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Diffstat (limited to 'src/tpm2/Attest_spt.c')
| -rw-r--r-- | src/tpm2/Attest_spt.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/src/tpm2/Attest_spt.c b/src/tpm2/Attest_spt.c new file mode 100644 index 0000000..0b8d29c --- /dev/null +++ b/src/tpm2/Attest_spt.c @@ -0,0 +1,209 @@ +/********************************************************************************/ +/* */ +/* */ +/* Written by Ken Goldman */ +/* IBM Thomas J. Watson Research Center */ +/* $Id: Attest_spt.c 1490 2019-07-26 21:13:22Z kgoldman $ */ +/* */ +/* Licenses and Notices */ +/* */ +/* 1. Copyright Licenses: */ +/* */ +/* - Trusted Computing Group (TCG) grants to the user of the source code in */ +/* this specification (the "Source Code") a worldwide, irrevocable, */ +/* nonexclusive, royalty free, copyright license to reproduce, create */ +/* derivative works, distribute, display and perform the Source Code and */ +/* derivative works thereof, and to grant others the rights granted herein. */ +/* */ +/* - The TCG grants to the user of the other parts of the specification */ +/* (other than the Source Code) the rights to reproduce, distribute, */ +/* display, and perform the specification solely for the purpose of */ +/* developing products based on such documents. */ +/* */ +/* 2. Source Code Distribution Conditions: */ +/* */ +/* - Redistributions of Source Code must retain the above copyright licenses, */ +/* this list of conditions and the following disclaimers. */ +/* */ +/* - Redistributions in binary form must reproduce the above copyright */ +/* licenses, this list of conditions and the following disclaimers in the */ +/* documentation and/or other materials provided with the distribution. */ +/* */ +/* 3. Disclaimers: */ +/* */ +/* - THE COPYRIGHT LICENSES SET FORTH ABOVE DO NOT REPRESENT ANY FORM OF */ +/* LICENSE OR WAIVER, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, WITH */ +/* RESPECT TO PATENT RIGHTS HELD BY TCG MEMBERS (OR OTHER THIRD PARTIES) */ +/* THAT MAY BE NECESSARY TO IMPLEMENT THIS SPECIFICATION OR OTHERWISE. */ +/* Contact TCG Administration (admin@trustedcomputinggroup.org) for */ +/* information on specification licensing rights available through TCG */ +/* membership agreements. */ +/* */ +/* - THIS SPECIFICATION IS PROVIDED "AS IS" WITH NO EXPRESS OR IMPLIED */ +/* WARRANTIES WHATSOEVER, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR */ +/* FITNESS FOR A PARTICULAR PURPOSE, ACCURACY, COMPLETENESS, OR */ +/* NONINFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS, OR ANY WARRANTY */ +/* OTHERWISE ARISING OUT OF ANY PROPOSAL, SPECIFICATION OR SAMPLE. */ +/* */ +/* - Without limitation, TCG and its members and licensors disclaim all */ +/* liability, including liability for infringement of any proprietary */ +/* rights, relating to use of information in this specification and to the */ +/* implementation of this specification, and TCG disclaims all liability for */ +/* cost of procurement of substitute goods or services, lost profits, loss */ +/* of use, loss of data or any incidental, consequential, direct, indirect, */ +/* or special damages, whether under contract, tort, warranty or otherwise, */ +/* arising in any way out of use or reliance upon this specification or any */ +/* information herein. */ +/* */ +/* (c) Copyright IBM Corp. and others, 2016 - 2018 */ +/* */ +/********************************************************************************/ + +#include "Tpm.h" +#include "Attest_spt_fp.h" +/* 7.2.2 Functions */ +/* 7.2.2.1 FillInAttestInfo() */ +/* Fill in common fields of TPMS_ATTEST structure. */ +void +FillInAttestInfo( + TPMI_DH_OBJECT signHandle, // IN: handle of signing object + TPMT_SIG_SCHEME *scheme, // IN/OUT: scheme to be used for signing + TPM2B_DATA *data, // IN: qualifying data + TPMS_ATTEST *attest // OUT: attest structure + ) +{ + OBJECT *signObject = HandleToObject(signHandle); + // Magic number + attest->magic = TPM_GENERATED_VALUE; + if(signObject == NULL) + { + // The name for a null handle is TPM_RH_NULL + // This is defined because UINT32_TO_BYTE_ARRAY does a cast. If the + // size of the cast is smaller than a constant, the compiler warns + // about the truncation of a constant value. + TPM_HANDLE nullHandle = TPM_RH_NULL; + attest->qualifiedSigner.t.size = sizeof(TPM_HANDLE); + UINT32_TO_BYTE_ARRAY(nullHandle, attest->qualifiedSigner.t.name); + } + else + { + // Certifying object qualified name + // if the scheme is anonymous, this is an empty buffer + if(CryptIsSchemeAnonymous(scheme->scheme)) + attest->qualifiedSigner.t.size = 0; + else + attest->qualifiedSigner = signObject->qualifiedName; + } + // current clock in plain text + TimeFillInfo(&attest->clockInfo); + // Firmware version in plain text + attest->firmwareVersion = ((UINT64)gp.firmwareV1 << (sizeof(UINT32) * 8)); + attest->firmwareVersion += gp.firmwareV2; + // Check the hierarchy of sign object. For NULL sign handle, the hierarchy + // will be TPM_RH_NULL + if((signObject == NULL) + || (!signObject->attributes.epsHierarchy + && !signObject->attributes.ppsHierarchy)) + { + // For signing key that is not in platform or endorsement hierarchy, + // obfuscate the reset, restart and firmware version information + UINT64 obfuscation[2]; + CryptKDFa(CONTEXT_INTEGRITY_HASH_ALG, &gp.shProof.b, OBFUSCATE_STRING, + &attest->qualifiedSigner.b, NULL, 128, + (BYTE *)&obfuscation[0], NULL, FALSE); + // Obfuscate data + attest->firmwareVersion += obfuscation[0]; + attest->clockInfo.resetCount += (UINT32)(obfuscation[1] >> 32); + attest->clockInfo.restartCount += (UINT32)obfuscation[1]; + } + // External data + if(CryptIsSchemeAnonymous(scheme->scheme)) + attest->extraData.t.size = 0; + else + { + // If we move the data to the attestation structure, then it is not + // used in the signing operation except as part of the signed data + attest->extraData = *data; + data->t.size = 0; + } +} +/* 7.2.2.2 SignAttestInfo() */ +/* Sign a TPMS_ATTEST structure. If signHandle is TPM_RH_NULL, a null signature is returned. */ +/* Error Returns Meaning */ +/* TPM_RC_ATTRIBUTES signHandle references not a signing key */ +/* TPM_RC_SCHEME scheme is not compatible with signHandle type */ +/* TPM_RC_VALUE digest generated for the given scheme is greater than the modulus of signHandle (for + an RSA key); invalid commit status or failed to generate r value (for an ECC key) */ +TPM_RC +SignAttestInfo( + OBJECT *signKey, // IN: sign object + TPMT_SIG_SCHEME *scheme, // IN: sign scheme + TPMS_ATTEST *certifyInfo, // IN: the data to be signed + TPM2B_DATA *qualifyingData, // IN: extra data for the signing + // process + TPM2B_ATTEST *attest, // OUT: marshaled attest blob to be + // signed + TPMT_SIGNATURE *signature // OUT: signature + ) +{ + BYTE *buffer; + HASH_STATE hashState; + TPM2B_DIGEST digest; + TPM_RC result; + // Marshal TPMS_ATTEST structure for hash + buffer = attest->t.attestationData; + attest->t.size = TPMS_ATTEST_Marshal(certifyInfo, &buffer, NULL); + if(signKey == NULL) + { + signature->sigAlg = TPM_ALG_NULL; + result = TPM_RC_SUCCESS; + } + else + { + TPMI_ALG_HASH hashAlg; + // Compute hash + hashAlg = scheme->details.any.hashAlg; + // need to set the receive buffer to get something put in it + digest.t.size = sizeof(digest.t.buffer); + digest.t.size = CryptHashBlock(hashAlg, attest->t.size, + attest->t.attestationData, + digest.t.size, digest.t.buffer); + // If there is qualifying data, need to rehash the data + // hash(qualifyingData || hash(attestationData)) + if(qualifyingData->t.size != 0) + { + CryptHashStart(&hashState, hashAlg); + CryptDigestUpdate2B(&hashState, &qualifyingData->b); + CryptDigestUpdate2B(&hashState, &digest.b); + CryptHashEnd2B(&hashState, &digest.b); + } + // Sign the hash. A TPM_RC_VALUE, TPM_RC_SCHEME, or + // TPM_RC_ATTRIBUTES error may be returned at this point + result = CryptSign(signKey, scheme, &digest, signature); + // Since the clock is used in an attestation, the state in NV is no longer + // "orderly" with respect to the data in RAM if the signature is valid + if(result == TPM_RC_SUCCESS) + { + // Command uses the clock so need to clear the orderly state if it is + // set. + result = NvClearOrderly(); + } + } + return result; +} +/* 7.2.2.3 IsSigningObject() */ +/* Checks to see if the object is OK for signing. This is here rather than in Object_spt.c because + all the attestation commands use this file but not Object_spt.c. */ +/* Return Values Meaning */ +/* TRUE object may sign */ +/* FALSE object may not sign */ +BOOL +IsSigningObject( + OBJECT *object // IN: + ) +{ + return ((object == NULL) + || ((IS_ATTRIBUTE(object->publicArea.objectAttributes, TPMA_OBJECT, sign) + && object->publicArea.type != TPM_ALG_SYMCIPHER))); +} + |