Re: [Qemu-devel] [PATCH 10/10] ui: convert VNC to use generic cipher API

["Daniel P. Berrange" <berrange@redhat.com>]

On Thu, May 21, 2015 at 06:51:03AM -0600, Eric Blake wrote:
> On 05/21/2015 04:56 AM, Daniel P. Berrange wrote:
> > Switch the VNC server over to use the generic cipher API, this
> > allows it to use the pluggable DES implementations, instead of
> > being hardcoded to use QEMU's built-in impl.
> > 
> > Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> > ---
> >  ui/vnc.c | 52 +++++++++++++++++++++++++++++++++++++++++-----------
> >  1 file changed, 41 insertions(+), 11 deletions(-)
> > 
> 
> > @@ -2515,9 +2515,11 @@ static void make_challenge(VncState *vs)
> >  static int protocol_client_auth_vnc(VncState *vs, uint8_t *data, size_t len)
> >  {
> >      unsigned char response[VNC_AUTH_CHALLENGE_SIZE];
> > -    int i, j, pwlen;
> > +    size_t i, pwlen;
> >      unsigned char key[8];
> >      time_t now = time(NULL);
> > +    QCryptoCipher *cipher;
> > +    Error *err;
> 
> Leaving this uninitialized...
> 
> >  
> >      if (!vs->vd->password) {
> >          VNC_DEBUG("No password configured on server");
> > @@ -2534,9 +2536,29 @@ static int protocol_client_auth_vnc(VncState *vs, uint8_t *data, size_t len)
> >      pwlen = strlen(vs->vd->password);
> >      for (i=0; i<sizeof(key); i++)
> >          key[i] = i<pwlen ? vs->vd->password[i] : 0;
> > -    deskey(key, EN0);
> > -    for (j = 0; j < VNC_AUTH_CHALLENGE_SIZE; j += 8)
> > -        des(response+j, response+j);
> > +
> > +    cipher = qcrypto_cipher_new(
> > +        QCRYPTO_CIPHER_ALG_DES_RFB,
> > +        QCRYPTO_CIPHER_MODE_ECB,
> > +        key, G_N_ELEMENTS(key),
> > +        &err);
> 
> means that gcrypto_cipher_new may assert if it tries to set an error but
> dereferences bogus memory.  Local errors must always start life at NULL.

Opps, yes, missed that.

Regards,
Daniel
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