diff options
| -rw-r--r-- | Documentation/device-mapper/dm-crypt.txt | 7 | ||||
| -rw-r--r-- | drivers/md/dm-crypt.c | 85 |
2 files changed, 70 insertions, 22 deletions
diff --git a/Documentation/device-mapper/dm-crypt.txt b/Documentation/device-mapper/dm-crypt.txt index 524de926290..59293ac4a5d 100644 --- a/Documentation/device-mapper/dm-crypt.txt +++ b/Documentation/device-mapper/dm-crypt.txt @@ -8,7 +8,7 @@ Parameters: <cipher> <key> <iv_offset> <device path> <offset> <cipher> Encryption cipher and an optional IV generation mode. - (In format cipher-chainmode-ivopts:ivmode). + (In format cipher[:keycount]-chainmode-ivopts:ivmode). Examples: des aes-cbc-essiv:sha256 @@ -20,6 +20,11 @@ Parameters: <cipher> <key> <iv_offset> <device path> <offset> Key used for encryption. It is encoded as a hexadecimal number. You can only use key sizes that are valid for the selected cipher. +<keycount> + Multi-key compatibility mode. You can define <keycount> keys and + then sectors are encrypted according to their offsets (sector 0 uses key0; + sector 1 uses key1 etc.). <keycount> must be a power of two. + <iv_offset> The IV offset is a sector count that is added to the sector number before creating the IV. diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index e0ebe685be6..b8b9267c4db 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -101,10 +101,9 @@ enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID }; */ struct crypt_cpu { struct ablkcipher_request *req; - struct crypto_ablkcipher *tfm; - /* ESSIV: struct crypto_cipher *essiv_tfm */ void *iv_private; + struct crypto_ablkcipher *tfms[0]; }; /* @@ -143,6 +142,7 @@ struct crypt_config { * per_cpu_ptr() only. */ struct crypt_cpu __percpu *cpu; + unsigned tfms_count; /* * Layout of each crypto request: @@ -161,6 +161,7 @@ struct crypt_config { unsigned long flags; unsigned int key_size; + unsigned int key_parts; u8 key[0]; }; @@ -184,7 +185,7 @@ static struct crypt_cpu *this_crypt_config(struct crypt_config *cc) */ static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc) { - return __this_cpu_ptr(cc->cpu)->tfm; + return __this_cpu_ptr(cc->cpu)->tfms[0]; } /* @@ -567,11 +568,12 @@ static void crypt_alloc_req(struct crypt_config *cc, struct convert_context *ctx) { struct crypt_cpu *this_cc = this_crypt_config(cc); + unsigned key_index = ctx->sector & (cc->tfms_count - 1); if (!this_cc->req) this_cc->req = mempool_alloc(cc->req_pool, GFP_NOIO); - ablkcipher_request_set_tfm(this_cc->req, this_cc->tfm); + ablkcipher_request_set_tfm(this_cc->req, this_cc->tfms[key_index]); ablkcipher_request_set_callback(this_cc->req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, kcryptd_async_done, dmreq_of_req(cc, this_cc->req)); @@ -1097,15 +1099,48 @@ static void crypt_encode_key(char *hex, u8 *key, unsigned int size) } } +static void crypt_free_tfms(struct crypt_config *cc, int cpu) +{ + struct crypt_cpu *cpu_cc = per_cpu_ptr(cc->cpu, cpu); + unsigned i; + + for (i = 0; i < cc->tfms_count; i++) + if (cpu_cc->tfms[i] && !IS_ERR(cpu_cc->tfms[i])) { + crypto_free_ablkcipher(cpu_cc->tfms[i]); + cpu_cc->tfms[i] = NULL; + } +} + +static