NAME

CSSM_CSP_CreateDeriveKeyContext

SYNOPSIS

CSSM_CC_HANDLE CSSMAPI CSSM_CSP_CreateDeriveKeyContext
    (CSSM_CSP_HANDLE CSPHandle,
    uint32 AlgorithmID,
    CSSM_KEY_TYPE DeriveKeyType,
    uint32 DeriveKeyLengthInBits,
    uint32 IterationCount,
    const CSSM_DATA_PTR Salt,
    const CSSM_CRYPTO_DATA_PTR Seed,
    const CSSM_CRYPTO_DATA_PTR PassPhrase)

DESCRIPTION

This function creates a cryptographic context to derive a symmetric key given a handle of a CSP, an algorithm, the type of symmetric key to derive, the length of the derived key, and an optional seed or an optional passphrase from which to derive a new key. The cryptographic context handle is returned. The cryptographic context handle can be used for calling the cryptographic derive key function.

PARAMETERS

CSPHandle (input)

The handle that describes the add-in cryptographic service provider module used to perform this function. If a NULL handle is specified, CSSM returns an error.

AlgorithmID (input)

The algorithm identification number for a derived key algorithm.

DeriveKeyType (input)

The type of symmetric key to derive.

DeriveKeyLengthInBits (input)

The length of the key to derive in bits.

InterationCount (input/optional)

The number of iterations to be performed during the derivation process. Used heavily by password-based derivation methods.

Salt (input/optional)

A Salt used in deriving the key.

Seed (input/optional)

A seed used to generate a random number. The caller can either pass a seed and seed length in bytes or pass in a callback function. If NULL is passed, the cryptographic service provider will use its default seed handling mechanism.

PassPhrase (input/optional)

The passphrase is required to unlock the private key. The passphrase structure accepts an immediate value for the passphrase or the caller can specify a callback function the CSP can use to obtain the passphrase. The passphrase is needed only for signature operations, not verify operations.

RETURN VALUE

Returns a cryptographic context handle. If the handle is NULL, an error has occurred. Use CSSM_GetError to obtain the error code.

ERRORS

CSSM__INVALID_CSP_HANDLE

Invalid provider handle.

CSSM__MEMORY_ERROR

Internal memory error.

SEE ALSO

CSSM_DeriveKey