Fixes for `TPM2_SetupPCRSel`. Added test cases. Fixes ZD 18492

src/tpm2.c

@@ -5650,6 +5650,7 @@ int TPM2_GetName(TPM2_CTX* ctx, UINT32 handleValue, int handleCnt, int idx, TPM2
     return TPM_RC_SUCCESS;
 }
 
+/* Caller must zeroize/memset(0) pcr (TPML_PCR_SELECTION) */
 void TPM2_SetupPCRSel(TPML_PCR_SELECTION* pcr, TPM_ALG_ID alg, int pcrIndex)
 {
     int i = 0;
@@ -5662,21 +5663,35 @@ void TPM2_SetupPCRSel(TPML_PCR_SELECTION* pcr, TPM_ALG_ID alg, int pcrIndex)
         else {
             /* iterate over all banks until the alg matches */
             for (i = 0; (word32)i < pcr->count; i++) {
-                if (pcr->pcrSelections[0].hash == alg)
+                if (pcr->pcrSelections[i].hash == alg)
                     break;
             }
 
             /* if no match increase the number of banks */
-            if ((word32)i >= pcr->count)
+            if ((word32)i >= pcr->count) {
+                if (pcr->count + 1 > HASH_COUNT) {
+                #ifdef DEBUG_WOLFTPM
+                    printf("TPM2_SetupPCRSel: Hash algorithm count error\n");
+                #endif
+                    return;
+                }
                 pcr->count++;
+            }
         }
 
         pcr->pcrSelections[i].hash = alg;
         pcr->pcrSelections[i].sizeofSelect = PCR_SELECT_MAX;
-        pcr->pcrSelections[i].pcrSelect[pcrIndex >> 3] = (1 << (pcrIndex & 0x7));
+        pcr->pcrSelections[i].pcrSelect[pcrIndex >> 3] |=
+            (1 << (pcrIndex & 0x7));
     }
+#ifdef DEBUG_WOLFTPM
+    else {
+        printf("Invalid PCR Index %d\n", pcrIndex);
+    }
+#endif
 }
 
+/* Caller must zeroize/memset(0) pcr (TPML_PCR_SELECTION) */
 void TPM2_SetupPCRSelArray(TPML_PCR_SELECTION* pcr, TPM_ALG_ID alg,
     byte* pcrArray, word32 pcrArraySz)
 {

tests/unit_tests.c

@@ -241,6 +241,62 @@ static void test_wolfTPM2_GetRandom(void)
         rc == 0 ? "Passed" : "Failed");
 }
 
+static void test_TPM2_PCRSel(void)
+{
+    int rc = 0;
+    TPML_PCR_SELECTION pcr;
+    byte   pcrArray[PCR_SELECT_MAX];
+    word32 pcrArraySz;
+
+    XMEMSET(&pcr, 0, sizeof(pcr));
+    XMEMSET(pcrArray, 0, sizeof(pcrArray));
+
+    pcrArraySz = 0;
+    pcrArray[pcrArraySz++] = 1;
+    pcrArray[pcrArraySz++] = 2;
+    pcrArray[pcrArraySz++] = 3;
+    TPM2_SetupPCRSelArray(&pcr, TPM_ALG_SHA, pcrArray, pcrArraySz);
+
+    pcrArraySz = 0;
+    pcrArray[pcrArraySz++] = 4;
+    pcrArray[pcrArraySz++] = 5;
+    pcrArray[pcrArraySz++] = 6;
+    TPM2_SetupPCRSelArray(&pcr, TPM_ALG_SHA256, pcrArray, pcrArraySz);
+
+    if (pcr.count != 2 ||
+        pcr.pcrSelections[0].hash != TPM_ALG_SHA ||
+        pcr.pcrSelections[0].pcrSelect[0] != 0x0E ||
+        pcr.pcrSelections[1].hash != TPM_ALG_SHA256 ||
+        pcr.pcrSelections[1].pcrSelect[0] != 0x70
+    ) {
+        rc = BAD_FUNC_ARG;
+    }
+    AssertIntEQ(rc, 0);
+
+    /* Test bad case - invalid PCR */
+    XMEMSET(&pcr, 0, sizeof(pcr));
+    pcrArray[0] = PCR_SELECT_MAX+1;
+    TPM2_SetupPCRSelArray(&pcr, TPM_ALG_SHA256, pcrArray, 1);
+    if (pcr.count != 0) {
+        rc = BAD_FUNC_ARG;
+    }
+
+    /* Test bad case - too many hash algorithms */
+    XMEMSET(&pcr, 0, sizeof(pcr));
+    pcrArray[0] = 1;
+    TPM2_SetupPCRSelArray(&pcr, TPM_ALG_SHA, pcrArray, 1);
+    pcrArray[0] = 2;
+    TPM2_SetupPCRSelArray(&pcr, TPM_ALG_SHA256, pcrArray, 1);
+    pcrArray[0] = 3;
+    TPM2_SetupPCRSelArray(&pcr, TPM_ALG_SHA384, pcrArray, 1);
+    if (pcr.count != 2) {
+        rc = BAD_FUNC_ARG;
+    }
+
+    printf("Test TPM Wrapper:\tPCR Select Array:\t%s\n",
+        rc == 0 ? "Passed" : "Failed");
+}
+
 static void test_wolfTPM2_Cleanup(void)
 {
     int rc;
@@ -603,6 +659,7 @@ int unit_tests(int argc, char *argv[])
     test_wolfTPM2_OpenExisting();
     test_wolfTPM2_GetCapabilities();
     test_wolfTPM2_GetRandom();
+    test_TPM2_PCRSel();
     test_TPM2_KDFa();
     test_wolfTPM2_ReadPublicKey();
     test_wolfTPM2_CSR();

