1 /* Microsoft Reference Implementation for TPM 2.0
2  *
3  *  The copyright in this software is being made available under the BSD License,
4  *  included below. This software may be subject to other third party and
5  *  contributor rights, including patent rights, and no such rights are granted
6  *  under this license.
7  *
8  *  Copyright (c) Microsoft Corporation
9  *
10  *  All rights reserved.
11  *
12  *  BSD License
13  *
14  *  Redistribution and use in source and binary forms, with or without modification,
15  *  are permitted provided that the following conditions are met:
16  *
17  *  Redistributions of source code must retain the above copyright notice, this list
18  *  of conditions and the following disclaimer.
19  *
20  *  Redistributions in binary form must reproduce the above copyright notice, this
21  *  list of conditions and the following disclaimer in the documentation and/or
22  *  other materials provided with the distribution.
23  *
24  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ""AS IS""
25  *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
27  *  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
28  *  ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
29  *  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30  *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
31  *  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 //
37 // Platform Endorsement Primary Seed
38 //
39 
40 #include "TpmError.h"
41 #include "Admin.h"
42 
43 #include <tee_internal_api.h>
44 #include <tee_internal_api_extensions.h>
45 
46 #define TEE_EPS_SIZE      (256/2)   // From TPM2B_RSA_TEST_PRIME in Hierarchy.c
47 
48 void
_plat__GetEPS(UINT16 Size,uint8_t * EndorsementSeed)49 _plat__GetEPS(UINT16 Size, uint8_t *EndorsementSeed)
50 {
51     TEE_Result Result = TEE_ERROR_ITEM_NOT_FOUND;
52     uint8_t EPS[TEE_EPS_SIZE] = { 0 };
53     size_t EPSLen;
54 
55     IMSG("Size=%" PRIu16 "",Size);
56     IMSG("EPS=%d",TEE_EPS_SIZE);
57 
58     pAssert(Size <= (TEE_EPS_SIZE));
59 
60     Result = TEE_GetPropertyAsBinaryBlock(TEE_PROPSET_CURRENT_TA,
61                                           "com.microsoft.ta.endorsementSeed",
62                                           EPS,
63                                           &EPSLen);
64 
65     if ((EPSLen < Size) || (Result != TEE_SUCCESS)) {
66         // We failed to access the property. We can't continue without it
67         // and we can't just fail to manufacture, so randomize EPS and
68         // continue. If necessary, fTPM TA storage can be cleared, or the
69         // TA updated, and we can trigger remanufacture and try again.
70         _plat__GetEntropy(EndorsementSeed, TEE_EPS_SIZE);
71         return;
72     }
73 
74     memcpy(EndorsementSeed, EPS, Size);
75 
76 #ifdef fTPMDebug
77     {
78         uint32_t x;
79         uint8_t *seed = EndorsementSeed;
80         DMSG("TEE_GetProperty 0x%x, seedLen 0x%x\n", Result, Size);
81         for (x = 0; x < Size; x = x + 8) {
82             DMSG(" seed(%2.2d): %2.2x,%2.2x,%2.2x,%2.2x,%2.2x,%2.2x,%2.2x,%2.2x\n", x,
83                 seed[x + 0], seed[x + 1], seed[x + 2], seed[x + 3],
84                 seed[x + 4], seed[x + 5], seed[x + 6], seed[x + 7]);
85         }
86     }
87 #endif
88 
89     return;
90 }
91