[libcamera-devel] [PATCH] android: jpeg: exif: Sanitize ASCII strings with utils::toAscii()

[Laurent Pinchart]

On Mon, Oct 05, 2020 at 04:39:53PM +0100, Kieran Bingham wrote:
> Hi Umang,
> 
> On 05/10/2020 14:11, Umang Jain wrote:
> > Use the newly introduced utils::toAscii() utility to remove all
> > non-ASCII characters for EXIF_FORMAT_ASCII strings.
> > 
> > Signed-off-by: Umang Jain <email at uajain.com>
> > ---
> >  src/android/jpeg/exif.cpp | 13 +++++++++----
> >  1 file changed, 9 insertions(+), 4 deletions(-)
> > 
> > diff --git a/src/android/jpeg/exif.cpp b/src/android/jpeg/exif.cpp
> > index 3fd5d55..bd528a7 100644
> > --- a/src/android/jpeg/exif.cpp
> > +++ b/src/android/jpeg/exif.cpp
> > @@ -8,6 +8,7 @@
> >  #include "exif.h"
> >  
> >  #include "libcamera/internal/log.h"
> > +#include "libcamera/internal/utils.h"
> >  
> >  using namespace libcamera;
> >  
> > @@ -171,15 +172,19 @@ void Exif::setRational(ExifIfd ifd, ExifTag tag, ExifRational item)
> >  
> >  void Exif::setString(ExifIfd ifd, ExifTag tag, ExifFormat format, const std::string &item)
> >  {
> > -	/* Pad 1 extra byte for null-terminated string in ASCII format. */
> > -	size_t length = format == EXIF_FORMAT_ASCII ?
> > -			item.length() + 1 : item.length();
> > +	size_t length = item.length();
> > +	std::string str = item;
> > +	if (format == EXIF_FORMAT_ASCII) {
> > +		str = utils::toAscii(str);
> > +		/* Pad 1 extra byte to null-terminate the ASCII string. */
> > +		length += 1;

length may have changed after the call to toAscii()

> 
> This could of course also be
> 		length++;
> 
> But += 1 is also quite readable here so I don't mind it staying.
> 
> Sanitizing the Ascii strings seems to make some sense, especially as we
> do it elsewhere - so here seems reasonable to me.
> 
> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> 
> 
> > +	}
> >  
> >  	ExifEntry *entry = createEntry(ifd, tag, format, length, length);
> >  	if (!entry)
> >  		return;
> >  
> > -	memcpy(entry->data, item.c_str(), length);
> > +	memcpy(entry->data, str.c_str(), length);
> >  	exif_entry_unref(entry);
> >  }
> >  

-- 
Regards,

Laurent Pinchart