Re: [PATCH 12/12] backends/tpm: Use qemu_hexdump_line() to avoid sprintf()

[Stefan Berger <stefanb@linux.ibm.com>]

On 4/10/24 12:06, Philippe Mathieu-Daudé wrote:
> sprintf() is deprecated on Darwin since macOS 13.0 / XCode 14.1,
> resulting in painful developper experience.
> 
> Use qemu_hexdump_line() to avoid sprintf() calls, silencing:
> 
>    backends/tpm/tpm_util.c:357:14: warning: 'sprintf' is deprecated:
>      This function is provided for compatibility reasons only.
>      Due to security concerns inherent in the design of sprintf(3),
>      it is highly recommended that you use snprintf(3) instead.
>      [-Wdeprecated-declarations]
>          p += sprintf(p, "%.2X ", buffer[i]);
>               ^ >
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>

> ---
>   backends/tpm/tpm_util.c | 24 ++++++++----------------
>   1 file changed, 8 insertions(+), 16 deletions(-)
> 
> diff --git a/backends/tpm/tpm_util.c b/backends/tpm/tpm_util.c
> index 1856589c3b..0747af2d1c 100644
> --- a/backends/tpm/tpm_util.c
> +++ b/backends/tpm/tpm_util.c
> @@ -21,6 +21,7 @@
>   
>   #include "qemu/osdep.h"
>   #include "qemu/error-report.h"
> +#include "qemu/cutils.h"
>   #include "qapi/error.h"
>   #include "qapi/visitor.h"
>   #include "tpm_int.h"
> @@ -336,27 +337,18 @@ void tpm_sized_buffer_reset(TPMSizedBuffer *tsb)
>   void tpm_util_show_buffer(const unsigned char *buffer,
>                             size_t buffer_size, const char *string)
>   {
> -    size_t len, i;
> -    char *line_buffer, *p;
> +    size_t len;
> +    char *line, *lineup;
>   
>       if (!trace_event_get_state_backends(TRACE_TPM_UTIL_SHOW_BUFFER)) {
>           return;
>       }
>       len = MIN(tpm_cmd_get_size(buffer), buffer_size);
>   
> -    /*
> -     * allocate enough room for 3 chars per buffer entry plus a
> -     * newline after every 16 chars and a final null terminator.
> -     */
> -    line_buffer = g_malloc(len * 3 + (len / 16) + 1);
> +    line = qemu_hexdump_line(buffer, 0, len, false);
> +    lineup = g_ascii_strup(line, -1);
> +    trace_tpm_util_show_buffer(string, len, lineup);
>   
> -    for (i = 0, p = line_buffer; i < len; i++) {
> -        if (i && !(i % 16)) {
> -            p += sprintf(p, "\n");
> -        }
> -        p += sprintf(p, "%.2X ", buffer[i]);
> -    }
> -    trace_tpm_util_show_buffer(string, len, line_buffer);
> -
> -    g_free(line_buffer);
> +    g_free(line);
> +    g_free(lineup);
>   }