org.ietf.jgss

Interface GSSContext

public interface GSSContext

This interface encapsulates the GSS-API security context and provides the security services (wrap(byte[],int,int,MessageProp), unwrap(byte[],int,int,MessageProp), getMIC(byte[],int,int,MessageProp), verifyMIC(byte[],int,int,byte[],int,int,MessageProp)) that are available over the context. Security contexts are established between peers using locally acquired credentials. Multiple contexts may exist simultaneously between a pair of peers, using the same or different set of credentials. GSS-API functions in a manner independent of the underlying transport protocol and depends on its calling application to transport its tokens between peers.

Before the context establishment phase is initiated, the context initiator may request specific characteristics desired of the established context. These can be set using the set methods. After the context is established, the caller can check the actual characteristic and services offered by the context using the query methods.

The context establishment phase begins with the first call to the init method by the context initiator. During this phase the initSecContext(byte[],int,int) and acceptSecContext(byte[],int,int) methods will produce GSS-API authentication tokens which the calling application needs to send to its peer. If an error occurs at any point, an exception will get thrown and the code will start executing in a catch block. If not, the normal flow of code continues and the application can make a call to the isEstablished() method. If this method returns false it indicates that a token is needed from its peer in order to continue the context establishment phase. A return value of true signals that the local end of the context is established. This may still require that a token be sent to the peer, if one is produced by GSS-API. During the context establishment phase, the isProtReady() method may be called to determine if the context can be used for the per-message operations. This allows applications to use per-message operations on contexts which aren't fully established.

After the context has been established or the isProtReady() method returns true, the query routines can be invoked to determine the actual characteristics and services of the established context. The application can also start using the per-message methods of wrap(byte[],int,int,MessageProp) and getMIC(byte[],int,int,MessageProp) to obtain cryptographic operations on application supplied data.

When the context is no longer needed, the application should call dispose() to release any system resources the context may be using.

Example Code

GSSManager mgr = GSSManager.getInstance();
// start by creating the name for a service entity
GSSName targetName = mgr.createName("service@host",
GSSName.NT_HOSTBASED_SERVICE);
// create a context using default credentials for the above entity
// and the implementation specific default mechanism
GSSContext context = mgr.createContext(targetName,
null,   // default mechanism
null,   // default credentials
GSSContext.INDEFINITE_LIFETIME);
// set desired context options - all others are false by default
context.requestConf(true);
context.requestMutualAuth(true);
context.requestReplayDet(true);
context.requestSequenceDet(true);
// establish a context between peers - using byte arrays
byte []inTok = new byte[0];
try
{
do
{
byte[] outTok = context.initSecContext(inTok, 0,
inTok.length);
// send the token if present
if (outTok != null)
sendToken(outTok);
// check if we should expect more tokens
if (context.isEstablished())
break;
// another token expected from peer
inTok = readToken();
}
while (true);
}
catch (GSSException e)
{
print("GSSAPI error: " + e.getMessage());
}
// display context information
print("Remaining lifetime in seconds = " + context.getLifetime());
print("Context mechanism = " + context.getMech().toString());
print("Initiator = " + context.getSrcName().toString());
print("Acceptor = " + context.getTargName().toString());
if (context.getConfState())
print("Confidentiality security service available");
if (context.getIntegState())
print("Integrity security service available");
// perform wrap on an application supplied message, appMsg,
// using QOP = 0, and requesting privacy service
byte[] appMsg ...
MessageProp mProp = new MessageProp(0, true);
byte[] tok = context.wrap(appMsg, 0, appMsg.length, mProp);
if (mProp.getPrivacy())
print("Message protected with privacy.");
sendToken(tok);
// release the local-end of the context
context.dispose();
 

Field Summary

static int
DEFAULT_LIFETIME
A lifetime constant representing the default context lifetime.
static int
INDEFINITE_LIFETIME
A lifetime constant representing indefinite context lifetime.

