The CryptDestroyHash function destroys the hash object referenced by the hHash parameter. After a hash object has been destroyed, it can no longer be used. The destruction of hash objects after their use is finished is recommended for security reasons.

The CryptVerifySignature function verifies the signature of a hash object. Before calling this function, CryptCreateHash must be called to create the handle of a hash object. CryptHashData or CryptHashSessionKey is then used to add data or session keys to the hash object. After CryptVerifySignature has been completed, only CryptDestroyHash can be called using the hHash handle.

The CryptCreateHash function initiates the hashing of a stream of data. It creates and returns to the calling application a handle to a CSP hash object. This handle is used in subsequent calls to CryptHashData and CryptHashSessionKey to hash session keys and other streams of data.

The CryptHashData function adds data to a specified hash object. This function and CryptHashSessionKey can be called multiple times to compute the hash of long or discontinuous data streams. Before calling this function, CryptCreateHash must be called to create a handle of a hash object.

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The CryptVerifySignature function verifies the signature of a hash object. Before calling this function, CryptCreateHash must be called to create the handle of a hash object. CryptHashData or CryptHashSessionKey is then used to add data or session keys to the hash object. After CryptVerifySignature has been completed, only CryptDestroyHash can be called using the hHash handle.

The CryptDestroyHash function destroys the hash object referenced by the hHash parameter. After a hash object has been destroyed, it can no longer be used. The destruction of hash objects after their use is finished is recommended for security reasons.