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gpg: Rename a variable in decrypt-data for clarity. 

* g10/decrypt-data.c (decode_filter_context_s): Rename field 'defer'
to 'holdback' and replace 'defer_filled' flag into 'holdbacklen'.
Change all users.

Signed-off-by: Werner Koch <wk@gnupg.org>
This commit is contained in:
Werner Koch 2018-01-24 08:59:06 +01:00
parent f3ef8b0dca
commit 83a15fa88e
No known key found for this signature in database
GPG Key ID: E3FDFF218E45B72B
1 changed files with 38 additions and 38 deletions
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76
g10/decrypt-data.c
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@ -56,11 +56,10 @@ struct decode_filter_context_s
/* The start IV for AEAD encryption. */
byte startiv[16];
/* The holdback buffer. For AEAD we need 32 bytes for MDC 22 bytes
* are enough. The flag indicates whether the holdback buffer is
* filled. */
char defer[32];
unsigned int defer_filled : 1;
/* The holdback buffer and its used length. For AEAD we need at
* least 32+1 byte for MDC 22 bytes are required. */
char holdback[48];
unsigned int holdbacklen;
/* Working on a partial length packet. */
unsigned int partial : 1;
@ -512,16 +511,16 @@ decrypt_data (ctrl_t ctrl, void *procctx, PKT_encrypted *ed, DEK *dek)
log_assert (dfx->cipher_hd);
log_assert (dfx->mdc_hash);
gcry_cipher_decrypt (dfx->cipher_hd, dfx->defer, 22, NULL, 0);
gcry_md_write (dfx->mdc_hash, dfx->defer, 2);
gcry_cipher_decrypt (dfx->cipher_hd, dfx->holdback, 22, NULL, 0);
gcry_md_write (dfx->mdc_hash, dfx->holdback, 2);
gcry_md_final (dfx->mdc_hash);
if ( dfx->defer[0] != '\xd3'
|| dfx->defer[1] != '\x14'
if ( dfx->holdback[0] != '\xd3'
|| dfx->holdback[1] != '\x14'
|| datalen != 20
|| memcmp (gcry_md_read (dfx->mdc_hash, 0), dfx->defer+2, datalen))
|| memcmp (gcry_md_read (dfx->mdc_hash, 0), dfx->holdback+2, datalen))
rc = gpg_error (GPG_ERR_BAD_SIGNATURE);
/* log_printhex("MDC message:", dfx->defer, 22); */
/* log_printhex("MDC message:", dfx->holdback, 22); */
/* log_printhex("MDC calc:", gcry_md_read (dfx->mdc_hash,0), datalen); */
}
@ -568,18 +567,18 @@ aead_underflow (decode_filter_ctx_t dfx, iobuf_t a, byte *buf, size_t *ret_len)
{
/* We got 32 bytes from A which are good for the last chunk's
* auth tag and the final chunk's auth tag. On the first time
* we don't have anything in the defer buffer and thus we move
* we don't have anything in the holdback buffer and thus we move
* those 32 bytes to the start of the buffer. All further calls
* will copy the deferred 32 bytes to the start of the
* will copy the 32 bytes from the holdback buffer to the start of the
* buffer. */
if (!dfx->defer_filled)
if (!dfx->holdbacklen)
{
memcpy (buf, buf+32, 32);
n = 32; /* Continue at this position. */
}
else
{
memcpy (buf, dfx->defer, 32);
memcpy (buf, dfx->holdback, 32);
}
/* Now fill up the provided buffer. */
@ -611,16 +610,16 @@ aead_underflow (decode_filter_ctx_t dfx, iobuf_t a, byte *buf, size_t *ret_len)
dfx->eof_seen = 1; /* Normal EOF. */
}
/* Move the trailing 32 bytes back to the defer buffer. We
/* Move the trailing 32 bytes back to the holdback buffer. We
* got at least 64 bytes and thus a memmove is not needed. */
n -= 32;
memcpy (dfx->defer, buf+n, 32);
dfx->defer_filled = 1;
memcpy (dfx->holdback, buf+n, 32);
dfx->holdbacklen = 32;
}
else if (!dfx->defer_filled)
else if (!dfx->holdbacklen)
{
/* EOF seen but empty defer buffer. This means that we did not
* read enough for the two auth tags. */
/* EOF seen but empty holdback buffer. This means that we did
* not read enough for the two auth tags. */
n -= 32;
memcpy (buf, buf+32, n );
