diff options
Diffstat (limited to 'block/blk-crypto.c')
| -rw-r--r-- | block/blk-crypto.c | 318 |
1 files changed, 260 insertions, 58 deletions
diff --git a/block/blk-crypto.c b/block/blk-crypto.c index c5bdaafffa29..3e7bf1974cbd 100644 --- a/block/blk-crypto.c +++ b/block/blk-crypto.c @@ -11,28 +11,42 @@ #include <linux/bio.h> #include <linux/blkdev.h> -#include <linux/keyslot-manager.h> +#include <linux/blk-crypto-profile.h> #include <linux/module.h> +#include <linux/ratelimit.h> #include <linux/slab.h> #include "blk-crypto-internal.h" const struct blk_crypto_mode blk_crypto_modes[] = { [BLK_ENCRYPTION_MODE_AES_256_XTS] = { + .name = "AES-256-XTS", .cipher_str = "xts(aes)", .keysize = 64, + .security_strength = 32, .ivsize = 16, }, [BLK_ENCRYPTION_MODE_AES_128_CBC_ESSIV] = { + .name = "AES-128-CBC-ESSIV", .cipher_str = "essiv(cbc(aes),sha256)", .keysize = 16, + .security_strength = 16, .ivsize = 16, }, [BLK_ENCRYPTION_MODE_ADIANTUM] = { + .name = "Adiantum", .cipher_str = "adiantum(xchacha12,aes)", .keysize = 32, + .security_strength = 32, .ivsize = 32, }, + [BLK_ENCRYPTION_MODE_SM4_XTS] = { + .name = "SM4-XTS", + .cipher_str = "xts(sm4)", + .keysize = 32, + .security_strength = 16, + .ivsize = 16, + }, }; /* @@ -66,9 +80,15 @@ static int __init bio_crypt_ctx_init(void) /* This is assumed in various places. */ BUILD_BUG_ON(BLK_ENCRYPTION_MODE_INVALID != 0); - /* Sanity check that no algorithm exceeds the defined limits. */ + /* + * Validate the crypto mode properties. This ideally would be done with + * static assertions, but boot-time checks are the next best thing. + */ for (i = 0; i < BLK_ENCRYPTION_MODE_MAX; i++) { - BUG_ON(blk_crypto_modes[i].keysize > BLK_CRYPTO_MAX_KEY_SIZE); + BUG_ON(blk_crypto_modes[i].keysize > + BLK_CRYPTO_MAX_RAW_KEY_SIZE); + BUG_ON(blk_crypto_modes[i].security_strength > + blk_crypto_modes[i].keysize); BUG_ON(blk_crypto_modes[i].ivsize > BLK_CRYPTO_MAX_IV_SIZE); } @@ -111,7 +131,6 @@ int __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask) *dst->bi_crypt_context = *src->bi_crypt_context; return 0; } -EXPORT_SYMBOL_GPL(__bio_crypt_clone); /* Increments @dun by @inc, treating @dun as a multi-limb integer. */ void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE], @@ -216,26 +235,27 @@ static bool bio_crypt_check_alignment(struct bio *bio) return true; } -blk_status_t __blk_crypto_init_request(struct request *rq) +blk_status_t __blk_crypto_rq_get_keyslot(struct request *rq) { - return blk_ksm_get_slot_for_key(rq->q->ksm, rq->crypt_ctx->bc_key, - &rq->crypt_keyslot); + return blk_crypto_get_keyslot(rq->q->crypto_profile, + rq->crypt_ctx->bc_key, + &rq->crypt_keyslot); +} + +void __blk_crypto_rq_put_keyslot(struct request *rq) +{ + blk_crypto_put_keyslot(rq->crypt_keyslot); + rq->crypt_keyslot = NULL; } -/** - * __blk_crypto_free_request - Uninitialize the crypto fields of a request. - * - * @rq: The request whose crypto fields to uninitialize. - * - * Completely uninitializes the crypto fields of a request. If a keyslot has - * been programmed into some inline encryption hardware, that keyslot is - * released. The rq->crypt_ctx is also freed. - */ void __blk_crypto_free_request(struct request *rq) { - blk_ksm_put_slot(rq->crypt_keyslot); + /* The keyslot, if one was needed, should have been released earlier. */ + if (WARN_ON_ONCE(rq->crypt_keyslot)) + __blk_crypto_rq_put_keyslot(rq); + mempool_free(rq->crypt_ctx, bio_crypt_ctx_pool); - blk_crypto_rq_set_defaults(rq); + rq->crypt_ctx = NULL; } /** @@ -272,7 +292,7 @@ bool __blk_crypto_bio_prep(struct bio **bio_ptr) } if (!bio_crypt_check_alignment(bio)) { - bio->bi_status = BLK_STS_IOERR; + bio->bi_status = BLK_STS_INVAL; goto fail; } @@ -280,10 +300,9 @@ bool __blk_crypto_bio_prep(struct bio **bio_ptr) * Success if