From patchwork Tue Nov 26 00:51:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: AKASHI Takahiro X-Patchwork-Id: 1200687 X-Patchwork-Delegate: xypron.glpk@gmx.de Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.denx.de (client-ip=81.169.180.215; helo=lists.denx.de; envelope-from=u-boot-bounces@lists.denx.de; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.b="ZaOv1/gV"; dkim-atps=neutral Received: from lists.denx.de (dione.denx.de [81.169.180.215]) by ozlabs.org (Postfix) with ESMTP id 47MQNX4W8Nz9sPT for ; Tue, 26 Nov 2019 11:52:28 +1100 (AEDT) Received: by lists.denx.de (Postfix, from userid 105) id 32F2CC21EF0; Tue, 26 Nov 2019 00:51:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lists.denx.de X-Spam-Level: X-Spam-Status: No, score=-0.0 required=5.0 tests=RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, T_DKIM_INVALID autolearn=unavailable autolearn_force=no version=3.4.0 Received: from lists.denx.de (localhost [IPv6:::1]) by lists.denx.de (Postfix) with ESMTP id 3CB34C21E70; Tue, 26 Nov 2019 00:50:51 +0000 (UTC) Received: by lists.denx.de (Postfix, from userid 105) id 79605C21E44; Tue, 26 Nov 2019 00:50:42 +0000 (UTC) Received: from mail-pf1-f196.google.com (mail-pf1-f196.google.com [209.85.210.196]) by lists.denx.de (Postfix) with ESMTPS id A0958C21E26 for ; Tue, 26 Nov 2019 00:50:40 +0000 (UTC) Received: by mail-pf1-f196.google.com with SMTP id x28so8270516pfo.6 for ; Mon, 25 Nov 2019 16:50:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=MVPPNWcBdJsSdxZ80FDt7J9kfSgBH5nRKk0DXCA41GQ=; b=ZaOv1/gVZLzcEX5IfdRm0fiShCRZOoByHrIGLvdf8gV2xGJNwfkUDhqhdPlpR57eeN CSM6JLdaDrc15UVJXaclK55cqKJen9vbbnp4Vlxt4HeB7/sfxACGu31SD78LUaiYGcR7 3g1bJGofQBFrLe7GOPzBrORSoTiTP5UAfWuDbiMJTRfiwmNLjoRvWMf6V8iXPWxMvKET bb9Nygcox2o3RCTqIBxfOHwAX8hw7CZnus3CxxurnEcE5KR+UkVvicXZizaBdhHaqk3j c8w/pgwvtd57ruKV2s6zDG90VAambsVPuVIyQWsMGOC38UCCHCgW/ARK4NR0ZTDqf+rG oAiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=MVPPNWcBdJsSdxZ80FDt7J9kfSgBH5nRKk0DXCA41GQ=; b=V2NAddaw9sPzZd7PnhsRDPnOh5Flgc+TmUpBdAfKWSprKrxpFI/MFwxt+ewIefDC+h 0lJm8oDwO27nm+nhuyfNohwZojc+QfXyECoqfhRDPPGBZDkQQNzvZBFkvCUqRkjfdsh4 zk3hLXBlz1XMZ/VVk49cRjM7mbhRJPr+IrcnrDDlebKfoAI8FuHBOmvgiBh4ZRheW5Dm H1V+y9r7V16LkBHJ9GTtcY/78eqsnLbs1pNSAxwh2yDUdHkKybyh5U7vu58kx3FvJR69 ReImsuJ+eU1q75AXkIBaEUW1CxNEyEu+/6sfBtBFedHIoFt2E+ddEGattETeNlGvvk+m hXYA== X-Gm-Message-State: APjAAAVgvKaFRlkNC3OhgTQNLhs8LaQlZ9GZ0mHL/X8QnnEdDNqYjo+1 nAIv/HQlR5wM2ig3n77eU7WNIQ== X-Google-Smtp-Source: APXvYqxrCLlOvVkdyEF0/Idyvv0OGeSQe/YsP162md3gKPgJEG7xHTmUkWDBuh2CzdSj5fy2qSQ8dg== X-Received: by 2002:a63:5f49:: with SMTP id t70mr36383764pgb.219.1574729438659; Mon, 25 Nov 2019 16:50:38 -0800 (PST) Received: from linaro.org ([121.95.100.191]) by smtp.googlemail.com with ESMTPSA id v189sm10143691pfv.133.2019.11.25.16.50.37 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 25 Nov 2019 16:50:38 -0800 (PST) From: AKASHI Takahiro To: xypron.glpk@gmx.de, agraf@csgraf.de, trini@konsulko.com Date: Tue, 26 Nov 2019 09:51:07 +0900 Message-Id: <20191126005120.31156-4-takahiro.akashi@linaro.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191126005120.31156-1-takahiro.akashi@linaro.org> References: <20191126005120.31156-1-takahiro.akashi@linaro.org> MIME-Version: 1.0 Cc: u-boot@lists.denx.de, mail@patrick-wildt.de Subject: [U-Boot] [PATCH v2 03/16] efi_loader: add signature verification functions X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.18 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" In this commit, implemented are a couple of helper functions which will be used to materialize variable authentication as well as image authentication in later patches. Signed-off-by: AKASHI Takahiro --- include/efi_api.h | 87 +++++ include/efi_loader.h | 72 ++++ lib/efi_loader/Makefile | 1 + lib/efi_loader/efi_signature.c | 584 +++++++++++++++++++++++++++++++++ 4 files changed, 744 insertions(+) create mode 100644 lib/efi_loader/efi_signature.c diff --git a/include/efi_api.h b/include/efi_api.h index 22396172e15f..47f24fc90873 100644 --- a/include/efi_api.h +++ b/include/efi_api.h @@ -18,6 +18,7 @@ #include #include +#include #ifdef CONFIG_EFI_LOADER #include @@ -307,6 +308,10 @@ struct efi_runtime_services { EFI_GUID(0x8be4df61, 0x93ca, 0x11d2, 0xaa, 0x0d, \ 0x00, 0xe0, 0x98, 0x03, 0x2b, 0x8c) +#define EFI_IMAGE_SECURITY_DATABASE_GUID \ + EFI_GUID(0xd719b2cb, 0x3d3a, 0x4596, 0xa3, 0xbc, \ + 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f) + #define EFI_FDT_GUID \ EFI_GUID(0xb1b621d5, 0xf19c, 0x41a5, \ 0x83, 0x0b, 0xd9, 0x15, 0x2c, 0x69, 0xaa, 0xe0) @@ -1616,4 +1621,86 @@ struct efi_unicode_collation_protocol { #define LOAD_OPTION_CATEGORY_BOOT 0x00000000 #define LOAD_OPTION_CATEGORY_APP 0x00000100 +/* Certificate types in signature database */ +#define EFI_CERT_SHA256_GUID \ + EFI_GUID(0xc1c41626, 0x504c, 0x4092, 0xac, 0xa9, \ + 0x41, 0xf9, 0x36, 0x93, 0x43, 0x28) +#define EFI_CERT_RSA2048_GUID \ + EFI_GUID(0x3c5766e8, 0x269c, 0x4e34, 0xaa, 0x14, \ + 0xed, 0x77, 0x6e, 0x85, 0xb3, 0xb6) +#define EFI_CERT_X509_GUID \ + EFI_GUID(0xa5c059a1, 0x94e4, 0x4aa7, 0x87, 0xb5, \ + 0xab, 0x15, 0x5c, 0x2b, 0xf0, 0x72) +#define EFI_CERT_X509_SHA256_GUID \ + EFI_GUID(0x3bd2a492, 0x96c0, 0x4079, 0xb4, 0x20, \ + 0xfc, 0xf9, 0x8e, 0xf1, 0x03, 0xed) +#define EFI_CERT_TYPE_PKCS7_GUID \ + EFI_GUID(0x4aafd29d, 0x68df, 0x49ee, 0x8a, 0xa9, \ + 0x34, 0x7d, 0x37, 0x56, 0x65, 0xa7) + +/** + * win_certificate_uefi_guid - A certificate that encapsulates + * a GUID-specific signature + * + * @hdr: Windows certificate header + * @cert_type: Certificate type + * @cert_data: Certificate data + */ +struct win_certificate_uefi_guid { + WIN_CERTIFICATE hdr; + efi_guid_t cert_type; + u8 cert_data[]; +} __attribute__((__packed__)); + +/** + * efi_variable_authentication_2 - A time-based authentication method + * descriptor + * + * This structure describes an authentication information for + * a variable with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS + * and should be included as part of a variable's value. + * Only EFI_CERT_TYPE_PKCS7_GUID is accepted. + * + * @time_stamp: Descriptor's time stamp + * @auth_info: Authentication info + */ +struct efi_variable_authentication_2 { + struct efi_time time_stamp; + struct win_certificate_uefi_guid auth_info; +} __attribute__((__packed__)); + +/** + * efi_signature_data - A format of signature + * + * This structure describes a single signature in signature database. + * + * @signature_owner: Signature owner + * @signature_data: Signature data + */ +struct efi_signature_data { + efi_guid_t signature_owner; + u8 signature_data[]; +} __attribute__((__packed__)); + +/** + * efi_signature_list - A format of signature database + * + * This structure describes a list of signatures with the same type. + * An authenticated variable's value is a concatenation of one or more + * efi_signature_list's. + * + * @signature_type: Signature type + * @signature_list_size: Size of signature list + * @signature_header_size: Size of signature header + * @signature_size: Size of signature + */ +struct efi_signature_list { + efi_guid_t signature_type; + u32 signature_list_size; + u32 signature_header_size; + u32 signature_size; +/* u8 signature_header[signature_header_size]; */ +/* struct efi_signature_data signatures[...][signature_size]; */ +} __attribute__((__packed__)); + #endif diff --git a/include/efi_loader.h b/include/efi_loader.h index 