From patchwork Mon Oct 11 10:02:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 12549627 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5FF6C4332F for ; Mon, 11 Oct 2021 10:03:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEBD660F5B for ; Mon, 11 Oct 2021 10:03:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235793AbhJKKFs (ORCPT ); Mon, 11 Oct 2021 06:05:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235839AbhJKKFe (ORCPT ); Mon, 11 Oct 2021 06:05:34 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A893C06176E for ; Mon, 11 Oct 2021 03:03:29 -0700 (PDT) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mZs8v-0006Sm-HC; Mon, 11 Oct 2021 12:02:49 +0200 Received: from afa by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1mZs8r-0002cx-VZ; Mon, 11 Oct 2021 12:02:45 +0200 From: Ahmad Fatoum To: =?utf-8?q?Horia_Geant=C4=83?= , Aymen Sghaier , Herbert Xu , "David S. Miller" Cc: kernel@pengutronix.de, David Gstir , Tim Harvey , Ahmad Fatoum , James Bottomley , Jarkko Sakkinen , Mimi Zohar , David Howells , James Morris , Eric Biggers , "Serge E. Hallyn" , Udit Agarwal , Jan Luebbe , Richard Weinberger , Franck LENORMAND , Sumit Garg , linux-integrity@vger.kernel.org, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v4 4/5] crypto: caam - add in-kernel interface for blob generator Date: Mon, 11 Oct 2021 12:02:37 +0200 Message-Id: <3ea6e5c37559eddfdc51f26c4dff0abbbc894839.1633946449.git-series.a.fatoum@pengutronix.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: References: MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: afa@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-integrity@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org The CAAM can be used to protect user-defined data across system reboot: - When the system is fused and boots into secure state, the master key is a unique never-disclosed device-specific key - random key is encrypted by key derived from master key - data is encrypted using the random key - encrypted data and its encrypted random key are stored alongside - This blob can now be safely stored in non-volatile memory On next power-on: - blob is loaded into CAAM - CAAM writes decrypted data either into memory or key register Add functions to realize encrypting and decrypting into memory alongside the CAAM driver. They will be used in a later commit as a source for the trusted key seal/unseal mechanism. Reviewed-by: David Gstir Tested-By: Tim Harvey Signed-off-by: Steffen Trumtrar Signed-off-by: Ahmad Fatoum Reviewed-by: Pankaj Gupta --- To: "Horia Geantă" To: Aymen Sghaier To: Herbert Xu To: "David S. Miller" Cc: James Bottomley Cc: Jarkko Sakkinen Cc: Mimi Zohar Cc: David Howells Cc: James Morris Cc: Eric Biggers Cc: "Serge E. Hallyn" Cc: Udit Agarwal Cc: Jan Luebbe Cc: David Gstir Cc: Richard Weinberger Cc: Franck LENORMAND Cc: Sumit Garg Cc: linux-integrity@vger.kernel.org Cc: keyrings@vger.kernel.org Cc: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-security-module@vger.kernel.org --- drivers/crypto/caam/Kconfig | 3 +- drivers/crypto/caam/Makefile | 1 +- drivers/crypto/caam/blob_gen.c | 230 ++++++++++++++++++++++++++++++++++- include/soc/fsl/caam-blob.h | 56 ++++++++- 4 files changed, 290 insertions(+) create mode 100644 drivers/crypto/caam/blob_gen.c create mode 100644 include/soc/fsl/caam-blob.h diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig index 84ea7cba5ee5..ea9f8b1ae981 100644 --- a/drivers/crypto/caam/Kconfig +++ b/drivers/crypto/caam/Kconfig @@ -151,6 +151,9 @@ config CRYPTO_DEV_FSL_CAAM_RNG_API Selecting this will register the SEC4 hardware rng to the hw_random API for supplying the kernel entropy pool. +config CRYPTO_DEV_FSL_CAAM_BLOB_GEN + bool + endif # CRYPTO_DEV_FSL_CAAM_JR endif # CRYPTO_DEV_FSL_CAAM diff --git a/drivers/crypto/caam/Makefile b/drivers/crypto/caam/Makefile index 3570286eb9ce..25f7ae5a4642 100644 --- a/drivers/crypto/caam/Makefile +++ b/drivers/crypto/caam/Makefile @@ -21,6 +21,7 @@ caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += caamalg_qi.o caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_AHASH_API) += caamhash.o caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_API) += caamrng.o caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_PKC_API) += caampkc.o pkc_desc.o +caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_BLOB_GEN) += blob_gen.o