From fe2d5295a11e2ab2d6f4e7ea074816000b32eba3 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 6 Sep 2005 14:49:44 -0700 Subject: [PATCH] [CRYPTO] Fix boundary check in standard multi-block cipher processors The boundary check in the standard multi-block cipher processors are broken when nbytes is not a multiple of bsize. In those cases it will always process an extra block. This patch corrects the check so that it processes at most nbytes of data. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- crypto/cipher.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/crypto/cipher.c b/crypto/cipher.c index 3df47f93c9db..dfd4bcfc5975 100644 --- a/crypto/cipher.c +++ b/crypto/cipher.c @@ -191,6 +191,8 @@ static unsigned int cbc_process_encrypt(const struct cipher_desc *desc, u8 *iv = desc->info; unsigned int done = 0; + nbytes -= bsize; + do { xor(iv, src); fn(crypto_tfm_ctx(tfm), dst, iv); @@ -198,7 +200,7 @@ static unsigned int cbc_process_encrypt(const struct cipher_desc *desc, src += bsize; dst += bsize; - } while ((done += bsize) < nbytes); + } while ((done += bsize) <= nbytes); return done; } @@ -219,6 +221,8 @@ static unsigned int cbc_process_decrypt(const struct cipher_desc *desc, u8 *iv = desc->info; unsigned int done = 0; + nbytes -= bsize; + do { u8 *tmp_dst = *dst_p; @@ -230,7 +234,7 @@ static unsigned int cbc_process_decrypt(const struct cipher_desc *desc, src += bsize; dst += bsize; - } while ((done += bsize) < nbytes); + } while ((done += bsize) <= nbytes); return done; } @@ -243,12 +247,14 @@ static unsigned int ecb_process(const struct cipher_desc *desc, u8 *dst, void (*fn)(void *, u8 *, const u8 *) = desc->crfn; unsigned int done = 0; + nbytes -= bsize; + do { fn(crypto_tfm_ctx(tfm), dst, src); src += bsize; dst += bsize; - } while ((done += bsize) < nbytes); + } while ((done += bsize) <= nbytes); return done; } -- 2.20.1