainElementValue()
                  throws ASN1Exception
```
    Drain the value bytes from the next ASN.1 element.
    
    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
```
byte[] drainElement()
             throws ASN1Exception
```
    Drain all of the bytes from the next ASN.1 element.
    
    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
```
byte[] drain()
```
    Drain all of the remaining bytes from the input stream.
    
    Returns:
    
    all of the remaining bytes from the input stream

Interface ASN1Decoder

Method Summary

Method Detail

startSequence

endSequence

startSet

endSet

startSetOf

endSetOf

startExplicit

startExplicit

endExplicit

decodeOctetString

decodeOctetStringAsString

decodeOctetStringAsString

decodeIA5String

decodeIA5StringAsBytes

decodeBitString

decodeBitStringAsInteger

decodeBitStringAsString

decodePrintableString

decodePrintableStringAsBytes

decodeObjectIdentifier

decodeInteger

decodeNull

decodeImplicit

decodeImplicit

decodeBoolean

isNextType

peekType

skipElement

hasNextElement

drainElementValue

drainElement

drain