Harden wolfTPM examples fwTPM and SPDM error handling and secret zeroization

examples/attestation/make_credential.c

@@ -143,9 +143,18 @@ int TPM2_MakeCredential_Example(void* userCtx, int argc, char *argv[])
     fp = XFOPEN("ak.name", "rb");
     if (fp != XBADFILE) {
         size_t nameReadSz = XFREAD((BYTE*)&name, 1, sizeof(name), fp);
-        printf("Read AK Name digest %s\n",
-            nameReadSz == sizeof(name) ? "success" : "failed");
         XFCLOSE(fp);
+        if (nameReadSz != sizeof(name)) {
+            printf("Read AK Name digest failed\n");
+            rc = BUFFER_E;
+            goto exit;
+        }
+        printf("Read AK Name digest success\n");
+    }
+    else {
+        printf("Failed to open ak.name\n");
+        rc = BAD_FUNC_ARG;
+        goto exit;
     }
 #endif
 

examples/bench/bench.c

@@ -516,19 +516,19 @@ int TPM2_Wrapper_BenchArgs(void* userCtx, int argc, char *argv[])
     /* SHA1 */
     rc = bench_sym_hash(&dev, "SHA1", TPM_ALG_SHA1, message.buffer,
         sizeof(message.buffer), cipher.buffer, TPM_SHA_DIGEST_SIZE, maxDuration);
-    if (rc != 0 && (rc & TPM_RC_HASH) != TPM_RC_HASH) goto exit;
+    if (rc != 0 && (rc & RC_MAX_FMT1) != TPM_RC_HASH) goto exit;
     /* SHA256 */
     rc = bench_sym_hash(&dev, "SHA256", TPM_ALG_SHA256, message.buffer,
         sizeof(message.buffer), cipher.buffer, TPM_SHA256_DIGEST_SIZE, maxDuration);
-    if (rc != 0 && (rc & TPM_RC_HASH) != TPM_RC_HASH) goto exit;
+    if (rc != 0 && (rc & RC_MAX_FMT1) != TPM_RC_HASH) goto exit;
     /* SHA384 */
     rc = bench_sym_hash(&dev, "SHA384", TPM_ALG_SHA384, message.buffer,
         sizeof(message.buffer), cipher.buffer, TPM_SHA384_DIGEST_SIZE, maxDuration);
-    if (rc != 0 && (rc & TPM_RC_HASH) != TPM_RC_HASH) goto exit;
+    if (rc != 0 && (rc & RC_MAX_FMT1) != TPM_RC_HASH) goto exit;
     /* SHA512 */
     rc = bench_sym_hash(&dev, "SHA512", TPM_ALG_SHA512, message.buffer,
         sizeof(message.buffer), cipher.buffer, TPM_SHA512_DIGEST_SIZE, maxDuration);
-    if (rc != 0 && (rc & TPM_RC_HASH) != TPM_RC_HASH) goto exit;
+    if (rc != 0 && (rc & RC_MAX_FMT1) != TPM_RC_HASH) goto exit;
 
 
     /* Create RSA key for encrypt/decrypt */

examples/firmware/ifx_fw_update.c

@@ -253,6 +253,7 @@ int TPM2_IFX_Firmware_Update(void* userCtx, int argc, char *argv[])
     if (manifest_file == NULL || firmware_file == NULL) {
         if (argc > 1) {
             printf("Manifest file or firmware file arguments missing!\n");
+            rc = BAD_FUNC_ARG;
         }
         goto exit;
     }

examples/gpio/gpio_config.c

@@ -176,6 +176,7 @@ int TPM2_GPIO_Config_Example(void* userCtx, int argc, char *argv[])
 #ifdef WOLFTPM_ST33
     if (caps.mfg != TPM_MFG_STM) {
         printf("TPM vendor mismatch. GPIO support requires an ST33 TPM 2.0 module\n");
+        rc = BAD_FUNC_ARG;
         goto exit;
     }
 
