diff --git a/Documentation/block/inline-encryption.rst b/Documentation/block/inline-encryption.rst index f03bd5b090d8..6380e6ab492b 100644 --- a/Documentation/block/inline-encryption.rst +++ b/Documentation/block/inline-encryption.rst @@ -492,6 +492,42 @@ when hardware support is available. This works in the following way: blk-crypto-fallback doesn't support hardware-wrapped keys. Therefore, hardware-wrapped keys can only be used with actual inline encryption hardware. +All the above deals with hardware-wrapped keys in ephemerally-wrapped form only. +To get such keys in the first place, new block device ioctls have been added to +provide a generic interface to creating and preparing such keys: + +- ``BLKCRYPTOIMPORTKEY`` converts a raw key to long-term wrapped form. It takes + in a pointer to a ``struct blk_crypto_import_key_arg``. The caller must set + ``raw_key_ptr`` and ``raw_key_size`` to the pointer and size (in bytes) of the + raw key to import. On success, ``BLKCRYPTOIMPORTKEY`` returns 0 and writes + the resulting long-term wrapped key blob to the buffer pointed to by + ``lt_key_ptr``, which is of maximum size ``lt_key_size``. It also updates + ``lt_key_size`` to be the actual size of the key. On failure, it returns -1 + and sets errno. An errno of ``EOPNOTSUPP`` indicates that the block device + does not support hardware-wrapped keys. An errno of ``EOVERFLOW`` indicates + that the output buffer did not have enough space for the key blob. + +- ``BLKCRYPTOGENERATEKEY`` is like ``BLKCRYPTOIMPORTKEY``, but it has the + hardware generate the key instead of importing one. It takes in a pointer to + a ``struct blk_crypto_generate_key_arg``. + +- ``BLKCRYPTOPREPAREKEY`` converts a key from long-term wrapped form to + ephemerally-wrapped form. It takes in a pointer to a ``struct + blk_crypto_prepare_key_arg``. The caller must set ``lt_key_ptr`` and + ``lt_key_size`` to the pointer and size (in bytes) of the long-term wrapped + key blob to convert. On success, ``BLKCRYPTOPREPAREKEY`` returns 0 and writes + the resulting ephemerally-wrapped key blob to the buffer pointed to by + ``eph_key_ptr``, which is of maximum size ``eph_key_size``. It also updates + ``eph_key_size`` to be the actual size of the key. On failure, it returns -1 + and sets errno. Errno values of ``EOPNOTSUPP`` and ``EOVERFLOW`` mean the + same as they do for ``BLKCRYPTOIMPORTKEY``. An errno of ``EBADMSG`` indicates + that the long-term wrapped key is invalid. + +Userspace needs to use either ``BLKCRYPTOIMPORTKEY`` or ``BLKCRYPTOGENERATEKEY`` +once to create a key, and then ``BLKCRYPTOPREPAREKEY`` each time the key is +unlocked and added to the kernel. Note that these ioctls have no relevance for +raw keys; they are only for hardware-wrapped keys. + Testability ----------- diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst index 6d1465315df3..d448c010d307 100644 --- a/Documentation/userspace-api/ioctl/ioctl-number.rst +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst @@ -85,6 +85,8 @@ Code Seq# Include File Comments 0x10 20-2F arch/s390/include/uapi/asm/hypfs.h 0x12 all linux/fs.h BLK* ioctls linux/blkpg.h + linux/blkzoned.h + linux/blk-crypto.h 0x15 all linux/fs.h FS_IOC_* ioctls 0x1b all InfiniBand Subsystem diff --git a/block/blk-crypto-internal.h b/block/blk-crypto-internal.h index 1893df9a8f06..ccf6dff6ff6b 100644 --- a/block/blk-crypto-internal.h +++ b/block/blk-crypto-internal.h @@ -83,6 +83,9 @@ int __blk_crypto_evict_key(struct blk_crypto_profile *profile, bool __blk_crypto_cfg_supported(struct blk_crypto_profile *profile, const struct blk_crypto_config *cfg); +int blk_crypto_ioctl(struct block_device *bdev, unsigned int cmd, + void __user *argp); + #else /* CONFIG_BLK_INLINE_ENCRYPTION */ static inline int blk_crypto_sysfs_register(struct gendisk *disk) @@ -130,6 +133,12 @@ static inline bool blk_crypto_rq_has_keyslot(struct request *rq) return false; } +static inline int blk_crypto_ioctl(struct block_device *bdev, unsigned int cmd, + void __user *argp) +{ + return -ENOTTY; +} + #endif /* CONFIG_BLK_INLINE_ENCRYPTION */ void __bio_crypt_advance(struct bio *bio, unsigned int bytes); diff --git a/block/blk-crypto-profile.c b/block/blk-crypto-profile.c index a990d9026c83..94a155912bf1 100644 --- a/block/blk-crypto-profile.c +++ b/block/blk-crypto-profile.c @@ -502,6 +502,61 @@ int blk_crypto_derive_sw_secret(struct block_device *bdev, return err; } +int blk_crypto_import_key(struct blk_crypto_profile *profile, + const u8 *raw_key, size_t raw_key_size, + u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]) +{ + int ret; + + if (!profile) + return -EOPNOTSUPP; + if (!