Method Summary

byte[]
acceptSecContext(byte[] inTok, int offset, int len)
Called by the context acceptor upon receiving a token from the peer.
void
acceptSecContext(InputStream inStream, OutputStream outStream)
Called by the context acceptor upon receiving a token from the peer.
void
dispose()
Releases any system resources and cryptographic information stored in the context object.
byte[]
export()
Provided to support the sharing of work between multiple processes.
boolean
getAnonymityState()
Returns "true" if this is an anonymous context.
boolean
getConfState()
Returns the confidentiality service state over the context.
boolean
getCredDelegState()
Returns the state of the delegated credentials for the context.
GSSCredential
getDelegCred()
Returns the delegated credential object on the acceptor's side.
boolean
getIntegState()
Returns the integrity service state over the context.
int
getLifetime()
Returns the context lifetime in seconds.
byte[]
getMIC(byte[] inMsg, int offset, int len, MessageProp msgProp)
Returns a token containing a cryptographic MIC for the supplied message, for transfer to the peer application.
void
getMIC(InputStream inStream, OutputStream outStream, MessageProp mgProp)
Produces a token containing a cryptographic MIC for the supplied message, for transfer to the peer application.
Oid
getMech()
Returns the mechanism oid for this context.
boolean
getMutualAuthState()
Returns the state of the mutual authentication option for the context.
boolean
getReplayDetState()
Returns the state of the replay detection option for the context.
boolean
getSequenceDetState()
Returns the state of the sequence detection option for the context.
GSSName
getSrcName()
Returns the name of the context initiator.
GSSName
getTargName()
Returns the name of the context target (acceptor).
int
getWrapSizeLimit(int qop, boolean confReq, int maxTokenSize)
Returns the maximum message size that, if presented to the wrap(byte[],int,int,MessageProp) method with the same confReq and qop parameters, will result in an output token containing no more than the maxTokenSize bytes.

This call is intended for use by applications that communicate over protocols that impose a maximum message size.

byte[]
initSecContext(byte[] inputBuf, int offset, int len)
Called by the context initiator to start the context creation process.
int
initSecContext(InputStream inStream, OutputStream outStream)
Called by the context initiator to start the context creation process.
boolean
isEstablished()
Used during context establishment to determine the state of the context.
boolean
isInitiator()
Returns "true" if this is the initiator of the context.
boolean
isProtReady()
Returns "true" if the per message operations can be applied over the context.
boolean
isTransferable()
Returns "true" if the context is transferable to other processes through the use of the export() method.
void
requestAnonymity(boolean state)
Requests anonymous support over the context.
void
requestConf(boolean state)
Requests that confidentiality service be available over the context.
void
requestCredDeleg(boolean state)
Sets the request state for the credential delegation flag for the context.
void
requestInteg(boolean state)
Requests that integrity services be available over the context.
void
requestLifetime(int lifetime)
Sets the desired lifetime for the context in seconds.
void
requestMutualAuth(boolean state)
Sets the request state of the mutual authentication flag for the context.
void
requestReplayDet(boolean state)
Sets the request state of the replay detection service for the context.
void
requestSequenceDet(boolean state)
Sets the request state for the sequence checking service of the context.
void
setChannelBinding(ChannelBinding cb)
Sets the channel bindings to be used during context establishment.
byte[]
unwrap(byte[] inBuf, int offset, int len, MessageProp msgProp)
Used by the peer application to process tokens generated with the wrap call.
void
unwrap(InputStream inStream, OutputStream outStream, MessageProp msgProp)
Used by the peer application to process tokens generated with the wrap call.
void
verifyMIC(byte[] inTok, int tokOffset, int tokLen, byte[] inMsg, int msgOffset, int msgLen, MessageProp msgProp)
Verifies the cryptographic MIC, contained in the token parameter, over the supplied message.
void
verifyMIC(InputStream tokStream, InputStream msgStream, MessageProp msgProp)
Verifies the cryptographic MIC, contained in the token parameter, over the supplied message.
byte[]
wrap(byte[] inBuf, int offset, int len, MessageProp msgProp)
Applies per-message security services over the established security context.
void
wrap(InputStream inStream, OutputStream outStream, MessageProp msgProp)
Allows to apply per-message security services over the established security context.