@@ -263,6 +264,7 @@ int TPM2_GPIO_Config_Example(void* userCtx, int argc, char *argv[])
 
     if (caps.mfg != TPM_MFG_NUVOTON) {
         printf("TPM vendor mismatch. GPIO support requires Nuvoton NPCT7xx TPM 2.0 module\n");
+        rc = BAD_FUNC_ARG;
         goto exit;
     }
 

examples/management/flush.c

@@ -101,7 +101,7 @@ int TPM2_Flush_Tool(void* userCtx, int argc, char *argv[])
     else {
         flushCtx.flushHandle = handle;
         printf("Freeing %X object\n", handle);
-        TPM2_FlushContext(&flushCtx);
+        rc = TPM2_FlushContext(&flushCtx);
     }
 
     wolfTPM2_Cleanup(&dev);

examples/pcr/policy.c

@@ -94,7 +94,7 @@ int TPM2_PCR_Policy_Test(void* userCtx, int argc, char *argv[])
         else if (XSTRCMP(argv[argc-1], "-xor") == 0) {
             paramEncAlg = TPM_ALG_XOR;
         }
-        else if (XMEMCMP(argv[argc-1], "-digest=", XSTRLEN("-digest=")) == 0) {
+        else if (XSTRNCMP(argv[argc-1], "-digest=", XSTRLEN("-digest=")) == 0) {
             const char *digestStr, *end;
             digestStr = argv[argc-1] + XSTRLEN("-digest=");
             end = XSTRSTR(digestStr, " ");
@@ -108,13 +108,13 @@ int TPM2_PCR_Policy_Test(void* userCtx, int argc, char *argv[])
                 digestLen > sizeof(digest)*2) {
                 printf("Invalid digest! Must be 16 or 32 bytes of hex like 01020304050607080910111213141516\n");
                 usage();
-                return 0;
+                return BAD_FUNC_ARG;
             }
             hexRet = hexToByte(digestStr, digest, digestLen);
             if (hexRet < 0) {
                 printf("Invalid hex digest string\n");
                 usage();
-                return 0;
+                return BAD_FUNC_ARG;
             }
             digestLen = (word32)hexRet;
         }
@@ -124,7 +124,7 @@ int TPM2_PCR_Policy_Test(void* userCtx, int argc, char *argv[])
             if (pcrIndex < (int)PCR_FIRST || pcrIndex > (int)PCR_LAST) {
                 printf("PCR index is out of range (0-23)\n");
                 usage();
-                return 0;
+                return BAD_FUNC_ARG;
             }
         }
         else {

examples/pcr/policy_sign.c

@@ -196,17 +196,17 @@ static int PolicySign(TPM_ALG_ID alg, const char* keyFile, const char* password,
                 rc = mp_init_multi(&r, &s, NULL, NULL, NULL, NULL);
                 if (rc == 0) {
                     rc = wc_ecc_sign_hash_ex(hash, hashSz, &rng, &key.ecc, &r, &s);
-                }
-                if (rc == 0) {
-                    word32 keySz = key.ecc.dp->size;
-                    *sigSz = keySz * 2;
-                    /* Pre-zero in case mp export fails and leaves the buffer
-                     * partially written. Fixed-width export of r and s
-                     * removes the data-dependent wire offset that previously
-                     * leaked the leading-zero count. */
-                    XMEMSET(sig, 0, *sigSz);
-                    mp_to_unsigned_bin_len(&r, &sig[0], keySz);
-                    mp_to_unsigned_bin_len(&s, &sig[keySz], keySz);
+                    if (rc == 0) {
+                        word32 keySz = key.ecc.dp->size;
+                        *sigSz = keySz * 2;
+                        /* Pre-zero in case mp export fails and leaves the buffer
+                         * partially written. Fixed-width export of r and s
+                         * removes the data-dependent wire offset that previously
+                         * leaked the leading-zero count. */
+                        XMEMSET(sig, 0, *sigSz);
+                        mp_to_unsigned_bin_len(&r, &sig[0], keySz);
+                        mp_to_unsigned_bin_len(&s, &sig[keySz], keySz);
+                    }
                     mp_clear(&r);
                     mp_clear(&s);
                 }

