From patchwork Fri Dec 13 04:19:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 851958 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 92EE618E368; Fri, 13 Dec 2024 04:20:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734063628; cv=none; b=a/G7fZIlBzRZGK++n86UQIHSOPljkVou8Hg+np8yK35BRVHxtrLcuBJLqw6aPdztggoccdsoUzlzyiMGp5C1EQ5Tkec7S7itgFjhM30vb0/5UjWImPx5Myv0AUixkvsoHYf6YxFfB3KPT+zuse42Z9rAC8+lTypnR4wlgwM9c9s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734063628; c=relaxed/simple; bh=upmhR6UpaCEsr2nmxCkRFfUzAUQhy1gG+fn5Qp9xlEI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=X9LvNL8tsSnEcO42niC7ZMQgc+TOkOXr6c0RvloIaSv3aMH9j9Xg0Xr5FJaAKNm3CdMIQEA821f/Mz9+PMBBZHYa7LHP6gaaRSYDnEWNFwaaTWLdrQ71gPgy/3+Y1sj+XKVWlwmaqAd+9gn5Vomq4UqksPC9L7jqN1S0N6mC8eM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=J/QArGwD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="J/QArGwD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44557C4AF0E; Fri, 13 Dec 2024 04:20:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1734063626; bh=upmhR6UpaCEsr2nmxCkRFfUzAUQhy1gG+fn5Qp9xlEI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=J/QArGwDj8UnZklwF3nqNd9kEchoSISRzrJjvGggMafixQGjetNu5JEsARse1dJVU 1MoxQ61lSVNhQGmqvYwFdYINKT+Q5Lx7a7qoqiCGswTJ0wLnfMuaD0tToK1xWPM1we HK9FIdCqlF+IOAm2wot0ceHVnpoXV291+A4zT2LmybvL+azXh6x75idJi8/XP+606W eQh+SG6rmTqUlG+62mteuwFJX7f51aPA/cvn8eyWam+tl6qbubgUHR01qdjt0k83tD 7yoQpGSXRfRLR0AX7X6aMuYi2Sxw7hheJ1YqyXpJ37GH3Ofpq5R3zmRfyDVBVaJ12y ciMvuoJk2BtSw== From: Eric Biggers To: linux-block@vger.kernel.org, linux-fscrypt@vger.kernel.org, linux-mmc@vger.kernel.org, linux-scsi@vger.kernel.org, linux-arm-msm@vger.kernel.org, Bartosz Golaszewski , Gaurav Kashyap Cc: Adrian Hunter , Alim Akhtar , Avri Altman , Bart Van Assche , Bjorn Andersson , Dmitry Baryshkov , "James E . J . Bottomley" , Jens Axboe , Konrad Dybcio , Manivannan Sadhasivam , "Martin K . Petersen" , Ulf Hansson , Bartosz Golaszewski Subject: [PATCH v10 08/15] firmware: qcom: scm: add calls for wrapped key support Date: Thu, 12 Dec 2024 20:19:51 -0800 Message-ID: <20241213041958.202565-9-ebiggers@kernel.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241213041958.202565-1-ebiggers@kernel.org> References: <20241213041958.202565-1-ebiggers@kernel.org> Precedence: bulk X-Mailing-List: linux-mmc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Gaurav Kashyap Add helper functions for the SCM calls required to support hardware-wrapped inline storage encryption keys. These SCM calls manage wrapped keys via Qualcomm's Hardware Key Manager (HWKM), which can only be accessed from TrustZone. QCOM_SCM_ES_GENERATE_ICE_KEY and QCOM_SCM_ES_IMPORT_ICE_KEY create a new long-term wrapped key, with the former making the hardware generate the key and the latter importing a raw key. QCOM_SCM_ES_PREPARE_ICE_KEY converts the key to ephemerally-wrapped form so that it can be used for inline storage encryption. These are planned to be wired up to new ioctls via the blk-crypto framework; see the proposed documentation for the hardware-wrapped keys feature for more information. Similarly there's also QCOM_SCM_ES_DERIVE_SW_SECRET which derives a "software secret" from an ephemerally-wrapped