Field Details

DEFAULT_LIFETIME

public static final int DEFAULT_LIFETIME
A lifetime constant representing the default context lifetime.
Field Value:
0

INDEFINITE_LIFETIME

public static final int INDEFINITE_LIFETIME
A lifetime constant representing indefinite context lifetime.
Field Value:
2147483647

Method Details

acceptSecContext

public byte[] acceptSecContext(byte[] inTok,
                               int offset,
                               int len)
            throws GSSException
Called by the context acceptor upon receiving a token from the peer. This call is equivalent to the stream based method except that the token buffers are handled as byte arrays instead of using stream objects.

This method may return an output token which the application will need to send to the peer for further processing by the init call.

null return value indicates that no token needs to be sent to the peer. The application can call isEstablished() to determine if the context establishment phase is complete for this peer. A return value of false from isEstablished() indicates that more tokens are expected to be supplied to this method.

Note that it is possible that acceptSecContext() return a token for the peer, and isEstablished() return true also. This indicates that the token needs to be sent to the peer, but the local end of the context is now fully established.

Upon completion of the context establishment, the available context options may be queried through the get methods.

Parameters:
inTok - Token generated by the peer.
offset - The offset within the inTok where the token begins.
len - The length of the token within the inTok (starting at the offset).
Returns:
The output token, if any.
Throws:
GSSException - If this operation fails.

acceptSecContext

public void acceptSecContext(InputStream inStream,
                             OutputStream outStream)
            throws GSSException
Called by the context acceptor upon receiving a token from the peer. This call is equivalent to the byte array method. It may write an output token to the outStream, which the application will need to send to the peer for processing by its initSecContext method. Typically, the application would do so by calling the OutputStream.flush() method on an OutputStream that encapsulates the connection between the two peers. The application can call isEstablished() to determine if the context establishment phase is complete for this peer. A return value of false from isEstablished() indicates that more tokens are expected to be supplied to this method.

Note that it is possible that acceptSecContext() return a token for the peer, and isEstablished() return true also. This indicates that the token needs to be sent to the peer, but the local end of the context is now fully established.

The GSS-API authentication tokens contain a definitive start and end. This method will attempt to read one of these tokens per invocation, and may block on the stream if only part of the token is available.

Upon completion of the context establishment, the available context options may be queried through the get methods.

Parameters:
inStream - Contains the token generated by the peer.
outStream - Output stream where the output token will be written. During the final stage of context establishment, there may be no bytes written.
Throws:
GSSException - If this operation fails.

dispose

public void dispose()
            throws GSSException
Releases any system resources and cryptographic information stored in the context object. This will invalidate the context.
Throws:
GSSException - If this operation fails.

export

public byte[] export()
            throws GSSException
Provided to support the sharing of work between multiple processes. This routine will typically be used by the context-acceptor, in an application where a single process receives incoming connection requests and accepts security contexts over them, then passes the established context to one or more other processes for message exchange.

This method deactivates the security context and creates an interprocess token which, when passed to the byte array constructor of the GSSContext interface in another process, will re-activate the context in the second process. Only a single instantiation of a given context may be active at any one time; a subsequent attempt by a context exporter to access the exported security context will fail.

The implementation may constrain the set of processes by which the interprocess token may be imported, either as a function of local security policy, or as a result of implementation decisions. For example, some implementations may constrain contexts to be passed only between processes that run under the same account, or which are part of the same process group.

The interprocess token may contain security-sensitive information (for example cryptographic keys). While mechanisms are encouraged to either avoid placing such sensitive information within interprocess tokens, or to encrypt the token before returning it to the application, in a typical GSS-API implementation this may not be possible. Thus the application must take care to protect the interprocess token, and ensure that any process to which the token is transferred is trustworthy.

