Tspi_TPM_DAA_JoinCreateDaaPubKey(3)

TCG Software Stack Developer's Reference

NAME
Tspi_TPM_DAA_JoinCreateDaaPubKey - computes the credential request for the DAA Issuer

SYNOPSIS
#include <tss/tss_typedef.h>
#include <tss/tss_structs.h>
#include <tss/tspi.h>

TSS_RESULT Tspi_TPM_DAA_JoinCreateDaaPubKey(
    TSS_HDAA                    hDAA,
    TSS_HTPM                    hTPM,
    UINT32                      authenticationChallengeLength,
    BYTE*                       authenticationChallenge,
    UINT32                      nonceIssuerLength,
    BYTE*                       nonceIssuer,
    UINT32                      attributesPlatformLength,
    BYTE**                      attributesPlatform,
    TSS_DAA_JOIN_SESSION*       joinSession,
    TSS_DAA_CREDENTIAL_REQUEST* credentialRequest
);

DESCRIPTION

Tspi_TPM_DAA_JoinCreateDaaPubKey is the second (between Tspi_TPM_DAA_JoinInit() and Tspi_TPM_DAA_JoinStoreCredential())
 out of 3 functions to execute in order to receive a DAA Credential. It computes the credential request for the DAA Issuer, which also includes the Platforms's DAA public key and the attributes that were chosen by the Platform, and which are not visible to the DAA Issuer. The Platform can commit to the attribute values it has chosen.

PARAMETERS

  hDAA
The hDAA parameter is used to specify the handle of the DAA object.

  hTPM
The hTPM parameter is the handle to the TPM object.

  authenticationChallengeLength
The authenticationChallengeLength parameter is length of authenticationChallenge (256 bytes - DAA_SIZE_NE1).

  authenticationChallenge
The authenticationChallenge parameter is the second nonce of the DAA Issuer that is encrypted by the endorsement public key. It is used as a challenge to authenticate the underlying TPM.

  nonceIssuerLength
The nonceIssuerLength parameter is the length of nonceIssuer (20 bytes).

  nonceIssuer
The nonceIssuer parameter is the nonce of the DAA Issuer.

  attributesPlatformLength
The attributesPlatformLength parameter is length of attributesPlatform array, which is determined by the DAA Issuer public key (). The length of a single attribute is ln/8. ln is defined as the size of the RSA modulus (2048).

  attributesPlatform
The attributesPlatform parameter is an array of attributes to be encoded into the DAA Credential not visible to the DAA Issuer.

  joinSession
The joinSession parameter is a structure containing the DAA Join session information.

  credentialRequest
The credentialRequest parameter is the credential request of the Platform, it contains the blinded DAA public key of the platform on which the DAA Issuer will issue the credential the blinded attributes chosen by the Platform.

RETURN CODES

Tspi_TPM_DAA_JoinCreateDaaPubKey returns TSS_SUCCESS on success, otherwise one of the following values is returned:

TSS_E_INVALID_HANDLE
    Either the DAA is not valid.

TSS_E_BAD_PARAMETER

TSS_E_INTERNAL_ERROR
    An internal SW error has been detected.

CONFORMING TO

Tspi_TPM_DAA_JoinCreateDaaPubKey conforms to the Trusted Computing Group Software Specification version 1.2

SEE ALSO

Tspi_TPM_DAA_JoinInit(3) Tspi_TPM_DAA_JoinStoreCredential(3)