(profile->key_types_supported & BLK_CRYPTO_KEY_TYPE_HW_WRAPPED)) + return -EOPNOTSUPP; + if (!profile->ll_ops.import_key) + return -EOPNOTSUPP; + blk_crypto_hw_enter(profile); + ret = profile->ll_ops.import_key(profile, raw_key, raw_key_size, + lt_key); + blk_crypto_hw_exit(profile); + return ret; +} + +int blk_crypto_generate_key(struct blk_crypto_profile *profile, + u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]) +{ + int ret; + + if (!profile) + return -EOPNOTSUPP; + if (!(profile->key_types_supported & BLK_CRYPTO_KEY_TYPE_HW_WRAPPED)) + return -EOPNOTSUPP; + if (!profile->ll_ops.generate_key) + return -EOPNOTSUPP; + blk_crypto_hw_enter(profile); + ret = profile->ll_ops.generate_key(profile, lt_key); + blk_crypto_hw_exit(profile); + return ret; +} + +int blk_crypto_prepare_key(struct blk_crypto_profile *profile, + const u8 *lt_key, size_t lt_key_size, + u8 eph_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]) +{ + int ret; + + if (!profile) + return -EOPNOTSUPP; + if (!(profile->key_types_supported & BLK_CRYPTO_KEY_TYPE_HW_WRAPPED)) + return -EOPNOTSUPP; + if (!profile->ll_ops.prepare_key) + return -EOPNOTSUPP; + blk_crypto_hw_enter(profile); + ret = profile->ll_ops.prepare_key(profile, lt_key, lt_key_size, + eph_key); + blk_crypto_hw_exit(profile); + return ret; +} + /** * blk_crypto_intersect_capabilities() - restrict supported crypto capabilities * by child device diff --git a/block/blk-crypto.c b/block/blk-crypto.c index 72975a980fbc..4b1ad84d1b5a 100644 --- a/block/blk-crypto.c +++ b/block/blk-crypto.c @@ -469,3 +469,146 @@ void blk_crypto_evict_key(struct block_device *bdev, 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; + } +} diff --git a/block/ioctl.c b/block/ioctl.c index 6554b728bae6..faa40f383e27 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -15,6 +15,7 @@ #include #include #include "blk.h" +#include "blk-crypto-internal.h" static int blkpg_do_ioctl(struct block_device *bdev, struct blkpg_partition __user *upart, int op) @@ -620,6 +621,10 @@ static int blkdev_common_ioctl(struct block_device *bdev, blk_mode_t mode, case BLKTRACESTOP: case BLKTRACETEARDOWN: return blk_trace_ioctl(bdev, cmd, argp); + case BLKCRYPTOIMPORTKEY: + case BLKCRYPTOGENERATEKEY: + case BLKCRYPTOPREPAREKEY: + return blk_crypto_ioctl(bdev, cmd, argp); case IOC_PR_REGISTER: return blkdev_pr_register(bdev, mode, argp); case IOC_PR_RESERVE: diff --git a/include/linux/blk-crypto-profile.h b/include/linux/blk-crypto-profile.h index 7764b4f7b45b..4f39e9cd7576 100644 --- a/include/linux/blk-crypto-profile.h +++ b/include/linux/blk-crypto-profile.h @@ -71,6 +71,48 @@ struct blk_crypto_ll_ops { int (*derive_sw_secret)(struct blk_crypto_profile *profile, const u8 *eph_key, size_t eph_key_size, u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE]); + + /** + * @import_key: Create a hardware-wrapped key by importing a raw key. + * + * This only needs to be implemented if BLK_CRYPTO_KEY_TYPE_HW_WRAPPED + * is supported. + * + * On success, must write the new key in long-term wrapped form to + * @lt_key and return its size in bytes. On failure, must return a + * -errno value. + */ + int (*import_key)(struct blk_crypto_profile *profile, + const u8 *raw_key, size_t raw_key_size, + u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]); + + /** + * @generate_key: Generate a hardware-wrapped key. + * + * This only needs to be implemented if BLK_CRYPTO_KEY_TYPE_HW_WRAPPED + * is