1 files changed, 229 insertions, 43 deletions

diff --git a/block/blk-crypto.c b/block/blk-crypto.c
index 45378586151f..3e7bf1974cbd 100644
--- a/block/blk-crypto.c
+++ b/block/blk-crypto.c
@@ -13,6 +13,7 @@
 #include <linux/blkdev.h>
 #include <linux/blk-crypto-profile.h>
 #include <linux/module.h>
+#include <linux/ratelimit.h>
 #include <linux/slab.h>
 
 #include "blk-crypto-internal.h"
@@ -22,24 +23,28 @@ const struct blk_crypto_mode blk_crypto_modes[] = {
 		.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,
 	},
 };
@@ -75,9 +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);
 	}
 
@@ -224,27 +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_crypto_get_keyslot(rq->q->crypto_profile,
 				      rq->crypt_ctx->bc_key,
 				      &rq->crypt_keyslot);
 }
 
-/**
- * __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)
+void __blk_crypto_rq_put_keyslot(struct request *rq)
 {
 	blk_crypto_put_keyslot(rq->crypt_keyslot);
+	rq->crypt_keyslot = NULL;
+}
+
+void __blk_crypto_free_request(struct request *rq)
+{
+	/* 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;
 }
 
 /**
@@ -281,7 +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;
 	}
 
@@ -314,17 +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)
@@ -337,8 +351,19 @@ 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 > mode->ivsize)
 		return -EINVAL;
@@ -349,9 +374,10 @@ 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;
 }
@@ -371,8 +397,10 @@ bool blk_crypto_config_supported_natively(struct block_device *bdev,
 bool blk_crypto_config_supported(struct block_device *bdev,
 				 const struct blk_crypto_config *cfg)
 {
-	return IS_ENABLED(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) ||
-	       blk_crypto_config_supported_natively(bdev, 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);
 }
 
 /**
@@ -386,43 +414,201 @@ bool blk_crypto_config_supported(struct block_device *bdev,
  * 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(struct block_device *bdev,
 			       const struct blk_crypto_key *key)
 {
 	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
- * @bdev: The block_device 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 the key wasn't in any keyslot; -errno on error.
+ * Context: May sleep.
  */
-int blk_crypto_evict_key(struct block_device *bdev,
-			 const struct blk_crypto_key *key)
+void blk_crypto_evict_key(struct block_device *bdev,
+			  const struct blk_crypto_key *key)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
+	int err;
 
 	if (blk_crypto_config_supported_natively(bdev, &key->crypto_cfg))
-		return __blk_crypto_evict_key(q->crypto_profile, key);
-
+		err = __blk_crypto_evict_key(q->crypto_profile, key);
+	else
+		err = blk_crypto_fallback_evict_key(key);
 	/*
-	 * If the block_device didn't support the key, then blk-crypto-fallback
-	 * may have been used, so try to evict the key from blk-crypto-fallback.
+	 * 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;
+	}
+}