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gpg: Fix AEAD encryption for chunk sizes other than 64 KiB.

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* g10/cipher-aead.c (do_flush): Init ERR.  Fix remaining chunklen
computation.
(do_free): Add dummy encryption.  Close the cipher handle.
* g10/decrypt-data.c (aead_underflow): Rewrite.
--

Until we have integrated test into the test suite extensive tests can
also be done with a script like this:

--8<---------------cut here---------------start------------->8---
#!/bin/sh

set -e
GPG="../g10/gpg --rfc4880bis --pinentry-mode=loopback"
GPG="$GPG --passphrase abc --batch"
MKTDATA="$HOME/b/gnupg-2.0/tools/mk-tdata"

for chunksize in 6 7 12 13 14 30; do
for count in $(seq 1 200) $(seq 8100 8200) \
             $(seq 16350 16400) $(seq 20000 20100); do
  if [ ! -f "testfile-$count" ]; then
    $MKTDATA $count >"testfile-$count"
  fi
  echo "testing chunk size 2^$chunksize with $count bytes"
  $GPG --force-aead --aead-algo ocb --s2k-mode 0 --cipher AES -v -z 0 \
      -c --chunk-size $chunksize \
       <"testfile-$count" >"testfile-$count.gpg" 2>/dev/null
  $GPG -vd <"testfile-$count.gpg" >"testfile-$count.out" 2>/dev/null
  if ! cmp "testfile-$count" "testfile-$count.out"; then
    echo "FAILED comparing count $count" >&2
    exit 1
  fi
done
done
echo All good
--8<---------------cut here---------------end--------------->8---

Signed-off-by: Werner Koch <wk@gnupg.org>
This commit is contained in:
Werner Koch 2018-01-24 13:45:05 +01:00
parent 83a15fa88e
commit ff1bdc23d9
No known key found for this signature in database
GPG key ID: E3FDFF218E45B72B
2 changed files with 250 additions and 230 deletions
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19
g10/cipher-aead.c
View file

@ -271,7 +271,7 @@ write_final_chunk (cipher_filter_context_t *cfx, iobuf_t a)
static gpg_error_t
do_flush (cipher_filter_context_t *cfx, iobuf_t a, byte *buf, size_t size)
{
gpg_error_t err;
gpg_error_t err = 0;
int newchunk = 0;
size_t n;
@ -285,9 +285,9 @@ do_flush (cipher_filter_context_t *cfx, iobuf_t a, byte *buf, size_t size)
else
n = cfx->bufsize - cfx->buflen;
if (cfx->chunklen + n >= cfx->chunksize)
if (cfx->chunklen + cfx->buflen + n >= cfx->chunksize)
{
size_t n1 = cfx->chunksize - cfx->chunklen;
size_t n1 = cfx->chunksize - (cfx->chunklen + cfx->buflen);
newchunk = 1;
if (DBG_FILTER)
log_debug ("chunksize %ju reached;"
@ -305,8 +305,8 @@ do_flush (cipher_filter_context_t *cfx, iobuf_t a, byte *buf, size_t size)
if (cfx->buflen == cfx->bufsize || newchunk)
{
if (DBG_FILTER)
log_debug ("encrypting: buflen=%zu %s %p\n",
cfx->buflen, newchunk?"(newchunk)":"", cfx->cipher_hd);
log_debug ("encrypting: buflen=%zu %s n=%zu\n",
cfx->buflen, newchunk?"(newchunk)":"", n);
if (newchunk)
gcry_cipher_final (cfx->cipher_hd);
if (!DBG_FILTER)
@ -372,6 +372,9 @@ do_free (cipher_filter_context_t *cfx, iobuf_t a)
{
gpg_error_t err = 0;
if (DBG_FILTER)
log_debug ("do_free: buflen=%zu\n", cfx->buflen);
/* FIXME: Check what happens if we just wrote the last chunk and no
* more bytes were to encrypt. We should then not call finalize and
* write the auth tag again, right? May this at all happen? */
@ -394,6 +397,8 @@ do_free (cipher_filter_context_t *cfx, iobuf_t a)
cfx->chunklen += cfx->buflen;
cfx->total += cfx->buflen;
}
else /* Dummy encryption. */
gcry_cipher_encrypt (cfx->cipher_hd, cfx->buffer, 0, NULL, 0);
/* Get and write the authentication tag. */
if (DBG_FILTER)
@ -411,8 +416,8 @@ do_free (cipher_filter_context_t *cfx, iobuf_t a)
leave:
xfree (cfx->buffer);
cfx->buffer = NULL;
/* gcry_cipher_close (cfx->cipher_hd); */
/* cfx->cipher_hd = NULL; */
gcry_cipher_close (cfx->cipher_hd);
cfx->cipher_hd = NULL;
return err;
}