From mboxrd@z Thu Jan 1 00:00:00 1970 From: Denis Kenzior Date: Tue, 26 Mar 2019 16:00:40 +0000 Subject: Re: [PATCH v8 03/10] crypto: akcipher - new verify API for public key algorithms Message-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit List-Id: References: <20190326125842.24110-1-vt@altlinux.org> <20190326125842.24110-4-vt@altlinux.org> In-Reply-To: <20190326125842.24110-4-vt@altlinux.org> To: Vitaly Chikunov , Herbert Xu , David Howells , Mimi Zohar , Dmitry Kasatkin , linux-integrity@vger.kernel.org, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org 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 > Cc: keyrings@vger.kernel.org > Signed-off-by: Vitaly Chikunov > --- > 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 to this and patch 4. Regards, -Denis