From patchwork Thu Nov 26 18:41:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sughosh Ganu X-Patchwork-Id: 1406845 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=pass (sender SPF authorized) smtp.mailfrom=lists.denx.de (client-ip=2a01:238:438b:c500:173d:9f52:ddab:ee01; helo=phobos.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 Received: from phobos.denx.de (phobos.denx.de [IPv6:2a01:238:438b:c500:173d:9f52:ddab:ee01]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4Chmqx6CkVz9s1l for ; Fri, 27 Nov 2020 05:43:57 +1100 (AEDT) Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 4F2FF826D7; Thu, 26 Nov 2020 19:42:44 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de Received: by phobos.denx.de (Postfix, from userid 109) id 9F1AD826ED; Thu, 26 Nov 2020 19:42:20 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on phobos.denx.de X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_HELO_NONE, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.2 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by phobos.denx.de (Postfix) with ESMTP id E1DB4826F3 for ; Thu, 26 Nov 2020 19:42:15 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: phobos.denx.de; spf=fail smtp.mailfrom=sughosh.ganu@linaro.org Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3C8D1165C; Thu, 26 Nov 2020 10:42:15 -0800 (PST) Received: from a076522.blr.arm.com (a076522.blr.arm.com [10.162.16.44]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C8D083F23F; Thu, 26 Nov 2020 10:42:12 -0800 (PST) From: Sughosh Ganu To: u-boot@lists.denx.de Cc: Takahiro Akashi , Heinrich Schuchardt , Alexander Graf , Lukasz Majewski , Tuomas Tynkkynen , Tom Rini , Sughosh Ganu Subject: [PATCH 09/14] efi_loader: Make the pkcs7 header parsing function an extern Date: Fri, 27 Nov 2020 00:11:05 +0530 Message-Id: <20201126184110.30521-10-sughosh.ganu@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201126184110.30521-1-sughosh.ganu@linaro.org> References: <20201126184110.30521-1-sughosh.ganu@linaro.org> X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.34 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" X-Virus-Scanned: clamav-milter 0.102.3 at phobos.denx.de X-Virus-Status: Clean The pkcs7 header parsing functionality is pretty generic, and can be used by other features like capsule authentication. Make the function an extern, also changing it's name to efi_parse_pkcs7_header Signed-off-by: Sughosh Ganu --- include/efi_loader.h | 4 ++ lib/efi_loader/efi_signature.c | 85 +++++++++++++++++++++++++++++++ lib/efi_loader/efi_variable.c | 93 ++-------------------------------- 3 files changed, 93 insertions(+), 89 deletions(-) diff --git a/include/efi_loader.h b/include/efi_loader.h index 76cd2b36f2..b9226208f5 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -810,6 +810,10 @@ bool efi_secure_boot_enabled(void); bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp, WIN_CERTIFICATE **auth, size_t *auth_len); +struct pkcs7_message *efi_parse_pkcs7_header(const void *buf, + size_t buflen, + u8 **tmpbuf); + /* runtime implementation of memcpy() */ void efi_memcpy_runtime(void *dest, const void *src, size_t n); diff --git a/lib/efi_loader/efi_signature.c b/lib/efi_loader/efi_signature.c index 79dee27421..9ab071b611 100644 --- a/lib/efi_loader/efi_signature.c +++ b/lib/efi_loader/efi_signature.c @@ -27,6 +27,91 @@ const efi_guid_t efi_guid_cert_x509_sha256 = EFI_CERT_X509_SHA256_GUID; const efi_guid_t efi_guid_cert_type_pkcs7 = EFI_CERT_TYPE_PKCS7_GUID; #ifdef CONFIG_EFI_SECURE_BOOT +static u8 pkcs7_hdr[] = { + /* SEQUENCE */ + 0x30, 0x82, 0x05, 0xc7, + /* OID: pkcs7-signedData */ + 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x07, 0x02, + /* Context Structured? */ + 0xa0, 0x82, 0x05, 0xb8, +}; + +/** + * efi_parse_pkcs7_header - parse a signature in payload + * @buf: Pointer to payload's value + * @buflen: Length of @buf + * @tmpbuf: Pointer to temporary buffer + * + * Parse a signature embedded in payload's value and instantiate + * a pkcs7_message structure. Since pkcs7_parse_message() accepts only + * pkcs7's signedData, some header needed be prepended for correctly + * parsing authentication data + * A temporary buffer will be allocated if needed, and it should be + * kept valid during the authentication because some data in the buffer + * will be referenced by efi_signature_verify(). + * + * Return: Pointer to pkcs7_message structure on success, NULL on error + */ +struct pkcs7_message *efi_parse_pkcs7_header(const void *buf, + size_t buflen, + u8 **tmpbuf) +{ + u8 *ebuf; + size_t