Code review feedback: Add documentation, minor test improvements

Author: kareem-wolfssl

doc/dox_comments/header_files/ssl.h

@@ -7245,6 +7245,11 @@ int wolfSSL_want(WOLFSSL* ssl);
     the list of checks to perform.  dn holds the domain name to check
     against the peer certificate when it’s received.
 
+    dn must be a fully qualified domain name or "localhost", otherwise
+    SSL_FAILURE is returned.  To also accept single-label names such as
+    "intranet", as issued by some private PKIs, build wolfSSL with
+    WOLFSSL_ALLOW_SINGLE_LABEL_HOSTNAME defined.
+
     \return SSL_SUCCESS upon success.
     \return SSL_FAILURE will be returned if a memory error was encountered.
 

tests/api/test_ossl_x509.c

@@ -1778,7 +1778,7 @@ int test_wolfssl_local_IsValidFQDN(void) {
         {"com",                          SINGLE_LABEL_OK}, /* single label */
         {"123.456",                      0},   /* all-numeric final label (no alpha) */
         {"example.123",                  0},   /* all-numeric TLD (no alpha) */
-        {"a",                            SINGLE_LABEL_OK}, /* single label, too short */
+        {"a",                            SINGLE_LABEL_OK}, /* single label, one character */
         {"example.123a",                 1},   /* TLD with at least one letter -- valid */
     };
 

tests/api/test_tls.c

@@ -717,6 +717,8 @@ static int test_single_label_host(const char* name, int expectRet,
         WOLFSSL_SUCCESS);
     ExpectIntEQ(wolfSSL_use_certificate_file(ssl_s, cert,
         WOLFSSL_FILETYPE_PEM), WOLFSSL_SUCCESS);
+    ExpectIntEQ(wolfSSL_use_PrivateKey_file(ssl_s, svrKeyFile,
+        WOLFSSL_FILETYPE_PEM), WOLFSSL_SUCCESS);
     wolfSSL_set_verify(ssl_c, WOLFSSL_VERIFY_PEER, NULL);
 
     ExpectIntEQ(wolfSSL_check_domain_name(ssl_c, name), expectRet);