Returns:
The exported context.
Throws:
GSSException - If this operation fails.

getAnonymityState

public boolean getAnonymityState()
Returns "true" if this is an anonymous context. When issued before context establishment completes or when the isProtReady method returns "false", it returns the desired state, otherwise it will indicate the actual state over the established context.
Returns:
True if this is an anonymous context.

getConfState

public boolean getConfState()
Returns the confidentiality service state over the context. When issued before context establishment completes or when the isProtReady method returns "false", it returns the desired state, otherwise it will indicate the actual state over the established context.
Returns:
True the confidentiality service state.

getCredDelegState

public boolean getCredDelegState()
Returns the state of the delegated credentials for the context. When issued before context establishment is completed or when the isProtReady method returns "false", it returns the desired state, otherwise it will indicate the actual state over the established context.
Returns:
The state of the delegated credentials for the context.

getDelegCred

public GSSCredential getDelegCred()
            throws GSSException
Returns the delegated credential object on the acceptor's side. To check for availability of delegated credentials call getDelegCredState(). This call is only valid on fully established contexts.
Returns:
The delegated credential object.
Throws:
GSSException - If this operation fails.

getIntegState

public boolean getIntegState()
Returns the integrity service state over the context. When issued before context establishment completes or when the isProtReady method returns "false", it returns the desired state, otherwise it will indicate the actual state over the established context.
Returns:
The integrity service state.

getLifetime

public int getLifetime()
Returns the context lifetime in seconds. When issued before context establishment completes or when the isProtReady method returns "false", it returns the desired lifetime, otherwise it will indicate the remaining lifetime for the context.
Returns:
The lifetime.

getMIC

public byte[] getMIC(byte[] inMsg,
                     int offset,
                     int len,
                     MessageProp msgProp)
            throws GSSException
Returns a token containing a cryptographic MIC for the supplied message, for transfer to the peer application. Unlike wrap, which encapsulates the user message in the returned token, only the message MIC is returned in the output token. This method is identical in functionality to its stream counterpart.

Note that privacy can only be applied through the wrap call.

Since some application-level protocols may wish to use tokens emitted by getMIC to provide "secure framing", implementations should support derivation of MICs from zero-length messages.

Parameters:
inMsg - Message to generate MIC over.
offset - The offset within the inMsg where the token begins.
len - The length of the token within the inMsg (starting at the offset).
msgProp - Instance of MessageProp that is used by the application to set the desired QOP. Set the desired QOP to 0 in msgProp to request the default QOP. Alternatively pass in null for msgProp to request default QOP.
Returns:
The MIC.
Throws:
GSSException - If this operation fails.

getMIC

public void getMIC(InputStream inStream,
                   OutputStream outStream,
                   MessageProp mgProp)
            throws GSSException
Produces a token containing a cryptographic MIC for the supplied message, for transfer to the peer application. Unlike wrap, which encapsulates the user message in the returned token, only the message MIC is produced in the output token. This method is identical in functionality to its byte array counterpart.

Note that privacy can only be applied through the wrap call.

Since some application-level protocols may wish to use tokens emitted by getMIC to provide "secure framing", implementations should support derivation of MICs from zero-length messages.

Parameters:
inStream - Input stream containing the message to generate the MIC over.
outStream - Output stream to write the GSS-API output token to.
mgProp - Instance of MessageProp that is used by the application to set the desired QOP. Set the desired QOP to 0 in msgProp to request the default QOP. Alternatively pass in null for msgProp to request default QOP.
Throws:
GSSException - If this operation fails.

getMech

public Oid getMech()
            throws GSSException
Returns the mechanism oid for this context. This method may be called before the context is fully established, but the mechanism returned may change on successive calls in negotiated mechanism case.
Returns:
The mechanism OID.
Throws:
GSSException - If this operation fails.

