From patchwork Thu Nov 12 12:59:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11899967 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 47EBD15E6 for ; Thu, 12 Nov 2020 12:59:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15E8321D91 for ; Thu, 12 Nov 2020 12:59:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="N5kODHF9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728388AbgKLM7W (ORCPT ); Thu, 12 Nov 2020 07:59:22 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:49734 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728428AbgKLM7S (ORCPT ); Thu, 12 Nov 2020 07:59:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605185955; h=from:from: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=dnJhHrlydFaDDYDVAILjoCMJPy7l/G38vJ71iG4RtWQ=; b=N5kODHF92UdHNh6ocdFz2Y4pd60VYrCe44NsT8s8tjgBvcPxrMNdoYt7F9yGLi2Ea4c4Y6 c8+YcTD9a55GwEhJYcH4M5pHJjtr69Y9uVnrWSaNwo5JPkUPt2ugzoIJ8m2QXs9wbrXwcT xFzYGf5gewKAIKpabbRdwECAy0vb1wA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-385-k4rmHDhkN72dmJfCls03fA-1; Thu, 12 Nov 2020 07:59:11 -0500 X-MC-Unique: k4rmHDhkN72dmJfCls03fA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D1F2A879523; Thu, 12 Nov 2020 12:59:09 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-115-47.rdu2.redhat.com [10.10.115.47]) by smtp.corp.redhat.com (Postfix) with ESMTP id B25D960C13; Thu, 12 Nov 2020 12:59:07 +0000 (UTC) Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 10/18] crypto/krb5: Implement the AES encrypt/decrypt from rfc8009 From: David Howells To: herbert@gondor.apana.org.au, bfields@fieldses.org Cc: dhowells@redhat.com, trond.myklebust@hammerspace.com, linux-crypto@vger.kernel.org, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 12 Nov 2020 12:59:06 +0000 Message-ID: <160518594688.2277919.5319312384536950170.stgit@warthog.procyon.org.uk> In-Reply-To: <160518586534.2277919.14475638653680231924.stgit@warthog.procyon.org.uk> References: <160518586534.2277919.14475638653680231924.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.23 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Implement encryption and decryption functions for AES + HMAC-SHA2 as described in rfc8009 sec 5. Signed-off-by: David Howells --- crypto/krb5/rfc8009_aes2.c | 205 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 203 insertions(+), 2 deletions(-) diff --git a/crypto/krb5/rfc8009_aes2.c b/crypto/krb5/rfc8009_aes2.c index 9f0f0f410d91..df517435be73 100644 --- a/crypto/krb5/rfc8009_aes2.c +++ b/crypto/krb5/rfc8009_aes2.c @@ -10,6 +10,7 @@ #include #include #include +#include #include "internal.h" static const struct krb5_buffer rfc8009_no_context = { .len = 0, .data = "" }; @@ -183,13 +184,213 @@ static int rfc8009_random_to_key(const struct krb5_enctype *krb5, return 0; } +/* + * Apply encryption and checksumming functions to part of an skbuff. + */ +static ssize_t rfc8009_encrypt(const struct krb5_enctype *krb5, + struct krb5_enc_keys *keys, + struct scatterlist *sg, unsigned nr_sg, size_t sg_len, + size_t data_offset, size_t data_len, + bool preconfounded) +{ + struct skcipher_request *req; + struct shash_desc *desc; + ssize_t ret, done; + size_t bsize, base_len, secure_offset, secure_len, pad_len, cksum_offset; + void *buffer; + u8 *cksum, *iv; + + if (WARN_ON(data_offset != krb5->conf_len)) + return -EINVAL; /* Can't set offset on skcipher */ + + base_len = krb5->conf_len + data_len; + secure_len = base_len; + pad_len = secure_len - base_len; + secure_offset = 0; + cksum_offset = secure_offset + secure_len; + + bsize = krb5_shash_size(keys->Ki) + + krb5_digest_size(keys->Ki) + + krb5_sync_skcipher_size(keys->Ke) + + krb5_sync_skcipher_ivsize(keys->Ke); + bsize = max_t(size_t, bsize, krb5->conf_len); + bsize = max_t(size_t, bsize, krb5->block_len); + buffer = kzalloc(bsize, GFP_NOFS); + if (!buffer) + return -ENOMEM; + + /* Insert the confounder into the skb */ + ret = -EFAULT; + if (!preconfounded) { + get_random_bytes(buffer, krb5->conf_len); + done = sg_pcopy_to_buffer(sg, nr_sg, buffer, krb5->conf_len, + secure_offset); + if (done != krb5->conf_len) + goto error; + } + + /* We 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; + } + + /* Encrypt the secure region with key Ke. */ + req = buffer + + krb5_shash_size(keys->Ki) + + krb5_digest_size(keys->Ki); + iv = buffer + + krb5_shash_size(keys->Ki) + + krb5_digest_size(keys->Ki) + + krb5_sync_skcipher_size(keys->Ke); + + skcipher_request_set_sync_tfm(req, keys->Ke); + skcipher_request_set_callback(req, 0, NULL, NULL); + skcipher_request_set_crypt(req, sg, sg, secure_len, iv); + ret = crypto_skcipher_encrypt(req); + if (ret < 0) + goto error; + + /* Calculate the checksum using key Ki */ + cksum = buffer + krb5_shash_size(keys->Ki); + + desc = buffer; + desc->tfm = keys->Ki; + ret = crypto_shash_init(desc); + if (ret < 0) + goto error; + + memset(iv, 0, crypto_sync_skcipher_ivsize(keys->Ke)); + ret = crypto_shash_update(desc, iv, crypto_sync_skcipher_ivsize(keys->Ke)); + if (ret < 0) + goto error; + + ret = crypto_shash_update_sg(desc, sg, secure_offset, secure_len); + if (ret < 0) + goto error; + + ret = crypto_shash_final(desc, cksum); + if (ret < 0) + goto error; + + /* Append the checksum into the buffer. */ + ret = -EFAULT; + sg_zero_buffer(sg, nr_sg, 3, cksum_offset); + done = sg_pcopy_from_buffer(sg, nr_sg, cksum, krb5->cksum_len, cksum_offset); + if (done != krb5->cksum_len) + goto error; + + ret = secure_len + krb5->cksum_len; + +error: + kfree_sensitive(buffer); + return ret; +} + +/* + * Apply decryption and checksumming functions to part of an skbuff. 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 krb5_enc_keys *keys, + struct scatterlist *sg, unsigned nr_sg, + size_t *_offset, size_t *_len, + int *_error_code) +{ + struct skcipher_request *req; + struct shash_desc *desc; + ssize_t done; + size_t bsize, secure_len, offset = *_offset, len = *_len; + void *buffer = NULL; + int ret; + u8 *cksum, *cksum2, *iv; + + if (WARN_ON(*_offset != 0)) + return -EINVAL; /* Can't set offset on skcipher */ + + if (len < krb5->conf_len + krb5->cksum_len) { + *_error_code = 1; //RXGK_SEALED_INCON; + return -EPROTO; + } + secure_len = len - krb5->cksum_len; + + bsize = krb5_shash_size(keys->Ki) + + krb5_digest_size(keys->Ki) * 2 + + krb5_sync_skcipher_size(keys->Ke) + + krb5_sync_skcipher_ivsize(keys->Ke); + buffer = kzalloc(bsize, GFP_NOFS); + if (!buffer) + return -ENOMEM; + + cksum = buffer + + krb5_shash_size(keys->Ki); + cksum2 = buffer + + krb5_shash_size(keys->Ki) + + krb5_digest_size(keys->Ki); + req = buffer + + krb5_shash_size(keys->Ki) + + krb5_digest_size(keys->Ki) * 2; + iv = buffer + + krb5_shash_size(keys->Ki) + + krb5_digest_size(keys->Ki) * 2 + + krb5_sync_skcipher_size(keys->Ke); + + /* Calculate the checksum using key Ki */ + desc = buffer; + desc->tfm = keys->Ki; + ret = crypto_shash_init(desc); + if (ret < 0) + goto error; + + ret = crypto_shash_update(desc, iv, crypto_sync_skcipher_ivsize(keys->Ke)); + if (ret < 0) + goto error; + + ret = crypto_shash_update_sg(desc, sg, 0, secure_len); + if (ret < 0) + goto error; + + ret = crypto_shash_final(desc, cksum); + if (ret < 0) + goto error; + + /* Get the checksum from the buffer. */ + ret = -EFAULT; + done = sg_pcopy_to_buffer(sg, nr_sg, cksum2, krb5->cksum_len, + offset + len - krb5->cksum_len); + if (done != krb5->cksum_len) + goto error; + + if (memcmp(cksum, cksum2, krb5->cksum_len) != 0) { + *_error_code = 1; //RXGK_SEALED_INCON; + ret = -EPROTO; + goto error; + } + + /* Decrypt the secure region with key Ke. */ + skcipher_request_set_sync_tfm(req, keys->Ke); + skcipher_request_set_callback(req, 0, NULL, NULL); + skcipher_request_set_crypt(req, sg, sg, secure_len, iv); + ret = crypto_skcipher_decrypt(req); + + *_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, .calc_Ke = rfc8009_calc_Ke, .calc_Ki = rfc8009_calc_Ki, - .encrypt = NULL, //rfc8009_encrypt, - .decrypt = NULL, //rfc8009_decrypt, + .encrypt = rfc8009_encrypt, + .decrypt = rfc8009_decrypt, .get_mic = rfc3961_get_mic, .verify_mic = rfc3961_verify_mic, };