escl : fix tls/ssl connection

backend/escl/escl.c

@@ -61,25 +61,6 @@ static const SANE_Device **devlist = NULL;
 static ESCL_Device *list_devices_primary = NULL;
 static int num_devices = 0;
 
-#ifdef CURL_SSLVERSION_MAX_DEFAULT
-static int proto_tls[] = {
-        CURL_SSLVERSION_MAX_DEFAULT,
-   #ifdef CURL_SSLVERSION_MAX_TLSv1_3
-        CURL_SSLVERSION_MAX_TLSv1_3,
-   #endif
-   #ifdef CURL_SSLVERSION_MAX_TLSv1_2
-        CURL_SSLVERSION_MAX_TLSv1_2,
-   #endif
-   #ifdef CURL_SSLVERSION_MAX_TLSv1_1
-        CURL_SSLVERSION_MAX_TLSv1_1,
-   #endif
-   #ifdef CURL_SSLVERSION_MAX_TLSv1_0
-        CURL_SSLVERSION_MAX_TLSv1_0,
-   #endif
-        -1
-};
-#endif
-
 
 typedef struct Handled {
     struct Handled *next;
@@ -120,17 +101,15 @@ escl_free_device(ESCL_Device *current)
 }
 
 
-#ifdef CURL_SSLVERSION_MAX_DEFAULT
 static int
-escl_tls_protocol_supported(char *url, int proto)
+escl_tls_protocol_supported(char *url)
 {
    CURLcode res = CURLE_UNSUPPORTED_PROTOCOL;
    CURL *curl = curl_easy_init();
    if(curl) {
       curl_easy_setopt(curl, CURLOPT_URL, url);
 
-      /* ask libcurl to use TLS version 1.0 or later */
-      curl_easy_setopt(curl, CURLOPT_SSLVERSION, proto);
+      curl_easy_setopt(curl, CURLOPT_USE_SSL, (long)CURLUSESSL_TRY);
       curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
       curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
       curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
@@ -145,33 +124,17 @@ escl_tls_protocol_supported(char *url, int proto)
 static int
 escl_is_tls(char * url, char *type)
 {
-    int tls_version = 0;
     if(!strcmp(type, "_uscans._tcp") ||
        !strcmp(type, "https"))
       {
-         while(proto_tls[tls_version] != -1)
-          {
-                if (escl_tls_protocol_supported(url, proto_tls[tls_version]) == CURLE_OK)
+                if (escl_tls_protocol_supported(url) == CURLE_OK)
                 {
-                        DBG(10, "curl tls compatible (%d)\n", proto_tls[tls_version]);
-                        break;
+                        DBG(10, "curl tls compatible\n");
+                        return 1;
                 }
-                tls_version++;
-          }
-         if (proto_tls[tls_version] < 1)
-            return 0;
       }
-      return proto_tls[tls_version];
-}
-#else
-static int
-escl_is_tls(char * url, char *type)
-{
-    (void)url;
-    (void)type;
     return 0;
 }
-#endif
 
 void
 escl_free_handler(escl_sane_t *handler)
@@ -1899,10 +1862,9 @@ escl_curl_url(CURL *handle, const ESCL_Device *device, SANE_String_Const path)
     DBG( 10, "After use hack\n");
     if (device->https) {
         DBG( 10, "Ignoring safety certificates, use https\n");
+        curl_easy_setopt(handle, CURLOPT_USE_SSL, (long)CURLUSESSL_TRY);
         curl_easy_setopt(handle, CURLOPT_SSL_VERIFYPEER, 0L);
         curl_easy_setopt(handle, CURLOPT_SSL_VERIFYHOST, 0L);
-        if (device->tls > 0)
-           curl_easy_setopt(handle, CURLOPT_SSLVERSION, device->tls);
     }
     if (device->unix_socket != NULL) {
         DBG( 10, "Using local socket %s\n", device->unix_socket );