examples/pkcs7/pkcs7.c

@@ -109,6 +109,7 @@ static int PKCS7_SignVerifyEx(WOLFTPM2_DEV* dev, int tpmDevId,
 {
     int rc;
     wc_PKCS7 pkcs7;
+    int pkcs7Init = 0;
     wc_HashAlg       hash;
     byte             hashBuf[TPM_MAX_DIGEST_SIZE];
     word32           hashSz;
@@ -155,6 +156,7 @@ static int PKCS7_SignVerifyEx(WOLFTPM2_DEV* dev, int tpmDevId,
     /* Generate and verify PKCS#7 files containing data using TPM key */
     rc = wc_PKCS7_Init(&pkcs7, NULL, tpmDevId);
     if (rc != 0) goto exit;
+    pkcs7Init = 1;
     rc = wc_PKCS7_InitWithCert(&pkcs7, derCert, derCertSz);
     if (rc != 0) goto exit;
 
@@ -177,6 +179,7 @@ static int PKCS7_SignVerifyEx(WOLFTPM2_DEV* dev, int tpmDevId,
     if (rc != 0) goto exit;
 
     wc_PKCS7_Free(&pkcs7);
+    pkcs7Init = 0;
 
     printf("PKCS7 Header %d\n", outputHeadSz);
     TPM2_PrintBin(outputHead, outputHeadSz);
@@ -232,6 +235,7 @@ static int PKCS7_SignVerifyEx(WOLFTPM2_DEV* dev, int tpmDevId,
     /* Test verify with TPM */
     rc = wc_PKCS7_Init(&pkcs7, NULL, tpmDevId);
     if (rc != 0) goto exit;
+    pkcs7Init = 1;
     rc = wc_PKCS7_InitWithCert(&pkcs7, NULL, 0);
     if (rc != 0) goto exit;
 
@@ -241,23 +245,29 @@ static int PKCS7_SignVerifyEx(WOLFTPM2_DEV* dev, int tpmDevId,
     if (rc != 0) goto exit;
 
     wc_PKCS7_Free(&pkcs7);
+    pkcs7Init = 0;
 
     printf("PKCS7 Container Verified (using TPM)\n");
 
     /* Test verify with software */
     rc = wc_PKCS7_Init(&pkcs7, NULL, INVALID_DEVID);
     if (rc != 0) goto exit;
+    pkcs7Init = 1;
     rc = wc_PKCS7_InitWithCert(&pkcs7, NULL, 0);
     if (rc != 0) goto exit;
     pkcs7.contentSz = dataChunkSz;
     rc = wc_PKCS7_VerifySignedData_ex(&pkcs7, hashBuf, hashSz,
         outputHead, outputHeadSz, outputFoot, outputFootSz);
     if (rc != 0) goto exit;
     wc_PKCS7_Free(&pkcs7);
+    pkcs7Init = 0;
 
     printf("PKCS7 Container Verified (using software)\n");
 
 exit:
+    if (pkcs7Init) {
+        wc_PKCS7_Free(&pkcs7);
+    }
     return rc;
 }
 #endif /* ENABLE_PKCS7EX_EXAMPLE */
@@ -268,6 +278,7 @@ static int PKCS7_SignVerify(WOLFTPM2_DEV* dev, int tpmDevId,
 {
     int rc;
     wc_PKCS7 pkcs7;
+    int pkcs7Init = 0;
     byte  data[] = "My encoded DER cert.";
     byte output[MAX_PKCS7_SIZE];
     int outputSz;
@@ -280,6 +291,7 @@ static int PKCS7_SignVerify(WOLFTPM2_DEV* dev, int tpmDevId,
     /* Generate and verify PKCS#7 files containing data using TPM key */
     rc = wc_PKCS7_Init(&pkcs7, NULL, tpmDevId);
     if (rc != 0) goto exit;
+    pkcs7Init = 1;
     rc = wc_PKCS7_InitWithCert(&pkcs7, derCert, derCertSz);
     if (rc != 0) goto exit;
 
