PPP: fix constness in PPP related files (GCC -Wcast-qual)

Signed-off-by: Dirk Ziegelmeier <dirk@ziegelmeier.net>

src/netif/ppp/polarssl/des.c

@@ -394,7 +394,7 @@ void des_setkey_dec( des_context *ctx, unsigned char key[8] )
  * DES-ECB block encryption/decryption
  */
 void des_crypt_ecb( des_context *ctx,
-                    unsigned char input[8],
+                    const unsigned char input[8],
                     unsigned char output[8] )
 {
     int i;

src/netif/ppp/polarssl/md4.c

@@ -83,7 +83,7 @@ void md4_starts( md4_context *ctx )
     ctx->state[3] = 0x10325476;
 }
 
-static void md4_process( md4_context *ctx, unsigned char data[64] )
+static void md4_process( md4_context *ctx, const unsigned char data[64] )
 {
     unsigned long X[16], A, B, C, D;
 
@@ -189,7 +189,7 @@ static void md4_process( md4_context *ctx, unsigned char data[64] )
 /*
  * MD4 process buffer
  */
-void md4_update( md4_context *ctx, unsigned char *input, int ilen )
+void md4_update( md4_context *ctx, const unsigned char *input, int ilen )
 {
     int fill;
     unsigned long left;
@@ -209,7 +209,7 @@ void md4_update( md4_context *ctx, unsigned char *input, int ilen )
     if( left && ilen >= fill )
     {
         MEMCPY( (void *) (ctx->buffer + left),
-                (void *) input, fill );
+                input, fill );
         md4_process( ctx, ctx->buffer );
         input += fill;
         ilen  -= fill;
@@ -226,7 +226,7 @@ void md4_update( md4_context *ctx, unsigned char *input, int ilen )
     if( ilen > 0 )
     {
         MEMCPY( (void *) (ctx->buffer + left),
-                (void *) input, ilen );
+                input, ilen );
     }
 }
 
@@ -257,7 +257,7 @@ void md4_finish( md4_context *ctx, unsigned char output[16] )
     last = ctx->total[0] & 0x3F;
     padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );
 
-    md4_update( ctx, (unsigned char *) md4_padding, padn );
+    md4_update( ctx, md4_padding, padn );
     md4_update( ctx, msglen, 8 );
 
     PUT_ULONG_LE( ctx->state[0], output,  0 );

src/netif/ppp/polarssl/md5.c

@@ -82,7 +82,7 @@ void md5_starts( md5_context *ctx )
     ctx->state[3] = 0x10325476;
 }
 
-static void md5_process( md5_context *ctx, unsigned char data[64] )
+static void md5_process( md5_context *ctx, const unsigned char data[64] )
 {
     unsigned long X[16], A, B, C, D;
 
@@ -208,7 +208,7 @@ static void md5_process( md5_context *ctx, unsigned char data[64] )
 /*
  * MD5 process buffer
  */
-void md5_update( md5_context *ctx, unsigned char *input, int ilen )
+void md5_update( md5_context *ctx, const unsigned char *input, int ilen )
 {
     int fill;
     unsigned long left;
@@ -228,7 +228,7 @@ void md5_update( md5_context *ctx, unsigned char *input, int ilen )
     if( left && ilen >= fill )
     {
         MEMCPY( (void *) (ctx->buffer + left),
-                (void *) input, fill );
+                input, fill );
         md5_process( ctx, ctx->buffer );
         input += fill;
         ilen  -= fill;
@@ -245,7 +245,7 @@ void md5_update( md5_context *ctx, unsigned char *input, int ilen )
     if( ilen > 0 )
     {
         MEMCPY( (void *) (ctx->buffer + left),
-                (void *) input, ilen );
+                input, ilen );
     }
 }
 
@@ -276,7 +276,7 @@ void md5_finish( md5_context *ctx, unsigned char output[16] )
     last = ctx->total[0] & 0x3F;
     padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );
 
-    md5_update( ctx, (unsigned char *) md5_padding, padn );
+    md5_update( ctx, md5_padding, padn );
     md5_update( ctx, msglen, 8 );
 
     PUT_ULONG_LE( ctx->state[0], output,  0 );

src/netif/ppp/polarssl/sha1.c

@@ -83,7 +83,7 @@ void sha1_starts( sha1_context *ctx )
     ctx->state[4] = 0xC3D2E1F0;
 }
 
-static void sha1_process( sha1_context *ctx, unsigned char data[64] )
+static void sha1_process( sha1_context *ctx, const unsigned char data[64] )
 {
     unsigned long temp, W[16], A, B, C, D, E;
 
@@ -242,7 +242,7 @@ static void sha1_process( sha1_context *ctx, unsigned char data[64] )
 /*
  * SHA-1 process buffer
  */
-void sha1_update( sha1_context *ctx, unsigned char *input, int ilen )
+void sha1_update( sha1_context *ctx, const unsigned char *input, int ilen )
 {
     int fill;
     unsigned long left;
@@ -262,7 +262,7 @@ void sha1_update( sha1_context *ctx, unsigned char *input, int ilen )
     if( left && ilen >= fill )
     {
         MEMCPY( (void *) (ctx->buffer + left),
-                (void *) input, fill );
+                input, fill );
         sha1_process( ctx, ctx->buffer );
         input += fill;
         ilen  -= fill;
@@ -279,7 +279,7 @@ void sha1_update( sha1_context *ctx, unsigned char *input, int ilen )
     if( ilen > 0 )
     {
         MEMCPY( (void *) (ctx->buffer + left),
-                (void *) input, ilen );
+                input, ilen );
     }
 }
 
@@ -310,7 +310,7 @@ void sha1_finish( sha1_context *ctx, unsigned char output[20] )
     last = ctx->total[0] & 0x3F;
     padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );
 
-    sha1_update( ctx, (unsigned char *) sha1_padding, padn );
+    sha1_update( ctx, sha1_padding, padn );
     sha1_update( ctx, msglen, 8 );
 
     PUT_ULONG_BE( ctx->state[0], output,  0 );