WinCAPICryptoHashHMAC Class Reference
[Windows Crypto API Interface]

#include <WinCAPICryptoHashHMAC.hpp>

Inheritance diagram for WinCAPICryptoHashHMAC:

[legend]Collaboration diagram for WinCAPICryptoHashHMAC:

[legend]List of all members.

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Detailed Description

Implementation of HMAC Hash functions in the Windows providers.

Uses the Windows Crypt* API functions to implement an HMAC.

Unfortunately the Windows Crypto API does not allow callers to enter an HMAC key directly. It relies on a seed being entered into a digest function that is then used to derive a key that can be used in an HMAC function.

Two types of key can therefore be used - a direct Windows key, or a "standard" string as the HMAC key. In the latter case, the HMAC function is implemented internally around a standard Windows hash function. In the former case, the Windows HMAC functions are used. (The latter case is mainly for interoperability testing, where the key is provided and needs to be entered "as is".

Public Member Functions
Constructors and Destructors
	WinCAPICryptoHashHMAC (HCRYPTPROV prov, XSECCryptoHash::HashType alg)
	Constructor.
virtual	~WinCAPICryptoHashHMAC ()
HMAC Functions
virtual void	setKey (XSECCryptoKey *key)
	Set the HMAC key.
Hash functions
virtual void	reset (void)
	Reset the hash function.
virtual void	hash (unsigned char *data, unsigned int length)
	Hash some data.
virtual unsigned int	finish (unsigned char *hash, unsigned int maxLength)
	Finish up a Digest operation and read the result.
Information functions
virtual HashType	getHashType (void)

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Constructor & Destructor Documentation

WinCAPICryptoHashHMAC::WinCAPICryptoHashHMAC (  HCRYPTPROV  prov, XSECCryptoHash::HashType  alg )

Constructor. Create the object, with the indicated algorithm (Currently supports MD5 and SHA1) Parameters: prov  handle to a provider that supports the required algorithm. Both PROV_RSA_FULL and PROV_DSS support MD5 and SHA1 alg  Digest algorithm to use

virtual WinCAPICryptoHashHMAC::~WinCAPICryptoHashHMAC (   )  [virtual]

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Member Function Documentation

virtual unsigned int WinCAPICryptoHashHMAC::finish (  unsigned char *  hash, unsigned int  maxLength )  [virtual]

Finish up a Digest operation and read the result. This call tells the CryptoHash object that the input is complete and to finalise the Digest. The output of the digest is read into the hash buffer (at most maxLength bytes). This is effectively the signature for the data that has been run through the HMAC function. Parameters: hash  The buffer the hash should be read into. maxLength  The maximum number of bytes to be read into hash Returns: The number of bytes copied into the hash buffer Implements XSECCryptoHash.

virtual HashType WinCAPICryptoHashHMAC::getHashType (  void   )  [virtual]

Determine the hash type of this object Returns: The hash type Implements XSECCryptoHash.

virtual void WinCAPICryptoHashHMAC::hash (  unsigned char *  data, unsigned int  length )  [virtual]

Hash some data. Take length bytes of data from the data buffer and update the hash that already exists. This function may (and normally will) be called many times for large blocks of data. Parameters: data  The buffer containing the data to be hashed. length  The number of bytes to be read from data Implements XSECCryptoHash.

virtual void WinCAPICryptoHashHMAC::reset (  void   )  [virtual]

Reset the hash function. Re-initialises the digest structure. Implements XSECCryptoHash.

virtual void WinCAPICryptoHashHMAC::setKey (  XSECCryptoKey *  key  )  [virtual]

Set the HMAC key. Sets the key - which needs to have a base class of WinCAPICryptoKeyHMAC. Parameters: key  The key the HMAC function should use. Implements XSECCryptoHash.

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The documentation for this class was generated from the following file:

• WinCAPICryptoHashHMAC.hpp

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