Fixed const-correctness issues

ChangeLog

@@ -8,6 +8,7 @@ Bugfix
    * Missing MSVC defines added
    * Compile errors with POLARSSL_RSA_NO_CRT
    * Header files with 'polarssl/'
+   * Const correctness
 
 = PolarSSL-1.3.0 released on 2013-10-01
 Features

include/polarssl/pk.h

@@ -112,7 +112,7 @@ typedef enum
 typedef struct
 {
     pk_debug_type type;
-    char *name;
+    const char *name;
     void *value;
 } pk_debug_item;
 

library/pkwrite.c

@@ -312,7 +312,7 @@ int pk_write_key_pem( pk_context *key, unsigned char *buf, size_t size )
 {
     int ret;
     unsigned char output_buf[4096];
-    char *begin, *end;
+    const char *begin, *end;
     size_t olen = 0;
 
     if( ( ret = pk_write_key_der( key, output_buf, sizeof(output_buf) ) ) < 0 )

library/x509_create.c

@@ -36,7 +36,7 @@ int x509_string_to_names( asn1_named_data **head, char *name )
     int ret = 0;
     char *s = name, *c = s;
     char *end = s + strlen( s );
-    char *oid = NULL;
+    const char *oid = NULL;
     int in_tag = 1;
     asn1_named_data *cur;