CryptHashData

The CryptHashData function is used by applications to feed data to a specified hash object. This function and CryptHashSessionKey can be called multiple times to compute the hash on long streams or on discontinuous streams.

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

#include <wincrypt.h>
BOOL WINAPI CryptHashData(
  HCRYPTHASH hHash,  // in
  BYTE *pbData,      // in
  DWORD cbData,      // in
  DWORD dwFlags      // in
);

Parameters

hHash
A handle to the hash object. An application obtains this handle by using the CryptCreateHash function.
pbData
The address of the data to be hashed.
cbData
The number of bytes of data to be hashed. This must be zero if the CRYPT_USERDATA flag is set.
dwFlags
The flag values. The following values are currently defined:

The Microsoft Base Cryptographic Provider ignores this parameter.

Return Values

If the function succeeds, the return value is TRUE. If it fails, the return value is FALSE. To retrieve extended error information, use the GetLastError function.

The following table lists the error codes most commonly returned by the GetLastError function. The error codes prefaced by "NTE" are generated by the particular CSP you are using.

Error code Description
ERROR_INVALID_HANDLE One of the parameters specifies an invalid handle.
ERROR_INVALID_PARAMETER One of the parameters contains an invalid value. This is most often an illegal pointer.
NTE_BAD_ALGID The hHash handle specifies an algorithm that this CSP does not support.
NTE_BAD_FLAGS The dwFlags parameter contains an invalid value.
NTE_BAD_HASH The hash object specified by the hHash parameter is invalid.
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NTE_BAD_KEY A keyed hash algorithm is being used, but the session key is no longer valid.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 will be generated if the session key is destroyed before the hashing operation is complete.
NTE_BAD_LEN The CRYPT_USERDATA flag is set and the cbData parameter has a nonzero value.
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.
NTE_NO_MEMORY The CSP ran out of memory during the operation.

Example

See CryptGetHashParam.

QuickInfo

  Windows NT: Requires version 4.0 or later.
  Windows: Requires Windows 95 OSR2 or later (or Windows 95 with IE 3.02 or later).
  Windows CE: Unsupported.
  Header: Declared in wincrypt.h.
  Import Library: Use advapi32.lib.

See Also

CryptCreateHash, CryptHashSessionKey, CryptSignHash