CryptMsgDuplicate function (wincrypt.h)

Article
02/22/2024

The CryptMsgDuplicate function duplicates a cryptographic message handle by incrementing its reference count.

Syntax

HCRYPTMSG CryptMsgDuplicate(
  [in] HCRYPTMSG hCryptMsg
);

Parameters

[in] hCryptMsg

Handle of the cryptographic message to be duplicated. Duplication is done by incrementing the reference count of the message. A copy of the message is not made.

Return value

The returned handle is the same as the handle input. A copy of the message is not created. When you have finished using the duplicated message handle, decrease the reference count by calling the CryptMsgClose function.

Remarks

CryptMsgDuplicate is used to increase the reference count on an HCRYPTMSG handle so that multiple calls to CryptMsgClose are required to actually release the handle.

Examples

For an example that uses this function, see Example C Program: Encoding and Decoding a Hashed Message.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2003 [desktop apps \| UWP apps]
Target Platform	Windows
Header	wincrypt.h
Library	Crypt32.lib
DLL	Crypt32.dll