Vadim Bendebury | 5679752 | 2015-05-20 10:32:25 -0700 | [diff] [blame] | 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 "ContextLoad_fp.h" |
| 10 | #include "Context_spt_fp.h" |
| 11 | // |
| 12 | // |
| 13 | // Error Returns Meaning |
| 14 | // |
| 15 | // TPM_RC_CONTEXT_GAP there is only one available slot and this is not the oldest saved |
| 16 | // session context |
| 17 | // TPM_RC_HANDLE 'context. savedHandle' does not reference a saved session |
| 18 | // TPM_RC_HIERARCHY 'context.hierarchy' is disabled |
| 19 | // TPM_RC_INTEGRITY context integrity check fail |
| 20 | // TPM_RC_OBJECT_MEMORY no free slot for an object |
| 21 | // TPM_RC_SESSION_MEMORY no free session slots |
| 22 | // TPM_RC_SIZE incorrect context blob size |
| 23 | // |
| 24 | TPM_RC |
| 25 | TPM2_ContextLoad( |
| 26 | ContextLoad_In *in, // IN: input parameter list |
| 27 | ContextLoad_Out *out // OUT: output parameter list |
| 28 | ) |
| 29 | { |
| 30 | // Local Variables |
| 31 | TPM_RC result = TPM_RC_SUCCESS; |
| 32 | |
| 33 | TPM2B_DIGEST integrityToCompare; |
| 34 | TPM2B_DIGEST integrity; |
| 35 | UINT16 integritySize; |
| 36 | UINT64 fingerprint; |
| 37 | BYTE *buffer; |
| 38 | INT32 size; |
| 39 | |
| 40 | TPM_HT handleType; |
| 41 | TPM2B_SYM_KEY symKey; |
| 42 | TPM2B_IV iv; |
| 43 | |
| 44 | // Input Validation |
| 45 | |
| 46 | // Check context blob size |
| 47 | handleType = HandleGetType(in->context.savedHandle); |
| 48 | |
| 49 | // Check integrity |
| 50 | // In this implementation, the same routine is used for both sessions |
| 51 | // and objects. |
| 52 | integritySize = CryptGetHashDigestSize(CONTEXT_INTEGRITY_HASH_ALG); |
| 53 | |
| 54 | // Get integrity from context blob |
| 55 | buffer = in->context.contextBlob.t.buffer; |
| 56 | size = (INT32) in->context.contextBlob.t.size; |
| 57 | result = TPM2B_DIGEST_Unmarshal(&integrity, &buffer, &size); |
| 58 | if(result != TPM_RC_SUCCESS) |
| 59 | return result; |
| 60 | if(integrity.t.size != integritySize) |
| 61 | return TPM_RC_SIZE; |
| 62 | |
| 63 | integritySize += sizeof(integrity.t.size); |
| 64 | // |
| 65 | |
| 66 | // Compute context integrity |
| 67 | ComputeContextIntegrity(&in->context, &integrityToCompare); |
| 68 | |
| 69 | // Compare integrity |
| 70 | if(!Memory2BEqual(&integrity.b, &integrityToCompare.b)) |
| 71 | return TPM_RC_INTEGRITY + RC_ContextLoad_context; |
| 72 | |
| 73 | // Compute context encryption key |
| 74 | ComputeContextProtectionKey(&in->context, &symKey, &iv); |
| 75 | |
| 76 | // Decrypt context data in place |
| 77 | CryptSymmetricDecrypt(in->context.contextBlob.t.buffer + integritySize, |
| 78 | CONTEXT_ENCRYPT_ALG, CONTEXT_ENCRYPT_KEY_BITS, |
| 79 | TPM_ALG_CFB, symKey.t.buffer, &iv, |
| 80 | in->context.contextBlob.t.size - integritySize, |
| 81 | in->context.contextBlob.t.buffer + integritySize); |
| 82 | |
| 83 | // Read the fingerprint value, skip the leading integrity size |
| 84 | MemoryCopy(&fingerprint, in->context.contextBlob.t.buffer + integritySize, |
| 85 | sizeof(fingerprint), sizeof(fingerprint)); |
| 86 | // Check fingerprint. If the check fails, TPM should be put to failure mode |
