From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752373AbbHMOX0 (ORCPT ); Thu, 13 Aug 2015 10:23:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43219 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752647AbbHMOXY (ORCPT ); Thu, 13 Aug 2015 10:23:24 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20150813035439.25108.62457.stgit@tstruk-mobl1> References: <20150813035439.25108.62457.stgit@tstruk-mobl1> <20150813035433.25108.3065.stgit@tstruk-mobl1> To: Tadeusz Struk Cc: dhowells@redhat.com, herbert@gondor.apana.org.au, keescook@chromium.org, jwboyer@redhat.com, smueller@chronox.de, richard@nod.at, steved@redhat.com, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, james.l.morris@oracle.com, jkosina@suse.cz, zohar@linux.vnet.ibm.com, davem@davemloft.net, vgoyal@redhat.com Subject: Re: [PATCH 1/2] crypto: KEYS: convert public key to the akcipher API MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <10794.1439475796.1@warthog.procyon.org.uk> Date: Thu, 13 Aug 2015 15:23:16 +0100 Message-ID: <10795.1439475796@warthog.procyon.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tadeusz Struk wrote: > const char *const pkey_algo_name[PKEY_ALGO__LAST] = { > - [PKEY_ALGO_DSA] = "DSA", > - [PKEY_ALGO_RSA] = "RSA", > + [PKEY_ALGO_DSA] = "dsa", > + [PKEY_ALGO_RSA] = "rsa", > }; Be aware that these are exposed to userspace through /proc. The change probably doesn't matter, but you might need to update the documentation. > +int public_key_verify_signature(const struct public_key *pkey, > const struct public_key_signature *sig) > { > ... > - return algo->verify_signature(pk, sig); > + return rsa_pkcs1_v1_5_verify_signature(pkey, sig); > } No. You can't assume RSA here. It's quite likely we'll have to support ECDSA or similar soon. This must be contingent on the algorithm selected. > { > const struct public_key *pk = key->payload.data; > + > return public_key_verify_signature(pk, sig); > } That's nothing to do with this patch. > +static int rsa_signture_verify(const u8 *H, const u8 *EM, size_t k, 'signture' -> 'signature'. > +/* > + * Perform the RSA signature verification. > + * @H: Value of hash of data and metadata > + * @EM: The computed signature value > + * @k: The size of EM (EM[0] is an invalid location but should hold 0x00) > + * @hash_size: The size of H > + * @asn1_template: The DigestInfo ASN.1 template > + * @asn1_size: Size of asm1_template[] > + */ > +static int rsa_signture_verify(const u8 *H, const u8 *EM, size_t k, > + size_t hash_size, const u8 *asn1_template, > + size_t asn1_size) > +{ Why is this here and not in crypto/rsa.c? > + /* initlialzie out buf */ 'initialise'. > - /* Decode the public key */ > - ret = asn1_ber_decoder(&x509_rsakey_decoder, ctx, > - ctx->key, ctx->key_size); > - if (ret < 0) > + cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL); > + if (!cert->pub->key) > goto error_decode; The generic public key code should *not* see the container wrappings (ASN.1 from an X.509 cert in this case). The public key could be supplied by OpenPGP instead, for example, or directly by a driver. Further, at this point, we need to make sure that the data we were given has the right bits and emit EBADMSG if it doesn't. Okay, I can accept that the public_key struct might just have a list of void * and size_t fields that get filled in, one for each integer that we extract rather than MPIs, but we should not expose the generic code to the stuff we've parsed away. > struct public_key { > - const struct public_key_algorithm *algo; > - u8 capabilities; > -#define PKEY_CAN_ENCRYPT 0x01 > -#define PKEY_CAN_DECRYPT 0x02 > -#define PKEY_CAN_SIGN 0x04 > -#define PKEY_CAN_VERIFY 0x08 You still need the capabilities. The X.509 certificate and the OpenPGP message indicate restrictions on the key that we need to honour. David