Printable View
hi,
I have a little problem with the CryptoApi (or better with advapi.dll) shipped with WindowsNT
When I try to access to the functions "CryptDuplicateKey" and "CryptDuplicateHash" I allways get an error, that the entrypoint was not found.
So these functions are described at the msdn I think, that they must be there (somewhere)
So, have anyone an idea, how they are accessed correctly or if they are not implemented ? (or any other good idea)
thx, Robert
If you tell me your Declare statement I can cross reference it against the MSDN documentation. Basically the info I have here tells me that these methods are from advapi32.lib which I guess would translate to advapi32.dll.
IN case it helps, here is the documentation for one of the C functions...
CheersCode:CryptDuplicateHash
The CryptDuplicateHash function is used to make an exact copy of a hash including its state.
BOOL WINAPI CryptDuplicateHash(
HCRYPTHASH hHash, // in
DWORD *pdwReserved, // in
DWORD dwFlags, // in
HCRYPTHASH *phHash // out
);
Parameters
hHash
Handle of the hash to be duplicated.
pdwReserved
Reserved for future use and must always be zero.
dwFlags
Reserved for future use and must always be zero.
phHash
Address of the handle of the duplicated hash.
Return Values
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 code prefaced by "NTE" is generated by the particular CSP you are using. Some possible error codes follow.
Value Meaning
ERROR_CALL_NOT
_IMPLEMENTED Because this is a new function, existing CSPs cannot implement it. This error is returned if the CSP does not support this function.
ERROR_INVALID
_PARAMETER One of the parameters contains an invalid value. This is most often an invalid pointer.
NTE_BAD_HASH The handle to the original hash is not valid.
Remarks
CryptDuplicateHash makes a copy of a hash and the exact state of the hash. This function might be used if a calling application needed to generate two hashes, but both hashes had to start with some common data hashed. A hash might be created, the common data hashed, a duplicate made with the CryptDuplicateHash function, and then the data unique to each hash would be added.
CryptDestroyHash must be called to destroy any hashes that are created with CryptDuplicateHash. Destroying the original hash does not cause the duplicate hash to be destroyed. Once a duplicate hash is made, it is separate from the original hash. There is no shared state between the two hashes.
so, here's the declaration :
Private Declare Function CryptDuplicateHash Lib "advapi32.dll" (ByRef hHash As Long, ByRef pdwReserved As Long, ByVal dwFlags As Long, ByRef phHash As Long) As Long
as far as i understand the msdn, it should be the right way to access it.
I think, that the function has an another name in the advapi32.dll
thx,
Robert