Fix for HASH_COUNT (make sure its at least 2 by default). Fix for TPM2_GetWolfRng to ensure NULL is set on RNG init error.

Author: dgarske

src/tpm2.c

@@ -6328,6 +6328,9 @@ int TPM2_GetWolfRng(WC_RNG** rng)
             printf("wc_InitRng_ex failed %d: %s\n",
                 (int)rc, wc_GetErrorString(rc));
         #endif
+            if (rng) {
+                *rng = NULL;
+            }
             return rc;
         }
         ctx->rngInit = 1;

wolftpm/tpm2_types.h

@@ -654,39 +654,50 @@ typedef int64_t  INT64;
 #define MAX_CAP_HANDLES (MAX_CAP_DATA / sizeof(TPM_HANDLE))
 #endif
 #ifndef HASH_COUNT
-    /* Calculate hash count based on wolfCrypt enables */
-    #ifndef NO_SHA
-        #define HASH_COUNT_SHA1 1
-    #else
-        #define HASH_COUNT_SHA1 0
-    #endif
+    #ifndef WOLFTPM2_NO_WOLFCRYPT
+        /* Calculate hash count based on wolfCrypt enables */
+        #ifndef NO_SHA
+            #define HASH_COUNT_SHA1 1
+        #else
+            #define HASH_COUNT_SHA1 0
+        #endif
 
-    #ifndef NO_SHA256
-        #define HASH_COUNT_SHA256 1
-    #else
-        #define HASH_COUNT_SHA256 0
-    #endif
+        #ifndef NO_SHA256
+            #define HASH_COUNT_SHA256 1
+        #else
+            #define HASH_COUNT_SHA256 0
+        #endif
 
-    #ifdef WOLFSSL_SHA384
-        #define HASH_COUNT_SHA384 1
-    #else
-        #define HASH_COUNT_SHA384 0
-    #endif
+        #ifdef WOLFSSL_SHA384
+            #define HASH_COUNT_SHA384 1
+        #else
+            #define HASH_COUNT_SHA384 0
+        #endif
 
-    #ifdef WOLFSSL_SHA512
-        #define HASH_COUNT_SHA512 1
-    #else
-        #define HASH_COUNT_SHA512 0
-    #endif
+        #ifdef WOLFSSL_SHA512
+            #define HASH_COUNT_SHA512 1
+        #else
+            #define HASH_COUNT_SHA512 0
+        #endif
 
-    #ifdef WOLFSSL_SHA3
-        #define HASH_COUNT_SHA3 1
+        #ifdef WOLFSSL_SHA3
+            #define HASH_COUNT_SHA3 1
+        #else
+            #define HASH_COUNT_SHA3 0
+        #endif
+
+        #define HASH_COUNT (HASH_COUNT_SHA1 + HASH_COUNT_SHA256 + \
+                            HASH_COUNT_SHA384 + HASH_COUNT_SHA512 + \
+                            HASH_COUNT_SHA3)
+        /* make sure hash count is at least 2 */
+        #if HASH_COUNT < 2
+            #undef  HASH_COUNT
+            #define HASH_COUNT 2
+        #endif
     #else
-        #define HASH_COUNT_SHA3 0
+        /* default to 2 for non-wolfCrypt builds */
+        #define HASH_COUNT 2
     #endif
-
-    #define HASH_COUNT (HASH_COUNT_SHA1 + HASH_COUNT_SHA256 + \
-                        HASH_COUNT_SHA384 + HASH_COUNT_SHA512 + HASH_COUNT_SHA3)
 #endif
 #ifndef MAX_CAP_ALGS
 #define MAX_CAP_ALGS (MAX_CAP_DATA / sizeof(TPMS_ALG_PROPERTY))