| 0e28bf61 | 17-Jul-2024 |
David Gstir <[email protected]> |
KEYS: trusted: dcp: fix leak of blob encryption key
Trusted keys unseal the key blob on load, but keep the sealed payload in
the blob field so that every subsequent read (export) will simply
convert
KEYS: trusted: dcp: fix leak of blob encryption key
Trusted keys unseal the key blob on load, but keep the sealed payload in
the blob field so that every subsequent read (export) will simply
convert this field to hex and send it to userspace.
With DCP-based trusted keys, we decrypt the blob encryption key (BEK)
in the Kernel due hardware limitations and then decrypt the blob payload.
BEK decryption is done in-place which means that the trusted key blob
field is modified and it consequently holds the BEK in plain text.
Every subsequent read of that key thus send the plain text BEK instead
of the encrypted BEK to userspace.
This issue only occurs when importing a trusted DCP-based key and
then exporting it again. This should rarely happen as the common use cases
are to either create a new trusted key and export it, or import a key
blob and then just use it without exporting it again.
Fix this by performing BEK decryption and encryption in a dedicated
buffer. Further always wipe the plain text BEK buffer to prevent leaking
the key via uninitialized memory.
Cc: [email protected] # v6.10+
Fixes: 2e8a0f40a39c ("KEYS: trusted: Introduce NXP DCP-backed trusted keys")
Signed-off-by: David Gstir <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
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| 050bf3c7 | 13-May-2024 |
Jarkko Sakkinen <[email protected]> |
KEYS: trusted: Do not use WARN when encode fails
When asn1_encode_sequence() fails, WARN is not the correct solution.
1. asn1_encode_sequence() is not an internal function (located
in lib/asn1_e
KEYS: trusted: Do not use WARN when encode fails
When asn1_encode_sequence() fails, WARN is not the correct solution.
1. asn1_encode_sequence() is not an internal function (located
in lib/asn1_encode.c).
2. Location is known, which makes the stack trace useless.
3. Results a crash if panic_on_warn is set.
It is also noteworthy that the use of WARN is undocumented, and it
should be avoided unless there is a carefully considered rationale to
use it.
Replace WARN with pr_err, and print the return value instead, which is
only useful piece of information.
Cc: [email protected] # v5.13+
Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs")
Signed-off-by: Jarkko Sakkinen <[email protected]>
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| 52ce7d97 | 29-Apr-2024 |
James Bottomley <[email protected]> |
KEYS: trusted: Add session encryption protection to the seal/unseal path
If some entity is snooping the TPM bus, the can see the data going in
to be sealed and the data coming out as it is unsealed.
KEYS: trusted: Add session encryption protection to the seal/unseal path
If some entity is snooping the TPM bus, the can see the data going in
to be sealed and the data coming out as it is unsealed. Add parameter
and response encryption to these cases to ensure that no secrets are
leaked even if the bus is snooped.
As part of doing this conversion it was discovered that policy
sessions can't work with HMAC protected authority because of missing
pieces (the tpm Nonce). I've added code to work the same way as
before, which will result in potential authority exposure (while still
adding security for the command and the returned blob), and a fixme to
redo the API to get rid of this security hole.
Signed-off-by: James Bottomley <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Tested-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
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| e1b72e1b | 29-Apr-2024 |
Jarkko Sakkinen <[email protected]> |
tpm: Store the length of the tpm_buf data separately.
TPM2B buffers, or sized buffers, have a two byte header, which contains the
length of the payload as a 16-bit big-endian number, without countin
tpm: Store the length of the tpm_buf data separately.
TPM2B buffers, or sized buffers, have a two byte header, which contains the
length of the payload as a 16-bit big-endian number, without counting in
the space taken by the header. This differs from encoding in the TPM header
where the length includes also the bytes taken by the header.
Unbound the length of a tpm_buf from the value stored to the TPM command
header. A separate encoding and decoding step so that different buffer
types can be supported, with variant header format and length encoding.
Signed-off-by: James Bottomley <[email protected]>
Reviewed-by: Stefan Berger <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Tested-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
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| 2e8a0f40 | 03-Apr-2024 |
David Gstir <[email protected]> |
KEYS: trusted: Introduce NXP DCP-backed trusted keys
DCP (Data Co-Processor) is the little brother of NXP's CAAM IP.
Beside of accelerated crypto operations, it also offers support for
hardware-boun
KEYS: trusted: Introduce NXP DCP-backed trusted keys
DCP (Data Co-Processor) is the little brother of NXP's CAAM IP.
Beside of accelerated crypto operations, it also offers support for
hardware-bound keys. Using this feature it is possible to implement a blob
mechanism similar to what CAAM offers. Unlike on CAAM, constructing and
parsing the blob has to happen in software (i.e. the kernel).
The software-based blob format used by DCP trusted keys encrypts
the payload using AES-128-GCM with a freshly generated random key and nonce.
The random key itself is AES-128-ECB encrypted using the DCP unique
or OTP key.
The DCP trusted key blob format is:
/*
* struct dcp_blob_fmt - DCP BLOB format.
*
* @fmt_version: Format version, currently being %1
* @blob_key: Random AES 128 key which is used to encrypt @payload,
* @blob_key itself is encrypted with OTP or UNIQUE device key in
* AES-128-ECB mode by DCP.
* @nonce: Random nonce used for @payload encryption.
* @payload_len: Length of the plain text @payload.
* @payload: The payload itself, encrypted using AES-128-GCM and @blob_key,
* GCM auth tag of size AES_BLOCK_SIZE is attached at the end of it.