device supports the encryption context, or if we succeeded * in falling back to the crypto API. */ - if (blk_ksm_crypto_cfg_supported(bio->bi_bdev->bd_disk->queue->ksm, - &bc_key->crypto_cfg)) + if (blk_crypto_config_supported_natively(bio->bi_bdev, + &bc_key->crypto_cfg)) return true; - if (blk_crypto_fallback_bio_prep(bio_ptr)) return true; fail: @@ -306,17 +325,20 @@ int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, /** * blk_crypto_init_key() - Prepare a key for use with blk-crypto * @blk_key: Pointer to the blk_crypto_key to initialize. - * @raw_key: Pointer to the raw key. Must be the correct length for the chosen - * @crypto_mode; see blk_crypto_modes[]. + * @key_bytes: the bytes of the key + * @key_size: size of the key in bytes + * @key_type: type of the key -- either raw or hardware-wrapped * @crypto_mode: identifier for the encryption algorithm to use * @dun_bytes: number of bytes that will be used to specify the DUN when this * key is used * @data_unit_size: the data unit size to use for en/decryption * * Return: 0 on success, -errno on failure. The caller is responsible for - * zeroizing both blk_key and raw_key when done with them. + * zeroizing both blk_key and key_bytes when done with them. */ -int blk_crypto_init_key(struct blk_crypto_key *blk_key, const u8 *raw_key, +int blk_crypto_init_key(struct blk_crypto_key *blk_key, + const u8 *key_bytes, size_t key_size, + enum blk_crypto_key_type key_type, enum blk_crypto_mode_num crypto_mode, unsigned int dun_bytes, unsigned int data_unit_size) @@ -329,10 +351,21 @@ int blk_crypto_init_key(struct blk_crypto_key *blk_key, const u8 *raw_key, return -EINVAL; mode = &blk_crypto_modes[crypto_mode]; - if (mode->keysize == 0) + switch (key_type) { + case BLK_CRYPTO_KEY_TYPE_RAW: + if (key_size != mode->keysize) + return -EINVAL; + break; + case BLK_CRYPTO_KEY_TYPE_HW_WRAPPED: + if (key_size < mode->security_strength || + key_size > BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE) + return -EINVAL; + break; + default: return -EINVAL; + } - if (dun_bytes == 0 || dun_bytes > BLK_CRYPTO_MAX_IV_SIZE) + if (dun_bytes == 0 || dun_bytes > mode->ivsize) return -EINVAL; if (!is_power_of_2(data_unit_size)) @@ -341,29 +374,39 @@ int blk_crypto_init_key(struct blk_crypto_key *blk_key, const u8 *raw_key, blk_key->crypto_cfg.crypto_mode = crypto_mode; blk_key->crypto_cfg.dun_bytes = dun_bytes; blk_key->crypto_cfg.data_unit_size = data_unit_size; + blk_key->crypto_cfg.key_type = key_type; blk_key->data_unit_size_bits = ilog2(data_unit_size); - blk_key->size = mode->keysize; - memcpy(blk_key->raw, raw_key, mode->keysize); + blk_key->size = key_size; + memcpy(blk_key->bytes, key_bytes, key_size); return 0; } +bool blk_crypto_config_supported_natively(struct block_device *bdev, + const struct blk_crypto_config *cfg) +{ + return __blk_crypto_cfg_supported(bdev_get_queue(bdev)->crypto_profile, + cfg); +} + /* * Check if bios with @cfg can be en/decrypted by blk-crypto (i.e. either the - * request queue it's submitted to supports inline crypto, or the + * block_device it's submitted to supports inline crypto, or the * blk-crypto-fallback is enabled and supports the cfg). */ -bool blk_crypto_config_supported(struct request_queue *q, +bool blk_crypto_config_supported(struct block_device *bdev, const struct blk_crypto_config *cfg) { - return IS_ENABLED(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) || - blk_ksm_crypto_cfg_supported(q->ksm, cfg); + if (IS_ENABLED(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) && + cfg->key_type == BLK_CRYPTO_KEY_TYPE_RAW) + return true; + return blk_crypto_config_supported_natively(bdev, cfg); } /** * blk_crypto_start_using_key() - Start using a blk_crypto_key on a device + * @bdev: block device to operate on * @key: A key to use on the device - * @q: the request queue for the device * * Upper layers must call this function to ensure that either the hardware * supports the key's crypto settings, or the crypto API fallback has transforms @@ -371,42 +414,201 @@ bool blk_crypto_config_supported(struct request_queue *q, * an skcipher, and *should not* be called from the data path, since that might * cause a deadlock * - * Return: 0 on success; -ENOPKG if the hardware doesn't support the key and - * blk-crypto-fallback is either disabled or the needed algorithm - * is disabled in the crypto API; or another -errno code. + * Return: 0 on success; -EOPNOTSUPP if the key is wrapped but the hardware does + * not support wrapped keys; -ENOPKG if the key is a raw key but the + * hardware does not support raw keys and blk-crypto-fallback is either + * disabled or the needed algorithm is disabled in the crypto API; or + * another -errno code if something else went wrong. */ -int blk_crypto_start_using_key(const struct blk_crypto_key *key, - struct request_queue *q) +int blk_crypto_start_using_key(struct block_device *bdev, + const struct blk_crypto_key *key) { - if (blk_ksm_crypto_cfg_supported(q->ksm, &key->crypto_cfg)) + if (blk_crypto_config_supported_natively(bdev, &key->crypto_cfg)) return 0; + if (key->crypto_cfg.key_type != BLK_CRYPTO_KEY_TYPE_RAW) { + pr_warn_ratelimited("%pg: no support for wrapped keys\n", bdev); + return -EOPNOTSUPP; + } return blk_crypto_fallback_start_using_mode(key->crypto_cfg.crypto_mode); } /** - * blk_crypto_evict_key() - Evict a key from any inline encryption hardware - * it may have been programmed into - * @q: The request queue who's associated inline encryption hardware this key - * might have been programmed into - * @key: The key to evict + * blk_crypto_evict_key() - Evict a blk_crypto_key from a block_device + * @bdev: a block_device on which I/O using the key may have been done + * @key: the key to evict + * + * For a given block_device, this function removes the given blk_crypto_key from + * the keyslot management structures and evicts it from any underlying hardware + * keyslot(s) or blk-crypto-fallback keyslot it may have been programmed into. * - * Upper layers (filesystems) must call this function to ensure that a key is - * evicted from any hardware that it might have been programmed into. The key - * must not be in use by any in-flight IO when this function is called. + * Upper layers must call this before freeing the blk_crypto_key. It must be + * called for every block_device the key may have been used on. The key must no + * longer be in use by any I/O when this function is called. * - * Return: 0 on success or if key is not present in the q's ksm, -err on error. + * Context: May sleep. */ -int blk_crypto_evict_key(struct request_queue *q, - const struct blk_crypto_key *key) +void blk_crypto_evict_key(struct block_device *bdev, + const struct blk_crypto_key *key) { - if (blk_ksm_crypto_cfg_supported(q->ksm, &key->crypto_cfg)) - return blk_ksm_evict_key(q->ksm, key); + struct request_queue *q = bdev_get_queue(bdev); + int err; + if (blk_crypto_config_supported_natively(bdev, &key->crypto_cfg)) + err = __blk_crypto_evict_key(q->crypto_profile, key); + else + err = blk_crypto_fallback_evict_key(key); /* - * If the request queue's associated inline encryption hardware didn't - * have support for the key, then the key might have been programmed - * into the fallback keyslot manager, so try to evict from there. + * An error can only occur here if the key failed to be evicted from a + * keyslot (due to a hardware or driver issue) or is allegedly still in + * use by I/O (due to a kernel bug). Even in these cases, the key is + * still unlinked from the keyslot management structures, and