Re: [PATCH v4] mmc: host: sdhci-msm: Add support for wrapped keys

[Adrian Hunter <adrian.hunter@intel.com>]

On 02/01/2026 14:40, Neeraj Soni wrote:
> Add the wrapped key support for sdhci-msm by implementing the needed
> methods in struct blk_crypto_ll_ops and setting the appropriate flag in
> blk_crypto_profile::key_types_supported.
> 
> Tested on SC7280 eMMC variant.
> 
> How to test:
> 
> Use the "v1.3.0" tag from https://github.com/google/fscryptctl and build
> fscryptctl that supports generating wrapped keys.
> 
> Enable the following config options:
> CONFIG_BLK_INLINE_ENCRYPTION=y
> CONFIG_QCOM_INLINE_CRYPTO_ENGINE=y
> CONFIG_FS_ENCRYPTION_INLINE_CRYPT=y
> CONFIG_MMC_CRYPTO=y
> 
> Enable "qcom_ice.use_wrapped_keys" via kernel command line.
> 
> $ mkfs.ext4 -F -O encrypt,stable_inodes /dev/disk/by-partlabel/vm-data
> $ mount /dev/disk/by-partlabel/vm-data -o inlinecrypt /mnt
> $ fscryptctl generate_hw_wrapped_key /dev/disk/by-partlabel/vm-data > /mnt/key.longterm
> $ fscryptctl prepare_hw_wrapped_key /dev/disk/by-partlabel/vm-data < /mnt/key.longterm > /tmp/key.ephemeral
> $ KEYID=$(fscryptctl add_key --hw-wrapped-key < /tmp/key.ephemeral /mnt)
> $ rm -rf /mnt/dir
> $ mkdir /mnt/dir
> $ fscryptctl set_policy --iv-ino-lblk-32 "$KEYID" /mnt/dir
> $ dmesg > /mnt/dir/test.txt
> $ sync
> 
> Reboot the board
> 
> $ mount /dev/disk/by-partlabel/vm-data -o inlinecrypt /mnt
> $ ls /mnt/dir # File should be encrypted
> $ fscryptctl prepare_hw_wrapped_key /dev/disk/by-partlabel/vm-data < /mnt/key.longterm > /tmp/key.ephemeral
> $ KEYID=$(fscryptctl add_key --hw-wrapped-key < /tmp/key.ephemeral /mnt)
> $ fscryptctl set_policy --iv-ino-lblk-32 "$KEYID" /mnt/dir
> $ cat /mnt/dir/test.txt # File should now be decrypted
> 
> Tested-by: Wenjia Zhang <wenjia.zhang@oss.qualcomm.com>
> Signed-off-by: Neeraj Soni <neeraj.soni@oss.qualcomm.com>

Doesn't apply cleanly to mmc next.  Otherwise:

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> 
> ---
> This is a reworked version of the patchset
> https://lore.kernel.org/all/20241101031539.13285-1-quic_spuppala@quicinc.com/
> that was sent by Seshu Madhavi Puppala.
> 
> My changes rebase it to use the custom crypto profile support.
> 
> Changes in v4:
> - Updated the link for fscryptctl tool in commit message to "https://github.com/google/fscryptctl".
> - Aligned the indentation at few places.
> - Unwrapped few lines of code.
> 
> Changes in v3:
> - Updated commit message with test details and moved "Signed-off-by" above the
>   scissors line.
> 
> Changes in v2:
> - Updated commit message for clarity.
> 
> Changes in v1:
> - Added initial support for wrapped keys.
> ---
>  drivers/mmc/host/sdhci-msm.c | 47 +++++++++++++++++++++++++++++++-----
>  1 file changed, 41 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 4e5edbf2fc9b..8ac4aee2cb3b 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -1911,11 +1911,6 @@ static int sdhci_msm_ice_init(struct sdhci_msm_host *msm_host,
>  	if (IS_ERR_OR_NULL(ice))
>  		return PTR_ERR_OR_ZERO(ice);
>  
> -	if (qcom_ice_get_supported_key_type(ice) != BLK_CRYPTO_KEY_TYPE_RAW) {
> -		dev_warn(dev, "Wrapped keys not supported. Disabling inline encryption support.\n");
> -		return 0;
> -	}
> -
>  	msm_host->ice = ice;
>  
>  	/* Initialize the blk_crypto_profile */
> @@ -1929,7 +1924,7 @@ static int sdhci_msm_ice_init(struct sdhci_msm_host *msm_host,
>  
>  	profile->ll_ops = sdhci_msm_crypto_ops;
>  	profile->max_dun_bytes_supported = 4;
> -	profile->key_types_supported = BLK_CRYPTO_KEY_TYPE_RAW;
> +	profile->key_types_supported = qcom_ice_get_supported_key_type(ice);
>  	profile->dev = dev;
>  
>  	/*
> @@ -2009,9 +2004,49 @@ static int sdhci_msm_ice_keyslot_evict(struct blk_crypto_profile *profile,
>  	return qcom_ice_evict_key(msm_host->ice, slot);
>  }
>  
> +static int sdhci_msm_ice_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])
> +{
> +	struct sdhci_msm_host *msm_host = sdhci_msm_host_from_crypto_profile(profile);
> +
> +	return qcom_ice_derive_sw_secret(msm_host->ice, eph_key, eph_key_size,
> +					 sw_secret);
> +}
> +
> +static int sdhci_msm_ice_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])
> +{
> +	struct sdhci_msm_host *msm_host = sdhci_msm_host_from_crypto_profile(profile);
> +
> +	return qcom_ice_import_key(msm_host->ice, raw_key, raw_key_size, lt_key);
> +}
> +
> +static int sdhci_msm_ice_generate_key(struct blk_crypto_profile *profile,
> +				      u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE])
> +{
> +	struct sdhci_msm_host *msm_host = sdhci_msm_host_from_crypto_profile(profile);
> +
> +	return qcom_ice_generate_key(msm_host->ice, lt_key);
> +}
> +
> +static int sdhci_msm_ice_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])
> +{
> +	struct sdhci_msm_host *msm_host = sdhci_msm_host_from_crypto_profile(profile);
> +
> +	return qcom_ice_prepare_key(msm_host->ice, lt_key, lt_key_size, eph_key);
> +}
> +
>  static const struct blk_crypto_ll_ops sdhci_msm_crypto_ops = {
>  	.keyslot_program	= sdhci_msm_ice_keyslot_program,
>  	.keyslot_evict		= sdhci_msm_ice_keyslot_evict,
> +	.derive_sw_secret	= sdhci_msm_ice_derive_sw_secret,
> +	.import_key		= sdhci_msm_ice_import_key,
> +	.generate_key		= sdhci_msm_ice_generate_key,
> +	.prepare_key		= sdhci_msm_ice_prepare_key,
>  };
>  
>  #else /* CONFIG_MMC_CRYPTO */