@@ -296,6 +308,7 @@ static int PKCS7_SignVerify(WOLFTPM2_DEV* dev, int tpmDevId,
     rc = wc_PKCS7_EncodeSignedData(&pkcs7, output, sizeof(output));
     if (rc <= 0) goto exit;
     wc_PKCS7_Free(&pkcs7);
+    pkcs7Init = 0;
     outputSz = rc;
 
     printf("PKCS7 Signed Container %d\n", outputSz);
@@ -321,26 +334,33 @@ static int PKCS7_SignVerify(WOLFTPM2_DEV* dev, int tpmDevId,
     /* Test verify with TPM */
     rc = wc_PKCS7_Init(&pkcs7, NULL, tpmDevId);
     if (rc != 0) goto exit;
+    pkcs7Init = 1;
     rc = wc_PKCS7_InitWithCert(&pkcs7, NULL, 0);
     if (rc != 0) goto exit;
     rc = wc_PKCS7_VerifySignedData(&pkcs7, output, outputSz);
     if (rc != 0) goto exit;
     wc_PKCS7_Free(&pkcs7);
+    pkcs7Init = 0;
 
     printf("PKCS7 Container Verified (using TPM)\n");
 
     /* Test verify with software */
     rc = wc_PKCS7_Init(&pkcs7, NULL, INVALID_DEVID);
     if (rc != 0) goto exit;
+    pkcs7Init = 1;
     rc = wc_PKCS7_InitWithCert(&pkcs7, NULL, 0);
     if (rc != 0) goto exit;
     rc = wc_PKCS7_VerifySignedData(&pkcs7, output, outputSz);
     if (rc != 0) goto exit;
     wc_PKCS7_Free(&pkcs7);
+    pkcs7Init = 0;
 
     printf("PKCS7 Container Verified (using software)\n");
 
 exit:
+    if (pkcs7Init) {
+        wc_PKCS7_Free(&pkcs7);
+    }
     return rc;
 }
 

examples/wrap/caps.c

@@ -129,6 +129,7 @@ int TPM2_Wrapper_CapsArgs(void* userCtx, int argc, char *argv[])
     rc = wolfTPM2_GetHandles(PERSISTENT_FIRST, NULL);
     if (rc >= 0) {
         printf("Found %d persistent handles\n", rc);
+        rc = TPM_RC_SUCCESS;
     }
 
     /* Print the available PCR's */

examples/wrap/getrandom.c

@@ -58,6 +58,7 @@ int TPM2_GetRandom_Example(void* userCtx, int argc, char* argv[])
     byte buf[GETRANDOM_MAX_BYTES];
     word32 len = GETRANDOM_DEFAULT_BYTES;
     word32 i;
+    int lenArg;
 
     if (argc > 1) {
         if (XSTRCMP(argv[1], "-?") == 0 ||
@@ -66,7 +67,12 @@ int TPM2_GetRandom_Example(void* userCtx, int argc, char* argv[])
             usage();
             return 0;
         }
-        len = (word32)XATOI(argv[1]);
+        lenArg = XATOI(argv[1]);
+        if (lenArg < 0) {
+            printf("Invalid length %d\n", lenArg);
+            return BAD_FUNC_ARG;
+        }
+        len = (word32)lenArg;
         if (len == 0) {
             len = GETRANDOM_DEFAULT_BYTES;
         }

examples/wrap/hash.c

@@ -146,6 +146,7 @@ int TPM2_Hash_Example(void* userCtx, int argc, char* argv[])
 
 exit:
 
