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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2BB80ECDE3A for ; Tue, 9 Oct 2018 16:48:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EE8D52087D for ; Tue, 9 Oct 2018 16:48:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EE8D52087D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-security-module-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726434AbeJJAGD (ORCPT ); Tue, 9 Oct 2018 20:06:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53728 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726415AbeJJAGD (ORCPT ); Tue, 9 Oct 2018 20:06:03 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 87D8F88319; Tue, 9 Oct 2018 16:48:12 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-149.rdu2.redhat.com [10.10.120.149]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0739C78560; Tue, 9 Oct 2018 16:48:10 +0000 (UTC) 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 Subject: [PATCH 11/22] KEYS: asym_tpm: extract key size & public key [ver #2] From: David Howells To: jmorris@namei.org Cc: Denis Kenzior , Marcel Holtmann , Marcel Holtmann , dhowells@redhat.com, denkenz@gmail.com, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 09 Oct 2018 17:48:10 +0100 Message-ID: <153910369026.12141.17387700226034691682.stgit@warthog.procyon.org.uk> In-Reply-To: <153910360263.12141.6032694262361399627.stgit@warthog.procyon.org.uk> References: <153910360263.12141.6032694262361399627.stgit@warthog.procyon.org.uk> User-Agent: StGit/unknown-version MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Tue, 09 Oct 2018 16:48:12 +0000 (UTC) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Denis Kenzior The parsed BER/DER blob obtained from user space contains a TPM_Key structure. This structure has some information about the key as well as the public key portion. This patch extracts this information for future use. Signed-off-by: Denis Kenzior Signed-off-by: David Howells Tested-by: Marcel Holtmann Reviewed-by: Marcel Holtmann --- crypto/asymmetric_keys/asym_tpm.c | 112 +++++++++++++++++++++++++++++++++++++ include/crypto/asym_tpm_subtype.h | 3 + 2 files changed, 115 insertions(+) diff --git a/crypto/asymmetric_keys/asym_tpm.c b/crypto/asymmetric_keys/asym_tpm.c index d0b2b97e8e54..308c51e055a4 100644 --- a/crypto/asymmetric_keys/asym_tpm.c +++ b/crypto/asymmetric_keys/asym_tpm.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include @@ -37,6 +38,110 @@ static void asym_tpm_destroy(void *payload0, void *payload3) kfree(tk); } +/* + * Parse enough information out of TPM_KEY structure: + * TPM_STRUCT_VER -> 4 bytes + * TPM_KEY_USAGE -> 2 bytes + * TPM_KEY_FLAGS -> 4 bytes + * TPM_AUTH_DATA_USAGE -> 1 byte + * TPM_KEY_PARMS -> variable + * UINT32 PCRInfoSize -> 4 bytes + * BYTE* -> PCRInfoSize bytes + * TPM_STORE_PUBKEY + * UINT32 encDataSize; + * BYTE* -> encDataSize; + * + * TPM_KEY_PARMS: + * TPM_ALGORITHM_ID -> 4 bytes + * TPM_ENC_SCHEME -> 2 bytes + * TPM_SIG_SCHEME -> 2 bytes + * UINT32 parmSize -> 4 bytes + * BYTE* -> variable + */ +static int extract_key_parameters(struct tpm_key *tk) +{ + const void *cur = tk->blob; + uint32_t len = tk->blob_len; + const void *pub_key; + uint32_t sz; + uint32_t key_len; + + if (len < 11) + return -EBADMSG; + + /* Ensure this is a legacy key */ + if (get_unaligned_be16(cur + 4) != 0x0015) + return -EBADMSG; + + /* Skip to TPM_KEY_PARMS */ + cur += 11; + len -= 11; + + if (len < 12) + return -EBADMSG; + + /* Make sure this is an RSA key */ + if (get_unaligned_be32(cur) != 0x00000001) + return -EBADMSG; + + /* Make sure this is TPM_ES_RSAESPKCSv15 encoding scheme */ + if (get_unaligned_be16(cur + 4) != 0x0002) + return -EBADMSG; + + /* Make sure this is TPM_SS_RSASSAPKCS1v15_DER signature scheme */ + if (get_unaligned_be16(cur + 6) != 0x0003) + return -EBADMSG; + + sz = get_unaligned_be32(cur + 8); + if (len < sz + 12) + return -EBADMSG; + + /* Move to TPM_RSA_KEY_PARMS */ + len -= 12; + cur += 12; + + /* Grab the RSA key length */ + key_len = get_unaligned_be32(cur); + + switch (key_len) { + case 512: + case 1024: + case 1536: + case 2048: + break; + default: + return -EINVAL; + } + + /* Move just past TPM_KEY_PARMS */ + cur += sz; + len -= sz; + + if (len < 4) + return -EBADMSG; + + sz = get_unaligned_be32(cur); + if (len < 4 + sz) + return -EBADMSG; + + /* Move to TPM_STORE_PUBKEY */ + cur += 4 + sz; + len -= 4 + sz; + + /* Grab the size of the public key, it should jive with the key size */ + sz = get_unaligned_be32(cur); + if (sz > 256) + return -EINVAL; + + pub_key = cur + 4; + + tk->key_len = key_len; + tk->pub_key = pub_key; + tk->pub_key_len = sz; + + return 0; +} + /* Given the blob, parse it and load it into the TPM */ struct tpm_key *tpm_key_create(const void *blob, uint32_t blob_len) { @@ -64,8 +169,15 @@ struct tpm_key *tpm_key_create(const void *blob, uint32_t blob_len) tk->blob_len = blob_len; + r = extract_key_parameters(tk); + if (r < 0) + goto error_extract; + return tk; +error_extract: + kfree(tk->blob); + tk->blob_len = 0; error_memdup: kfree(tk); error: diff --git a/include/crypto/asym_tpm_subtype.h b/include/crypto/asym_tpm_subtype.h index 03550b850998..48198c36d6b9 100644 --- a/include/crypto/asym_tpm_subtype.h +++ b/include/crypto/asym_tpm_subtype.h @@ -7,6 +7,9 @@ struct tpm_key { void *blob; u32 blob_len; + uint16_t key_len; /* Size in bits of the key */ + const void *pub_key; /* pointer inside blob to the public key bytes */ + uint16_t pub_key_len; /* length of the public key */ }; struct tpm_key *tpm_key_create(const void *blob, uint32_t blob_len);