key and will be wired up to the corresponding operation in the blk_crypto_profile. These will all be used by the ICE driver in drivers/soc/qcom/ice.c. Signed-off-by: Gaurav Kashyap Signed-off-by: Bartosz Golaszewski [EB: merged related patches, fixed error handling, fixed naming, fixed docs for size parameters, fixed qcom_scm_has_wrapped_key_support(), improved comments, improved commit message.] Signed-off-by: Eric Biggers --- drivers/firmware/qcom/qcom_scm.c | 214 +++++++++++++++++++++++++ drivers/firmware/qcom/qcom_scm.h | 4 + include/linux/firmware/qcom/qcom_scm.h | 8 + 3 files changed, 226 insertions(+) diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c index 72bf87ddcd96..36f3ddcb9020 100644 --- a/drivers/firmware/qcom/qcom_scm.c +++ b/drivers/firmware/qcom/qcom_scm.c @@ -1277,10 +1277,224 @@ int qcom_scm_ice_set_key(u32 index, const u8 *key, u32 key_size, return ret; } EXPORT_SYMBOL_GPL(qcom_scm_ice_set_key); +bool qcom_scm_has_wrapped_key_support(void) +{ + return __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_ES, + QCOM_SCM_ES_DERIVE_SW_SECRET) && + __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_ES, + QCOM_SCM_ES_GENERATE_ICE_KEY) && + __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_ES, + QCOM_SCM_ES_PREPARE_ICE_KEY) && + __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_ES, + QCOM_SCM_ES_IMPORT_ICE_KEY); +} +EXPORT_SYMBOL_GPL(qcom_scm_has_wrapped_key_support); + +/** + * qcom_scm_derive_sw_secret() - Derive software secret from wrapped key + * @eph_key: an ephemerally-wrapped key + * @eph_key_size: size of @eph_key in bytes + * @sw_secret: output buffer for the software secret + * @sw_secret_size: size of the software secret to derive in bytes + * + * Derive a software secret from an ephemerally-wrapped key for software crypto + * operations. This is done by calling into the secure execution environment, + * which then calls into the hardware to unwrap and derive the secret. + * + * For more information on sw_secret, see the "Hardware-wrapped keys" section of + * Documentation/block/inline-encryption.rst. + * + * Return: 0 on success; -errno on failure. + */ +int qcom_scm_derive_sw_secret(const u8 *eph_key, size_t eph_key_size, + u8 *sw_secret, size_t sw_secret_size) +{ + struct qcom_scm_desc desc = { + .svc = QCOM_SCM_SVC_ES, + .cmd = QCOM_SCM_ES_DERIVE_SW_SECRET, + .arginfo = QCOM_SCM_ARGS(4, QCOM_SCM_RW, QCOM_SCM_VAL, + QCOM_SCM_RW, QCOM_SCM_VAL), + .owner = ARM_SMCCC_OWNER_SIP, + }; + int ret; + + void *eph_key_buf __free(qcom_tzmem) = qcom_tzmem_alloc(__scm->mempool, + eph_key_size, + GFP_KERNEL); + if (!eph_key_buf) + return -ENOMEM; + + void *sw_secret_buf __free(qcom_tzmem) = qcom_tzmem_alloc(__scm->mempool, + sw_secret_size, + GFP_KERNEL); + if (!sw_secret_buf) + return -ENOMEM; + + memcpy(eph_key_buf, eph_key, eph_key_size); + desc.args[0] = qcom_tzmem_to_phys(eph_key_buf); + desc.args[1] = eph_key_size; + desc.args[2] = qcom_tzmem_to_phys(sw_secret_buf); + desc.args[3] = sw_secret_size; + + ret = qcom_scm_call(__scm->dev, &desc, NULL); + if (!ret) + memcpy(sw_secret, sw_secret_buf, sw_secret_size); + + memzero_explicit(eph_key_buf, eph_key_size); + memzero_explicit(sw_secret_buf, sw_secret_size); + return