getMutualAuthState

public boolean getMutualAuthState()
Returns the state of the mutual authentication option for the context. When issued before context establishment completes or when the isProtReady method returns "false", it returns the desired state, otherwise it will indicate the actual state over the established context.
Returns:
The state of the mutual authentication option.

getReplayDetState

public boolean getReplayDetState()
Returns the state of the replay detection option for the context. When issued before context establishment completes or when the isProtReady method returns "false", it returns the desired state, otherwise it will indicate the actual state over the established context.
Returns:
The state of the replay detection option.

getSequenceDetState

public boolean getSequenceDetState()
Returns the state of the sequence detection option for the context. When issued before context establishment completes or when the isProtReady method returns "false", it returns the desired state, otherwise it will indicate the actual state over the established context.
Returns:
The state of the sequence detection option.

getSrcName

public GSSName getSrcName()
            throws GSSException
Returns the name of the context initiator. This call is valid only after the context is fully established or the isProtReady method returns "true". It is guaranteed to return an MN.
Returns:
The name of the context initiator.
Throws:
GSSException - If this operation fails.

getTargName

public GSSName getTargName()
            throws GSSException
Returns the name of the context target (acceptor). This call is valid only after the context is fully established or the isProtReady method returns "true". It is guaranteed to return an MN.
Returns:
The name of the context target.
Throws:
GSSException - If this operation fails.

getWrapSizeLimit

public int getWrapSizeLimit(int qop,
                            boolean confReq,
                            int maxTokenSize)
            throws GSSException
Returns the maximum message size that, if presented to the wrap(byte[],int,int,MessageProp) method with the same confReq and qop parameters, will result in an output token containing no more than the maxTokenSize bytes.

This call is intended for use by applications that communicate over protocols that impose a maximum message size. It enables the application to fragment messages prior to applying protection.

GSS-API implementations are recommended but not required to detect invalid QOP values when getWrapSizeLimit is called. This routine guarantees only a maximum message size, not the availability of specific QOP values for message protection.

Successful completion of this call does not guarantee that wrap will be able to protect a message of the computed length, since this ability may depend on the availability of system resources at the time that wrap is called. However, if the implementation itself imposes an upper limit on the length of messages that may be processed by wrap, the implementation should not return a value that is greater than this length.

Parameters:
qop - Indicates the level of protection wrap will be asked to provide.
confReq - Indicates if wrap will be asked to provide privacy service.
maxTokenSize - The desired maximum size of the token emitted by wrap(byte[],int,int,MessageProp).
Returns:
The maximum wrapped output size.
Throws:
GSSException - If this operation fails.

initSecContext

public byte[] initSecContext(byte[] inputBuf,
                             int offset,
                             int len)
            throws GSSException
Called by the context initiator to start the context creation process. This is equivalent to the stream based method except that the token buffers are handled as byte arrays instead of using stream objects. This method may return an output token which the application will need to send to the peer for processing by the accept call. Typically, the application would do so by calling the OutputStream.flush() method on an OutputStream that encapsulates the connection between the two peers. The application can call isEstablished() to determine if the context establishment phase is complete for this peer. A return value of false from isEstablished() indicates that more tokens are expected to be supplied to the initSecContext() method. Note that it is possible that the initSecContext() method return a token for the peer, and isEstablished() to return true also. This indicates that the token needs to be sent to the peer, but the local end of the context is now fully established.

Upon completion of the context establishment, the available context options may be queried through the get methods.

Parameters:
inputBuf - Token generated by the peer. This parameter is ignored on the first call.
offset - The offset within the inputBuf where the token begins.
len - The length of the token within the inputBuf (starting at the offset).
Returns:
The output token, if any.
Throws:
GSSException - If this operation fails.

initSecContext

public int initSecContext(InputStream inStream,
                          OutputStream outStream)
            throws GSSException
Called by the context initiator to start the context creation process. This is equivalent to the byte array based method. This method may write an output token to the outStream, which the application will need to send to the peer for processing by the accept call. Typically, the application would do so by calling the OutputStream.flush() method on an OutputStream that encapsulates the connection between the two peers. The application can call isEstablished() to determine if the context establishment phase is complete for this peer. A return value of false from isEstablished indicates that more tokens are expected to be supplied to the initSecContext() method. Note that it is possible that the initSecContext() method return a token for the peer, and #isEstablished() return true also. This indicates that the token needs to be sent to the peer, but the local end of the context is now fully established.

