CPImportKey

The CPImportKey function is used to transfer a cryptographic key from a key blob to the CSP.

BOOL CPImportKey(
  HCRYPTPROV hProv,   // in
  CONST BYTE *pbData, // in
  DWORD dwDataLen,    // in
  HCRYPTKEY hImpKey,  // in
  DWORD dwFlags,      // in
  HCRYPTKEY *phKey    // out
);
 

Parameters

hProv

Handle to a particular key container (or "context") within the CSP. This handle is obtained via a call to CPAcquireContext.

pbData

Buffer containing the key blob. This key blob was generated by the CPExportKey function, either by this CSP or by some other CSP running on a distant computer.

This key blob consists of a standard header followed by the (often encrypted) key material.

dwDataLen

Length (in bytes) of the key blob.

hImpKey

The meaning of this parameter differs, depending on the CSP type and the type of key blob being imported.

If a signed key blob is being imported, the key is used to validate the signature of the key blob. In this case, this parameter should contain a handle to the key exchange public key of the party that created the key blob.

If the key blob is encrypted with the key exchange key pair (for example, a SIMPLEBLOB), then this parameter may be the handle to the key exchange key.

If the key blob is encrypted with a session key (as is often done by Fortezza CSPs, for example), then this parameter should contain a handle to this session key.

If the key blob is not encrypted (for example, a PUBLICKEYBLOB) , then this parameter is not used, and should be set to zero.

dwFlags

The flag values. This parameter is currently used only when a public/private key pair is being imported into the CSP (in the form of a PRIVATEKEYBLOB). In this case, if the key being imported is eventually to be re-exported, then the CRYPT_EXPORTABLE flag must be placed in this parameter. If this flag is not used then calls to CryptExportKey with the key handle will fail.

CRYPT_NO_SALT. Specifies that a no-salt value gets allocated for a 40-bit symmetric key. For more information, see Microsoft Cryptographic Providers—Release Notes.

phKey

Address to which the function copies a handle to the key that was imported.

Return Values

If the function succeeds TRUE should be returned; otherwise, return FALSE. When FALSE is returned, the appropriate error code (see the following table) must be set via SetLastError.

See Also

CPExportKey, CPGenKey, CryptImportKey