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2019-03-23crypto: cfb - remove bogus memcpy() with src == destEric Biggers1-4/+4
commit 6c2e322b3621dc8be72e5c86d4fdb587434ba625 upstream. The memcpy() in crypto_cfb_decrypt_inplace() uses walk->iv as both the source and destination, which has undefined behavior. It is unneeded because walk->iv is already used to hold the previous ciphertext block; thus, walk->iv is already updated to its final value. So, remove it. Also, note that in-place decryption is the only case where the previous ciphertext block is not directly available. Therefore, as a related cleanup I also updated crypto_cfb_encrypt_segment() to directly use the previous ciphertext block rather than save it into walk->iv. This makes it consistent with in-place encryption and out-of-place decryption; now only in-place decryption is different, because it has to be. Fixes: a7d85e06ed80 ("crypto: cfb - add support for Cipher FeedBack mode") Cc: <stable@vger.kernel.org> # v4.17+ Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23crypto: cfb - add missing 'chunksize' propertyEric Biggers1-0/+6
commit 394a9e044702e6a8958a5e89d2a291605a587a2a upstream. Like some other block cipher mode implementations, the CFB implementation assumes that while walking through the scatterlist, a partial block does not occur until the end. But the walk is incorrectly being done with a blocksize of 1, as 'cra_blocksize' is set to 1 (since CFB is a stream cipher) but no 'chunksize' is set. This bug causes incorrect encryption/decryption for some scatterlist layouts. Fix it by setting the 'chunksize'. Also extend the CFB test vectors to cover this bug as well as cases where the message length is not a multiple of the block size. Fixes: a7d85e06ed80 ("crypto: cfb - add support for Cipher FeedBack mode") Cc: <stable@vger.kernel.org> # v4.17+ Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09crypto: cfb - fix decryptionDmitry Eremin-Solenikov1-1/+1
commit fa4600734b74f74d9169c3015946d4722f8bcf79 upstream. crypto_cfb_decrypt_segment() incorrectly XOR'ed generated keystream with IV, rather than with data stream, resulting in incorrect decryption. Test vectors will be added in the next patch. Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-13crypto: do not free algorithm before usingPan Bian1-2/+4
commit e5bde04ccce64d808f8b00a489a1fe5825d285cb upstream. In multiple functions, the algorithm fields are read after its reference is dropped through crypto_mod_put. In this case, the algorithm memory may be freed, resulting in use-after-free bugs. This patch delays the put operation until the algorithm is never used. Fixes: 79c65d179a40 ("crypto: cbc - Convert to skcipher") Fixes: a7d85e06ed80 ("crypto: cfb - add support for Cipher FeedBack mode") Fixes: 043a44001b9e ("crypto: pcbc - Convert to skcipher") Cc: <stable@vger.kernel.org> Signed-off-by: Pan Bian <bianpan2016@163.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-21crypto: remove several VLAsSalvatore Mesoraca1-4/+3
We avoid various VLAs[1] by using constant expressions for block size and alignment mask. [1] http://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-03-09crypto: cfb - add support for Cipher FeedBack modeJames Bottomley1-0/+353
TPM security routines require encryption and decryption with AES in CFB mode, so add it to the Linux Crypto schemes. CFB is basically a one time pad where the pad is generated initially from the encrypted IV and then subsequently from the encrypted previous block of ciphertext. The pad is XOR'd into the plain text to get the final ciphertext. https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#CFB Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>