dfx->eof_seen = 2; /* EOF with incomplete tag. */
@ -628,9 +627,9 @@ aead_underflow (decode_filter_ctx_t dfx, iobuf_t a, byte *buf, size_t *ret_len)
else
{
/* EOF seen (i.e. read less than 32 bytes). */
memcpy (buf, dfx->defer, 32);
memcpy (buf, dfx->holdback, 32);
n -= 32;
memcpy (dfx->defer, buf+n, 32);
memcpy (dfx->holdback, buf+n, 32);
dfx->eof_seen = 1; /* Normal EOF. */
}
@ -676,7 +675,7 @@ aead_underflow (decode_filter_ctx_t dfx, iobuf_t a, byte *buf, size_t *ret_len)
if (DBG_FILTER)
log_debug ("bytes left: %zu off=%zu\n", n, off);
log_assert (n >= 16);
log_assert (dfx->defer_filled);
log_assert (dfx->holdbacklen);
if (DBG_CRYPTO)
log_printhex (buf+off, 16, "tag:");
err = gcry_cipher_checktag (dfx->cipher_hd, buf + off, 16);
@ -717,7 +716,7 @@ aead_underflow (decode_filter_ctx_t dfx, iobuf_t a, byte *buf, size_t *ret_len)
* large 2^n sized buffers. There is no assert because
* gcry_cipher_decrypt would detect such an error. */
gcry_cipher_final (dfx->cipher_hd);
/*log_printhex (buf+off, n, "buf+off:");*/
/* log_printhex (buf+off, n, "buf+off:"); */
}
err = gcry_cipher_decrypt (dfx->cipher_hd, buf + off, n, NULL, 0);
if (err)
@ -731,15 +730,16 @@ aead_underflow (decode_filter_ctx_t dfx, iobuf_t a, byte *buf, size_t *ret_len)
if (dfx->eof_seen)
{
/* log_printhex (buf+off, n, "buf+off:"); */
log_printhex (buf+off, n, "buf+off:");
if (DBG_FILTER)
log_debug ("eof seen: chunklen=%ju total=%ju off=%zu n=%zu\n",
(uintmax_t)dfx->chunklen, (uintmax_t)dfx->total, off, n);
log_assert (dfx->defer_filled);
err = gcry_cipher_checktag (dfx->cipher_hd, dfx->defer, 16);
log_assert (dfx->holdbacklen);
err = gcry_cipher_checktag (dfx->cipher_hd, dfx->holdback, 16);
if (err)
{
log_printhex (dfx->holdback, 16, "tag:");
log_error ("gcry_cipher_checktag failed (2): %s\n",
gpg_strerror (err));
/* Return Bad Signature like we do with MDC encryption. */
@ -765,7 +765,7 @@ aead_underflow (decode_filter_ctx_t dfx, iobuf_t a, byte *buf, size_t *ret_len)
gpg_strerror (err));
goto leave;
}
err = gcry_cipher_checktag (dfx->cipher_hd, dfx->defer+16, 16);
err = gcry_cipher_checktag (dfx->cipher_hd, dfx->holdback+16, 16);
if (err)
{
if (DBG_FILTER)
@ -881,8 +881,8 @@ mdc_decode_filter (void *opaque, int control, IOBUF a,
}
if (n == 44)
{
/* We have enough stuff - flush the deferred stuff. */
if ( !dfx->defer_filled ) /* First time. */
/* We have enough stuff - flush the holdback buffer. */
if ( !dfx->holdbacklen ) /* First time. */
{
memcpy (buf, buf+22, 22);
n = 22;
@ -890,7 +890,7 @@ mdc_decode_filter (void *opaque, int control, IOBUF a,
else
{
memcpy (buf, dfx->defer, 22);
memcpy (buf, dfx->holdback, 22);
}
/* Fill up the buffer. */
if (dfx->partial)
@ -921,13 +921,13 @@ mdc_decode_filter (void *opaque, int control, IOBUF a,
dfx->eof_seen = 1; /* Normal EOF. */
}
/* Move the trailing 22 bytes back to the defer buffer. We
/* Move the trailing 22 bytes back to the holdback buffer. We
have at least 44 bytes thus a memmove is not needed. */
n -= 22;
memcpy (dfx->defer, buf+n, 22 );
dfx->defer_filled = 1;
memcpy (dfx->holdback, buf+n, 22 );
dfx->holdbacklen = 22;
}
else if ( !dfx->defer_filled ) /* EOF seen but empty defer buffer. */
else if ( !dfx->holdbacklen ) /* EOF seen but empty holdback. */
{
/* This is bad because it means an incomplete hash. */
n -= 22;
@ -936,9 +936,9 @@ mdc_decode_filter (void *opaque, int control, IOBUF a,
}
else /* EOF seen (i.e. read less than 22 bytes). */
{
memcpy (buf, dfx->defer, 22 );
memcpy (buf, dfx->holdback, 22 );
n -= 22;
memcpy (dfx->defer, buf+n, 22 );
memcpy (dfx->holdback, buf+n, 22 );
dfx->eof_seen = 1; /* Normal EOF. */
}