ret; +} +EXPORT_SYMBOL_GPL(qcom_scm_derive_sw_secret); + +/** + * qcom_scm_generate_ice_key() - Generate a wrapped key for storage encryption + * @lt_key: output buffer for the long-term wrapped key + * @lt_key_size: size of @lt_key in bytes. Must be the exact wrapped key size + * used by the SoC. + * + * Generate a key using the built-in HW module in the SoC. The resulting key is + * returned wrapped with the platform-specific Key Encryption Key. + * + * Return: 0 on success; -errno on failure. + */ +int qcom_scm_generate_ice_key(u8 *lt_key, size_t lt_key_size) +{ + struct qcom_scm_desc desc = { + .svc = QCOM_SCM_SVC_ES, + .cmd = QCOM_SCM_ES_GENERATE_ICE_KEY, + .arginfo = QCOM_SCM_ARGS(2, QCOM_SCM_RW, QCOM_SCM_VAL), + .owner = ARM_SMCCC_OWNER_SIP, + }; + int ret; + + void *lt_key_buf __free(qcom_tzmem) = qcom_tzmem_alloc(__scm->mempool, + lt_key_size, + GFP_KERNEL); + if (!lt_key_buf) + return -ENOMEM; + + desc.args[0] = qcom_tzmem_to_phys(lt_key_buf); + desc.args[1] = lt_key_size; + + ret = qcom_scm_call(__scm->dev, &desc, NULL); + if (!ret) + memcpy(lt_key, lt_key_buf, lt_key_size); + + memzero_explicit(lt_key_buf, lt_key_size); + return ret; +} +EXPORT_SYMBOL_GPL(qcom_scm_generate_ice_key); + +/** + * qcom_scm_prepare_ice_key() - Re-wrap a key with the per-boot ephemeral key + * @lt_key: a long-term wrapped key + * @lt_key_size: size of @lt_key in bytes + * @eph_key: output buffer for the ephemerally-wrapped key + * @eph_key_size: size of @eph_key in bytes. Must be the exact wrapped key size + * used by the SoC. + * + * Given a long-term wrapped key, re-wrap it with the per-boot ephemeral key for + * added protection. The resulting key will only be valid for the current boot. + * + * Return: 0 on success; -errno on failure. + */ +int qcom_scm_prepare_ice_key(const u8 *lt_key, size_t lt_key_size, + u8 *eph_key, size_t eph_key_size) +{ + struct qcom_scm_desc desc = { + .svc = QCOM_SCM_SVC_ES, + .cmd = QCOM_SCM_ES_PREPARE_ICE_KEY, + .arginfo = QCOM_SCM_ARGS(4, QCOM_SCM_RO, QCOM_SCM_VAL, + QCOM_SCM_RW, QCOM_SCM_VAL), + .owner = ARM_SMCCC_OWNER_SIP, + }; + int ret; + + void *lt_key_buf __free(qcom_tzmem) = qcom_tzmem_alloc(__scm->mempool, + lt_key_size, + GFP_KERNEL); + if (!lt_key_buf) + return -ENOMEM; + + void *eph_key_buf __free(qcom_tzmem) = qcom_tzmem_alloc(__scm->mempool, + eph_key_size, + GFP_KERNEL); + if (!eph_key_buf) + return -ENOMEM; + + memcpy(lt_key_buf, lt_key, lt_key_size); + desc.args[0] = qcom_tzmem_to_phys(lt_key_buf); + desc.args[1] = lt_key_size; + desc.args[2] = qcom_tzmem_to_phys(eph_key_buf); + desc.args[3] = eph_key_size; + + ret = qcom_scm_call(__scm->dev, &desc, NULL); + if (!ret) + memcpy(eph_key, eph_key_buf, eph_key_size); + + memzero_explicit(lt_key_buf, lt_key_size); + memzero_explicit(eph_key_buf, eph_key_size); + return ret; +} +EXPORT_SYMBOL_GPL(qcom_scm_prepare_ice_key); + +/** + * qcom_scm_import_ice_key() - Import key for storage encryption + * @raw_key: the raw key to import + * @raw_key_size: size of @raw_key in bytes + * @lt_key: output buffer for the long-term wrapped key + * @lt_key_size: size of @lt_key in bytes. Must be the exact wrapped key size + * used by the SoC. + * + * Import a raw key and return a long-term wrapped