381da80cdce0..622bae6a6906 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -21,6 +21,7 @@ static inline int guidcmp(const void *g1, const void *g2) #if CONFIG_IS_ENABLED(EFI_LOADER) #include +#include /* Maximum number of configuration tables */ #define EFI_MAX_CONFIGURATION_TABLES 16 @@ -169,6 +170,11 @@ extern const efi_guid_t efi_guid_hii_config_routing_protocol; extern const efi_guid_t efi_guid_hii_config_access_protocol; extern const efi_guid_t efi_guid_hii_database_protocol; extern const efi_guid_t efi_guid_hii_string_protocol; +/* GUIDs for authentication */ +extern const efi_guid_t efi_guid_image_security_database; +extern const efi_guid_t efi_guid_sha256; +extern const efi_guid_t efi_guid_cert_x509; +extern const efi_guid_t efi_guid_cert_x509_sha256; extern unsigned int __efi_runtime_start, __efi_runtime_stop; extern unsigned int __efi_runtime_rel_start, __efi_runtime_rel_stop; @@ -650,6 +656,72 @@ void efi_deserialize_load_option(struct efi_load_option *lo, u8 *data); unsigned long efi_serialize_load_option(struct efi_load_option *lo, u8 **data); efi_status_t efi_bootmgr_load(efi_handle_t *handle); +#ifdef CONFIG_EFI_SECURE_BOOT +#include + +#define EFI_REGS_MAX 16 /* currently good enough */ + +/** + * efi_image_regions - A list of memory regions + * + * @num: Number of regions + * @reg: array of regions + */ +struct efi_image_regions { + int num; + struct image_region reg[EFI_REGS_MAX]; +}; + +/** + * efi_sig_data - A decoded data of struct efi_signature_data + * + * This structure represents an internal form of signature in + * signature database. A listed list may represent a signature list. + * + * @next: Pointer to next entry + * @onwer: Signature owner + * @data: Pointer to signature data + * @size: Size of signature data + */ +struct efi_sig_data { + struct efi_sig_data *next; + efi_guid_t owner; + void *data; + size_t size; +}; + +/** + * efi_signature_store - A decoded data of signature database + * + * This structure represents an internal form of signature database. + * + * @next: Pointer to next entry + * @sig_type: Signature type + * @sig_data_list: Pointer to signature list + */ +struct efi_signature_store { + struct efi_signature_store *next; + efi_guid_t sig_type; + struct efi_sig_data *sig_data_list; +}; + +struct x509_certificate; +struct pkcs7_message; + +bool efi_signature_verify_cert(struct x509_certificate *cert, + struct efi_signature_store *dbx); +bool efi_signature_verify_signers(struct pkcs7_message *msg, + struct efi_signature_store *dbx); +bool efi_signature_verify_with_sigdb(struct efi_image_regions *regs, + struct pkcs7_message *msg, + struct efi_signature_store *db, + struct x509_certificate **cert); + +efi_status_t efi_image_region_add(struct efi_image_regions *regs, + const void *start, const void *end, + int nocheck); +#endif /* CONFIG_EFI_SECURE_BOOT */ + #else /* CONFIG_IS_ENABLED(EFI_LOADER) */ /* Without CONFIG_EFI_LOADER we don't have a runtime section, stub it out */ diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile index 7db406028618..3ffbfe78a46b 100644 --- a/lib/efi_loader/Makefile +++ b/lib/efi_loader/Makefile @@ -42,3 +42,4 @@ obj-$(CONFIG_PARTITIONS) += efi_disk.o obj-$(CONFIG_NET) += efi_net.o obj-$(CONFIG_GENERATE_ACPI_TABLE) += efi_acpi.o obj-$(CONFIG_GENERATE_SMBIOS_TABLE) += efi_smbios.o +obj-y += efi_signature.o diff --git a/lib/efi_loader/efi_signature.c b/lib/efi_loader/efi_signature.c new file mode 100644 index 000000000000..87a39b790f67 --- /dev/null +++ b/lib/efi_loader/efi_signature.c @@ -0,0 +1,584 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2018 Patrick Wildt + * Copyright (c) 2019 Linaro Limited, Author: AKASHI Takahiro + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +/* + * avoid