Decryption functions

This section describes PKCS#11 decryption functions.

C_DecryptInit

This function operates as specified in PKCS#11.

The session will retain its initialized state even when a C_Decrypt or C_DecryptFinal operation has occurred.

If the CKF_LOGIN_REQUIRED flag is set for the Token associated with the provided session the session state must be either CKS_RW_USER_FUNCTIONS or CKS_RO_USER_FUNCTIONS,otherwise the error result CKR_USER_NOT_LOGGED_IN is returned.

If the object referenced by the hKey parameter has the CKA_USAGE_COUNT attribute its value is incremented by this function.

Synopsis

C_DecryptInit(
        CK_SESSION_HANDLE hSession,
        CK_MECHANISM_PTR pMechanism,
        CK_OBJECT_HANDLE hKey
);

C_Decrypt

This function operates as specified in PKCS#11 except for the following:

Symmetric cipher operations are terminated by this function. Although this function terminates the current decryption operation the session’s decryption state is not cleared.

Cryptoki specifies that a successful return from one of these functions (when not used for length prediction) should result in the cipher state of that session being reset (to the uninitialized state). ProtectToolkit-C, however, leaves the state initialized so that another operation (using the same key) can be performed without calling the appropriate C_xxxInit function.

Synopsis

C_Decrypt(
    CK_SESSION_HANDLE hSession,
    CK_BYTE_PTR pEncryptedData,
    CK_ULONG ulEncryptedDataLen,
    CK_BYTE_PTR pData,
    CK_ULONG_PTR pulDataLen
);

C_DecryptUpdate

This function operates as specified in PKCS#11.

Synopsis

C_DecryptUpdate(CK_SESSION_HANDLE hSession,
    CK_BYTE_PTR pEncryptedPart,
    CK_ULONG ulEncryptedPartLen,
    CK_BYTE_PTR pPart,
    CK_ULONG_PTR pulPartLen
);

C_DecryptFinal

This function operates as specified in PKCS#11.

Although this function will terminate the current encryption operation the session’s decryption state will not be cleared.

Cryptoki specifies that a successful return from one of these functions (when not used for length prediction) should result in the cipher state of that session being reset (to the uninitialized state). ProtectToolkit-C, however, leaves the state initialized so that another operation (using the same key) can be performed without calling the appropriate C_xxxInit function.

Synopsis

C_DecryptFinal(

        CK_SESSION_HANDLE hSession,

        CK_BYTE_PTR pLastPart,

        CK_ULONG_PTR pulLastPartLen

);