From patchwork Fri Oct 19 18:23:02 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Winkler, Tomas" X-Patchwork-Id: 10649991 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 611223B73 for ; Fri, 19 Oct 2018 18:28:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5019C2841F for ; Fri, 19 Oct 2018 18:28:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4495C28417; Fri, 19 Oct 2018 18:28:43 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CE741283B2 for ; Fri, 19 Oct 2018 18:28:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727509AbeJTCfW (ORCPT ); Fri, 19 Oct 2018 22:35:22 -0400 Received: from mga01.intel.com ([192.55.52.88]:54192 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728145AbeJTCfV (ORCPT ); Fri, 19 Oct 2018 22:35:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Oct 2018 11:28:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,401,1534834800"; d="scan'208";a="267150326" Received: from twinkler-lnx.jer.intel.com ([10.12.91.48]) by orsmga005.jf.intel.com with ESMTP; 19 Oct 2018 11:28:05 -0700 From: Tomas Winkler To: Jarkko Sakkinen , Jason Gunthorpe Cc: Nayna Jain , Alexander Usyskin , Tadeusz Struk , linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Tomas Winkler Subject: [PATCH v7 16/21] tpm: tpm1: rewrite tpm1_get_random() using tpm_buf structure Date: Fri, 19 Oct 2018 21:23:02 +0300 Message-Id: <20181019182307.17745-17-tomas.winkler@intel.com> X-Mailer: git-send-email 2.14.4 In-Reply-To: <20181019182307.17745-1-tomas.winkler@intel.com> References: <20181019182307.17745-1-tomas.winkler@intel.com> Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP 1. Use tpm_buf in tpm1_get_random() 2. Fix comment in tpm_get_random() so it is clear that the function is expected to return number of random bytes. Signed-off-by: Tomas Winkler Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen --- V3: New in the series. V4: Resend. V5: A small adjustment in the kdoc. V6-7: Resend. drivers/char/tpm/tpm-interface.c | 2 +- drivers/char/tpm/tpm.h | 11 ------ drivers/char/tpm/tpm1-cmd.c | 84 +++++++++++++++++++++++----------------- 3 files changed, 49 insertions(+), 48 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index ba50554e34d3..8e1d2bc2df82 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -601,7 +601,7 @@ EXPORT_SYMBOL_GPL(tpm_pm_resume); * @out: destination buffer for the random bytes * @max: the max number of bytes to write to @out * - * Return: same as with tpm_transmit_cmd() + * Return: number of random bytes read or a negative error value. */ int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max) { diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index daca1d0190b1..6895f183396b 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -396,20 +396,9 @@ struct tpm_pcrread_in { * compiler warnings about stack frame size. */ #define TPM_MAX_RNG_DATA 128 -struct tpm_getrandom_out { - __be32 rng_data_len; - u8 rng_data[TPM_MAX_RNG_DATA]; -} __packed; - -struct tpm_getrandom_in { - __be32 num_bytes; -} __packed; - typedef union { struct tpm_pcrread_in pcrread_in; struct tpm_pcrread_out pcrread_out; - struct tpm_getrandom_in getrandom_in; - struct tpm_getrandom_out getrandom_out; } tpm_cmd_params; struct tpm_cmd_t { diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c index 8a84db315676..b5c4fa158c30 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -505,58 +505,70 @@ ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap, EXPORT_SYMBOL_GPL(tpm1_getcap); #define TPM_ORD_GET_RANDOM 70 -#define TPM_GETRANDOM_RESULT_SIZE 18 -static const struct tpm_input_header tpm_getrandom_header = { - .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND), - .length = cpu_to_be32(14), - .ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM) -}; +struct tpm1_get_random_out { + __be32 rng_data_len; + u8 rng_data[TPM_MAX_RNG_DATA]; +} __packed; -int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max) +/** + * tpm1_get_random() - get random bytes from the TPM's RNG + * @chip: a &struct tpm_chip instance + * @dest: destination buffer for the random bytes + * @max: the maximum number of bytes to write to @dest + * + * Return: + * * number of bytes read + * * -errno or a TPM return code otherwise + */ +int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max) { - struct tpm_cmd_t tpm_cmd; + struct tpm1_get_random_out *out; + u32 num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA); + struct tpm_buf buf; + u32 total = 0; + int retries = 5; u32 recd; - u32 num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA); - u32 rlength; - int err, total = 0, retries = 5; - u8 *dest = out; + int rc; - if (!out || !num_bytes || max > TPM_MAX_RNG_DATA) - return -EINVAL; + rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM); + if (rc) + return rc; do { - tpm_cmd.header.in = tpm_getrandom_header; - tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes); - - err = tpm_transmit_cmd(chip, NULL, &tpm_cmd, - TPM_GETRANDOM_RESULT_SIZE + num_bytes, - offsetof(struct tpm_getrandom_out, - rng_data), - 0, "attempting get random"); - if (err) - break; + tpm_buf_append_u32(&buf, num_bytes); + + rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, + sizeof(out->rng_data_len), 0, + "attempting get random"); + if (rc) + goto out; - recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len); + out = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE]; + + recd = be32_to_cpu(out->rng_data_len); if (recd > num_bytes) { - total = -EFAULT; - break; + rc = -EFAULT; + goto out; } - rlength = be32_to_cpu(tpm_cmd.header.out.length); - if (rlength < TPM_HEADER_SIZE + - offsetof(struct tpm_getrandom_out, rng_data) + - recd) { - total = -EFAULT; - break; + if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + + sizeof(out->rng_data_len) + recd) { + rc = -EFAULT; + goto out; } - memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd); + memcpy(dest, out->rng_data, recd); dest += recd; total += recd; num_bytes -= recd; - } while (retries-- && (size_t)total < max); - return total ? total : -EIO; + tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM); + } while (retries-- && total < max); + + rc = total ? (int)total : -EIO; +out: + tpm_buf_destroy(&buf); + return rc; } #define TPM_ORDINAL_PCRREAD 21