[PATCH v4 0/5] KEYS: asymmetric: tpm2_key_rsa

Jarkko Sakkinen
2024-05-22T00:53:00Z

## Overview

Introduce tpm2_key_rsa module, which implements asymmetric TPM2 RSA key.
The feature can be enabled with the CONFIG_ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE
kconfig option. This feature allows the private key to be uploaded to
the TPM2 for signing, and software can use the public key to verify
the signatures.

The idea in the design is to over time to have submodule per key type
For instance, tpm2_key_ecdsa could be one potential future addition in
the future. Perhaps, it might sense to consider at that point also a
top-level tpm2_key module. The gist is that the naming convention is
free from potential future bottlencks.

### Testing

tpm2_createprimary --hierarchy o -G rsa2048 -c owner.txt
tpm2_evictcontrol -c owner.txt 0x81000001
tpm2_getcap handles-persistent
openssl genrsa -out private.pem 2048
tpm2_import -C 0x81000001 -G rsa -i private.pem -u key.pub -r key.priv
tpm2_encodeobject -C 0x81000001 -u key.pub -r key.priv -o key.priv.pem
openssl asn1parse -inform pem -in key.priv.pem -noout -out key.priv.der
serial=`cat key.priv.der | keyctl padd asymmetric tpm @u`
echo "abcdefg" > plaintext.txt
keyctl pkey_encrypt $serial 0 plaintext.txt enc=pkcs1 > encrypted.dat
keyctl pkey_decrypt $serial 0 encrypted.dat enc=pkcs1 > decrypted.dat
keyctl pkey_sign $serial 0 plaintext.txt enc=pkcs1 hash=sha256 > signed.dat
keyctl pkey_verify $serial 0 plaintext.txt signed.dat enc=pkcs1 hash=sha256

## References

- v1: https://lore.kernel.org/linux-integrity/20240520184727.22038-1-jarkko@kernel.org/
- Derived from https://lore.kernel.org/all/20200518172704.29608-1-prestwoj@gmail.com/

James Prestwood (1):
keys: asymmetric: ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE

Jarkko Sakkinen (4):
crypto: rsa-pkcs1pad: export rsa1_asn_lookup()
KEYS: trusted: Change -EINVAL to -E2BIG
KEYS: trusted: Move tpm2_key_decode() to the TPM driver
tpm: tpm2_key: Extend parser to TPM_LoadableKey

crypto/asymmetric_keys/Kconfig | 15 +
crypto/asymmetric_keys/Makefile | 1 +
crypto/asymmetric_keys/tpm2_key_rsa.c | 670 ++++++++++++++++++
crypto/rsa-pkcs1pad.c | 16 +-
drivers/char/tpm/Kconfig | 1 +
drivers/char/tpm/Makefile | 5 +
drivers/char/tpm/tpm2_key.c | 118 +++
.../char/tpm}/tpm2key.asn1 | 0
include/crypto/rsa-pkcs1pad.h | 20 +
include/crypto/tpm2_key.h | 35 +
include/linux/tpm.h | 2 +
security/keys/trusted-keys/Makefile | 2 -
security/keys/trusted-keys/trusted_tpm2.c | 131 +---
13 files changed, 898 insertions(+), 118 deletions(-)
create mode 100644 crypto/asymmetric_keys/tpm2_key_rsa.c
create mode 100644 drivers/char/tpm/tpm2_key.c
rename {security/keys/trusted-keys => drivers/char/tpm}/tpm2key.asn1 (100%)
create mode 100644 include/crypto/rsa-pkcs1pad.h
create mode 100644 include/crypto/tpm2_key.h

--
2.45.1