wolftpm/tpm2.h

@@ -3363,7 +3363,7 @@ WOLFTPM_API int TPM2_GetNonce(byte* nonceBuf, int nonceSz);
     \brief Helper function to prepare a correct PCR selection
             For example, when preparing to create a TPM2_Quote
 
-    \param pcr pointer to a structure of type TPML_PCR_SELECTION
+    \param pcr pointer to a structure of type TPML_PCR_SELECTION. Note: Caller must zeroize/memset(0)
     \param alg value of type TPM_ALG_ID specifying the type of hash algorithm used
     \param pcrIndex value between 0 and 23 specifying the PCR register for use
 
@@ -3371,7 +3371,7 @@ WOLFTPM_API int TPM2_GetNonce(byte* nonceBuf, int nonceSz);
     \code
     int pcrIndex = 16; // This is a PCR register for DEBUG & testing purposes
     PCR_Read_In pcrRead;
-
+    XMEMSET(&pcrRead, 0, sizeof(pcrRead));
     TPM2_SetupPCRSel(&pcrRead.pcrSelectionIn, TPM_ALG_SHA256, pcrIndex);
     \endcode
 
@@ -3388,17 +3388,22 @@ WOLFTPM_API void TPM2_SetupPCRSel(TPML_PCR_SELECTION* pcr, TPM_ALG_ID alg,
     \brief Helper function to prepare a correct PCR selection with multiple indices
             For example, when preparing to create a TPM2_Quote
 
-    \param pcr pointer to a structure of type TPML_PCR_SELECTION
+    \param pcr pointer to a structure of type TPML_PCR_SELECTION. Note: Caller must zeroize/memset(0)
     \param alg value of type TPM_ALG_ID specifying the type of hash algorithm used
     \param pcrArray array of values between 0 and 23 specifying the PCR register for use
-    \param pcrArrayLen length of the pcrArray
+    \param pcrArraySz length of the pcrArray
 
     _Example_
     \code
-    int pcrIndex = 16; // This is a PCR register for DEBUG & testing purposes
     PCR_Read_In pcrRead;
+    byte   pcrArray[PCR_SELECT_MAX];
+    word32 pcrArraySz = 0;
 
-    TPM2_SetupPCRSel(&pcrRead.pcrSelectionIn, TPM_ALG_SHA256, pcrIndex);
+    XMEMSET(&pcrRead, 0, sizeof(pcrRead));
+    XMEMSET(pcrArray, 0, sizeof(pcrArray));
+    pcrArray[pcrArraySz++] = 16; // This is a PCR register for DEBUG & testing purposes
+
+    TPM2_SetupPCRSelArray(&pcrRead.pcrSelectionIn, TPM_ALG_SHA256, pcrArray, pcrArraySz);
     \endcode
 
     \sa TPM2_PCR_Read
@@ -3407,7 +3412,7 @@ WOLFTPM_API void TPM2_SetupPCRSel(TPML_PCR_SELECTION* pcr, TPM_ALG_ID alg,
     \sa TPM2_Quote
 */
 WOLFTPM_API void TPM2_SetupPCRSelArray(TPML_PCR_SELECTION* pcr, TPM_ALG_ID alg,
-    byte* pcrArray, word32 pcrArrayLen);
+    byte* pcrArray, word32 pcrArraySz);
 
 /*!
     \ingroup TPM2_Proprietary