[FFmpeg-devel] [PATCH] aes: fix array index out of bounds warnings

[Reimar Döffinger]

On Sat, Jun 26, 2010 at 12:54:21AM +0100, Mans Rullgard wrote:
> ---
>  libavutil/aes.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/libavutil/aes.c b/libavutil/aes.c
> index d3a271c..763f856 100644
> --- a/libavutil/aes.c
> +++ b/libavutil/aes.c
> @@ -130,7 +130,7 @@ int av_aes_init(AVAES *a, const uint8_t *key, int key_bits, int decrypt) {
>      uint8_t  log8[256];
>      uint8_t alog8[512];
>  
> -    if(!enc_multbl[0][sizeof(enc_multbl)/sizeof(enc_multbl[0][0])-1]){
> +    if(!enc_multbl[FF_ARRAY_ELEMS(enc_multbl)-1][FF_ARRAY_ELEMS(enc_multbl[0])-1]){
>          j=1;
>          for(i=0; i<255; i++){
>              alog8[i]=
> @@ -184,7 +184,7 @@ int av_aes_init(AVAES *a, const uint8_t *key, int key_bits, int decrypt) {
>      }else{
>          for(i=0; i<(rounds+1)>>1; i++){
>              for(j=0; j<16; j++)
> -                FFSWAP(int, a->round_key[i][0][j], a->round_key[rounds-i][0][j]);
> +                FFSWAP(int, a->round_key[i][j>>2][j&3], a->round_key[rounds-i][j>>2][j&3]);

If the compilers were any good this would be the same, but last time this was checked IIRC
produced quite a lot slower code.