the caller + * is allowed and expected to free it right away. There's nothing + * callers can do to handle errors, so just log them and return void. */ - return blk_crypto_fallback_evict_key(key); + if (err) + pr_warn_ratelimited("%pg: error %d evicting key\n", bdev, err); } EXPORT_SYMBOL_GPL(blk_crypto_evict_key); + +static int blk_crypto_ioctl_import_key(struct blk_crypto_profile *profile, + void __user *argp) +{ + struct blk_crypto_import_key_arg arg; + u8 raw_key[BLK_CRYPTO_MAX_RAW_KEY_SIZE]; + u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]; + int ret; + + if (copy_from_user(&arg, argp, sizeof(arg))) + return -EFAULT; + + if (memchr_inv(arg.reserved, 0, sizeof(arg.reserved))) + return -EINVAL; + + if (arg.raw_key_size < 16 || arg.raw_key_size > sizeof(raw_key)) + return -EINVAL; + + if (copy_from_user(raw_key, u64_to_user_ptr(arg.raw_key_ptr), + arg.raw_key_size)) { + ret = -EFAULT; + goto out; + } + ret = blk_crypto_import_key(profile, raw_key, arg.raw_key_size, lt_key); + if (ret < 0) + goto out; + if (ret > arg.lt_key_size) { + ret = -EOVERFLOW; + goto out; + } + arg.lt_key_size = ret; + if (copy_to_user(u64_to_user_ptr(arg.lt_key_ptr), lt_key, + arg.lt_key_size) || + copy_to_user(argp, &arg, sizeof(arg))) { + ret = -EFAULT; + goto out; + } + ret = 0; + +out: + memzero_explicit(raw_key, sizeof(raw_key)); + memzero_explicit(lt_key, sizeof(lt_key)); + return ret; +} + +static int blk_crypto_ioctl_generate_key(struct blk_crypto_profile *profile, + void __user *argp) +{ + struct blk_crypto_generate_key_arg arg; + u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]; + int ret; + + if (copy_from_user(&arg, argp, sizeof(arg))) + return -EFAULT; + + if (memchr_inv(arg.reserved, 0, sizeof(arg.reserved))) + return -EINVAL; + + ret = blk_crypto_generate_key(profile, lt_key); + if (ret < 0) + goto out; + if (ret > arg.lt_key_size) { + ret = -EOVERFLOW; + goto out; + } + arg.lt_key_size = ret; + if (copy_to_user(u64_to_user_ptr(arg.lt_key_ptr), lt_key, + arg.lt_key_size) || + copy_to_user(argp, &arg, sizeof(arg))) { + ret = -EFAULT; + goto out; + } + ret = 0; + +out: + memzero_explicit(lt_key, sizeof(lt_key)); + return ret; +} + +static int blk_crypto_ioctl_prepare_key(struct blk_crypto_profile *profile, + void __user *argp) +{ + struct blk_crypto_prepare_key_arg arg; + u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]; + u8 eph_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]; + int ret; + + if (copy_from_user(&arg, argp, sizeof(arg))) + return -EFAULT; + + if (memchr_inv(arg.reserved, 0, sizeof(arg.reserved))) + return -EINVAL; + + if (arg.lt_key_size > sizeof(lt_key)) + return -EINVAL; + + if (copy_from_user(lt_key, u64_to_user_ptr(arg.lt_key_ptr), + arg.lt_key_size)) { + ret = -EFAULT; + goto out; + } + ret = blk_crypto_prepare_key(profile, lt_key, arg.lt_key_size, eph_key); + if (ret < 0) + goto out; + if (ret > arg.eph_key_size) { + ret = -EOVERFLOW; + goto out; + } + arg.eph_key_size = ret; + if (copy_to_user(u64_to_user_ptr(arg.eph_key_ptr), eph_key, + arg.eph_key_size) || + copy_to_user(argp, &arg, sizeof(arg))) { + ret = -EFAULT; + goto out; + } + ret = 0; + +out: + memzero_explicit(lt_key, sizeof(lt_key)); + memzero_explicit(eph_key, sizeof(eph_key)); + return ret; +} + +int blk_crypto_ioctl(struct block_device *bdev, unsigned int cmd, + void __user *argp) +{ + struct blk_crypto_profile *profile = + bdev_get_queue(bdev)->crypto_profile; + + if (!profile) + return -EOPNOTSUPP; + + switch (cmd) { + case BLKCRYPTOIMPORTKEY: + return blk_crypto_ioctl_import_key(profile, argp); + case BLKCRYPTOGENERATEKEY: + return blk_crypto_ioctl_generate_key(profile, argp); + case BLKCRYPTOPREPAREKEY: + return blk_crypto_ioctl_prepare_key(profile, argp); + default: + return -ENOTTY; + } +} |
