Check for overflow of outlen in blake2{s,b}_final

Fix warnings with -Wcast-qual

Fix blake2{sp,bp}_final's return value

1 files changed, 6 insertions, 3 deletions

diff --git a/ref/blake2b-ref.c b/ref/blake2b-ref.c
index a840bb8..fe27f85 100644
--- a/ref/blake2b-ref.c
+++ b/ref/blake2b-ref.c
@@ -149,7 +149,7 @@ static inline int blake2b_init0( blake2b_state *S )
 int blake2b_init_param( blake2b_state *S, const blake2b_param *P )
 {
   blake2b_init0( S );
-  uint8_t *p = ( uint8_t * )( P );
+  const uint8_t *p = ( const uint8_t * )( P );
 
   /* IV XOR ParamBlock */
   for( size_t i = 0; i < 8; ++i )
@@ -310,7 +310,10 @@ int blake2b_update( blake2b_state *S, const uint8_t *in, uint64_t inlen )
 /* Is this correct? */
 int blake2b_final( blake2b_state *S, uint8_t *out, uint8_t outlen )
 {
-  uint8_t buffer[BLAKE2B_OUTBYTES];
+  uint8_t buffer[BLAKE2B_OUTBYTES] = {0};
+
+  if( outlen > BLAKE2B_OUTBYTES )
+    return -1;
 
   if( S->buflen > BLAKE2B_BLOCKBYTES )
   {
@@ -353,7 +356,7 @@ int blake2b( uint8_t *out, const void *in, const void *key, const uint8_t outlen
     if( blake2b_init( S, outlen ) < 0 ) return -1;
   }
 
-  blake2b_update( S, ( uint8_t * )in, inlen );
+  blake2b_update( S, ( const uint8_t * )in, inlen );
   blake2b_final( S, out, outlen );
   return 0;
 }