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

# FC_DecryptDigestUpdate

## [Name](#name)

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FC_DecryptDigestUpdate - continue a multi-part decrypt and digest operation
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## [Syntax](#syntax)

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```{code}
CK_RV FC_DecryptDigestUpdate(
  CK_SESSION_HANDLE hSession,
  CK_BYTE_PTR pEncryptedPart,
  CK_ULONG ulEncryptedPartLen,
  CK_BYTE_PTR pPart,
  CK_ULONG_PTR pulPartLen
);
```

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## [Parameters](#parameters)

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`hSession`

: [in] session handle.

`pEncryptedPart`

: [in] pointer to the encrypted data part.

`ulEncryptedPartLen`

: [in] length of encrypted data in bytes.

`pPart`

: [in] pointer to the location which receives the recovered data part or NULL.

`pulPartLen`

: [in] pointer to the length of the recovered part buffer.
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## [Description](#description)

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`FC_DecryptDigestUpdate` continues a multi-part decrypt and digest operation. After calling
both `FC_DecryptInit` and `FC_DigestInit` to set up the operations this function may be
called multiple times. The operation is finished by calls to `FC_DigestFinal` and
`FC_DecryptFinal`.

A user must log into the token (to assume the NSS User role) before calling
`FC_DecryptDigestUpdate`.
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## [Return value](#return_value)

## [Examples](#examples)

## [See also](#see_also)

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- [NSC_DecryptDigestUpdate](/en-US/NSC_DecryptDigestUpdate)
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