From 69affe7fc52c14e4b81408a2076e9e58ba4af60a Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 21 Sep 2006 11:45:53 +1000 Subject: [BLOCK] cryptoloop: Use block ciphers where applicable This patch converts cryptoloop to use the new block cipher type where applicable. As a result the ECB-specific and CBC-specific transfer functions have been merged. Signed-off-by: Herbert Xu --- drivers/block/cryptoloop.c | 160 +++++++++++++++------------------------------ 1 file changed, 54 insertions(+), 106 deletions(-) diff --git a/drivers/block/cryptoloop.c b/drivers/block/cryptoloop.c index 3d4261c39f1..40535036e89 100644 --- a/drivers/block/cryptoloop.c +++ b/drivers/block/cryptoloop.c @@ -40,11 +40,13 @@ static int cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info) { int err = -EINVAL; + int cipher_len; + int mode_len; char cms[LO_NAME_SIZE]; /* cipher-mode string */ char *cipher; char *mode; char *cmsp = cms; /* c-m string pointer */ - struct crypto_tfm *tfm = NULL; + struct crypto_blkcipher *tfm; /* encryption breaks for non sector aligned offsets */ @@ -53,20 +55,39 @@ cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info) strncpy(cms, info->lo_crypt_name, LO_NAME_SIZE); cms[LO_NAME_SIZE - 1] = 0; - cipher = strsep(&cmsp, "-"); - mode = strsep(&cmsp, "-"); - - if (mode == NULL || strcmp(mode, "cbc") == 0) - tfm = crypto_alloc_tfm(cipher, CRYPTO_TFM_MODE_CBC | - CRYPTO_TFM_REQ_MAY_SLEEP); - else if (strcmp(mode, "ecb") == 0) - tfm = crypto_alloc_tfm(cipher, CRYPTO_TFM_MODE_ECB | - CRYPTO_TFM_REQ_MAY_SLEEP); - if (tfm == NULL) + + cipher = cmsp; + cipher_len = strcspn(cmsp, "-"); + + mode = cmsp + cipher_len; + mode_len = 0; + if (*mode) { + mode++; + mode_len = strcspn(mode, "-"); + } + + if (!mode_len) { + mode = "cbc"; + mode_len = 3; + } + + if (cipher_len + mode_len + 3 > LO_NAME_SIZE) return -EINVAL; - err = tfm->crt_u.cipher.cit_setkey(tfm, info->lo_encrypt_key, - info->lo_encrypt_key_size); + memmove(cms, mode, mode_len); + cmsp = cms + mode_len; + *cmsp++ = '('; + memcpy(cmsp, info->lo_crypt_name, cipher_len); + cmsp += cipher_len; + *cmsp++ = ')'; + *cmsp = 0; + + tfm = crypto_alloc_blkcipher(cms, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + err = crypto_blkcipher_setkey(tfm, info->lo_encrypt_key, + info->lo_encrypt_key_size); if (err != 0) goto out_free_tfm; @@ -75,99 +96,49 @@ cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info) return 0; out_free_tfm: - crypto_free_tfm(tfm); + crypto_free_blkcipher(tfm); out: return err; } -typedef int (*encdec_ecb_t)(struct crypto_tfm *tfm, +typedef int (*encdec_cbc_t)(struct blkcipher_desc *desc, struct scatterlist *sg_out, struct scatterlist *sg_in, unsigned int nsg); - -static int -cryptoloop_transfer_ecb(struct loop_device *lo, int cmd, - struct page *raw_page, unsigned raw_off, - struct page *loop_page, unsigned loop_off, - int size, sector_t IV) -{ - struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data; - struct scatterlist sg_out = { NULL, }; - struct scatterlist sg_in = { NULL, }; - - encdec_ecb_t encdecfunc; - struct page *in_page, *out_page; - unsigned in_offs, out_offs; - - if (cmd == READ) { - in_page = raw_page; - in_offs = raw_off; - out_page = loop_page; - out_offs = loop_off; - encdecfunc = tfm->crt_u.cipher.cit_decrypt; - } else { - in_page = loop_page; - in_offs = loop_off; - out_page = raw_page; - out_offs = raw_off; - encdecfunc = tfm->crt_u.cipher.cit_encrypt; - } - - while (size > 0) { - const int sz = min(size, LOOP_IV_SECTOR_SIZE); - - sg_in.page = in_page; - sg_in.offset = in_offs; - sg_in.length = sz; - - sg_out.page = out_page; - sg_out.offset = out_offs; - sg_out.length = sz; - - encdecfunc(tfm, &sg_out, &sg_in, sz); - - size -= sz; - in_offs += sz; - out_offs += sz; - } - - return 0; -} - -typedef int (*encdec_cbc_t)(struct crypto_tfm *tfm, - struct scatterlist *sg_out, - struct scatterlist *sg_in, - unsigned int nsg, u8 *iv); - static int -cryptoloop_transfer_cbc(struct loop_device *lo, int cmd, - struct page *raw_page, unsigned raw_off, - struct page *loop_page, unsigned loop_off, - int size, sector_t IV) +cryptoloop_transfer(struct loop_device *lo, int cmd, + struct page *raw_page, unsigned raw_off, + struct page *loop_page, unsigned loop_off, + int size, sector_t IV) { - struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data; + struct crypto_blkcipher *tfm = lo->key_data; + struct blkcipher_desc desc = { + .tfm = tfm, + .flags = CRYPTO_TFM_REQ_MAY_SLEEP, + }; struct scatterlist sg_out = { NULL, }; struct scatterlist sg_in = { NULL, }; encdec_cbc_t encdecfunc; struct page *in_page, *out_page; unsigned in_offs, out_offs; + int err; if (cmd == READ) { in_page = raw_page; in_offs = raw_off; out_page = loop_page; out_offs = loop_off; - encdecfunc = tfm->crt_u.cipher.cit_decrypt_iv; + encdecfunc = crypto_blkcipher_crt(tfm)->decrypt; } else { in_page = loop_page; in_offs = loop_off; out_page = raw_page; out_offs = raw_off; - encdecfunc = tfm->crt_u.cipher.cit_encrypt_iv; + encdecfunc = crypto_blkcipher_crt(tfm)->encrypt; } while (size > 0) { @@ -183,7 +154,10 @@ cryptoloop_transfer_cbc(struct loop_device *lo, int cmd, sg_out.offset = out_offs; sg_out.length = sz; - encdecfunc(tfm, &sg_out, &sg_in, sz, (u8 *)iv); + desc.info = iv; + err = encdecfunc(&desc, &sg_out, &sg_in, sz); + if (err) + return err; IV++; size -= sz; @@ -194,32 +168,6 @@ cryptoloop_transfer_cbc(struct loop_device *lo, int cmd, return 0; } -static int -cryptoloop_transfer(struct loop_device *lo, int cmd, - struct page *raw_page, unsigned raw_off, - struct page *loop_page, unsigned loop_off, - int size, sector_t IV) -{ - struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data; - if(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB) - { - lo->transfer = cryptoloop_transfer_ecb; - return cryptoloop_transfer_ecb(lo, cmd, raw_page, raw_off, - loop_page, loop_off, size, IV); - } - if(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_CBC) - { - lo->transfer = cryptoloop_transfer_cbc; - return cryptoloop_transfer_cbc(lo, cmd, raw_page, raw_off, - loop_page, loop_off, size, IV); - } - - /* This is not supposed to happen */ - - printk( KERN_ERR "cryptoloop: unsupported cipher mode in cryptoloop_transfer!\n"); - return -EINVAL; -} - static int cryptoloop_ioctl(struct loop_device *lo, int cmd, unsigned long arg) { @@ -229,9 +177,9 @@ cryptoloop_ioctl(struct loop_device *lo, int cmd, unsigned long arg) static int cryptoloop_release(struct loop_device *lo) { - struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data; + struct crypto_blkcipher *tfm = lo->key_data; if (tfm != NULL) { - crypto_free_tfm(tfm); + crypto_free_blkcipher(tfm); lo->key_data = NULL; return 0; } -- cgit v1.2.3