Copyright (C) 2006 International Business Machines Corporation
Written by Anthony Bussani based on the Trusted Computing Group Software Stack Specification Version 1.2

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1 TCG Software Stack Developer's Reference

Tspi_TPM_DAA_Sign - creates a DAA Signature that proofs ownership of the DAA Credential

 #include <tss/tss_typedef.h>  #include <tss/tss_structs.h>  #include <tss/tspi.h>  "TSS_RESULT Tspi_TPM_DAA_Sign("  " TSS_HDAA " hDAA ","  " TSS_HTPM " hTPM ","  " TSS_HKEY " hDaaCredential ","  " TSS_DAA_SELECTED_ATTRIB " revealAttributes ","  " UINT32 " verifierBaseNameLength ","  " BYTE* " verifierBaseName ","  " UINT32 " verifierNonceLength ","  " BYTE* " verifierNonce ","  " TSS_DAA_SIGN_DATA " signData ","  " TSS_DAA_SIGNATURE* " daaSignature  ");" 

\Tspi_TPM_DAA_Sign creates a DAA Signature that proofs ownership of the DAA Credential and includes a signature on either a public AIK or a message. If anonymity revocation is enabled, the value Nv is not provided in the clear anymore but encrypted under the public key of anonymity revocation authority, a trusted third party (TTP). Thus the DAA Verifier cannot check for revocation or link a transaction/signature to prior ones. Depending on how is chosen, the protocol either allows implementing anonymity revocation (i.e., using the DAA Issuer's long-term base name as the DAA Verifier's base name ), or having the TTP doing the linking of different signatures for the same DAA Verifier (i.e., using the DAA Verifier's base name ).

The hDAA parameter is used to specify the handle of the DAA object. The hTPM parameter is the handle to the TPM object. The hDaaCredential parameter is the Handle of the DAA Credential. The revealAttributes parameter is the attributes which the credential owner wants to reveal to the DAA Verifier. The verifierBaseNameLength parameter is the Length of verifierBaseName. The verifierBaseName parameter is the base name chosen by the DAA Verifier. If it equals to null, the platform chooses a random base name. The verifierNonceLength parameter is the length of verifierNonceName (20 bytes). The verifierNonce parameter is the nonce created by the DAA Verifier. The signData parameter is the handle of the received DAA Credential. The daaSignature parameter is the DAA signature containing the proof of ownership of the DAA Credential, as well as a signature on either an AIK or a message.

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

TSS_E_INVALID_HANDLE Either the DAA or the TPM handler is not valid.

TSS_E_BAD_PARAMETER

TSS_E_INTERNAL_ERROR An internal SW error has been detected.

Tspi_TPM_DAA_Sign conforms to the Trusted Computing Group Software Specification version 1.2