fix examples/pem/ and scripts/pem.test:

examples/pem/pem.c:
* improve error messages,
* add wc_SetSeed_Cb() if WC_RNG_SEED_CB, and
* add wolfCrypt_Init() and wolfCrypt_Cleanup().

scripts/pem.test:
* fix exit code to unmask script failure,
* add configured feature detection,
* improve error messages and handling,
* add configuration gating around subtests, and
* comment out currently failing subtests.

Author: douzzer

examples/pem/pem.c

@@ -39,6 +39,8 @@
 
 #if defined(WOLFSSL_PEM_TO_DER) && !defined(NO_FILESYSTEM)
 
+static const char *progname;
+
 /* Increment allocated data by this much. */
 #define DATA_INC_LEN        256
 /* Maximum block size of a cipher. */
@@ -554,15 +556,20 @@ static int EncryptDer(unsigned char* in, word32 in_len, char* password,
         if (ret == WC_NO_ERR_TRACE(LENGTH_ONLY_E)) {
             ret = 0;
         }
-        else if (ret == 0) {
-            ret = 1;
+        else {
+            fprintf(stderr,
+                    "%s: wc_CreateEncryptedPKCS8Key() with enc_alg_id %d: "
+                    "unexpected retval: %s.\n",
+                    progname, enc_alg_id, wc_GetErrorString(ret));
+            if (ret == 0)
+                ret = 1;
         }
     }
     if (ret == 0) {
         /* Allocate memory for encrypted DER data. */
         *enc = (unsigned char*)XMALLOC(*enc_len, NULL, DYNAMIC_TYPE_TMP_BUFFER);
         if (*enc == NULL) {
-            ret = 1;
+            ret = MEMORY_E;
         }
     }
     if (ret == 0) {
@@ -749,6 +756,12 @@ int main(int argc, char* argv[])
     int log = 0;
 #endif
 
+    progname = strrchr(argv[0], '/');
+    if (progname)
+        ++progname;
+    else
+        progname = argv[0];
+
     memset(&info, 0, sizeof(info));
 
     /* Skip over program name. */
@@ -951,6 +964,22 @@ int main(int argc, char* argv[])
     }
 #endif
 
+#ifdef WC_RNG_SEED_CB
+    ret = wc_SetSeed_Cb(WC_GENERATE_SEED_DEFAULT);
+    if (ret != 0) {
+        fprintf(stderr, "%s: wc_SetSeed_Cb() failed: %s.\n",
+                progname, wc_GetErrorString(ret));
+        exit(1);
+    }
+#endif
+
+    ret = wolfCrypt_Init();
+    if (ret != 0) {
+        fprintf(stderr, "%s: wolfCrypt_Init() failed: %s.\n",
+                progname, wc_GetErrorString(ret));
+        exit(1);
+    }
+
     /* Convert PEM type string to value. */
     if (type_str != NULL) {
         ret = StringToType(type_str, &type);
@@ -1037,7 +1066,7 @@ int main(int argc, char* argv[])
         XFREE(in, NULL, DYNAMIC_TYPE_TMP_BUFFER);
     }
     if (ret < 0) {
-        fprintf(stderr, "%s\n", wc_GetErrorString(ret));
+        fprintf(stderr, "%s: %s\n", progname, wc_GetErrorString(ret));
     }
 
     if ((in_file != stdin) && (in_file != NULL))
@@ -1046,6 +1075,12 @@ int main(int argc, char* argv[])
     if ((out_file != stdout) && (out_file != NULL))
         (void)fclose(out_file);
 
+    ret = wolfCrypt_Cleanup();
+    if (ret != 0) {
+        fprintf(stderr, "%s: wolfCrypt_Cleanup() failed: %s.\n",
+                progname, wc_GetErrorString(ret));
+    }
+
     return (ret == 0) ? 0 : 1;
 }