From 915e8561d559abba1b81934e31e54a3f850fa7bf Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Wed, 6 Jul 2005 13:53:47 -0700 Subject: [CRYPTO] Handle unaligned iv from encrypt_iv/decrypt_iv Even though cit_iv is now always aligned, the user can still supply an unaligned iv through crypto_cipher_encrypt_iv/crypto_cipher_decrypt_iv. This patch will check the alignment of the user-supplied iv and copy it if necessary. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- crypto/cipher.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) (limited to 'crypto') diff --git a/crypto/cipher.c b/crypto/cipher.c index d3295ce14a5..1c92c6bb138 100644 --- a/crypto/cipher.c +++ b/crypto/cipher.c @@ -154,6 +154,31 @@ static int crypt(const struct cipher_desc *desc, return 0; } +static int crypt_iv_unaligned(struct cipher_desc *desc, + struct scatterlist *dst, + struct scatterlist *src, + unsigned int nbytes) +{ + struct crypto_tfm *tfm = desc->tfm; + unsigned int alignmask = crypto_tfm_alg_alignmask(tfm); + u8 *iv = desc->info; + + if (unlikely(((unsigned long)iv & alignmask))) { + unsigned int ivsize = tfm->crt_cipher.cit_ivsize; + u8 buffer[ivsize + alignmask]; + u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); + int err; + + desc->info = memcpy(tmp, iv, ivsize); + err = crypt(desc, dst, src, nbytes); + memcpy(iv, tmp, ivsize); + + return err; + } + + return crypt(desc, dst, src, nbytes); +} + static unsigned int cbc_process_encrypt(const struct cipher_desc *desc, u8 *dst, const u8 *src, unsigned int nbytes) @@ -298,7 +323,7 @@ static int cbc_encrypt_iv(struct crypto_tfm *tfm, desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt; desc.info = iv; - return crypt(&desc, dst, src, nbytes); + return crypt_iv_unaligned(&desc, dst, src, nbytes); } static int cbc_decrypt(struct crypto_tfm *tfm, @@ -330,7 +355,7 @@ static int cbc_decrypt_iv(struct crypto_tfm *tfm, desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt; desc.info = iv; - return crypt(&desc, dst, src, nbytes); + return crypt_iv_unaligned(&desc, dst, src, nbytes); } static int nocrypt(struct crypto_tfm *tfm, -- cgit v1.2.3