From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A06B2C44501 for ; Tue, 14 Jul 2026 09:32:27 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wjZUw-0003lN-25; Tue, 14 Jul 2026 05:32:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wjZUu-0003ks-3s for qemu-arm@nongnu.org; Tue, 14 Jul 2026 05:32:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wjZUr-0000vu-BC for qemu-arm@nongnu.org; Tue, 14 Jul 2026 05:32:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1784021530; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=imQvlJ6xk7HfeVfEIkFIq2CJ82cuwFXXyGav6xvanHk=; b=P/sQilELIey7V/ycYltDkdFaD+XBq74rLT0S2dTkgeaHu5F6By2e3EIQhq0bP7v49ogkRq tbbgfoj/UHfDLDT8rH5blC2Rm4DUoz9lwTIA0Xjf8Fq7gpiRjSeWjxG88i0vucFCcZf/Dy rmNkRQwm5DgVIvtb2UGsUrYndH91t40= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-261-D8Cn037fPUeD4gFRXYaZTQ-1; Tue, 14 Jul 2026 05:32:07 -0400 X-MC-Unique: D8Cn037fPUeD4gFRXYaZTQ-1 X-Mimecast-MFC-AGG-ID: D8Cn037fPUeD4gFRXYaZTQ_1784021525 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 82AE81956094; Tue, 14 Jul 2026 09:32:05 +0000 (UTC) Received: from redhat.com (unknown [10.44.33.163]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5A896180049F; Tue, 14 Jul 2026 09:32:00 +0000 (UTC) Date: Tue, 14 Jul 2026 10:31:56 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Jamin Lin Cc: =?utf-8?Q?C=C3=A9dric?= Le Goater , Peter Maydell , Steven Lee , Troy Lee , Kane Chen , Andrew Jeffery , Joel Stanley , Eric Blake , Markus Armbruster , Fabiano Rosas , Laurent Vivier , Paolo Bonzini , "open list:All patches CC here" , "open list:ASPEED BMCs" , Troy Lee Subject: Re: [PATCH v1 09/15] crypto/cipher-gcrypt: Implement AES-GCM Message-ID: References: <20260714072900.3023742-1-jamin_lin@aspeedtech.com> <20260714072900.3023742-10-jamin_lin@aspeedtech.com> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/2.4.0 (2026-06-19) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-Mimecast-MFC-PROC-ID: kfJ6mb-xzvAkkIDi7YDaVL8_3qAICcufUXZl-C-emQk_1784021525 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: permerror client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 12 X-Spam_score: 1.2 X-Spam_bar: + X-Spam_report: (1.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.01, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, T_SPF_PERMERROR=0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-arm@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-arm-bounces+qemu-arm=archiver.kernel.org@nongnu.org Sender: qemu-arm-bounces+qemu-arm=archiver.kernel.org@nongnu.org On Tue, Jul 14, 2026 at 08:57:24AM +0000, Jamin Lin wrote: > Hi Daniel > > > Subject: Re: [PATCH v1 09/15] crypto/cipher-gcrypt: Implement AES-GCM > > > > On Tue, Jul 14, 2026 at 07:29:14AM +0000, Jamin Lin wrote: > > > Map QCRYPTO_CIPHER_MODE_GCM to GCRY_CIPHER_MODE_GCM and > > advertise it > > > in > > > qcrypto_cipher_supports() for 128-bit block ciphers. Add a GCM driver > > > whose setiv accepts the (typically 96-bit) nonce, whose > > > encrypt/decrypt do not require block-aligned lengths, and which > > > implements setaad via > > > gcry_cipher_authenticate() and gettag via gcry_cipher_gettag(). > > > > > > Signed-off-by: Jamin Lin > > > --- > > > crypto/cipher-gcrypt.c.inc | 101 > > > +++++++++++++++++++++++++++++++++++++ > > > 1 file changed, 101 insertions(+) > > > > > > diff --git a/crypto/cipher-gcrypt.c.inc b/crypto/cipher-gcrypt.c.inc > > > index 12eb9ddb5a..fce09a3c77 100644 > > > --- a/crypto/cipher-gcrypt.c.inc > > > +++ b/crypto/cipher-gcrypt.c.inc > > > @@ -65,6 +65,8 @@ static int > > qcrypto_cipher_mode_to_gcry_mode(QCryptoCipherMode mode) > > > return GCRY_CIPHER_MODE_CBC; > > > case QCRYPTO_CIPHER_MODE_CTR: > > > return GCRY_CIPHER_MODE_CTR; > > > + case QCRYPTO_CIPHER_MODE_GCM: > > > + return GCRY_CIPHER_MODE_GCM; > > > default: > > > return GCRY_CIPHER_MODE_NONE; > > > } > > > @@ -104,6 +106,10 @@ bool