From patchwork Fri Jan 17 18:35:25 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13943864 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EBAB31E0B61 for ; Fri, 17 Jan 2025 18:37:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737139049; cv=none; b=eDdFTMWQpKtMwgErcdCi2U0IjITwjmP8uIhcYY0TO3a3f0dfO9OUL5tsosEsV9MXQDjcaunpGCISBriQ7uYEtkTDMHul1IJISzF3Yg4HuWuUgxO0rJ+DZcIYTb1+9jbxIzYwv4FFoc0RCHV2m3Mat2+E1RlnEzpVR8GNACx1jgk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737139049; c=relaxed/simple; bh=+f+N2pDYteNRJ9CHlE2evYMjJyUFUhqqJzdKAVSUOsY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jwVPZY72NrloxhxtfxUBAokjsLOWBGlJVpUechRqa2yLSvbAuwlf76fxacmT4rWCqYOoipKenota3QbKYyoaRtP4Lb7/0fw1CrZvDbwWCv5CPZS3F8HYuli5cMIYevxvAyh6qp03P2E4yeuUnRdklzc9PdkB2gScFCbwS6Gwm24= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=SWhxIpg5; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SWhxIpg5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1737139047; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dyoQf0QIlekvhILl2AaZHPikE1EBHsF2ovW/aa5GPZs=; b=SWhxIpg5c5vPK+ldRjE39B9XLK21UNMKZ5ykCrfv+iGw6XArTCMOPEoJJAYdiZja1ppARF ob9JNwlA53JUd3TxH2+BsWjMCsmIjl+VckklLGM+UaUueqmW3wJJhN96Lgh4kQYCz2a6Nu uTN45GnAiWuI3WnibPXfiaD/JQp0FZo= Received: from mx-prod-mc-03.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-416-aY_J-KHCPbGQEkvsmKi1rg-1; Fri, 17 Jan 2025 13:37:23 -0500 X-MC-Unique: aY_J-KHCPbGQEkvsmKi1rg-1 X-Mimecast-MFC-AGG-ID: aY_J-KHCPbGQEkvsmKi1rg Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D4F8B19560BB; Fri, 17 Jan 2025 18:37:20 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.42.28.5]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 893AD19560BF; Fri, 17 Jan 2025 18:37:16 +0000 (UTC) From: David Howells To: Herbert Xu , Chuck Lever Cc: David Howells , Trond Myklebust , "David S. Miller" , Marc Dionne , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Eric Biggers , Ard Biesheuvel , linux-crypto@vger.kernel.org, linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH 16/24] crypto/krb5: Implement the AES encrypt/decrypt from rfc8009 Date: Fri, 17 Jan 2025 18:35:25 +0000 Message-ID: <20250117183538.881618-17-dhowells@redhat.com> In-Reply-To: <20250117183538.881618-1-dhowells@redhat.com> References: <20250117183538.881618-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Implement encryption and decryption functions for AES + HMAC-SHA2 as described in rfc8009 sec 5. Signed-off-by: David Howells cc: Herbert Xu cc: "David S. Miller" cc: Chuck Lever cc: Marc Dionne cc: Eric Dumazet cc: Jakub Kicinski cc: Paolo Abeni cc: Simon Horman cc: linux-afs@lists.infradead.org cc: linux-nfs@vger.kernel.org cc: linux-crypto@vger.kernel.org cc: netdev@vger.kernel.org --- crypto/krb5/rfc8009_aes2.c | 139 ++++++++++++++++++++++++++++++++++++- 1 file changed, 137 insertions(+), 2 deletions(-) diff --git a/crypto/krb5/rfc8009_aes2.c b/crypto/krb5/rfc8009_aes2.c index d7225187ce8b..bcf84284abff 100644 --- a/crypto/krb5/rfc8009_aes2.c +++ b/crypto/krb5/rfc8009_aes2.c @@ -234,6 +234,141 @@ int authenc_load_encrypt_keys(const struct krb5_enctype *krb5, return 0; } +/* + * Apply encryption and checksumming functions to a message. Unlike for + * RFC3961, for RFC8009, we have to chuck the starting IV into the hash first. + */ +static ssize_t rfc8009_encrypt(const struct krb5_enctype *krb5, + struct crypto_aead *aead, + struct scatterlist *sg, unsigned int nr_sg, size_t sg_len, + size_t data_offset, size_t data_len, + bool preconfounded) +{ + struct aead_request *req; + struct scatterlist bsg[2]; + ssize_t ret, done; + size_t bsize, base_len, secure_offset, secure_len, pad_len, cksum_offset; + void *buffer; + u8 *iv, *ad; + + if (WARN_ON(data_offset != krb5->conf_len)) + return -EINVAL; /* Data is in wrong place */ + + secure_offset = 0; + base_len = krb5->conf_len + data_len; + pad_len = 0; + secure_len = base_len + pad_len; + cksum_offset = secure_len; + if (WARN_ON(cksum_offset + krb5->cksum_len > sg_len)) + return -EFAULT; + + bsize = krb5_aead_size(aead) + + krb5_aead_ivsize(aead) * 2; + buffer = kzalloc(bsize, GFP_NOFS); + if (!buffer) + return -ENOMEM; + + req = buffer; + iv = buffer + krb5_aead_size(aead); + ad = buffer + krb5_aead_size(aead) + krb5_aead_ivsize(aead); + + /* Insert the confounder into the buffer */ + ret = -EFAULT; + if (!preconfounded) { + get_random_bytes(buffer, krb5->conf_len); + done = sg_pcopy_from_buffer(sg, nr_sg, buffer, krb5->conf_len, + secure_offset); + if (done != krb5->conf_len) + goto error; + } + + /* We may need to pad out to the crypto blocksize. */ + if (pad_len) { + done = sg_zero_buffer(sg, nr_sg, pad_len, data_offset + data_len); + if (done != pad_len) + goto error; + } + + /* We need to include the starting IV in the hash. */ + sg_init_table(bsg, 2); + sg_set_buf(&bsg[0], ad, krb5_aead_ivsize(aead)); + sg_chain(bsg, 2, sg); + + /* Hash and encrypt the message. */ + aead_request_set_tfm(req, aead); + aead_request_set_callback(req, 0, NULL, NULL); + aead_request_set_ad(req, krb5_aead_ivsize(aead)); + aead_request_set_crypt(req, bsg, bsg, secure_len, iv); + ret = crypto_aead_encrypt(req); + if (ret < 0) + goto error; + + ret = secure_len + krb5->cksum_len; + +error: + kfree_sensitive(buffer); + return ret; +} + +/* + * Apply decryption and checksumming functions to a message. Unlike for + * RFC3961, for RFC8009, we have to chuck the starting IV into the hash first. + * + * The offset and length are updated to reflect the actual content of the + * encrypted region. + */ +static int rfc8009_decrypt(const struct krb5_enctype *krb5, + struct crypto_aead *aead, + struct scatterlist *sg, unsigned int nr_sg, + size_t *_offset, size_t *_len) +{ + struct aead_request *req; + struct scatterlist bsg[2]; + size_t bsize; + void *buffer; + int ret; + u8 *iv, *ad; + + if (WARN_ON(*_offset != 0)) + return -EINVAL; /* Can't set offset on aead */ + + if (*_len < krb5->conf_len + krb5->cksum_len) + return -EPROTO; + + bsize = krb5_aead_size(aead) + + krb5_aead_ivsize(aead) * 2; + buffer = kzalloc(bsize, GFP_NOFS); + if (!buffer) + return -ENOMEM; + + req = buffer; + iv = buffer + krb5_aead_size(aead); + ad = buffer + krb5_aead_size(aead) + krb5_aead_ivsize(aead); + + /* We need to include the starting IV in the hash. */ + sg_init_table(bsg, 2); + sg_set_buf(&bsg[0], ad, krb5_aead_ivsize(aead)); + sg_chain(bsg, 2, sg); + + /* Decrypt the message and verify its checksum. */ + aead_request_set_tfm(req, aead); + aead_request_set_callback(req, 0, NULL, NULL); + aead_request_set_ad(req, krb5_aead_ivsize(aead)); + aead_request_set_crypt(req, bsg, bsg, *_len, iv); + ret = crypto_aead_decrypt(req); + if (ret < 0) + goto error; + + /* Adjust the boundaries of the data. */ + *_offset += krb5->conf_len; + *_len -= krb5->conf_len + krb5->cksum_len; + ret = 0; + +error: + kfree_sensitive(buffer); + return ret; +} + static const struct krb5_crypto_profile rfc8009_crypto_profile = { .calc_PRF = rfc8009_calc_PRF, .calc_Kc = rfc8009_calc_Ki, @@ -243,8 +378,8 @@ static const struct krb5_crypto_profile rfc8009_crypto_profile = { .load_encrypt_keys = authenc_load_encrypt_keys, .derive_checksum_key = rfc3961_derive_checksum_key, .load_checksum_key = rfc3961_load_checksum_key, - .encrypt = NULL, //rfc8009_encrypt, - .decrypt = NULL, //rfc8009_decrypt, + .encrypt = rfc8009_encrypt, + .decrypt = rfc8009_decrypt, .get_mic = rfc3961_get_mic, .verify_mic = rfc3961_verify_mic, };