1// This file was extracted from the TCG Published
2// Trusted Platform Module Library
3// Part 3: Commands
4// Family "2.0"
5// Level 00 Revision 01.16
6// October 30, 2014
7
8#include "InternalRoutines.h"
9#include "NV_Extend_fp.h"
10#include "NV_spt_fp.h"
11//
12//
13//     Error Returns               Meaning
14//
15//     TPM_RC_ATTRIBUTES           the TPMA_NV_EXTEND attribute is not SET in the Index referenced
16//                                 by nvIndex
17//     TPM_RC_NV_AUTHORIZATION     the authorization was valid but the authorizing entity (authHandle) is
18//                                 not allowed to write to the Index referenced by nvIndex
19//     TPM_RC_NV_LOCKED            the Index referenced by nvIndex is locked for writing
20//
21TPM_RC
22TPM2_NV_Extend(
23   NV_Extend_In      *in            // IN: input parameter list
24   )
25{
26   TPM_RC                  result;
27   NV_INDEX                nvIndex;
28
29   TPM2B_DIGEST            oldDigest;
30   TPM2B_DIGEST            newDigest;
31   HASH_STATE              hashState;
32
33// Input Validation
34
35   // Common access checks, NvWriteAccessCheck() may return TPM_RC_NV_AUTHORIZATION
36   // or TPM_RC_NV_LOCKED
37   result = NvWriteAccessChecks(in->authHandle, in->nvIndex);
38   if(result != TPM_RC_SUCCESS)
39       return result;
40
41   // Get NV index info
42   NvGetIndexInfo(in->nvIndex, &nvIndex);
43
44   // Make sure that this is an extend index
45   if(nvIndex.publicArea.attributes.TPMA_NV_EXTEND != SET)
46       return TPM_RC_ATTRIBUTES + RC_NV_Extend_nvIndex;
47
48   // If the Index is not-orderly, or if this is the first write, NV will
49   // need to be updated.
50   if(   nvIndex.publicArea.attributes.TPMA_NV_ORDERLY == CLEAR
51      || nvIndex.publicArea.attributes.TPMA_NV_WRITTEN == CLEAR)
52   {
53       // Check if NV is available. NvIsAvailable may return TPM_RC_NV_UNAVAILABLE
54       // TPM_RC_NV_RATE or TPM_RC_SUCCESS.
55       result = NvIsAvailable();
56       if(result != TPM_RC_SUCCESS)
57           return result;
58   }
59
60// Internal Data Update
61
62   // Perform the write.
63   oldDigest.t.size = CryptGetHashDigestSize(nvIndex.publicArea.nameAlg);
64   pAssert(oldDigest.t.size <= sizeof(oldDigest.t.buffer));
65   if(nvIndex.publicArea.attributes.TPMA_NV_WRITTEN == SET)
66   {
67       NvGetIndexData(in->nvIndex, &nvIndex, 0,
68                      oldDigest.t.size, oldDigest.t.buffer);
69   }
70   else
71   {
72       MemorySet(oldDigest.t.buffer, 0, oldDigest.t.size);
73   }
74   // Start hash
75   newDigest.t.size = CryptStartHash(nvIndex.publicArea.nameAlg, &hashState);
76
77   // Adding old digest
78   CryptUpdateDigest2B(&hashState, &oldDigest.b);
79
80   // Adding new data
81   CryptUpdateDigest2B(&hashState, &in->data.b);
82
83   // Complete hash
84   CryptCompleteHash2B(&hashState, &newDigest.b);
85
86   // Write extended hash back.
87   // Note, this routine will SET the TPMA_NV_WRITTEN attribute if necessary
88   return NvWriteIndexData(in->nvIndex, &nvIndex, 0,
89                           newDigest.t.size, newDigest.t.buffer);
90}
91