Hi Vitaly,
On 03/26/2019 07:58 AM, Vitaly Chikunov wrote:
Previous akcipher .verify() just `decrypts' (using RSA encrypt which is
using public key) signature to uncover message hash, which was then
compared in upper level public_key_verify_signature() with the expected
hash value, which itself was never passed into verify().
This approach was incompatible with EC-DSA family of algorithms,
because, to verify a signature EC-DSA algorithm also needs a hash value
as input; then it's used (together with a signature divided into halves
`r||s') to produce a witness value, which is then compared with `r' to
determine if the signature is correct. Thus, for EC-DSA, nor
requirements of .verify() itself, nor its output expectations in
public_key_verify_signature() wasn't sufficient.
Make improved .verify() call which gets hash value as input and produce
complete signature check without any output besides status.
Now for the top level verification only crypto_akcipher_verify() needs
to be called and its return value inspected.
Make sure that `digest' is in kmalloc'd memory (in place of `output`) in
{public,tpm}_key_verify_signature() as insisted by Herbert Xu, and will
be changed in the following commit.
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: keyrings@xxxxxxxxxxxxxxx
Signed-off-by: Vitaly Chikunov <vt@xxxxxxxxxxxx>
---
crypto/asymmetric_keys/asym_tpm.c | 34 ++++++++-----------------
crypto/asymmetric_keys/public_key.c | 34 ++++++++-----------------
crypto/rsa-pkcs1pad.c | 29 +++++++++++++--------
crypto/testmgr.c | 50 ++++++++++++++++++++++---------------
include/crypto/akcipher.h | 36 ++++++++++++++++----------
5 files changed, 92 insertions(+), 91 deletions(-)
The TPM bits, public_key and akcipher changes look good to me. Didn't
look into testmgr.
Feel free to add
Reviewed-by: Denis Kenzior <denkenz@xxxxxxxxx>
to this and patch 4.
Regards,
-Denis
