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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 A5434C11D3D for ; Thu, 27 Feb 2020 17:49:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6852D2469F for ; Thu, 27 Feb 2020 17:49:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="uNLW7IT4"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="uNLW7IT4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729506AbgB0Rtc (ORCPT ); Thu, 27 Feb 2020 12:49:32 -0500 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:48942 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729232AbgB0Rtb (ORCPT ); Thu, 27 Feb 2020 12:49:31 -0500 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 3441D8EE181; Thu, 27 Feb 2020 09:49:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1582825771; bh=CeGIjB8Z8c/Mw0ttF8y1yqBMYzgjTDLgZPRhl2lA1jw=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=uNLW7IT4ksDsyGAKI2OCYTUJUIcmnMS23tb9JraSTV0c0Sml814ntRNhIi4ZLnmWD 6GFoX6/bXNYOPufi0hhpwYUKTV8BdcTPEl2/HeADbhnYvwnb/npnEjH9r1boLgrk2s dmGFUmO9Vxl4Wg8Fcivg5Z2F+rgIKgMgZ3cKBeeE= Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id v7HU5a_T1Lqe; Thu, 27 Feb 2020 09:49:31 -0800 (PST) Received: from jarvis.ext.hansenpartnership.com (jarvis.ext.hansenpartnership.com [153.66.160.226]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id B8BE48EE079; Thu, 27 Feb 2020 09:49:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1582825771; bh=CeGIjB8Z8c/Mw0ttF8y1yqBMYzgjTDLgZPRhl2lA1jw=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=uNLW7IT4ksDsyGAKI2OCYTUJUIcmnMS23tb9JraSTV0c0Sml814ntRNhIi4ZLnmWD 6GFoX6/bXNYOPufi0hhpwYUKTV8BdcTPEl2/HeADbhnYvwnb/npnEjH9r1boLgrk2s dmGFUmO9Vxl4Wg8Fcivg5Z2F+rgIKgMgZ3cKBeeE= Message-ID: <1582825769.18445.18.camel@HansenPartnership.com> Subject: Re: [PATCH v5 3/6] security: keys: trusted fix tpm2 authorizations From: James Bottomley To: Jarkko Sakkinen Cc: linux-integrity@vger.kernel.org, Mimi Zohar , David Woodhouse , keyrings@vger.kernel.org Date: Thu, 27 Feb 2020 09:49:29 -0800 In-Reply-To: <1582820506.18445.3.camel@HansenPartnership.com> References: <20200130101812.6271-1-James.Bottomley@HansenPartnership.com> <20200130101812.6271-4-James.Bottomley@HansenPartnership.com> <20200225164850.GB15662@linux.intel.com> <1582765091.4245.33.camel@HansenPartnership.com> <20200227161949.GD5140@linux.intel.com> <1582820506.18445.3.camel@HansenPartnership.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Thu, 2020-02-27 at 08:21 -0800, James Bottomley wrote: > On Thu, 2020-02-27 at 18:19 +0200, Jarkko Sakkinen wrote: [...] > Ok, I'll add that commit as the fixes; it certainly makes no sense to > backport this change before the above commit. This is what I currently have. Do you want me to resend the whole series? James ----8>8>8>----- From: James Bottomley Subject: [PATCH v6 3/6] security: keys: trusted: fix TPM2 authorizations In TPM 1.2 an authorization was a 20 byte number. The spec actually recommended you to hash variable length passwords and use the sha1 hash as the authorization. Because the spec doesn't require this hashing, the current authorization for trusted keys is a 40 digit hex number. For TPM 2.0 the spec allows the passing in of variable length passwords and passphrases directly, so we should allow that in trusted keys for ease of use. Update the 'blobauth' parameter to take this into account, so we can now use plain text passwords for the keys. so before keyctl add trusted kmk "new 32 blobauth=f572d396fae9206628714fb2ce00f72e94f2258f" after we will accept both the old hex sha1 form as well as a new directly supplied password: keyctl add trusted kmk "new 32 blobauth=hello keyhandle=81000001" Since a sha1 hex code must be exactly 40 bytes long and a direct password must be 20 or less, we use the length as the discriminator for which form is input. Note this is both and enhancement and a potential bug fix. The TPM 2.0 spec requires us to strip leading zeros, meaning empyty authorization is a zero length HMAC whereas we're currently passing in 20 bytes of zeros. A lot of TPMs simply accept this as OK, but the Microsoft TPM emulator rejects it with TPM_RC_BAD_AUTH, so this patch makes the Microsoft TPM emulator work with trusted keys. Signed-off-by: James Bottomley Fixes: 0fe5480303a1 ("keys, trusted: seal/unseal with TPM 2.0 chips") --- v6: change comment, eliminate else clauses and add fixes tag diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h index a94c03a61d8f..b2ed3481c6a0 100644 --- a/include/keys/trusted-type.h +++ b/include/keys/trusted-type.h @@ -30,6 +30,7 @@ struct trusted_key_options { uint16_t keytype; uint32_t keyhandle; unsigned char keyauth[TPM_DIGEST_SIZE]; + uint32_t blobauth_len; unsigned char blobauth[TPM_DIGEST_SIZE]; uint32_t pcrinfo_len; unsigned char pcrinfo[MAX_PCRINFO_SIZE]; diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index d2c5ec1e040b..add9f071d818 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -781,13 +781,33 @@ static int getoptions(char *c, struct trusted_key_payload *pay, return -EINVAL; break; case Opt_blobauth: - if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) - return -EINVAL; - res = hex2bin(opt->blobauth, args[0].from, - SHA1_DIGEST_SIZE); - if (res < 0) - return -EINVAL; + /* + * TPM 1.2 authorizations are sha1 hashes passed in as + * hex strings. TPM 2.0 authorizations are simple + * passwords (although it can take a hash as well) + */ + opt->blobauth_len = strlen(args[0].from); + + if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) { + res = hex2bin(opt->blobauth, args[0].from, + TPM_DIGEST_SIZE); + if (res < 0) + return -EINVAL; + + opt->blobauth_len = TPM_DIGEST_SIZE; + return 0; + } + + if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) { + memcpy(opt->blobauth, args[0].from, + opt->blobauth_len); + return 0; + } + + return -EINVAL; + break; + case Opt_migratable: if (*args[0].from == '0') pay->migratable = 0; diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index 08ec7f48f01d..b4a5058107c2 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -91,10 +91,12 @@ int tpm2_seal_trusted(struct tpm_chip *chip, TPM_DIGEST_SIZE); /* sensitive */ - tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1); + tpm_buf_append_u16(&buf, 4 + options->blobauth_len + payload->key_len + 1); + + tpm_buf_append_u16(&buf, options->blobauth_len); + if (options->blobauth_len) + tpm_buf_append(&buf, options->blobauth, options->blobauth_len); - tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE); - tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE); tpm_buf_append_u16(&buf, payload->key_len + 1); tpm_buf_append(&buf, payload->key, payload->key_len); tpm_buf_append_u8(&buf, payload->migratable); @@ -258,7 +260,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, NULL /* nonce */, 0, TPM2_SA_CONTINUE_SESSION, options->blobauth /* hmac */, - TPM_DIGEST_SIZE); + options->blobauth_len); rc = tpm_send(chip, buf.data, tpm_buf_length(&buf)); if (rc > 0)