| 87 | if(fingerprint != in->context.sequence) |
| 88 | FAIL(FATAL_ERROR_INTERNAL); |
| 89 | |
| 90 | // Perform object or session specific input check |
| 91 | switch(handleType) |
| 92 | { |
| 93 | case TPM_HT_TRANSIENT: |
| 94 | { |
| 95 | // Get a pointer to the object in the context blob |
| 96 | OBJECT *outObject = (OBJECT *)(in->context.contextBlob.t.buffer |
| 97 | + integritySize + sizeof(fingerprint)); |
| 98 | |
| 99 | // Discard any changes to the handle that the TRM might have made |
| 100 | in->context.savedHandle = TRANSIENT_FIRST; |
| 101 | |
| 102 | // If hierarchy is disabled, no object context can be loaded in this |
| 103 | // hierarchy |
| 104 | if(!HierarchyIsEnabled(in->context.hierarchy)) |
| 105 | return TPM_RC_HIERARCHY + RC_ContextLoad_context; |
| 106 | |
| 107 | // Restore object. A TPM_RC_OBJECT_MEMORY error may be returned at |
| 108 | // this point |
| 109 | result = ObjectContextLoad(outObject, &out->loadedHandle); |
| 110 | if(result != TPM_RC_SUCCESS) |
| 111 | return result; |
| 112 | |
| 113 | // If this is a sequence object, the crypto library may need to |
| 114 | // reformat the data into an internal format |
| 115 | if(ObjectIsSequence(outObject)) |
| 116 | SequenceDataImportExport(ObjectGet(out->loadedHandle), |
| 117 | outObject, IMPORT_STATE); |
| 118 | |
| 119 | break; |
| 120 | } |
| 121 | case TPM_HT_POLICY_SESSION: |
| 122 | case TPM_HT_HMAC_SESSION: |
| 123 | { |
| 124 | |
| 125 | SESSION *session = (SESSION *)(in->context.contextBlob.t.buffer |
| 126 | + integritySize + sizeof(fingerprint)); |
| 127 | |
| 128 | // This command may cause the orderlyState to be cleared due to |
| 129 | // the update of state reset data. If this is the case, check if NV is |
| 130 | // available first |
| 131 | if(gp.orderlyState != SHUTDOWN_NONE) |
| 132 | { |
| 133 | // The command needs NV update. Check if NV is available. |
| 134 | // A TPM_RC_NV_UNAVAILABLE or TPM_RC_NV_RATE error may be returned |
| 135 | // at this point |
| 136 | result = NvIsAvailable(); |
| 137 | if(result != TPM_RC_SUCCESS) |
| 138 | return result; |
| 139 | } |
| 140 | |
| 141 | // Check if input handle points to a valid saved session |
| 142 | if(!SessionIsSaved(in->context.savedHandle)) |
| 143 | return TPM_RC_HANDLE + RC_ContextLoad_context; |
| 144 | |
| 145 | // Restore session. A TPM_RC_SESSION_MEMORY, TPM_RC_CONTEXT_GAP error |
| 146 | // may be returned at this point |
| 147 | result = SessionContextLoad(session, &in->context.savedHandle); |
| 148 | if(result != TPM_RC_SUCCESS) |
| 149 | return result; |
| 150 | |
| 151 | out->loadedHandle = in->context.savedHandle; |
| 152 | |
| 153 | // orderly state should be cleared because of the update of state |
| 154 | // reset and state clear data |
| 155 | g_clearOrderly = TRUE; |
| 156 | |
| 157 | break; |
| 158 | } |
| 159 | default: |
| 160 | // Context blob may only have an object handle or a session handle. |
| 161 | // All the other handle type should be filtered out at unmarshal |
| 162 | pAssert(FALSE); |
| 163 | break; |
| 164 | } |
| 165 | |
| 166 | return TPM_RC_SUCCESS; |
| 167 | } |