Review comment

examples/endorsement/verify_ek_cert.c

@@ -33,7 +33,7 @@
 #include <wolftpm/tpm2_asn.h>
 
 #include <stdio.h>
-
+#ifndef WOLFTPM2_NO_ASN
 #ifndef WOLFTPM2_NO_WRAPPER
 
 #include <examples/endorsement/endorsement.h>
@@ -327,19 +327,20 @@ exit:
 /* --- END TPM2.0 Endorsement certificate tool  -- */
 /******************************************************************************/
 #endif /* !WOLFTPM2_NO_WRAPPER */
+#endif /* !WOLFTPM2_NO_ASN */
 
 #ifndef NO_MAIN_DRIVER
 int main(int argc, char *argv[])
 {
     int rc = -1;
 
-#ifndef WOLFTPM2_NO_WRAPPER
+#if !defined(WOLFTPM2_NO_WRAPPER) && !defined(WOLFTPM2_NO_ASN)
     rc = TPM2_EndorsementCertVerify_Example(NULL, argc, argv);
 #else
     printf("Wrapper code not compiled in\n");
     (void)argc;
     (void)argv;
-#endif /* !WOLFTPM2_NO_WRAPPER */
+#endif /* !WOLFTPM2_NO_WRAPPER && !WOLFTPM2_NO_ASN */
 
     return rc;
 }

src/tpm2_asn.c

@@ -23,11 +23,9 @@
     #include <config.h>
 #endif
 
-#include <wolftpm/tpm2_wrap.h>
 #include <wolftpm/tpm2_asn.h>
 
 #ifndef WOLFTPM2_NO_ASN
-#ifndef WOLFTPM2_NO_WRAPPER
 
 int TPM2_ASN_GetLength_ex(const uint8_t* input, word32* inOutIdx, int* len,
                            word32 maxIdx, int check)
@@ -144,88 +142,101 @@ int TPM2_ASN_RsaDecodeSignature(uint8_t** pInput, int inputSz)
 int TPM2_ASN_DecodeX509Cert(uint8_t* input, int inputSz,
     DecodedX509* x509)
 {
-    int rc;
+    int rc = 0;
     word32 idx = 0;
     int tot_len, cert_len = 0, len, pubkey_len = 0, sig_len = 0;
 
-    if (input == NULL || x509 == NULL)
+    if (input == NULL || x509 == NULL) {
-        return TPM_RC_VALUE;
+        rc = TPM_RC_VALUE;
+    }
 
     /* Decode outer SEQUENCE */
+    if (rc == 0) {
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_SEQUENCE | TPM2_ASN_CONSTRUCTED,
                                &idx, &tot_len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
 
     /* Store certificate location */
+    if (rc == 0) {
         x509->certBegin = idx;
         x509->cert = &input[idx];
 
         /* Decode certificate SEQUENCE */
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_SEQUENCE | TPM2_ASN_CONSTRUCTED,
                                &idx, &cert_len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
 
+    if (rc == 0) {
         x509->certSz = cert_len + (idx - x509->certBegin);
 
         /* Decode version */
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_CONTEXT_SPECIFIC | TPM2_ASN_CONSTRUCTED,
                                &idx, &len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
 
-    if (input[idx] != TPM2_ASN_INTEGER || input[idx] != 1)
+    if (rc == 0) {
-        return TPM_RC_VALUE;
+        /* check version == 1 */
+        if (input[idx] != TPM2_ASN_INTEGER || input[idx] != 1) {
+            rc = TPM_RC_VALUE;
+        }
+    }
 
-    idx += len;
+    if (rc == 0) {
+        idx += len; /* skip version */
 
         /* Skip serial number */
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_INTEGER, &idx, &len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
+
-    idx += len;
+    if (rc == 0) {
+        idx += len; /* skip serial */
 
         /* Skip algorithm identifier */
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_SEQUENCE | TPM2_ASN_CONSTRUCTED,
                                &idx, &len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
+
-    idx += len;
+    if (rc == 0) {
+        idx += len; /* skip signature oid */
 
         /* Skip issuer */
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_SEQUENCE | TPM2_ASN_CONSTRUCTED,
                                &idx, &len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
+
-    idx += len;
+    if (rc == 0) {
+        idx += len; /* skip issuer */
 
         /* Skip validity */
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_SEQUENCE | TPM2_ASN_CONSTRUCTED,
                                &idx, &len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
+
-    idx += len;
+    if (rc == 0) {
+        idx += len; /* skip validity */
 
         /* Skip subject */
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_SEQUENCE | TPM2_ASN_CONSTRUCTED,
                                &idx, &len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
+
-    idx += len;
+    if (rc == 0) {
+        idx += len; /* skip subject */
 
         /* Skip subject public key info */
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_SEQUENCE | TPM2_ASN_CONSTRUCTED,
                                &idx, &len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
+
-    idx += len;
+    if (rc == 0) {
+        idx += len; /* skip subject public key info */
 
         /* Get public key */
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_BIT_STRING, &idx, &pubkey_len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
 
+    if (rc == 0) {
+        /* skip leading zero for bit string */
         if (input[idx] == 0x00) {
             idx++;
             pubkey_len--;
@@ -237,32 +248,38 @@ int TPM2_ASN_DecodeX509Cert(uint8_t* input, int inputSz,
         idx = x509->certBegin + x509->certSz;
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_SEQUENCE | TPM2_ASN_CONSTRUCTED,
                                &idx, &len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
 
+    if (rc == 0) {
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_OBJECT_ID, &idx, &len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
-    idx += len;
 
+    if (rc == 0) {
+        idx += len; /* skip oid */
+
+        /* Skip signature algorithm parameters */
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_TAG_NULL, &idx, &len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
+
-    idx += len;
+    if (rc == 0) {
+        idx += len; /* skip tag */
 
         /* Get signature */
         rc = TPM2_ASN_GetHeader(input, TPM2_ASN_BIT_STRING, &idx, &sig_len, inputSz);
-    if (rc < 0)
+    }
-        return rc;
 
+    if (rc == 0) {
+        /* skip leading zero for bit string */
         if (input[idx] == 0x00) {
             idx++;
             sig_len--;
         }
+        /* signature */
         x509->sigSz = sig_len;
         x509->signature = &input[idx];
-
+        rc = TPM_RC_SUCCESS;
-    return TPM_RC_SUCCESS;
+        }
+    return rc;
 }
 
 int TPM2_ASN_DecodeRsaPubKey(uint8_t* input, int inputSz,
@@ -330,5 +347,4 @@ int TPM2_ASN_RsaUnpadPkcsv15(uint8_t** pSig, int* sigSz)
     return rc;
 }
 
-#endif /* !WOLFTPM2_NO_WRAPPER */
 #endif /* !WOLFTPM2_NO_ASN */

wolftpm/tpm2_asn.h

@@ -26,7 +26,6 @@
 #include <wolftpm/tpm2_types.h>
 
 #ifndef WOLFTPM2_NO_ASN
-#ifndef WOLFTPM2_NO_WRAPPER
 
 #ifdef __cplusplus
     extern "C" {
@@ -144,6 +143,5 @@ WOLFTPM_API int TPM2_ASN_RsaUnpadPkcsv15(uint8_t** pSig, int* sigSz);
     }  /* extern "C" */
 #endif
 
-#endif /* !WOLFTPM2_NO_WRAPPER */
 #endif /* !WOLFTPM2_NO_ASN */
 #endif /* WOLFTPM_TPM2_ASN_H */