From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lothar =?UTF-8?B?V2HDn21hbm4=?= Date: Fri, 12 May 2017 10:25:50 +0200 Subject: [U-Boot] [PATCH 3/5] x86: baytrail: secureboot: Add functions for verification of u-boot In-Reply-To: <1494515696-2087-4-git-send-email-agust@denx.de> References: <1494515696-2087-1-git-send-email-agust@denx.de> <1494515696-2087-4-git-send-email-agust@denx.de> Message-ID: <20170512102550.1aa42156@ipc1.ka-ro> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable To: u-boot@lists.denx.de Hi, On Thu, 11 May 2017 17:14:54 +0200 Anatolij Gustschin wrote: > From: Markus Valentin >=20 > Introduce functions that check the integrity of u-boot by utilising the > hashes stored in the oem-data block. >=20 > The verification functions get called in fsp_init() >=20 > Signed-off-by: Markus Valentin > --- > arch/x86/cpu/baytrail/Makefile | 1 + > arch/x86/cpu/baytrail/secure_boot.c | 117 +++++++++++++++= ++++++ > .../include/asm/arch-baytrail/fsp/fsp_configs.h | 3 + > arch/x86/lib/fsp/fsp_support.c | 15 +++ > 4 files changed, 136 insertions(+) > create mode 100644 arch/x86/cpu/baytrail/secure_boot.c >=20 > diff --git a/arch/x86/cpu/baytrail/Makefile b/arch/x86/cpu/baytrail/Makef= ile > index a0216f3..dbf9a82 100644 > --- a/arch/x86/cpu/baytrail/Makefile > +++ b/arch/x86/cpu/baytrail/Makefile > @@ -8,4 +8,5 @@ obj-y +=3D cpu.o > obj-y +=3D early_uart.o > obj-y +=3D fsp_configs.o > obj-y +=3D valleyview.o > +obj-$(CONFIG_BAYTRAIL_SECURE_BOOT) +=3D secure_boot.o > obj-$(CONFIG_GENERATE_ACPI_TABLE) +=3D acpi.o > diff --git a/arch/x86/cpu/baytrail/secure_boot.c b/arch/x86/cpu/baytrail/= secure_boot.c > new file mode 100644 > index 0000000..37c83db > --- /dev/null > +++ b/arch/x86/cpu/baytrail/secure_boot.c > @@ -0,0 +1,117 @@ > +/* > + * Copyright (C) 2017 Markus Valentin > + * > + * SPDX-License-Identifier: GPL-2.0+ > + */ > + > +#include > + > +#define SB_MANIFEST_BASE 0xFFFE0000 > +#define SB_MANIFEST_SIZE 0x400 > +#define SB_MANIFEST_OEM_DATA_OFFSET 0x58 > +#define SB_MANIFEST_OEM_HASH_OFFSET (SB_MANIFEST_OEM_DATA_OFFSET + 4) > +#define SB_MANIFEST_OEM_HASH_BASE (SB_MANIFEST_BASE +\ > + SB_MANIFEST_OEM_HASH_OFFSET) > +#define SB_MANIFEST_END (SB_MANIFEST_BASE + SB_MANIFEST_SIZE) > + > +#define PUB_KEY_MODULUS_SIZE 0x100 > +#define U_BOOT_STAGE_SIZE 0xDD360 > +#define U_BOOT_OFFSET 0x2CA0 > + > +#define U_BOOT_STAGE_START (CONFIG_SYS_TEXT_BASE + U_BOOT_OFFSET) > +#define U_BOOT_STAGE_END (U_BOOT_STAGE_START + U_BOOT_STAGE_SIZE) > + > +#define SHA256_U_BOOT_STAGE_ID 0 > +#define SHA256_FSP_STAGE2_ID 1 > +#define SHA256_FIT_PUB_KEY_ID 2 > + > +#define FIT_KEY_NAME "dev" > + > +/** > + * This function compares a hash which gets retrieved from the oem data = block > + * with the runtime calculated hash of start_address+size. If they match, > + * this function returns true. If not, it returns false. > + * > + * @param hash_id offset of oem-data block for hash to compare > + * @param start_address address where the hash calculation should start > + * @param size length of the region for hash calculation > + * @return true on success, false on error > + */ > +static bool verify_oem_sha256(unsigned int hash_id, > + void *start_address, > + size_t size) > +{ > + uint8_t value[SHA256_SUM_LEN]; > 'unsigned char' here ... > + int value_len; > + > + /* calculate address of hash to compare in the oemdata block*/ > + void *hash_to_verify =3D (void *)SB_MANIFEST_OEM_HASH_BASE + > + (SHA256_SUM_LEN * hash_id); > +#ifdef DEBUG > + unsigned int i =3D 0; > + uint8_t oem_value[SHA256_SUM_LEN]; > + > + memcpy(oem_value, hash_to_verify, SHA256_SUM_LEN); > + printf("SB: Hash to verify:\t"); > + for (i =3D 0; i < SHA256_SUM_LEN; i++) > + printf("%X", oem_value[i]); > + printf("\n"); > +#endif > + > + /* caluclate the hash of the binary */ > + calculate_hash(start_address, size, "sha256", (unsigned char *)value, > + &value_len); > ... would avoid the '(unsigned char *)' cast here. > + > +#ifdef DEBUG > + printf("SB: calculated hash:\t"); > + for (i =3D 0; i < SHA256_SUM_LEN; i++) > + printf("%X", value[i]); > + printf("\n"); > +#endif > + /* compare the two hash values */ > + if (memcmp(hash_to_verify, value, SHA256_SUM_LEN)) > + return false; > + return true; > +} > + > +/** > + * This function verifies the integrity for u-boot, its devicetree and t= he ucode > + * appended or inserted to the devicetree. > + * > + * @return true on success, false on error > + */ > +bool verify_u_boot_bin(void) > +{ > + return verify_oem_sha256(SHA256_U_BOOT_STAGE_ID, > + (void *)U_BOOT_STAGE_START, > + U_BOOT_STAGE_SIZE); > +} > + > +/** > + * This function verifies the integrity for the modulus of the public ke= y which > + * is stored in the u-boot devicetree for fit image verification. It tri= es to > + * find the "rsa,modulus" property in the dtb and then verifies it with = the > + * checksum stored in the oem-data block > + * > + * @return true on success, false on error > + */ > +bool verify_public_key(void) > +{ > + void *fit_public_key_modulus; > 'const void *' here ... > + > + int offset =3D fdt_node_offset_by_prop_value(gd->fdt_blob, -1, > + "key-name-hint", > + FIT_KEY_NAME, > + 4); > + > + fit_public_key_modulus =3D (void *)fdt_getprop(gd->fdt_blob, offset, > + "rsa,modulus", NULL); > ... would eliminate the need for the '(void *)' cast here. > + if (!fit_public_key_modulus) { > + debug("SB: Could not fetch public key from U-Boot Devicetree\n"); > + return false; > + } > + > + return verify_oem_sha256(SHA256_FIT_PUB_KEY_ID, > + fit_public_key_modulus, > + PUB_KEY_MODULUS_SIZE); > +} Lothar Wa=C3=9Fmann