duplicated inclusion: + * #include "../lib/crypto/x509_parser.h" + */ +#include "../lib/crypto/pkcs7_parser.h" + +const efi_guid_t efi_guid_image_security_database = + EFI_IMAGE_SECURITY_DATABASE_GUID; +const efi_guid_t efi_guid_sha256 = EFI_CERT_SHA256_GUID; +const efi_guid_t efi_guid_cert_rsa2048 = EFI_CERT_RSA2048_GUID; +const efi_guid_t efi_guid_cert_x509 = EFI_CERT_X509_GUID; +const efi_guid_t efi_guid_cert_x509_sha256 = EFI_CERT_X509_SHA256_GUID; + +#ifdef CONFIG_EFI_SECURE_BOOT + +/** + * efi_hash_regions - calculate a hash value + * @regs: List of regions + * @hash: Pointer to a pointer to buffer holding a hash value + * @size: Size of buffer to be returned + * + * Calculate a sha256 value of @regs and return a value in @hash. + * + * Return: true on success, false on error + */ +static bool efi_hash_regions(struct efi_image_regions *regs, void **hash, + size_t *size) +{ + *size = 0; + *hash = calloc(1, SHA256_SUM_LEN); + if (!*hash) { + debug("Out of memory\n"); + return false; + } + *size = SHA256_SUM_LEN; + + hash_calculate("sha256", regs->reg, regs->num, *hash); +#ifdef DEBUG + debug("hash calculated:\n"); + print_hex_dump(" ", DUMP_PREFIX_OFFSET, 16, 1, + *hash, SHA256_SUM_LEN, false); +#endif + + return true; +} + +/** + * efi_hash_msg_content - calculate a hash value of contentInfo + * @msg: Signature + * @hash: Pointer to a pointer to buffer holding a hash value + * @size: Size of buffer to be returned + * + * Calculate a sha256 value of contentInfo in @msg and return a value in @hash. + * + * Return: true on success, false on error + */ +static bool efi_hash_msg_content(struct pkcs7_message *msg, void **hash, + size_t *size) +{ + struct image_region regtmp; + + *size = 0; + *hash = calloc(1, SHA256_SUM_LEN); + if (!*hash) { + debug("Out of memory\n"); + free(msg); + return false; + } + *size = SHA256_SUM_LEN; + + regtmp.data = msg->data; + regtmp.size = msg->data_len; + + hash_calculate("sha256", ®tmp, 1, *hash); +#ifdef DEBUG + debug("hash calculated based on contentInfo:\n"); + print_hex_dump(" ", DUMP_PREFIX_OFFSET, 16, 1, + *hash, SHA256_SUM_LEN, false); +#endif + + return true; +} + +/** + * efi_signature_verify - verify a signature with a certificate + * @regs: List of regions to be authenticated + * @signed_info: Pointer to PKCS7's signed_info + * @cert: x509 certificate + * + * Signature pointed to by @signed_info against image pointed to by @regs + * is verified by a certificate pointed to by @cert. + * @signed_info holds a signature, including a message digest which is to be + * compared with a hash value calculated from @regs. + * + * Return: true if signature is verified, false if not + */ +static bool efi_signature_verify(struct efi_image_regions *regs, + struct pkcs7_message *msg, + struct pkcs7_signed_info *ps_info, + struct x509_certificate *cert) +{ + struct image_sign_info info; + struct image_region regtmp[2]; + void *hash; + size_t size; + char c; + bool verified; + + debug("%s: Enter, %p, %p, %p(issuer: %s, subject: %s)\n", __func__, + regs, ps_info, cert, cert->issuer, cert->subject); + + verified = false; + + memset(&info, '\0', sizeof(info)); + info.padding = image_get_padding_algo("pkcs-1.5"); + /* + * Note: image_get_[checksum|crypto]_algo takes an string + * argument like "," + * TODO: support other hash algorithms + */ + if (!strcmp(ps_info->sig->hash_algo, "sha1")) { + info.checksum = image_get_checksum_algo("sha1,rsa2048"); + info.name = "sha1,rsa2048"; + } else if (!strcmp(ps_info->sig->hash_algo, "sha256")) { + info.checksum = image_get_checksum_algo("sha256,rsa2048"); + info.name = "sha256,rsa2048"; + } else { + debug("unknown msg digest algo: %s\n", ps_info->sig->hash_algo); + goto