key. Uses the SoC's HWKM to + * wrap the raw key using the platform-specific Key Encryption Key. + * + * Return: 0 on success; -errno on failure. + */ +int qcom_scm_import_ice_key(const u8 *raw_key, size_t raw_key_size, + u8 *lt_key, size_t lt_key_size) +{ + struct qcom_scm_desc desc = { + .svc = QCOM_SCM_SVC_ES, + .cmd = QCOM_SCM_ES_IMPORT_ICE_KEY, + .arginfo = QCOM_SCM_ARGS(4, QCOM_SCM_RO, QCOM_SCM_VAL, + QCOM_SCM_RW, QCOM_SCM_VAL), + .owner = ARM_SMCCC_OWNER_SIP, + }; + int ret; + + void *raw_key_buf __free(qcom_tzmem) = qcom_tzmem_alloc(__scm->mempool, + raw_key_size, + GFP_KERNEL); + if (!raw_key_buf) + return -ENOMEM; + + void *lt_key_buf __free(qcom_tzmem) = qcom_tzmem_alloc(__scm->mempool, + lt_key_size, + GFP_KERNEL); + if (!lt_key_buf) + return -ENOMEM; + + memcpy(raw_key_buf, raw_key, raw_key_size); + desc.args[0] = qcom_tzmem_to_phys(raw_key_buf); + desc.args[1] = raw_key_size; + desc.args[2] = qcom_tzmem_to_phys(lt_key_buf); + desc.args[3] = lt_key_size; + + ret = qcom_scm_call(__scm->dev, &desc, NULL); + if (!ret) + memcpy(lt_key, lt_key_buf, lt_key_size); + + memzero_explicit(raw_key_buf, raw_key_size); + memzero_explicit(lt_key_buf, lt_key_size); + return ret; +} +EXPORT_SYMBOL_GPL(qcom_scm_import_ice_key); + /** * qcom_scm_hdcp_available() - Check if secure environment supports HDCP. * * Return true if HDCP is supported, false if not. */ diff --git a/drivers/firmware/qcom/qcom_scm.h b/drivers/firmware/qcom/qcom_scm.h index e36b2f67607f..097369d38b84 100644 --- a/drivers/firmware/qcom/qcom_scm.h +++ b/drivers/firmware/qcom/qcom_scm.h @@ -126,10 +126,14 @@ struct qcom_tzmem_pool *qcom_scm_get_tzmem_pool(void); #define QCOM_SCM_OCMEM_UNLOCK_CMD 0x02 #define QCOM_SCM_SVC_ES 0x10 /* Enterprise Security */ #define QCOM_SCM_ES_INVALIDATE_ICE_KEY 0x03 #define QCOM_SCM_ES_CONFIG_SET_ICE_KEY 0x04 +#define QCOM_SCM_ES_DERIVE_SW_SECRET 0x07 +#define QCOM_SCM_ES_GENERATE_ICE_KEY 0x08 +#define QCOM_SCM_ES_PREPARE_ICE_KEY 0x09 +#define QCOM_SCM_ES_IMPORT_ICE_KEY 0x0a #define QCOM_SCM_SVC_HDCP 0x11 #define QCOM_SCM_HDCP_INVOKE 0x01 #define QCOM_SCM_SVC_LMH 0x13 diff --git a/include/linux/firmware/qcom/qcom_scm.h b/include/linux/firmware/qcom/qcom_scm.h index 4621aec0328c..983e1591bbba 100644 --- a/include/linux/firmware/qcom/qcom_scm.h +++ b/include/linux/firmware/qcom/qcom_scm.h @@ -103,10 +103,18 @@ int qcom_scm_ocmem_unlock(enum qcom_scm_ocmem_client id, u32 offset, u32 size); bool qcom_scm_ice_available(void); int qcom_scm_ice_invalidate_key(u32 index); int qcom_scm_ice_set_key(u32 index, const u8 *key, u32 key_size, enum qcom_scm_ice_cipher cipher, u32 data_unit_size); +bool qcom_scm_has_wrapped_key_support(void); +int qcom_scm_derive_sw_secret(const u8 *eph_key, size_t eph_key_size, + u8 *sw_secret, size_t sw_secret_size); +int qcom_scm_generate_ice_key(u8 *lt_key, size_t lt_key_size); +int qcom_scm_prepare_ice_key(const u8 *lt_key, size_t lt_key_size, + u8 *eph_key, size_t eph_key_size); +int qcom_scm_import_ice_key(const u8 *raw_key, size_t raw_key_size, + u8 *lt_key, size_t lt_key_size); bool qcom_scm_hdcp_available(void); int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp); int qcom_scm_iommu_set_pt_format(u32 sec_id, u32 ctx_num, u32 pt_fmt);