programs/ssl: Fixes incorrect EOF check in ssl_context_info.c

read_next_b64_code() function, that parses base64 encoded input doesn't recognize the EOF and returns when "Too many bad symbols are detected". This issue got identified when gcc complained for type-limit error during cmake. This patch fixes the issue by changing the variable type to int and removing type-cast of fgetc() output to 'char'. Signed-off-by: Nayna Jain <[email protected]>
Mbed-TLS · Aug 14, 2020 · 89cf0f3 · 89cf0f3
1 parent ee7e85f
commit 89cf0f3
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diff --git a/ChangeLog.d/bugfix_type_limit_warning_ssl_context_info.txt b/ChangeLog.d/bugfix_type_limit_warning_ssl_context_info.txt
@@ -0,0 +1,3 @@
+Bugfix
+   * read_next_b64_code() isn't correctly checking against EOF because it checks against 'char' rather than 'int'. This is identified via type-limit warning reported by gcc.
+     Reported and fix contributed by naynajain in #3449.
diff --git a/programs/ssl/ssl_context_info.c b/programs/ssl/ssl_context_info.c
@@ -379,13 +379,13 @@ size_t read_next_b64_code( uint8_t **b64, size_t *max_len )
     int valid_balance = 0;  /* balance between valid and invalid characters */
     size_t len = 0;
     char pad = 0;
-    char c = 0;
+    int c = 0;
 
     while( EOF != c )
     {
         char c_valid = 0;
 
-        c = (char) fgetc( b64_file );
+        c = fgetc( b64_file );
 
         if( pad > 0 )
         {