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 "ContextSave_fp.h" |
| 10 | #include "Context_spt_fp.h" |
| 11 | // |
| 12 | // |
| 13 | // Error Returns Meaning |
| 14 | // |
| 15 | // TPM_RC_CONTEXT_GAP a contextID could not be assigned for a session context save |
| 16 | // TPM_RC_TOO_MANY_CONTEXTS no more contexts can be saved as the counter has maxed out |
| 17 | // |
| 18 | TPM_RC |
| 19 | TPM2_ContextSave( |
| 20 | ContextSave_In *in, // IN: input parameter list |
| 21 | ContextSave_Out *out // OUT: output parameter list |
| 22 | ) |
| 23 | { |
| 24 | TPM_RC result; |
| 25 | UINT16 fingerprintSize; // The size of fingerprint in context |
| 26 | // blob. |
| 27 | UINT64 contextID = 0; // session context ID |
| 28 | TPM2B_SYM_KEY symKey; |
| 29 | TPM2B_IV iv; |
| 30 | |
| 31 | TPM2B_DIGEST integrity; |
| 32 | UINT16 integritySize; |
| 33 | BYTE *buffer; |
Jocelyn Bohr | 32be404 | 2015-07-29 15:14:01 -0700 | [diff] [blame] | 34 | INT32 bufferSize; |
Vadim Bendebury | 5679752 | 2015-05-20 10:32:25 -0700 | [diff] [blame] | 35 | |
| 36 | // This command may cause the orderlyState to be cleared due to |
| 37 | // the update of state reset data. If this is the case, check if NV is |
| 38 | // available first |
| 39 | if(gp.orderlyState != SHUTDOWN_NONE) |
| 40 | { |
| 41 | // The command needs NV update. Check if NV is available. |
| 42 | // A TPM_RC_NV_UNAVAILABLE or TPM_RC_NV_RATE error may be returned at |
| 43 | // this point |
| 44 | result = NvIsAvailable(); |
| 45 | if(result != TPM_RC_SUCCESS) return result; |
| 46 | } |
| 47 | |
| 48 | // Internal Data Update |
| 49 | |
| 50 | // Initialize output handle. At the end of command action, the output |
| 51 | // handle of an object will be replaced, while the output handle |
| 52 | // for a session will be the same as input |
| 53 | out->context.savedHandle = in->saveHandle; |
| 54 | |
| 55 | // Get the size of fingerprint in context blob. The sequence value in |
| 56 | // TPMS_CONTEXT structure is used as the fingerprint |
| 57 | fingerprintSize = sizeof(out->context.sequence); |
| 58 | |
| 59 | // Compute the integrity size at the beginning of context blob |
| 60 | integritySize = sizeof(integrity.t.size) |
| 61 | + CryptGetHashDigestSize(CONTEXT_INTEGRITY_HASH_ALG); |
| 62 | |
| 63 | // Perform object or session specific context save |
| 64 | switch(HandleGetType(in->saveHandle)) |
| 65 | { |
| 66 | case TPM_HT_TRANSIENT: |
| 67 | { |
| 68 | OBJECT *object = ObjectGet(in->saveHandle); |
| 69 | OBJECT *outObject = |
| 70 | (OBJECT *)(out->context.contextBlob.t.buffer |
| 71 | + integritySize + fingerprintSize); |
| 72 | |
| 73 | // Set size of the context data. The contents of context blob is vendor |
| 74 | // defined. In this implementation, the size is size of integrity |
| 75 | // plus fingerprint plus the whole internal OBJECT structure |
| 76 | out->context.contextBlob.t.size = integritySize + |
| 77 | fingerprintSize + sizeof(OBJECT); |
| 78 | // Make sure things fit |
| 79 | pAssert(out->context.contextBlob.t.size |
| 80 | < sizeof(out->context.contextBlob.t.buffer)); |
| 81 | |
| 82 | // Copy the whole internal OBJECT structure to context blob, leave |
| 83 | // the size for fingerprint |
| 84 | *outObject = *object; |
| 85 | |
| 86 | // Increment object context ID |
| 87 | gr.objectContextID++; |
| 88 | // If object context ID overflows, TPM should be put in failure mode |
| 89 | if(gr.objectContextID == 0) |
| 90 | FAIL(FATAL_ERROR_INTERNAL); |
| 91 | |
| 92 | // Fill in other return values for an object. |
| 93 | out->context.sequence = gr.objectContextID; |
| 94 | // For regular object, savedHandle is 0x80000000. For sequence object, |
| 95 | // savedHandle is 0x80000001. For object with stClear, savedHandle |
| 96 | // is 0x80000002 |
| 97 | if(ObjectIsSequence(object)) |
| 98 | { |
| 99 | out->context.savedHandle = 0x80000001; |
| 100 | SequenceDataImportExport(object, outObject, EXPORT_STATE); |
| 101 | } |
| 102 | else if(object->attributes.stClear == SET) |
| 103 | { |
| 104 | out->context.savedHandle = 0x80000002; |
| 105 | } |
| 106 | else |