*
* The total size of a DCP BLOB is sizeof(struct dcp_blob_fmt) + @payload_len +
* AES_BLOCK_SIZE.
*/
struct dcp_blob_fmt {
__u8 fmt_version;
__u8 blob_key[AES_KEYSIZE_128];
__u8 nonce[AES_KEYSIZE_128];
__le32 payload_len;
__u8 payload[];
} __packed;
By default the unique key is used. It is also possible to use the
OTP key. While the unique key should be unique it is not documented how
this key is derived. Therefore selection the OTP key is supported as
well via the use_otp_key module parameter.
Co-developed-by: Richard Weinberger <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>
Co-developed-by: David Oberhollenzer <[email protected]>
Signed-off-by: David Oberhollenzer <[email protected]>
Signed-off-by: David Gstir <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
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| c745cd17 | 22-Aug-2023 |
Sumit Garg <[email protected]> |
KEYS: trusted: tee: Refactor register SHM usage
The OP-TEE driver using the old SMC based ABI permits overlapping shared
buffers, but with the new FF-A based ABI each physical page may only
be regis
KEYS: trusted: tee: Refactor register SHM usage
The OP-TEE driver using the old SMC based ABI permits overlapping shared
buffers, but with the new FF-A based ABI each physical page may only
be registered once.
As the key and blob buffer are allocated adjancently, there is no need
for redundant register shared memory invocation. Also, it is incompatibile
with FF-A based ABI limitation. So refactor register shared memory
implementation to use only single invocation to register both key and blob
buffers.
[jarkko: Added cc to stable.]
Cc: [email protected] # v5.16+
Fixes: 4615e5a34b95 ("optee: add FF-A support")
Reported-by: Jens Wiklander <[email protected]>
Signed-off-by: Sumit Garg <[email protected]>
Tested-by: Jens Wiklander <[email protected]>
Reviewed-by: Jens Wiklander <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
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| e9c5048c | 13-May-2022 |
Ahmad Fatoum <[email protected]> |
KEYS: trusted: Introduce support for NXP CAAM-based trusted keys
The Cryptographic Acceleration and Assurance Module (CAAM) is an IP core
built into many newer i.MX and QorIQ SoCs by NXP.
The CAAM
KEYS: trusted: Introduce support for NXP CAAM-based trusted keys
The Cryptographic Acceleration and Assurance Module (CAAM) is an IP core
built into many newer i.MX and QorIQ SoCs by NXP.
The CAAM does crypto acceleration, hardware number generation and
has a blob mechanism for encapsulation/decapsulation of sensitive material.
This blob mechanism depends on a device specific random 256-bit One Time
Programmable Master Key that is fused in each SoC at manufacturing
time. This key is unreadable and can only be used by the CAAM for AES
encryption/decryption of user data.
This makes it a suitable backend (source) for kernel trusted keys.
Previous commits generalized trusted keys to support multiple backends
and added an API to access the CAAM blob mechanism. Based on these,
provide the necessary glue to use the CAAM for trusted keys.
Reviewed-by: David Gstir <[email protected]>
Reviewed-by: Pankaj Gupta <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Tested-by: Tim Harvey <[email protected]>
Tested-by: Matthias Schiffer <[email protected]>
Tested-by: Pankaj Gupta <[email protected]>
Tested-by: Michael Walle <[email protected]> # on ls1028a (non-E and E)
Tested-by: John Ernberg <[email protected]> # iMX8QXP
Signed-off-by: Ahmad Fatoum <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
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| fcd7c269 | 13-May-2022 |
Ahmad Fatoum <[email protected]> |
KEYS: trusted: allow use of kernel RNG for key material
The two existing trusted key sources don't make use of the kernel RNG,
but instead let the hardware doing the sealing/unsealing also
generate
KEYS: trusted: allow use of kernel RNG for key material
The two existing trusted key sources don't make use of the kernel RNG,
but instead let the hardware doing the sealing/unsealing also
generate the random key material. However, both users and future
backends may want to place less trust into the quality of the trust
source's random number generator and instead reuse the kernel entropy
pool, which can be seeded from multiple entropy sources.
Make this possible by adding a new trusted.rng parameter,
that will force use of the kernel RNG. In its absence, it's up
to the trust source to decide, which random numbers to use,
maintaining the existing behavior.
Suggested-by: Jarkko Sakkinen <[email protected]>
Acked-by: Sumit Garg <[email protected]>
Acked-by: Pankaj Gupta <[email protected]>
Reviewed-by: David Gstir <[email protected]>
Reviewed-by: Pankaj Gupta <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Tested-by: Pankaj Gupta <[email protected]>
Tested-by: Michael Walle <[email protected]> # on ls1028a (non-E and E)
Tested-by: John Ernberg <[email protected]> # iMX8QXP
Signed-off-by: Ahmad Fatoum <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
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| c5d1ed84 | 26-Jan-2022 |
Dave Kleikamp <[email protected]> |
KEYS: trusted: Avoid calling null function trusted_key_exit
If one loads and unloads the trusted module, trusted_key_exit can be
NULL. Call it through static_call_cond() to avoid a kernel trap.
Fix
KEYS: trusted: Avoid calling null function trusted_key_exit
If one loads and unloads the trusted module, trusted_key_exit can be
NULL. Call it through static_call_cond() to avoid a kernel trap.
Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
Signed-off-by: Dave Kleikamp <[email protected]>
Cc: Sumit Garg <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Jarkko Sakkinen <[email protected]>
Cc: Mimi Zohar <[email protected]>
Cc: David Howells <[email protected]>
Cc: James Morris <[email protected]>
Cc: "Serge E. Hallyn" <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Reviewed-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
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