[vlc-devel] [PATCH 2/2] include: strings: Add size check to vlc_hex_encode_binary

[Thomas Guillem]

On Thu, Apr 16, 2020, at 16:05, Marvin Scholz wrote:
> ---
>  include/vlc_hash.h    | 16 ++++++++--------
>  include/vlc_strings.h |  5 +++--
>  src/text/strings.c    |  6 ++++--
>  3 files changed, 15 insertions(+), 12 deletions(-)
> 
> diff --git a/include/vlc_hash.h b/include/vlc_hash.h
> index 1e7757ac58..b5136677d2 100644
> --- a/include/vlc_hash.h
> +++ b/include/vlc_hash.h
> @@ -57,14 +57,14 @@
>   * \param[out]    output Output buffer to write the string to
>   */
>  #ifndef __cplusplus
> -#define vlc_hash_FinishHex(ctx, output, size)                       \
> -    do {                                                            \
> -        char out_tmp[_Generic((ctx),                                \
> -            vlc_hash_md5_t *: VLC_HASH_MD5_DIGEST_SIZE)];           \
> -        _Generic((ctx),                                             \
> -            vlc_hash_md5_t *: vlc_hash_md5_Finish)                  \
> -        (ctx, out_tmp, sizeof(out_tmp));                            \
> -        vlc_hex_encode_binary(out_tmp, sizeof(out_tmp), output);    \
> +#define vlc_hash_FinishHex(ctx, output, size)                           \
> +    do {                                                                \
> +        char out_tmp[_Generic((ctx),                                    \
> +            vlc_hash_md5_t *: VLC_HASH_MD5_DIGEST_SIZE)];               \
> +        _Generic((ctx),                                                 \
> +            vlc_hash_md5_t *: vlc_hash_md5_Finish)                      \
> +        (ctx, out_tmp, sizeof(out_tmp));                                \
> +        vlc_hex_encode_binary(out_tmp, sizeof(out_tmp), output, size);  \
>      } while (0)
>  #endif
>  
> diff --git a/include/vlc_strings.h b/include/vlc_strings.h
> index 930d3347fb..5b4436141f 100644
> --- a/include/vlc_strings.h
> +++ b/include/vlc_strings.h
> @@ -125,10 +125,11 @@ VLC_API char *vlc_xml_encode(const char *str) 
> VLC_MALLOC;
>   * string in hexadecimal representation.
>   *
>   * \param      input    Input buffer
> - * \param      size     Input buffer size
> + * \param      in_size  Input buffer size
>   * \param[out] output   Output buffer to write the string to
> + * \param      out_size Output buffer size
>   */
> -VLC_API void vlc_hex_encode_binary(const void *input, size_t size, 
> char *output);
> +VLC_API void vlc_hex_encode_binary(const void *input, size_t in_size, 
> char *output, size_t out_size);
>  
>  /**
>   * Base64 encoding.
> diff --git a/src/text/strings.c b/src/text/strings.c
> index 9676687aae..fc0babc7ce 100644
> --- a/src/text/strings.c
> +++ b/src/text/strings.c
> @@ -347,11 +347,13 @@ char *vlc_xml_encode (const char *str)
>  }
>  
>  /* Hex encoding */
> -void vlc_hex_encode_binary(const void *input, size_t size, char *output)
> +void vlc_hex_encode_binary(const void *input, size_t in_size,
> +                           char *output, size_t out_size)
>  {
> +    assert(out_size >= in_size * 2 + 1); // 2 chars per byte + null

Missing a (void) out_size; to clear warning on builds with NDEBUG.

Otherwise, LGTM for the set.

>      const unsigned char *buffer = input;
>  
> -    for (size_t i = 0; i < size; i++) {
> +    for (size_t i = 0; i < in_size; i++) {
>          sprintf(&output[i * 2], "%02hhx", buffer[i]);
>      }
>  }
> -- 
> 2.24.1 (Apple Git-126)
> 
> _______________________________________________
> vlc-devel mailing list
> To unsubscribe or modify your subscription options:
> https://mailman.videolan.org/listinfo/vlc-devel