int crypt_alloc_tfms(struct crypt_config *cc, int cpu, char *ciphermode) +{ + struct crypt_cpu *cpu_cc = per_cpu_ptr(cc->cpu, cpu); + unsigned i; + int err; + + for (i = 0; i < cc->tfms_count; i++) { + cpu_cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0); + if (IS_ERR(cpu_cc->tfms[i])) { + err = PTR_ERR(cpu_cc->tfms[i]); + crypt_free_tfms(cc, cpu); + return err; + } + } + + return 0; +} + static int crypt_setkey_allcpus(struct crypt_config *cc) { - int cpu, err = 0, r; + unsigned subkey_size = cc->key_size >> ilog2(cc->tfms_count); + int cpu, err = 0, i, r; for_each_possible_cpu(cpu) { - r = crypto_ablkcipher_setkey(per_cpu_ptr(cc->cpu, cpu)->tfm, - cc->key, cc->key_size); - if (r) - err = r; + for (i = 0; i < cc->tfms_count; i++) { + r = crypto_ablkcipher_setkey(per_cpu_ptr(cc->cpu, cpu)->tfms[i], + cc->key + (i * subkey_size), subkey_size); + if (r) + err = r; + } } return err; @@ -1158,8 +1193,7 @@ static void crypt_dtr(struct dm_target *ti) cpu_cc = per_cpu_ptr(cc->cpu, cpu); if (cpu_cc->req) mempool_free(cpu_cc->req, cc->req_pool); - if (cpu_cc->tfm) - crypto_free_ablkcipher(cpu_cc->tfm); + crypt_free_tfms(cc, cpu); } if (cc->bs) @@ -1192,8 +1226,7 @@ static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key) { struct crypt_config *cc = ti->private; - struct crypto_ablkcipher *tfm; - char *tmp, *cipher, *chainmode, *ivmode, *ivopts; + char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount; char *cipher_api = NULL; int cpu, ret = -EINVAL; @@ -1209,10 +1242,20 @@ static int crypt_ctr_cipher(struct dm_target *ti, /* * Legacy dm-crypt cipher specification - * cipher-mode-iv:ivopts + * cipher[:keycount]-mode-iv:ivopts */ tmp = cipher_in; - cipher = strsep(&tmp, "-"); + keycount = strsep(&tmp, "-"); + cipher = strsep(&keycount, ":"); + + if (!keycount) + cc->tfms_count = 1; + else if (sscanf(keycount, "%u", &cc->tfms_count) != 1 || + !is_power_of_2(cc->tfms_count)) { + ti->error = "Bad cipher key count specification"; + return -EINVAL; + } + cc->key_parts = cc->tfms_count; cc->cipher = kstrdup(cipher, GFP_KERNEL); if (!cc->cipher) @@ -1225,7 +1268,9 @@ static int crypt_ctr_cipher(struct dm_target *ti, if (tmp) DMWARN("Ignoring unexpected additional cipher options"); - cc->cpu = alloc_percpu(struct crypt_cpu); + cc->cpu = __alloc_percpu(sizeof(*(cc->cpu)) + + cc->tfms_count * sizeof(*(cc->cpu->tfms)), + __alignof__(struct crypt_cpu)); if (!cc->cpu) { ti->error = "Cannot allocate per cpu state"; goto bad_mem; @@ -1258,13 +1303,11 @@ static int crypt_ctr_cipher(struct dm_target *ti, /* Allocate cipher */ for_each_possible_cpu(cpu) { - tfm = crypto_alloc_ablkcipher(cipher_api, 0, 0); - if (IS_ERR(tfm)) { - ret = PTR_ERR(tfm); + ret = crypt_alloc_tfms(cc, cpu, cipher_api); + if (ret < 0) { ti->error = "Error allocating crypto tfm"; goto bad; } - per_cpu_ptr(cc->cpu, cpu)->tfm = tfm; } /* Initialize and set key */ @@ -1587,7 +1630,7 @@ static int crypt_iterate_devices(struct dm_target *ti, static struct target_type crypt_target = { .name = "crypt", - .version = {1, 9, 0}, + .version = {1, 10, 0}, .module = THIS_MODULE, .ctr = crypt_ctr, .dtr = crypt_dtr, |