The GSS-API authentication tokens contain a definitive start and end. This method will attempt to read one of these tokens per invocation, and may block on the stream if only part of the token is available.

Upon completion of the context establishment, the available context options may be queried through the get methods. @param inStream Contains the token generated by the peer. This parameter is ignored on the first call. @param outStream Output stream where the output token will be written. During the final stage of context establishment, there may be no bytes written. @return The number of bytes written to outStream, or 0 if no token is written. @throws GSSException If this operation fails.


isEstablished

public boolean isEstablished()
Used during context establishment to determine the state of the context. Returns true if this is a fully established context on the caller's side and no more tokens are needed from the peer. Should be called after a call to initSecContext(byte[],int,int) or acceptSecContext(byte[],int,int) when no GSSException is thrown.
Returns:
True of this context is fully established on this side.

isInitiator

public boolean isInitiator()
            throws GSSException
Returns "true" if this is the initiator of the context. This call is only valid after the context creation process has started.
Returns:
True if this is the initiator.
Throws:
GSSException - If this operation fails.

isProtReady

public boolean isProtReady()
Returns "true" if the per message operations can be applied over the context. Some mechanisms may allow the usage of per-message operations before the context is fully established. This will also indicate that the get methods will return actual context state characteristics instead of the desired ones.
Returns:
True if the per message operations can be applied over the context.

isTransferable

public boolean isTransferable()
            throws GSSException
Returns "true" if the context is transferable to other processes through the use of the export() method. This call is only valid on fully established contexts.
Returns:
True if the context is transferable.
Throws:
GSSException - If this operation fails.

requestAnonymity

public void requestAnonymity(boolean state)
            throws GSSException
Requests anonymous support over the context. This method is only valid before the context creation process begins and only for the initiator.
Parameters:
state - Boolean representing if anonymity support is requested.
Throws:
GSSException - If this operation fails.

requestConf

public void requestConf(boolean state)
            throws GSSException
Requests that confidentiality service be available over the context. This method is only valid before the context creation process begins and only for the initiator.
Parameters:
state - Boolean indicating if confidentiality services are to be requested for the context.
Throws:
GSSException - If this operation fails.

requestCredDeleg

public void requestCredDeleg(boolean state)
            throws GSSException
Sets the request state for the credential delegation flag for the context. This method is only valid before the context creation process begins and only for the initiator.
Parameters:
state - Boolean representing if credential delegation is desired.
Throws:
GSSException - If this operation fails.

requestInteg

public void requestInteg(boolean state)
            throws GSSException
Requests that integrity services be available over the context. This method is only valid before the context creation process begins and only for the initiator.
Parameters:
state - Boolean indicating if integrity services are to be requested for the context.
Throws:
GSSException - If this operation fails.

requestLifetime

public void requestLifetime(int lifetime)
            throws GSSException
Sets the desired lifetime for the context in seconds. This method is only valid before the context creation process begins and only for the initiator. Use INDEFINITE_LIFETIME and DEFAULT_LIFETIME to request indefinite or default context lifetime.
Parameters:
lifetime - The desired context lifetime in seconds.
Throws:
GSSException - If this operation fails.

requestMutualAuth

public void requestMutualAuth(boolean state)
            throws GSSException
Sets the request state of the mutual authentication flag for the context. This method is only valid before the context creation process begins and only for the initiator.
Parameters:
state - Boolean representing if mutual authentication should be requested during context establishment.
Throws:
GSSException - If this operation fails.