supported. + * + * On success, must write the new key in long-term wrapped form to + * @lt_key and return its size in bytes. On failure, must return a + * -errno value. + */ + int (*generate_key)(struct blk_crypto_profile *profile, + u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]); + + /** + * @prepare_key: Prepare a hardware-wrapped key to be used. + * + * Prepare a hardware-wrapped key to be used by converting it from + * long-term wrapped form to ephemerally-wrapped form. This only needs + * to be implemented if BLK_CRYPTO_KEY_TYPE_HW_WRAPPED is supported. + * + * On success, must write the key in ephemerally-wrapped form to + * @eph_key and return its size in bytes. On failure, must return + * -EBADMSG if the key is invalid, or another -errno on other error. + */ + int (*prepare_key)(struct blk_crypto_profile *profile, + const u8 *lt_key, size_t lt_key_size, + u8 eph_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]); }; /** @@ -163,6 +205,17 @@ void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile); void blk_crypto_profile_destroy(struct blk_crypto_profile *profile); +int blk_crypto_import_key(struct blk_crypto_profile *profile, + const u8 *raw_key, size_t raw_key_size, + u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]); + +int blk_crypto_generate_key(struct blk_crypto_profile *profile, + u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]); + +int blk_crypto_prepare_key(struct blk_crypto_profile *profile, + const u8 *lt_key, size_t lt_key_size, + u8 eph_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]); + void blk_crypto_intersect_capabilities(struct blk_crypto_profile *parent, const struct blk_crypto_profile *child); diff --git a/include/linux/blk-crypto.h b/include/linux/blk-crypto.h index 81f932b3ea37..58b0c5254a67 100644 --- a/include/linux/blk-crypto.h +++ b/include/linux/blk-crypto.h @@ -8,6 +8,7 @@ #include #include +#include enum blk_crypto_mode_num { BLK_ENCRYPTION_MODE_INVALID, diff --git a/include/uapi/linux/blk-crypto.h b/include/uapi/linux/blk-crypto.h new file mode 100644 index 000000000000..97302c6eb6af --- /dev/null +++ b/include/uapi/linux/blk-crypto.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _UAPI_LINUX_BLK_CRYPTO_H +#define _UAPI_LINUX_BLK_CRYPTO_H + +#include +#include + +struct blk_crypto_import_key_arg { + /* Raw key (input) */ + __u64 raw_key_ptr; + __u64 raw_key_size; + /* Long-term wrapped key blob (output) */ + __u64 lt_key_ptr; + __u64 lt_key_size; + __u64 reserved[4]; +}; + +struct blk_crypto_generate_key_arg { + /* Long-term wrapped key blob (output) */ + __u64 lt_key_ptr; + __u64 lt_key_size; + __u64 reserved[4]; +}; + +struct blk_crypto_prepare_key_arg { + /* Long-term wrapped key blob (input) */ + __u64 lt_key_ptr; + __u64 lt_key_size; + /* Ephemerally-wrapped key blob (output) */ + __u64 eph_key_ptr; + __u64 eph_key_size; + __u64 reserved[4]; +}; + +/* + * These ioctls share the block device ioctl space; see uapi/linux/fs.h. + * 140-141 are reserved for future blk-crypto ioctls; any more than that would + * require an additional allocation from the block device ioctl space. + */ +#define BLKCRYPTOIMPORTKEY _IOWR(0x12, 137, struct blk_crypto_import_key_arg) +#define BLKCRYPTOGENERATEKEY _IOWR(0x12, 138, struct blk_crypto_generate_key_arg) +#define BLKCRYPTOPREPAREKEY _IOWR(0x12, 139, struct blk_crypto_prepare_key_arg) + +#endif /* _UAPI_LINUX_BLK_CRYPTO_H */ diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index 2bbe00cf1248..e762e1af650c 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -212,10 +212,8 @@ struct fsxattr { #define BLKROTATIONAL _IO(0x12,126) #define BLKZEROOUT _IO(0x12,127) #define BLKGETDISKSEQ _IOR(0x12,128,__u64) -/* - * A jump here: 130-136 are reserved for zoned block devices - * (see uapi/linux/blkzoned.h) - */ +/* 130-136 are used by zoned block device ioctls (uapi/linux/blkzoned.h) */ +/* 137-141 are used by blk-crypto ioctls (uapi/linux/blk-crypto.h) */ #define BMAP_IOCTL 1 /* obsolete - kept for compatibility */ #define FIBMAP _IO(0x00,1) /* bmap access */