CryptHashSessionKey function (wincrypt.h)

The CryptHashSessionKey function computes the cryptographic hash of a session key object. This function can be called multiple times with the same hash handle to compute the hash of multiple keys. Calls to CryptHashSessionKey can be interspersed with calls to CryptHashData.

Before calling this function, CryptCreateHash must be called to create the handle of a hash object.

Syntax

BOOL CryptHashSessionKey(
  [in] HCRYPTHASH hHash,
  [in] HCRYPTKEY  hKey,
  [in] DWORD      dwFlags
);

Parameters

[in] hHash

A handle to the hash object.

[in] hKey

A handle to the key object to be hashed.

[in] dwFlags

The following flag value is defined.

Value	Meaning
CRYPT_LITTLE_ENDIAN 0x00000001	When this flag is set, the bytes of the key are hashed in little-endian form. Note that by default (when dwFlags is zero), the bytes of the key are hashed in big-endian form.

Return value

If the function succeeds, the return value is TRUE.

If the function fails, the return value is FALSE. For extended error information, call GetLastError.

The error codes prefaced by "NTE" are generated by the particular CSP you are using. Some possible error codes follow.

Return code	Description
ERROR_INVALID_HANDLE	One of the parameters specifies a handle that is not valid.
ERROR_INVALID_PARAMETER	One of the parameters contains a value that is not valid. This is most often a pointer that is not valid.
NTE_BAD_ALGID	The hHash handle specifies an algorithm that this CSP does not support.
NTE_BAD_FLAGS	The dwFlags parameter is nonzero.
NTE_BAD_HASH	The hash object specified by the hHash parameter is not valid.
NTE_BAD_HASH_STATE	An attempt was made to add data to a hash object that is already marked "finished."
NTE_BAD_KEY	A keyed hash algorithm is being used, but the session key is no longer valid. This error is generated if the session key is destroyed before the hashing operation is complete.
NTE_BAD_UID	The CSP context that was specified when the hash object was created cannot be found.
NTE_FAIL	The function failed in some unexpected way.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	wincrypt.h
Library	Advapi32.lib
DLL	Advapi32.dll

See also

CryptCreateHash

CryptGenKey

CryptHashData

Hash and Digital Signature Functions