requestReplayDet

public void requestReplayDet(boolean state)
            throws GSSException
Sets the request state of the replay detection service for the context. This method is only valid before the context creation process begins and only for the initiator.
Parameters:
state - Boolean representing if replay detection is desired over the established context.
Throws:
GSSException - If this operation fails.

requestSequenceDet

public void requestSequenceDet(boolean state)
            throws GSSException
Sets the request state for the sequence checking service of the context. This method is only valid before the context creation process begins and only for the initiator.
Parameters:
state - Boolean representing if sequence detection is desired over the established context.
Throws:
GSSException - If this operation fails.

setChannelBinding

public void setChannelBinding(ChannelBinding cb)
            throws GSSException
Sets the channel bindings to be used during context establishment. This method is only valid before the context creation process begins.
Parameters:
cb - Channel bindings to be used.
Throws:
GSSException - If this operation fails.

unwrap

public byte[] unwrap(byte[] inBuf,
                     int offset,
                     int len,
                     MessageProp msgProp)
            throws GSSException
Used by the peer application to process tokens generated with the wrap call. This call is equal in functionality to its stream counterpart. The method will return the message supplied in the peer application to the wrap call, verifying the embedded MIC.

The MessageProp object is instantiated by the application and is used by the underlying mechanism to return information to the caller such as the QOP, whether confidentiality was applied to the message, and other supplementary message state information.

Since some application-level protocols may wish to use tokens emitted by wrap to provide "secure framing", implementations should support the wrapping and unwrapping of zero-length messages.

Parameters:
inBuf - GSS-API wrap token received from peer.
offset - The offset within the inBuf where the token begins.
len - The length of the token within the inBuf (starting at the offset).
msgProp - Upon return from the method, this object will contain the applied QOP, the privacy state of the message, and supplementary information stating whether the token was a duplicate, old, out of sequence or arriving after a gap.
Returns:
The unwrapped token.
Throws:
GSSException - If this operation fails.

unwrap

public void unwrap(InputStream inStream,
                   OutputStream outStream,
                   MessageProp msgProp)
            throws GSSException
Used by the peer application to process tokens generated with the wrap call. This call is equal in functionality to its byte array counterpart. It will produce the message supplied in the peer application to the wrap call, verifying the embedded MIC.

The MessageProp object is instantiated by the application and is used by the underlying mechanism to return information to the caller such as the QOP, whether confidentiality was applied to the message, and other supplementary message state information.

Since some application-level protocols may wish to use tokens emitted by wrap to provide "secure framing", implementations should support the wrapping and unwrapping of zero-length messages.

Parameters:
inStream - Input stream containing the GSS-API wrap token received from the peer.
outStream - The output stream to write the application message to.
msgProp - Upon return from the method, this object will contain the applied QOP, the privacy state of the message, and supplementary information stating whether the token was a duplicate, old, out of sequence or arriving after a gap.
Throws:
GSSException - If this operation fails.

verifyMIC

public void verifyMIC(byte[] inTok,
                      int tokOffset,
                      int tokLen,
                      byte[] inMsg,
                      int msgOffset,
                      int msgLen,
                      MessageProp msgProp)
            throws GSSException
Verifies the cryptographic MIC, contained in the token parameter, over the supplied message. This method is equivalent in functionality to its stream counterpart.

The MessageProp object is instantiated by the application and is used by the underlying mechanism to return information to the caller such as the QOP indicating the strength of protection that was applied to the message and other supplementary message state information.

Since some application-level protocols may wish to use tokens emitted by getMIC to provide "secure framing", implementations should support the calculation and verification of MICs over zero-length messages.