ebuflen, len; + struct pkcs7_message *msg; + + /* + * This is the best assumption to check if the binary is + * already in a form of pkcs7's signedData. + */ + if (buflen > sizeof(pkcs7_hdr) && + !memcmp(&((u8 *)buf)[4], &pkcs7_hdr[4], 11)) { + msg = pkcs7_parse_message(buf, buflen); + if (IS_ERR(msg)) + return NULL; + return msg; + } + + /* + * Otherwise, we should add a dummy prefix sequence for pkcs7 + * message parser to be able to process. + * NOTE: EDK2 also uses similar hack in WrapPkcs7Data() + * in CryptoPkg/Library/BaseCryptLib/Pk/CryptPkcs7VerifyCommon.c + * TODO: + * The header should be composed in a more refined manner. + */ + EFI_PRINT("Makeshift prefix added to authentication data\n"); + ebuflen = sizeof(pkcs7_hdr) + buflen; + if (ebuflen <= 0x7f) { + EFI_PRINT("Data is too short\n"); + return NULL; + } + + ebuf = malloc(ebuflen); + if (!ebuf) { + EFI_PRINT("Out of memory\n"); + return NULL; + } + + memcpy(ebuf, pkcs7_hdr, sizeof(pkcs7_hdr)); + memcpy(ebuf + sizeof(pkcs7_hdr), buf, buflen); + len = ebuflen - 4; + ebuf[2] = (len >> 8) & 0xff; + ebuf[3] = len & 0xff; + len = ebuflen - 0x13; + ebuf[0x11] = (len >> 8) & 0xff; + ebuf[0x12] = len & 0xff; + + msg = pkcs7_parse_message(ebuf, ebuflen); + + if (IS_ERR(msg)) { + free(ebuf); + return NULL; + } + + *tmpbuf = ebuf; + return msg; +} /** * efi_hash_regions - calculate a hash value diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c index 0c689cfb47..ba0874e9e7 100644 --- a/lib/efi_loader/efi_variable.c +++ b/lib/efi_loader/efi_variable.c @@ -24,91 +24,6 @@ #include #ifdef CONFIG_EFI_SECURE_BOOT -static u8 pkcs7_hdr[] = { - /* SEQUENCE */ - 0x30, 0x82, 0x05, 0xc7, - /* OID: pkcs7-signedData */ - 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x07, 0x02, - /* Context Structured? */ - 0xa0, 0x82, 0x05, 0xb8, -}; - -/** - * efi_variable_parse_signature - parse a signature in variable - * @buf: Pointer to variable's value - * @buflen: Length of @buf - * @tmpbuf: Pointer to temporary buffer - * - * Parse a signature embedded in variable's value and instantiate - * a pkcs7_message structure. Since pkcs7_parse_message() accepts only - * pkcs7's signedData, some header needed be prepended for correctly - * parsing authentication data, particularly for variable's. - * A temporary buffer will be allocated if needed, and it should be - * kept valid during the authentication because some data in the buffer - * will be referenced by efi_signature_verify(). - * - * Return: Pointer to pkcs7_message structure on success, NULL on error - */ -static struct pkcs7_message *efi_variable_parse_signature(const void *buf, - size_t buflen, - u8 **tmpbuf) -{ - u8 *ebuf; - size_t ebuflen, len; - struct pkcs7_message *msg; - - /* - * This is the best assumption to check if the binary is - * already in a form of pkcs7's signedData. - */ - if (buflen > sizeof(pkcs7_hdr) && - !memcmp(&((u8 *)buf)[4], &pkcs7_hdr[4], 11)) { - msg = pkcs7_parse_message(buf, buflen); - if (IS_ERR(msg)) - return NULL; - return msg; - } - - /* - * Otherwise, we should add a dummy prefix sequence for pkcs7 - * message parser to be able to process. - * NOTE: EDK2 also uses similar hack in WrapPkcs7Data() - * in CryptoPkg/Library/BaseCryptLib/Pk/CryptPkcs7VerifyCommon.c - * TODO: - * The header should be composed in a more refined manner. - */ - EFI_PRINT("Makeshift prefix added to authentication data\n"); - ebuflen = sizeof(pkcs7_hdr) + buflen; - if (ebuflen <= 0x7f) { - EFI_PRINT("Data is too short\n"); - return NULL; - } - - ebuf = malloc(ebuflen); - if (!ebuf) { - EFI_PRINT("Out of memory\n"); - return NULL; - } - - memcpy(ebuf, pkcs7_hdr, sizeof(pkcs7_hdr)); - memcpy(ebuf + sizeof(pkcs7_hdr), buf, buflen); - len = ebuflen - 4; - ebuf[2] = (len >> 8) & 0xff; - ebuf[3] = len & 0xff; - len = ebuflen - 0x13; - ebuf[0x11] = (len >> 8) & 0xff; - ebuf[0x12] = len & 0xff; - - msg = pkcs7_parse_message(ebuf, ebuflen); - - if (IS_ERR(msg)) { - free(ebuf); - return NULL; - } - - *tmpbuf = ebuf; - return msg; -} /** * efi_variable_authenticate - authenticate a variable @@ -215,10 +130,10 @@ static efi_status_t efi_variable_authenticate(u16 *variable, goto err; /* ebuf should be kept valid during the authentication */ - var_sig = efi_variable_parse_signature(auth->auth_info.cert_data, - auth->auth_info.hdr.dwLength - - sizeof(auth->auth_info), - &ebuf); + var_sig = efi_parse_pkcs7_header(auth->auth_info.cert_data, + auth->auth_info.hdr.dwLength + - sizeof(auth->auth_info), + &ebuf); if (!var_sig) { EFI_PRINT("Parsing variable's signature failed\n"); goto err;