curl_schannel: Removed buffer limit and optimized buffer strategy

Since there are servers that seem to return very big encrypted
data packages, we need to be able to handle those without having
an internal size limit. To avoid the buffer growing to fast to
early the initial size was decreased and the minimum free space
in the buffer was decreased as well.

diff --git a/lib/curl_schannel.c b/lib/curl_schannel.c
index 7db5f7a0dc556e844951bf089cfc0df20e6d125b..f57dc1f4db046485362ffdab639099ec3ee306c9 100644 (file)
--- a/lib/curl_schannel.c
+++ b/lib/curl_schannel.c
@@ -284,7 +284,7 @@ schannel_connect_step2(struct connectdata *conn, int sockindex)
   CURLcode code;
   bool doread;
 
-  doread = (connssl->connecting_state != ssl_connect_2_writing)?TRUE:FALSE;
+  doread = (connssl->connecting_state != ssl_connect_2_writing) ? TRUE : FALSE;
 
   infof(data, "schannel: SSL/TLS connection with %s port %hu (step 2/3)\n",
         conn->host.name, conn->remote_port);
@@ -302,12 +302,7 @@ schannel_connect_step2(struct connectdata *conn, int sockindex)
 
   /* if we need a bigger buffer to read a full message, increase buffer now */
   if(connssl->encdata_length - connssl->encdata_offset <
-     CURL_SCHANNEL_BUFFER_MIN_SIZE) {
-    if(connssl->encdata_length >= CURL_SCHANNEL_BUFFER_MAX_SIZE) {
-      failf(data, "schannel: memory buffer size limit reached");
-      return CURLE_OUT_OF_MEMORY;
-    }
-
+     CURL_SCHANNEL_BUFFER_FREE_SIZE) {
     /* increase internal encrypted data buffer */
     connssl->encdata_length *= CURL_SCHANNEL_BUFFER_STEP_FACTOR;
     connssl->encdata_buffer = realloc(connssl->encdata_buffer,
@@ -831,13 +826,7 @@ schannel_recv(struct connectdata *conn, int sockindex,
 
   /* increase buffer in order to fit the requested amount of data */
   while(connssl->encdata_length - connssl->encdata_offset <
-        CURL_SCHANNEL_BUFFER_MIN_SIZE || connssl->encdata_length < len) {
-    if(connssl->encdata_length >= CURL_SCHANNEL_BUFFER_MAX_SIZE) {
-      failf(data, "schannel: memory buffer size limit reached");
-      *err = CURLE_OUT_OF_MEMORY;
-      return -1;
-    }
-
+        CURL_SCHANNEL_BUFFER_FREE_SIZE || connssl->encdata_length < len) {
     /* increase internal encrypted data buffer */
     connssl->encdata_length *= CURL_SCHANNEL_BUFFER_STEP_FACTOR;
     connssl->encdata_buffer = realloc(connssl->encdata_buffer,
@@ -907,16 +896,10 @@ schannel_recv(struct connectdata *conn, int sockindex,
               inbuf[1].cbBuffer);
 
         /* increase buffer in order to fit the received amount of data */
-        size = inbuf[1].cbBuffer > CURL_SCHANNEL_BUFFER_MIN_SIZE ?
-               inbuf[1].cbBuffer : CURL_SCHANNEL_BUFFER_MIN_SIZE;
+        size = inbuf[1].cbBuffer > CURL_SCHANNEL_BUFFER_FREE_SIZE ?
+               inbuf[1].cbBuffer : CURL_SCHANNEL_BUFFER_FREE_SIZE;
         while(connssl->decdata_length - connssl->decdata_offset < size ||
               connssl->decdata_length < len) {
-          if(connssl->decdata_length >= CURL_SCHANNEL_BUFFER_MAX_SIZE) {
-            failf(data, "schannel: memory buffer size limit reached");
-            *err = CURLE_OUT_OF_MEMORY;
-            return -1;
-          }
-
           /* increase internal decrypted data buffer */
           connssl->decdata_length *= CURL_SCHANNEL_BUFFER_STEP_FACTOR;
           connssl->decdata_buffer = realloc(connssl->decdata_buffer,

diff --git a/lib/curl_schannel.h b/lib/curl_schannel.h
index 909ed1857f228a9de6d21a3ad190de382f1e1fcd..37126ac7d04d9b2ef66c43ae898907f86f859bd5 100644 (file)
--- a/lib/curl_schannel.h
+++ b/lib/curl_schannel.h
@@ -93,14 +93,8 @@
 #endif
 
 
-#ifdef BUFSIZE
-#define CURL_SCHANNEL_BUFFER_INIT_SIZE  BUFSIZE
-#else
-#define CURL_SCHANNEL_BUFFER_INIT_SIZE  4096
-#endif
-
-#define CURL_SCHANNEL_BUFFER_MIN_SIZE    CURL_SCHANNEL_BUFFER_INIT_SIZE / 2
-#define CURL_SCHANNEL_BUFFER_MAX_SIZE    CURL_SCHANNEL_BUFFER_INIT_SIZE * 128
+#define CURL_SCHANNEL_BUFFER_INIT_SIZE   4096
+#define CURL_SCHANNEL_BUFFER_FREE_SIZE   1024
 #define CURL_SCHANNEL_BUFFER_STEP_FACTOR 2