[PATCH v4 0/4] crypto: add rsa pss support for x509

From: Hongbo Li
Date: Wed Apr 07 2021 - 09:42:28 EST


From: Hongbo Li <herberthbli@xxxxxxxxxxx>

This series of patches add support for x509 cert signed by RSA
with PSS encoding method which is described in RFC8017 [1].

According to RFC8017, there're two encoding methods for signing and
verification. One is PKCS1-v1_5 which is already supported by linux,
the other one is PSS which is not supported by linux yet.

Patch1 make x509 support rsa pss encoding. Because the hash algo used
by x509_get_sig_params() is in the asn1 "RSASSA-PSS-params"[2],
we need to parse it at x509 layer, and could ignore other params.

Patch2 adds rsa pss template. It will parse pss related params [2], such as
mgfhash and saltlen. Then do the rsa-pss verification according
to RFC8017 section [3] and [4]. The mgf function is according to
section [5].

Patch3 adds test vector for rsa pss.

Patch4 is the rsa-pss's ima patch. Also a rsa-pss patch for ima-evm-utils
has been sent. So we could use rsa-pss for ima.

Test by the following script, it tests different saltlen, hash, mgfhash.

keyctl newring test @u

while :; do
for modbits in 1024 2048 4096; do
if [ $modbits -eq 1024 ]; then
saltlen=(-1 -2 0 20 32 48 64 94)
elif [ $modbits -eq 2048 ]; then
saltlen=(-1 -2 0 20 32 48 64 222)
else
saltlen=(-1 -2 0 20 32 48 64 478)
fi

for slen in ${saltlen[@]}; do
for hash in sha1 sha224 sha256 sha384 sha512; do
for mgfhash in sha1 sha224 sha256 sha384 sha512; do
certfile="cert.der"
echo slen $slen
openssl req \
-x509 \
-${hash} \
-newkey rsa:$modbits \
-keyout key.pem \
-days 365 \
-subj '/CN=test' \
-nodes \
-sigopt rsa_padding_mode:pss \
-sigopt rsa_mgf1_md:$mgfhash \
-sigopt rsa_pss_saltlen:${slen} \
-outform der \
-out ${certfile} 2>/dev/null

exp=0
id=$(keyctl padd asymmetric testkey %keyring:test < "${certfile}")
rc=$?
if [ $rc -ne $exp ]; then
case "$exp" in
0) echo "Error: Could not load rsa-pss certificate!";;
esac
echo "modbits $modbits sha: $hash mgfhash $mgfhash saltlen: $slen"
exit 1
else
case "$rc" in
0) echo "load cert: keyid: $id modbits $modbits hash: $hash mgfhash $mgfhash saltlen $slen"
esac
fi
done
done
done
done
done

Best Regards

Hongbo

[1] https://tools.ietf.org/html/rfc8017#section-9.1
[2] https://tools.ietf.org/html/rfc8017#appendix-A.2.3
[3] https://tools.ietf.org/html/rfc8017#section-8.1.2
[4] https://tools.ietf.org/html/rfc8017#section-9.1.2
[5] https://tools.ietf.org/html/rfc8017#appendix-B.2.1

v3->v4:
-add RFC link, and more description of the patches

v2->v3:
-add the crypto/rsa-psspad.c which is missed in previous patch

v1->v2:
-rebase patches to cryptodev/master to fix the issues that
reported-by: kernel test robot <lkp@xxxxxxxxx>

Hongbo Li (4):
x509: add support for rsa-pss
crypto: support rsa-pss encoding
crypto: add rsa pss test vector
ima: add support for rsa pss verification

crypto/Makefile | 7 +-
crypto/asymmetric_keys/Makefile | 7 +-
crypto/asymmetric_keys/public_key.c | 5 +
crypto/asymmetric_keys/x509_cert_parser.c | 71 ++++-
crypto/asymmetric_keys/x509_rsapss_params.asn1 | 19 ++
crypto/rsa-psspad.c | 398 +++++++++++++++++++++++++
crypto/rsa.c | 14 +-
crypto/rsa_helper.c | 127 ++++++++
crypto/rsapss_params.asn1 | 21 ++
crypto/testmgr.c | 7 +
crypto/testmgr.h | 90 ++++++
include/crypto/internal/rsa.h | 25 +-
include/linux/oid_registry.h | 2 +
security/integrity/digsig_asymmetric.c | 18 +-
14 files changed, 791 insertions(+), 20 deletions(-)
create mode 100644 crypto/asymmetric_keys/x509_rsapss_params.asn1
create mode 100644 crypto/rsa-psspad.c
create mode 100644 crypto/rsapss_params.asn1

--
1.8.3.1