out; + } + info.crypto = image_get_crypto_algo(info.name); + + info.key = cert->pub->key; + info.keylen = cert->pub->keylen; + + /* verify signature */ + debug("%s: crypto: %s, signature len:%x\n", __func__, + info.name, ps_info->sig->s_size); + if (ps_info->aa_set & (1UL << sinfo_has_message_digest)) { + debug("%s: RSA verify authentication attribute\n", __func__); + /* + * NOTE: This path will be executed only for + * PE image authentication + */ + + /* check if hash matches digest first */ + debug("checking msg digest first, len:0x%x\n", + ps_info->msgdigest_len); + +#ifdef DEBUG + debug("hash in database:\n"); + print_hex_dump(" ", DUMP_PREFIX_OFFSET, 16, 1, + ps_info->msgdigest, ps_info->msgdigest_len, + false); +#endif + /* against contentInfo first */ + if ((msg->data && efi_hash_msg_content(msg, &hash, &size)) || + /* for signed image */ + efi_hash_regions(regs, &hash, &size)) { + /* for authenticated variable */ + if (ps_info->msgdigest_len != size || + memcmp(hash, ps_info->msgdigest, size)) { + debug("Digest doesn't match\n"); + free(hash); + goto out; + } + + free(hash); + } else { + debug("Digesting image failed\n"); + goto out; + } + + /* against digest */ + c = 0x31; + regtmp[0].data = &c; + regtmp[0].size = 1; + regtmp[1].data = ps_info->authattrs; + regtmp[1].size = ps_info->authattrs_len; + + if (!rsa_verify(&info, regtmp, 2, + ps_info->sig->s, ps_info->sig->s_size)) + verified = true; + } else { + debug("%s: RSA verify content data\n", __func__); + /* against all data */ + if (!rsa_verify(&info, regs->reg, regs->num, + ps_info->sig->s, ps_info->sig->s_size)) + verified = true; + } + +out: + debug("%s: Exit, verified: %d\n", __func__, verified); + return verified; +} + +/** + * efi_signature_verify_with_list - verify a signature with signature list + * @regs: List of regions to be authenticated + * @msg: Signature + * @signed_info: Pointer to PKCS7's signed_info + * @siglist: Signature list for certificates + * @valid_cert: x509 certificate that verifies this signature + * + * Signature pointed to by @signed_info against image pointed to by @regs + * is verified by signature list pointed to by @siglist. + * Signature database is a simple concatenation of one or more + * signature list(s). + * + * Return: true if signature is verified, false if not + */ +static +bool efi_signature_verify_with_list(struct efi_image_regions *regs, + struct pkcs7_message *msg, + struct pkcs7_signed_info *signed_info, + struct efi_signature_store *siglist, + struct x509_certificate **valid_cert) +{ + struct x509_certificate *cert; + struct efi_sig_data *sig_data; + bool verified = false; + + debug("%s: Enter, %p, %p, %p, %p\n", __func__, + regs, signed_info, siglist, valid_cert); + + if (!signed_info) { + void *hash; + size_t size; + + debug("%s: unsigned image\n", __func__); + /* + * verify based on calculated hash value + * TODO: support other hash algorithms + */ + if (guidcmp(&siglist->sig_type, &efi_guid_sha256)) { + debug("Digest algorithm is not supported: %pUl\n", + &siglist->sig_type); + goto out; + } + + if (!efi_hash_regions(regs, &hash, &size)) { + debug("Digesting unsigned image failed\n"); + goto out; + } + + /* go through the list */ + for (sig_data = siglist->sig_data_list; sig_data; + sig_data = sig_data->next) { +#ifdef DEBUG + debug("Msg digest in database:\n"); + print_hex_dump(" ", DUMP_PREFIX_OFFSET, 16, 1, + sig_data->data, sig_data->size, false); +#endif + if ((sig_data->size == size) && + !memcmp(sig_data->data, hash, size)) { + verified = true; + free(hash); + goto out; + } + } + free(hash); + goto out; + } + + debug("%s: signed image\n", __func__); + if (guidcmp(&siglist->sig_type, &efi_guid_cert_x509)) { + debug("Signature