+    wolfTPM2_UnloadHandle(&dev, &hash.handle);
     wolfTPM2_Cleanup(&dev);
 
     return rc;

hal/tpm_io.c

@@ -183,27 +183,33 @@ int TPM2_IoCb(TPM2_CTX* ctx, INT32 isRead, UINT32 addr,
         (void)userCtx;
     #endif
 #else
-    /* Build TPM header */
-    txBuf[1] = (addr>>16) & 0xFF;
-    txBuf[2] = (addr>>8)  & 0xFF;
-    txBuf[3] = (addr)     & 0xFF;
-    if (isRead) {
-        txBuf[0] = TPM_TIS_READ | ((size & 0xFF) - 1);
-        XMEMSET(&txBuf[TPM_TIS_HEADER_SZ], 0,
-            sizeof(txBuf) - TPM_TIS_HEADER_SZ);
+    if (buf == NULL || size == 0 ||
+            size > (UINT16)(sizeof(txBuf) - TPM_TIS_HEADER_SZ)) {
+        ret = BAD_FUNC_ARG;
     }
     else {
-        txBuf[0] = TPM_TIS_WRITE | ((size & 0xFF) - 1);
-        XMEMCPY(&txBuf[TPM_TIS_HEADER_SZ], buf, size);
-        XMEMSET(&txBuf[TPM_TIS_HEADER_SZ + size], 0,
-            sizeof(txBuf) - TPM_TIS_HEADER_SZ - size);
-    }
-    XMEMSET(rxBuf, 0, sizeof(rxBuf));
-
-    ret = TPM2_IoCb_SPI(ctx, txBuf, rxBuf, size + TPM_TIS_HEADER_SZ, userCtx);
-
-    if (isRead) {
-        XMEMCPY(buf, &rxBuf[TPM_TIS_HEADER_SZ], size);
+        /* Build TPM header */
+        txBuf[1] = (addr>>16) & 0xFF;
+        txBuf[2] = (addr>>8)  & 0xFF;
+        txBuf[3] = (addr)     & 0xFF;
+        if (isRead) {
+            txBuf[0] = TPM_TIS_READ | ((size & 0xFF) - 1);
+            XMEMSET(&txBuf[TPM_TIS_HEADER_SZ], 0,
+                sizeof(txBuf) - TPM_TIS_HEADER_SZ);
+        }
+        else {
+            txBuf[0] = TPM_TIS_WRITE | ((size & 0xFF) - 1);
+            XMEMCPY(&txBuf[TPM_TIS_HEADER_SZ], buf, size);
+            XMEMSET(&txBuf[TPM_TIS_HEADER_SZ + size], 0,
+                sizeof(txBuf) - TPM_TIS_HEADER_SZ - size);
+        }
+        XMEMSET(rxBuf, 0, sizeof(rxBuf));
+
+        ret = TPM2_IoCb_SPI(ctx, txBuf, rxBuf, size + TPM_TIS_HEADER_SZ, userCtx);
+
+        if (isRead) {
+            XMEMCPY(buf, &rxBuf[TPM_TIS_HEADER_SZ], size);
+        }
     }
 #endif
 

hal/tpm_io_espressif.c

@@ -187,6 +187,7 @@ static esp_err_t show_binary(byte* theVar, size_t dataSz) {
     hex_buffer[maxSz * 2] = '\0';
     ESP_LOGI("TAG", "%s", hex_buffer);
     ESP_LOGI(TAG, "*********************************************************");
+    TPM2_ForceZero(hex_buffer, sizeof(hex_buffer));
     return ESP_OK;
 }
 #endif

src/fwtpm/fwtpm.c

@@ -40,6 +40,7 @@ int FWTPM_Init(FWTPM_CTX* ctx)
 {
     int rc;
     int rngInit = 0;
+    int wcInit = 0;
     FWTPM_NV_HAL savedNvHal;
     struct FWTPM_CLOCK_HAL_S savedClockHal;
 #ifndef FWTPM_NO_PP
@@ -96,6 +97,7 @@ int FWTPM_Init(FWTPM_CTX* ctx)
     /* Initialize wolfCrypt RNG */
     rc = wolfCrypt_Init();
     if (rc == 0) {
+        wcInit = 1;
         rc = wc_InitRng(&ctx->rng);
         if (rc == 0) {
             rngInit = 1;
@@ -141,7 +143,9 @@ int FWTPM_Init(FWTPM_CTX* ctx)
         if (rngInit) {
             wc_FreeRng(&ctx->rng);
         }
-        wolfCrypt_Cleanup();
+        if (wcInit) {
+            wolfCrypt_Cleanup();
+        }
     }
 
     return rc;