[Spice-devel] [PATCH spice-common 1/2] Use a single copy of subject string

[Christophe Fergeau]

On Thu, Dec 13, 2018 at 02:20:24PM +0000, Frediano Ziglio wrote:
> A full copy can keep both the key and the value instead of
> allocating twice the memory.
> Also this remove a warning produced by Coverity that is assuming
> that allocating strlen(string_variable) is wrong.

We are parsing key1=val1,key2=val2,... and in doing that, we currently
store 'key1' in key, and 'val1' in val, and then 'key2', 'val2', and so
on.
After your patch, we store 'key1\0val1\0' in key, which fits and saves
some memory.

Acked-by: Christophe Fergeau <cfergeau at redhat.com>

> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
>  common/ssl_verify.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/common/ssl_verify.c b/common/ssl_verify.c
> index 0ac00a6..74f95bb 100644
> --- a/common/ssl_verify.c
> +++ b/common/ssl_verify.c
> @@ -282,7 +282,7 @@ static X509_NAME* subject_to_x509_name(const char *subject, int *nentries)
>  {
>      X509_NAME* in_subject;
>      const char *p;
> -    char *key, *val, *k, *v = NULL;
> +    char *key, *val = NULL, *k, *v = NULL;
>      enum {
>          KEY,
>          VALUE
> @@ -291,11 +291,10 @@ static X509_NAME* subject_to_x509_name(const char *subject, int *nentries)
>      spice_return_val_if_fail(subject != NULL, NULL);
>      spice_return_val_if_fail(nentries != NULL, NULL);
>  
> -    key = (char*)alloca(strlen(subject));
> -    val = (char*)alloca(strlen(subject));
> +    key = (char*)alloca(strlen(subject)+1);
>      in_subject = X509_NAME_new();
>  
> -    if (!in_subject || !key || !val) {
> +    if (!in_subject || !key) {
>          spice_debug("failed to allocate");
>          return NULL;
>      }
> @@ -328,6 +327,7 @@ static X509_NAME* subject_to_x509_name(const char *subject, int *nentries)
>              } else if (*p == '=' && !escape) {
>                  state = VALUE;
>                  *k = 0;
> +                val = k + 1;
>                  v = val;
>              } else
>                  *k++ = *p;
> -- 
> 2.17.2
> 
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