qcrypto_cipher_supports(QCryptoCipherAlgo > > alg, > > > case QCRYPTO_CIPHER_MODE_XTS: > > > case QCRYPTO_CIPHER_MODE_CTR: > > > return true; > > > + case QCRYPTO_CIPHER_MODE_GCM: > > > + /* GCM requires a 128-bit block cipher. */ > > > + return gcry_cipher_get_algo_blklen( > > > + qcrypto_cipher_alg_to_gcry_alg(alg)) == 16; > > > default: > > > return false; > > > } > > > @@ -228,6 +234,99 @@ static const struct QCryptoCipherDriver > > qcrypto_gcrypt_ctr_driver = { > > > .cipher_free = qcrypto_gcrypt_ctx_free, }; > > > > > > +/* > > > + * GCM is an AEAD stream mode: the IV/nonce need not match the block > > > +size, > > > + * the message length need not be a multiple of the block size, > > > +associated > > > + * data is fed with gcry_cipher_authenticate() and the authentication > > > +tag is > > > + * read back with gcry_cipher_gettag(). > > > + */ > > > +static int qcrypto_gcrypt_gcm_setiv(QCryptoCipher *cipher, > > > + const uint8_t *iv, size_t niv, > > > + Error **errp) { > > > + QCryptoCipherGcrypt *ctx = container_of(cipher, > > QCryptoCipherGcrypt, base); > > > + gcry_error_t err; > > > + > > > + gcry_cipher_reset(ctx->handle); > > > + err = gcry_cipher_setiv(ctx->handle, iv, niv); > > > + if (err != 0) { > > > + error_setg(errp, "Cannot set IV: %s", gcry_strerror(err)); > > > + return -1; > > > + } > > > + > > > + return 0; > > > +} > > > > > > +static int qcrypto_gcrypt_gcm_encrypt(QCryptoCipher *cipher, const void > > *in, > > > + void *out, size_t len, Error > > > +**errp) { > > > + QCryptoCipherGcrypt *ctx = container_of(cipher, > > QCryptoCipherGcrypt, base); > > > + gcry_error_t err; > > > + > > > + err = gcry_cipher_encrypt(ctx->handle, out, len, in, len); > > > + if (err != 0) { > > > + error_setg(errp, "Cannot encrypt data: %s", gcry_strerror(err)); > > > + return -1; > > > + } > > > + > > > + return 0; > > > +} > > > + > > > +static int qcrypto_gcrypt_gcm_decrypt(QCryptoCipher *cipher, const void > > *in, > > > + void *out, size_t len, Error > > > +**errp) { > > > + QCryptoCipherGcrypt *ctx = container_of(cipher, > > QCryptoCipherGcrypt, base); > > > + gcry_error_t err; > > > + > > > + err = gcry_cipher_decrypt(ctx->handle, out, len, in, len); > > > + if (err != 0) { > > > + error_setg(errp, "Cannot decrypt data: %s", gcry_strerror(err)); > > > + return -1; > > > + } > > > + > > > + return 0; > > > +} > > > > Is there a reason you can't use the common qcrypto_gcrypt_setiv, > > qcrypto_gcrypt_decrypt and qcrypto_gcrypt_encrypt methods ? > > > > Thanks for the review and suggestion. > > The GCM path differs from the common methods in two input checks that GCM legitimately violates: > > - qcrypto_gcrypt_setiv() rejects niv != blocksize, but GCM uses a > 96-bit (12-byte) nonce. > - qcrypto_gcrypt_encrypt()/decrypt() reject a length that is not a > multiple of the block size, but GCM must accept arbitrary lengths > (e.g. the 60-byte NIST test vectors). > > So reusing the common methods means relaxing those two checks for GCM, > e.g.: > /* qcrypto_gcrypt_setiv() */ > if (cipher->mode != QCRYPTO_CIPHER_MODE_GCM && niv != ctx->blocksize) { > error_setg(errp, "Expected IV size %zu not %zu", ctx->blocksize, niv); > return -1; > } > /* qcrypto_gcrypt_encrypt() / _decrypt() */ > if (cipher->mode != QCRYPTO_CIPHER_MODE_GCM && > (len & (ctx->blocksize - 1))) { > error_setg(errp, "Length %zu must be a multiple of block size %zu", > len, ctx->blocksize); > return -1; > } > > I kept them separate to avoid adding GCM special-cases to the shared > block-cipher path, but I'm happy to switch the GCM driver to the common > qcrypto_gcrypt_{setiv,encrypt,decrypt} (dropping the GCM-specific ones and > keeping only the AEAD setaad/gettag hooks) > > If you prefer. I'll make that change in v2 if that's the direction you'd like. No, leave it as it is. Reviewed-by: Daniel P. Berrangé Acked-by: Daniel P. Berrangé With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|