| 107 | { |
| 108 | out->context.savedHandle = 0x80000000; |
| 109 | } |
| 110 | |
| 111 | // Get object hierarchy |
| 112 | out->context.hierarchy = ObjectDataGetHierarchy(object); |
| 113 | |
| 114 | break; |
| 115 | } |
| 116 | case TPM_HT_HMAC_SESSION: |
| 117 | case TPM_HT_POLICY_SESSION: |
| 118 | { |
| 119 | SESSION *session = SessionGet(in->saveHandle); |
| 120 | |
| 121 | // Set size of the context data. The contents of context blob is vendor |
| 122 | // defined. In this implementation, the size of context blob is the |
| 123 | // size of a internal session structure plus the size of |
| 124 | // fingerprint plus the size of integrity |
| 125 | out->context.contextBlob.t.size = integritySize + |
| 126 | fingerprintSize + sizeof(*session); |
| 127 | |
| 128 | // Make sure things fit |
| 129 | pAssert(out->context.contextBlob.t.size |
| 130 | < sizeof(out->context.contextBlob.t.buffer)); |
| 131 | |
| 132 | // Copy the whole internal SESSION structure to context blob. |
| 133 | // Save space for fingerprint at the beginning of the buffer |
| 134 | // This is done before anything else so that the actual context |
| 135 | // can be reclaimed after this call |
| 136 | MemoryCopy(out->context.contextBlob.t.buffer |
| 137 | + integritySize + fingerprintSize, |
| 138 | session, sizeof(*session), |
| 139 | sizeof(out->context.contextBlob.t.buffer) |
| 140 | - integritySize - fingerprintSize); |
| 141 | |
| 142 | // Fill in the other return parameters for a session |
| 143 | // Get a context ID and set the session tracking values appropriately |
| 144 | // TPM_RC_CONTEXT_GAP is a possible error. |
| 145 | // SessionContextSave() will flush the in-memory context |
| 146 | // so no additional errors may occur after this call. |
| 147 | result = SessionContextSave(out->context.savedHandle, &contextID); |
| 148 | if(result != TPM_RC_SUCCESS) return result; |
| 149 | |
| 150 | // sequence number is the current session contextID |
| 151 | out->context.sequence = contextID; |
| 152 | |
| 153 | // use TPM_RH_NULL as hierarchy for session context |
| 154 | out->context.hierarchy = TPM_RH_NULL; |
| 155 | |
| 156 | break; |
| 157 | } |
| 158 | default: |
| 159 | // SaveContext may only take an object handle or a session handle. |
| 160 | // All the other handle type should be filtered out at unmarshal |
| 161 | pAssert(FALSE); |
| 162 | break; |
| 163 | } |
| 164 | |
| 165 | // Save fingerprint at the beginning of encrypted area of context blob. |
| 166 | // Reserve the integrity space |
| 167 | MemoryCopy(out->context.contextBlob.t.buffer + integritySize, |
| 168 | &out->context.sequence, sizeof(out->context.sequence), |
| 169 | sizeof(out->context.contextBlob.t.buffer) - integritySize); |
| 170 | |
| 171 | // Compute context encryption key |
| 172 | ComputeContextProtectionKey(&out->context, &symKey, &iv); |
| 173 | |
| 174 | // Encrypt context blob |
| 175 | CryptSymmetricEncrypt(out->context.contextBlob.t.buffer + integritySize, |
| 176 | CONTEXT_ENCRYPT_ALG, CONTEXT_ENCRYPT_KEY_BITS, |
| 177 | TPM_ALG_CFB, symKey.t.buffer, &iv, |
| 178 | out->context.contextBlob.t.size - integritySize, |
| 179 | out->context.contextBlob.t.buffer + integritySize); |
| 180 | |
| 181 | // Compute integrity hash for the object |
| 182 | // In this implementation, the same routine is used for both sessions |
| 183 | // and objects. |
| 184 | ComputeContextIntegrity(&out->context, &integrity); |
| 185 | |
| 186 | // add integrity at the beginning of context blob |
| 187 | buffer = out->context.contextBlob.t.buffer; |
Jocelyn Bohr | 5aac585 | 2015-08-20 16:05:05 -0700 | [diff] [blame] | 188 | bufferSize = sizeof(TPM2B_DIGEST); |
Jocelyn Bohr | 32be404 | 2015-07-29 15:14:01 -0700 | [diff] [blame] | 189 | TPM2B_DIGEST_Marshal(&integrity, &buffer, &bufferSize); |
Vadim Bendebury | 5679752 | 2015-05-20 10:32:25 -0700 | [diff] [blame] | 190 | |
| 191 | // orderly state should be cleared because of the update of state reset and |
| 192 | // state clear data |
| 193 | g_clearOrderly = TRUE; |
| 194 | |
| 195 | return TPM_RC_SUCCESS; |
| 196 | } |