From c191638aad7947d1136a68f4867605348208680c Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Mon, 18 Mar 2019 15:37:16 +0800 Subject: [PATCH] crypto: cfb - add missing 'chunksize' property mainline inclusion from mainline-394a9e044702e6a8958a5e89d2a291605a587a2a master commit 394a9e044702e6a8958a5e89d2a291605a587a2a category: bugfix bugzilla: 11393 CVE: NA --------------------------- 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: # v4.17+ Cc: James Bottomley Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Jason Yan Reviewed-by: ZhangXiaoxu Signed-off-by: Yang Yingliang --- crypto/cfb.c | 6 ++++++ crypto/testmgr.h | 25 +++++++++++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/crypto/cfb.c b/crypto/cfb.c index cb52716614d8..4abfe32ff845 100644 --- a/crypto/cfb.c +++ b/crypto/cfb.c @@ -298,6 +298,12 @@ static int crypto_cfb_create(struct crypto_template *tmpl, struct rtattr **tb) inst->alg.base.cra_blocksize = 1; inst->alg.base.cra_alignmask = alg->cra_alignmask; + /* + * To simplify the implementation, configure the skcipher walk to only + * give a partial block at the very end, never earlier. + */ + inst->alg.chunksize = alg->cra_blocksize; + inst->alg.ivsize = alg->cra_blocksize; inst->alg.min_keysize = alg->cra_cipher.cia_min_keysize; inst->alg.max_keysize = alg->cra_cipher.cia_max_keysize; diff --git a/crypto/testmgr.h b/crypto/testmgr.h index 11e6f17fe724..862ee1d04263 100644 --- a/crypto/testmgr.h +++ b/crypto/testmgr.h @@ -11416,6 +11416,31 @@ static const struct cipher_testvec aes_cfb_tv_template[] = { "\x75\xa3\x85\x74\x1a\xb9\xce\xf8" "\x20\x31\x62\x3d\x55\xb1\xe4\x71", .len = 64, + .also_non_np = 1, + .np = 2, + .tap = { 31, 33 }, + }, { /* > 16 bytes, not a multiple of 16 bytes */ + .key = "\x2b\x7e\x15\x16\x28\xae\xd2\xa6" + "\xab\xf7\x15\x88\x09\xcf\x4f\x3c", + .klen = 16, + .iv = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f", + .ptext = "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96" + "\xe9\x3d\x7e\x11\x73\x93\x17\x2a" + "\xae", + .ctext = "\x3b\x3f\xd9\x2e\xb7\x2d\xad\x20" + "\x33\x34\x49\xf8\xe8\x3c\xfb\x4a" + "\xc8", + .len = 17, + }, { /* < 16 bytes */ + .key = "\x2b\x7e\x15\x16\x28\xae\xd2\xa6" + "\xab\xf7\x15\x88\x09\xcf\x4f\x3c", + .klen = 16, + .iv = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f", + .ptext = "\x6b\xc1\xbe\xe2\x2e\x40\x9f", + .ctext = "\x3b\x3f\xd9\x2e\xb7\x2d\xad", + .len = 7, }, }; -- GitLab