type is not supported: %pUl\n", + &siglist->sig_type); + goto out; + } + + /* go through the list */ + for (sig_data = siglist->sig_data_list; sig_data; + sig_data = sig_data->next) { + /* TODO: support owner check based on policy */ + + cert = x509_cert_parse(sig_data->data, sig_data->size); + if (IS_ERR(cert)) { + debug("Parsing x509 certificate failed\n"); + goto out; + } + + verified = efi_signature_verify(regs, msg, signed_info, cert); + + if (verified) { + if (valid_cert) + *valid_cert = cert; + else + x509_free_certificate(cert); + break; + } else { + x509_free_certificate(cert); + } + } + +out: + debug("%s: Exit, verified: %d\n", __func__, verified); + return verified; +} + +/** + * efi_signature_verify_with_sigdb - verify a signature with db + * @regs: List of regions to be authenticated + * @msg: Signature + * @db: Signature database for trusted certificates + * @cert: x509 certificate that verifies this signature + * + * Signature pointed to by @msg against image pointed to by @regs + * is verified by signature database pointed to by @db. + * + * Return: true if signature is verified, false if not + */ +bool efi_signature_verify_with_sigdb(struct efi_image_regions *regs, + struct pkcs7_message *msg, + struct efi_signature_store *db, + struct x509_certificate **cert) +{ + struct pkcs7_signed_info *info; + struct efi_signature_store *siglist; + bool verified = false; + + debug("%s: Enter, %p, %p, %p, %p\n", __func__, regs, msg, db, cert); + + if (!db) + goto out; + + if (!db->sig_data_list) + goto out; + + /* for unsigned image */ + if (!msg) { + debug("%s: Verify unsigned image with db\n", __func__); + for (siglist = db; siglist; siglist = siglist->next) + if (efi_signature_verify_with_list(regs, NULL, NULL, + siglist, cert)) { + verified = true; + goto out; + } + + goto out; + } + + /* for signed image or variable */ + debug("%s: Verify signed image with db\n", __func__); + for (info = msg->signed_infos; info; info = info->next) { + debug("Signed Info: digest algo: %s, pkey algo: %s\n", + info->sig->hash_algo, info->sig->pkey_algo); + + for (siglist = db; siglist; siglist = siglist->next) { + if (efi_signature_verify_with_list(regs, msg, info, + siglist, cert)) { + verified = true; + goto out; + } + } + } + +out: + debug("%s: Exit, verified: %d\n", __func__, verified); + return verified; +} + +/** + * efi_search_siglist - search signature list for a certificate + * @cert: x509 certificate + * @siglist: Signature list + * @revoc_time: Pointer to buffer for revocation time + * + * Search signature list pointed to by @siglist and find a certificate + * pointed to by @cert. + * If found, revocation time that is specified in signature database is + * returned in @revoc_time. + * + * Return: true if certificate is found, false if not + */ +static bool efi_search_siglist(struct x509_certificate *cert, + struct efi_signature_store *siglist, + time64_t *revoc_time) +{ + struct image_region reg[1]; + void *hash = NULL, *msg = NULL; + struct efi_sig_data *sig_data; + bool found = false; + + /* can be null */ + if (!siglist->sig_data_list) + return false; + + if (guidcmp(&siglist->sig_type, &efi_guid_cert_x509_sha256)) { + /* TODO: other hash algos */ + debug("Certificate's digest type is not supported: %pUl\n", + &siglist->sig_type); + goto out; + } + + /* calculate hash of TBSCertificate */ + msg = calloc(1, SHA256_SUM_LEN); + if (!msg) { + debug("Out of memory\n"); + goto out; + } + + hash = calloc(1, SHA256_SUM_LEN); + if (!hash) { + debug("Out of memory\n"); + goto out; + } + + reg[0].data = cert->tbs; + reg[0].size = cert->tbs_size; + hash_calculate("sha256", reg, 1, msg); + + /* go through signature list */ + for (sig_data = siglist->sig_data_list; sig_data; + sig_data = sig_data->next) { + /* + * struct efi_cert_x509_sha256 { + * u8 tbs_hash[256/8]; + * time64_t revocation_time; + * }; + */ + if ((sig_data->size == SHA256_SUM_LEN) && + !memcmp(sig_data->data, hash, SHA256_SUM_LEN)) { + memcpy(revoc_time, sig_data->data + SHA256_SUM_LEN, + sizeof(*revoc_time)); + found = true; + goto out; + } + } + +out: + free(hash); + free(msg); + + return found; +} + +/** + * efi_signature_verify_cert - verify a certificate with dbx + * @cert: x509 certificate + * @dbx: Signature database + * + * Search signature database pointed to by @dbx and find a certificate + * pointed to by @cert. + * This function is expected to be used against "dbx". + * + * Return: true if a certificate is not rejected, false otherwise. + */ +bool efi_signature_verify_cert(struct x509_certificate *cert, + struct efi_signature_store *dbx) +{ + struct efi_signature_store *siglist; + time64_t revoc_time; + bool found = false; + + debug("%s: Enter, %p, %p\n", __func__, dbx, cert); + + if (!cert) + return false; + + for (siglist = dbx; siglist; siglist = siglist->next) { + if (efi_search_siglist(cert, siglist, &revoc_time)) { + /* TODO */ + /* compare signing time with revocation time */ + + found = true; + break; + } + } + + debug("%s: Exit, verified: %d\n", __func__, !found); + return !found; +} + +/** + * efi_signature_verify_signers - verify signers' certificates with dbx + * @msg: Signature + * @dbx: Signature database + * + * Determine if any of signers' certificates in @msg may be verified + * by any of certificates in signature database pointed to by @dbx. + * This function is expected to be used against "dbx". + * + * Return: true if none of certificates is rejected, false otherwise. + */ +bool efi_signature_verify_signers(struct pkcs7_message *msg, + struct efi_signature_store *dbx) +{ + struct pkcs7_signed_info *info; + bool found = false; + + debug("%s: Enter, %p, %p\n", __func__, msg, dbx); + + if (!msg) + goto out; + + for (info = msg->signed_infos; info; info = info->next) { + if (info->signer && + !efi_signature_verify_cert(info->signer, dbx)) { + found = true; + goto out; + } + } +out: + debug("%s: Exit, verified: %d\n", __func__, !found); + return !found; +} + +/** + * efi_image_region_add - add an entry of region + * @regs: Pointer to array of regions + * @start: Start address of region + * @end: End address of region + * @nocheck: flag against overlapped regions + * + * Take one entry of region [@start, @end] and append it to the list + * pointed to by @regs. If @nocheck is false, overlapping among entries + * will be checked first. + * + * Return: 0 on success, status code (negative) on error + */ +efi_status_t efi_image_region_add(struct efi_image_regions *regs, + const void *start, const void *end, + int nocheck) +{ + struct image_region *reg; + int i, j; + + if (regs->num >= EFI_REGS_MAX) { + debug("%s: no more room for regions\n", __func__); + return EFI_OUT_OF_RESOURCES; + } + + if (end < start) + return EFI_INVALID_PARAMETER; + + for (i = 0; i < regs->num; i++) { + reg = ®s->reg[i]; + if (nocheck) + continue; + + if (start > reg->data + reg->size) + continue; + + if ((start >= reg->data && start < reg->data + reg->size) || + (end > reg->data && end < reg->data + reg->size)) { + debug("%s: new region already part of another\n", + __func__); + return EFI_INVALID_PARAMETER; + } + + if (start < reg->data && end < reg->data + reg->size) { + for (j = regs->num - 1; j >= i; j--) + memcpy(®s->reg[j], ®s->reg[j + 1], + sizeof(*reg)); + break; + } + } + + reg = ®s->reg[i]; + reg->data = start; + reg->size = end - start; + regs->num++; + + return EFI_SUCCESS; +} +#endif /* CONFIG_EFI_SECURE_BOOT */