caam-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += qi.o ifneq ($(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI),) diff --git a/drivers/crypto/caam/blob_gen.c b/drivers/crypto/caam/blob_gen.c new file mode 100644 index 000000000000..513d3f90e438 --- /dev/null +++ b/drivers/crypto/caam/blob_gen.c @@ -0,0 +1,230 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 Pengutronix, Steffen Trumtrar + * Copyright (C) 2021 Pengutronix, Ahmad Fatoum + */ + +#include +#include + +#include "compat.h" +#include "desc_constr.h" +#include "desc.h" +#include "error.h" +#include "intern.h" +#include "jr.h" +#include "regs.h" + +struct caam_blob_priv { + struct device jrdev; +}; + +struct caam_blob_job_result { + int err; + struct completion completion; +}; + +static void caam_blob_job_done(struct device *dev, u32 *desc, u32 err, void *context) +{ + struct caam_blob_job_result *res = context; + int ecode = 0; + + dev_dbg(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err); + + if (err) + ecode = caam_jr_strstatus(dev, err); + + res->err = ecode; + + /* + * Upon completion, desc points to a buffer containing a CAAM job + * descriptor which encapsulates data into an externally-storable + * blob. + */ + complete(&res->completion); +} + +static u32 *caam_blob_alloc_desc(size_t keymod_len) +{ + size_t len; + + /* header + (key mod immediate) + 2x pointers + op */ + len = 4 + (4 + ALIGN(keymod_len, 4)) + 2*(4 + 4 + CAAM_PTR_SZ_MAX) + 4; + + if (len > CAAM_DESC_BYTES_MAX) + return NULL; + + return kzalloc(len, GFP_KERNEL | GFP_DMA); +} + +int caam_encap_blob(struct caam_blob_priv *priv, const char *keymod, + void *input, void *output, size_t length) +{ + u32 *desc; + struct device *jrdev = &priv->jrdev; + dma_addr_t dma_in, dma_out; + struct caam_blob_job_result testres; + size_t keymod_len = strlen(keymod); + int ret; + + if (length <= CAAM_BLOB_OVERHEAD || keymod_len > CAAM_BLOB_KEYMOD_LENGTH) + return -EINVAL; + + desc = caam_blob_alloc_desc(keymod_len); + if (!desc) { + dev_err(jrdev, "unable to allocate desc\n"); + return -ENOMEM; + } + + dma_in = dma_map_single(jrdev, input, length - CAAM_BLOB_OVERHEAD, DMA_TO_DEVICE); + if (dma_mapping_error(jrdev, dma_in)) { + dev_err(jrdev, "unable to map input DMA buffer\n"); + ret = -ENOMEM; + goto out_free; + } + + dma_out = dma_map_single(jrdev, output, length, DMA_FROM_DEVICE); + if (dma_mapping_error(jrdev, dma_out)) { + dev_err(jrdev, "unable to map output DMA buffer\n"); + ret = -ENOMEM; + goto out_unmap_in; + } + + /* + * A data blob is encrypted using a blob key (BK); a random number. + * The BK is used as an AES-CCM key. The initial block (B0) and the + * initial counter (Ctr0) are generated automatically and stored in + * Class 1 Context DWords 0+1+2+3. The random BK is stored in the + * Class 1 Key Register. Operation Mode is set to AES-CCM. + */ + + init_job_desc(desc, 0); + append_key_as_imm(desc, keymod, keymod_len, keymod_len, + CLASS_2 | KEY_DEST_CLASS_REG); + append_seq_in_ptr_intlen(desc, dma_in, length - CAAM_BLOB_OVERHEAD, 0); + append_seq_out_ptr_intlen(desc, dma_out, length, 0); + append_operation(desc, OP_TYPE_ENCAP_PROTOCOL | OP_PCLID_BLOB); + + print_hex_dump_debug("data@"__stringify(__LINE__)": ", + DUMP_PREFIX_ADDRESS, 16, 1, input, + length - CAAM_BLOB_OVERHEAD, false); + print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ", + DUMP_PREFIX_ADDRESS, 16, 1, desc, + desc_bytes(desc), false); + + testres.err = 0; + init_completion(&testres.completion); + + ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres); + if (ret == -EINPROGRESS) { + wait_for_completion(&testres.completion); + ret = testres.err; + print_hex_dump_debug("output@"__stringify(__LINE__)": ", + DUMP_PREFIX_ADDRESS, 16, 1, output, + length, false); + } + + dma_unmap_single(jrdev, dma_out, length, DMA_FROM_DEVICE); +out_unmap_in: + dma_unmap_single(jrdev, dma_in, length - CAAM_BLOB_OVERHEAD, DMA_TO_DEVICE); +out_free: + kfree(desc); + + return ret; +} +EXPORT_SYMBOL(caam_encap_blob); + +int caam_decap_blob(struct caam_blob_priv *priv, const char *keymod, + void *input, void *output, size_t length) +{ + u32 *desc; + struct device *jrdev = &priv->jrdev; + dma_addr_t dma_in, dma_out; + struct caam_blob_job_result testres; + size_t keymod_len = strlen(keymod); + int ret; + + if (length <= CAAM_BLOB_OVERHEAD || keymod_len > CAAM_BLOB_KEYMOD_LENGTH) + return -EINVAL; + + desc = caam_blob_alloc_desc(keymod_len); + if (!desc) { + dev_err(jrdev, "unable to allocate desc\n"); + return -ENOMEM; + } + + dma_in = dma_map_single(jrdev, input, length, DMA_TO_DEVICE); + if (dma_mapping_error(jrdev, dma_in)) { + dev_err(jrdev, "unable to map input DMA buffer\n"); + ret = -ENOMEM; + goto out_free; + } + + dma_out = dma_map_single(jrdev, output, length - CAAM_BLOB_OVERHEAD, DMA_FROM_DEVICE); + if (dma_mapping_error(jrdev, dma_out)) { + dev_err(jrdev, "unable to map output DMA buffer\n"); + ret = -ENOMEM; + goto out_unmap_in; + } + + /* + * A data blob is encrypted using a blob key (BK); a random number. + * The BK is used as an AES-CCM key. The initial block (B0) and the + * initial counter (Ctr0) are generated automatically and stored in + * Class 1 Context DWords 0+1+2+3. The random BK is stored in the + * Class 1 Key Register. Operation Mode is set to AES-CCM. + */ + + init_job_desc(desc, 0); + append_key_as_imm(desc, keymod, keymod_len, keymod_len, + CLASS_2 | KEY_DEST_CLASS_REG); + append_seq_in_ptr(desc, dma_in, length, 0); + append_seq_out_ptr(desc, dma_out, length - CAAM_BLOB_OVERHEAD, 0); + append_operation(desc, OP_TYPE_DECAP_PROTOCOL | OP_PCLID_BLOB); + + print_hex_dump_debug("data@"__stringify(__LINE__)": ", + DUMP_PREFIX_ADDRESS, 16, 1, input, + length, false); + print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ", + DUMP_PREFIX_ADDRESS, 16, 1, desc, + desc_bytes(desc), false); + + testres.err = 0; + init_completion(&testres.completion); + + ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres); + if (ret == -EINPROGRESS) { + wait_for_completion(&testres.completion); + ret = testres.err; + print_hex_dump_debug("output@"__stringify(__LINE__)": ", + DUMP_PREFIX_ADDRESS, 16, 1, output, + length - CAAM_BLOB_OVERHEAD, false); + } + + dma_unmap_single(jrdev, dma_out, length - CAAM_BLOB_OVERHEAD, DMA_FROM_DEVICE); +out_unmap_in: + dma_unmap_single(jrdev, dma_in, length, DMA_TO_DEVICE); +out_free: + kfree(desc); + + return ret; +} +EXPORT_SYMBOL(caam_decap_blob); + +struct caam_blob_priv *caam_blob_gen_init(void) +{ + struct device *jrdev; + + jrdev = caam_jr_alloc(); + if (IS_ERR(jrdev)) + return ERR_CAST(jrdev); + + return container_of(jrdev, struct caam_blob_priv, jrdev); +} +EXPORT_SYMBOL(caam_blob_gen_init); + +void caam_blob_gen_exit(struct caam_blob_priv *priv) +{ + caam_jr_free(&priv->jrdev); +} +EXPORT_SYMBOL(caam_blob_gen_exit); diff --git a/include/soc/fsl/caam-blob.h b/include/soc/fsl/caam-blob.h new file mode 100644 index 000000000000..83fd990ebdce --- /dev/null +++ b/include/soc/fsl/caam-blob.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 Pengutronix, Ahmad Fatoum + */ + +#ifndef __CAAM_BLOB_GEN +#define __CAAM_BLOB_GEN + +#include + +#define CAAM_BLOB_KEYMOD_LENGTH 16 +#define CAAM_BLOB_OVERHEAD (32 + 16) +#define CAAM_BLOB_MAX_LEN 4096 + +struct caam_blob_priv; + +/** caam_blob_gen_init - initialize blob generation + * + * returns either pointer to new caam_blob_priv instance + * or error pointer + */ +struct caam_blob_priv *caam_blob_gen_init(void); + +/** caam_blob_gen_exit - free blob generation resources + * + * @priv: instance returned by caam_blob_gen_init + */ +void caam_blob_gen_exit(struct caam_blob_priv *priv); + +/** caam_encap_blob - encapsulate blob + * + * @priv: instance returned by caam_blob_gen_init + * @keymod: string to use as key modifier for blob encapsulation + * can't be longer than CAAM_BLOB_KEYMOD_LENGTH + * @input: buffer which CAAM will DMA from + * @output: buffer which CAAM will DMA to + * @length: buffer length including blob overhead + * CAAM_BLOB_OVERHEAD < length <= CAAM_BLOB_MAX_LEN + */ +int caam_encap_blob(struct caam_blob_priv *priv, const char *keymod, + void *input, void *output, size_t length); + +/** caam_decap_blob - decapsulate blob + * + * @priv: instance returned by caam_blob_gen_init + * @keymod: string to use as key modifier for blob decapsulation + * can't be longer than CAAM_BLOB_KEYMOD_LENGTH + * @input: buffer which CAAM will DMA from + * @output: buffer which CAAM will DMA to + * @length: buffer length including blob overhead + * CAAM_BLOB_OVERHEAD < length <= CAAM_BLOB_MAX_LEN + */ +int caam_decap_blob(struct caam_blob_priv *priv, const char *keymod, + void *input, void *output, size_t length); + +#endif