NAME
CSSM_GenerateKey, CSP_GenerateKey — Generate a symmetric key (CDSA)
SYNOPSIS
# include <cssm.h>
API:
CSSM_RETURN CSSMAPI CSSM_GenerateKey
(CSSM_CC_HANDLE CCHandle,
uint32 KeyUsage,
uint32 KeyAttr,
const CSSM_DATA *KeyLabel,
const CSSM_RESOURCE_CONTROL_CONTEXT *CredAndAclEntry,
CSSM_KEY_PTR Key)
SPI:
CSSM_RETURN CSSMCSPI CSP_GenerateKey
(CSSM_CSP_HANDLE CSPHandle,
CSSM_CC_HANDLE CCHandle,
const CSSM_CONTEXT *Context,
uint32 KeyUsage,
uint32 KeyAttr,
const CSSM_DATA *KeyLabel,
const CSSM_RESOURCE_CONTROL_CONTEXT *CredAndAclEntry,
CSSM_KEY_PTR Key) |
LIBRARY
Common Security Services Manager library (cdsa$incssm300_shr.exe)
API PARAMETERS
| CCHandle (input) | | The handle that describes the context of this cryptographic
operation used to link to the CSP-managed information. |
| KeyUsage (input) | | A bit mask indicating all permitted uses for the
new key. |
| KeyAttr (input) | | A bit mask defining attribute values for the new
key. |
| KeyLabel (input/optional) |
| | | Pointer to a byte string that will be used as the
label for the key. |
| CredAndAclEntry (input/optional) |
| | | A structure containing one or more credentials authorized
for creating a key and the prototype ACL entry that will control
future use of the newly created key. The credentials and ACL entry
prototype can be presented as immediate values or callback functions
can be provided for use by the CSP to acquire the credentials and/or
the ACL entry interactively. If the CSP provides public access for
creating a key, then the credentials can be NULL. If the CSP defines
a default initial ACL entry for the new key, then the ACL entry
prototype can be an empty list. |
| Key (output) | | Pointer to CSSM_KEY structure used to hold the new
key. The CSSM_KEY structure should be empty upon input to this function.
The CSP will ignore any values residing in this structure at function
invocation. Input values should be supplied in the cryptographic context, KeyUsage, KeyAttr,
and KeyLabel input parameters. |
SPI PARAMETERS
| CSPHandle (input) |
| | | The handle that describes the add-in Cryptographic
Service Provider module used to perform up-calls to CSSM for the
memory functions managed by CSSM. |
| Context (input) | | Pointer to CSSM_CONTEXT structure that describes
the attributes with this context. |
| Key (output) | | Pointer to CSSM_KEY structure used to obtain the
key. Upon function invocation, any values in the CSSM_Key structure
should be ignored. All input values should be supplied in the cryptographic Context, KeyUsage, KeyAttr,
and KeyLabel input parameters. |
DESCRIPTION
This function generates a symmetric key. The KeyUsage,
and KeyAttr are used to initialize the keyheader
for the newly created key. These values are not retained in the
cryptographic Context, which contains additional parameters for
this operation. The CSP may cache keying material associated with
the new symmetric key. When the symmetric key is no longer in active
use, the application can invoke the CSSM_FreeKey() interface to allow cached keying material associated
with the symmetric key to be removed.
Authorization policy can restrict the set of callers who can
create a new resource. In this case, the caller must present a set
of access credentials for authorization. Upon successfully authenticating
the credentials, the template that verified the presented samples
identifies the ACL entry that will be used in the authorization computation.
If the caller is authorized, the new resource is created.
The caller must provide an initial ACL entry to be associated
with the newly created resource. This entry is used to control future
access to the new resource and (since the subject is deemed to be
the "Owner") exercise control over its associated ACL. The caller
can specify the following items for initializing an ACL entry:
Subject - A CSSM_LIST structure, containing
the type of the subject and a template value that can be used to
verify samples that are presented in credentials when resource access
is requested.
Delegation flag - A value indicating whether the
Subject can delegate the permissions recorded in the AuthorizationTag.
(This item only applies to public key subjects).
Authorization tag - The set of permissions that
are granted to the Subject.
Validity period - The start time and the stop time
for which the ACL entry is valid.
ACL entry tag - A user-defined string value associated
with the ACL entry.
The service provider can modify the caller-provided initial
ACL entry to conform to any innate resource-access policy that the
service provider may be required to enforce. If the initial ACL
entry provided by the caller contains values or permissions that
are not supported by the service provider, then the service provider
can modify the initial ACL appropriately or can fail the request
to create the new resource. Service providers list their supported AuthorizationTag values
in their Module Directory Services primary record.
NOTES
The KeyData field of the CSSM_KEY structure
is allocated by the CSP. The application is required to free this memory
using the CSSM_FreeKey() (CSSM API), or CSP_FreeKey() (CSP SPI), function or with the memory functions registered
for the CSPHandle.
RETURN VALUE
A CSSM_RETURN value indicating success or specifying a particular
error condition. The value CSSM_OK indicates success. All other
values represent an error condition.
ERRORS
Errors are described in the CDSA Technical Standard.
CSSMERR_CSP_KEY_LABEL_ALREADY_EXISTS |
SEE ALSO
Books
Intel CDSA Application Developer's Guide
Online Help
Functions for the CSSM API:
CSSM_GenerateRandom, CSSM_GenerateKeyPair
Functions for the CSP SPI:
CSP_GenerateRandom, CSP_GenerateKeyPair