Parameters:
inTok - Token generated by peer's getMIC method.
tokOffset - The offset within the inTok where the token begins.
tokLen - The length of the token within the inTok (starting at the offset).
inMsg - Application message to verify the cryptographic MIC over.
msgOffset - The offset within the inMsg where the message begins.
msgLen - The length of the message within the inMsg (starting at the offset).
msgProp - Upon return from the method, this object will contain the applied QOP and supplementary information stating whether the token was a duplicate, old, out of sequence or arriving after a gap. The confidentiality state will be set to false.
Throws:
GSSException - If this operation fails.

verifyMIC

public void verifyMIC(InputStream tokStream,
                      InputStream msgStream,
                      MessageProp msgProp)
            throws GSSException
Verifies the cryptographic MIC, contained in the token parameter, over the supplied message. This method is equivalent in functionality to its byte array counterpart.

The MessageProp object is instantiated by the application and is used by the underlying mechanism to return information to the caller such as the QOP indicating the strength of protection that was applied to the message and other supplementary message state information.

Since some application-level protocols may wish to use tokens emitted by getMIC to provide "secure framing", implementations should support the calculation and verification of MICs over zero-length messages.

Parameters:
tokStream - Input stream containing the token generated by peer's getMIC method.
msgStream - Input stream containing the application message to verify the cryptographic MIC over.
msgProp - Upon return from the method, this object will contain the applied QOP and supplementary information stating whether the token was a duplicate, old, out of sequence or arriving after a gap. The confidentiality state will be set to false.
Throws:
GSSException - If this operation fails.

wrap

public byte[] wrap(byte[] inBuf,
                   int offset,
                   int len,
                   MessageProp msgProp)
            throws GSSException
Applies per-message security services over the established security context. The method will return a token with a cryptographic MIC and may optionally encrypt the specified inBuf. This method is equivalent in functionality to its stream counterpart. The returned byte array will contain both the MIC and the message.

The MessageProp object is instantiated by the application and used to specify a QOP value which selects cryptographic algorithms, and a privacy service to optionally encrypt the message. The underlying mechanism that is used in the call may not be able to provide the privacy service. It sets the actual privacy service that it does provide in this MessageProp object which the caller should then query upon return. If the mechanism is not able to provide the requested QOP, it throws a GSSException with the GSSException.BAD_QOP code.

Since some application-level protocols may wish to use tokens emitted by wrap to provide "secure framing", implementations should support the wrapping of zero-length messages.

The application will be responsible for sending the token to the peer.

Parameters:
inBuf - Application data to be protected.
offset - The offset within the inBuf where the data begins.
len - The length of the data within the inBuf (starting at the offset).
msgProp - Instance of MessageProp that is used by the application to set the desired QOP and privacy state. Set the desired QOP to 0 to request the default QOP. Upon return from this method, this object will contain the the actual privacy state that was applied to the message by the underlying mechanism.
Returns:
The wrapped data.
Throws:
GSSException - If this operation fails.

wrap

public void wrap(InputStream inStream,
                 OutputStream outStream,
                 MessageProp msgProp)
            throws GSSException
Allows to apply per-message security services over the established security context. The method will produce a token with a cryptographic MIC and may optionally encrypt the message in inStream. The outStream will contain both the MIC and the message.

The MessageProp object is instantiated by the application and used to specify a QOP value which selects cryptographic algorithms, and a privacy service to optionally encrypt the message. The underlying mechanism that is used in the call may not be able to provide the privacy service. It sets the actual privacy service that it does provide in this MessageProp object which the caller should then query upon return. If the mechanism is not able to provide the requested QOP, it throws a GSSException with the GSSException.BAD_QOP code.

Since some application-level protocols may wish to use tokens emitted by wrap to provide "secure framing", implementations should support the wrapping of zero-length messages.

The application will be responsible for sending the token to the peer.

Parameters:
inStream - Input stream containing the application data to be protected.
outStream - The output stream to write the protected message to. The application is responsible for sending this to the other peer for processing in its unwrap method.
msgProp - Instance of MessageProp that is used by the application to set the desired QOP and privacy state. Set the desired QOP to 0 to request the default QOP. Upon return from this method, this object will contain the the actual privacy state that was applied to the message by the underlying mechanism.
Throws:
GSSException - If this operation fails.

GSSContext.java -- The GSS context interface. Copyright (C) 2004 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.