(mozilla-projects-nss-reference-fc-setoperationstate)=

# FC_SetOperationState

## [Name](#name)

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FC_SetOperationState - restore the cryptographic operation state of a session.
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## [Syntax](#syntax)

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```{code}
CK_RV FC_SetOperationState(
  CK_SESSION_HANDLE hSession,
  CK_BYTE_PTR pOperationState,
  CK_ULONG ulOperationStateLen,
  CK_OBJECT_HANDLE hEncryptionKey,
  CK_OBJECT_HANDLE hAuthenticationKey
);
```

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## [Parameters](#parameters)

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`hSession`

: [in] handle of the open session.

`pOperationState`

: [in] pointer to a byte array containing the operation state.

`ulOperationStateLen`

: [in] contains the total length (in bytes) of the operation state.

`hEncryptionKey`

: [in] handle of the encryption or decryption key to be used in a stored session or zero if no
  key is needed.

`hAuthenticationKey`

: [in] handle of the authentication key to be used in the stored session or zero if none is
  needed.
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## [Description](#description)

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`FC_SetOperationState` restores the cryptographic operations state of a session from an array
of bytes obtained with `FC_GetOperationState`. This function only works for digest operations
for now. Therefore, a user may call `FC_SetOperationState` without logging into the token (to
assume the NSS User role).
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## [Return value](#return_value)

## [Examples](#examples)

## [See also](#see_also)

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- {ref}`mozilla_projects_nss_reference_fc_getoperationstate`,
  [NSC_SetOperationState](/en-US/NSC_SetOperationState)
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