diff options
Diffstat (limited to 'arch/arm/mach-socfpga/secure_vab.c')
| -rw-r--r-- | arch/arm/mach-socfpga/secure_vab.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/arch/arm/mach-socfpga/secure_vab.c b/arch/arm/mach-socfpga/secure_vab.c new file mode 100644 index 0000000000..e2db588506 --- /dev/null +++ b/arch/arm/mach-socfpga/secure_vab.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 Intel Corporation <www.intel.com> + * + */ + +#include <asm/arch/mailbox_s10.h> +#include <asm/arch/secure_vab.h> +#include <asm/arch/smc_api.h> +#include <asm/unaligned.h> +#include <common.h> +#include <exports.h> +#include <linux/errno.h> +#include <linux/intel-smc.h> +#include <log.h> + +#define CHUNKSZ_PER_WD_RESET (256 * SZ_1K) + +/* + * Read the length of the VAB certificate from the end of image + * and calculate the actual image size (excluding the VAB certificate). + */ +static size_t get_img_size(u8 *img_buf, size_t img_buf_sz) +{ + u8 *img_buf_end = img_buf + img_buf_sz; + u32 cert_sz = get_unaligned_le32(img_buf_end - sizeof(u32)); + u8 *p = img_buf_end - cert_sz - sizeof(u32); + + /* Ensure p is pointing within the img_buf */ + if (p < img_buf || p > (img_buf_end - VAB_CERT_HEADER_SIZE)) + return 0; + + if (get_unaligned_le32(p) == SDM_CERT_MAGIC_NUM) + return (size_t)(p - img_buf); + + return 0; +} + +/* + * Vendor Authorized Boot (VAB) is a security feature for authenticating + * the images such as U-Boot, ARM trusted Firmware, Linux kernel, + * device tree blob and etc loaded from FIT. User can also trigger + * the VAB authentication from U-Boot command. + * + * This function extracts the VAB certificate and signature block + * appended at the end of the image, then send to Secure Device Manager + * (SDM) for authentication. This function will validate the SHA384 + * of the image against the SHA384 hash stored in the VAB certificate + * before sending the VAB certificate to SDM for authentication. + * + * RETURN + * 0 if authentication success or + * if authentication is not required and bypassed on a non-secure device + * negative error code if authentication fail + */ +int socfpga_vendor_authentication(void **p_image, size_t *p_size) +{ + int retry_count = 20; + u8 hash384[SHA384_SUM_LEN]; + u64 img_addr, mbox_data_addr; + size_t img_sz, mbox_data_sz; + u8 *cert_hash_ptr, *mbox_relocate_data_addr; + u32 resp = 0, resp_len = 1; + int ret; + + img_addr = (uintptr_t)*p_image; + + debug("Authenticating image at address 0x%016llx (%ld bytes)\n", + img_addr, *p_size); + + img_sz = get_img_size((u8 *)img_addr, *p_size); + debug("img_sz = %ld\n", img_sz); + + if (!img_sz) { + puts("VAB certificate not found in image!\n"); + return -ENOKEY; + } + + if (!IS_ALIGNED(img_sz, sizeof(u32))) { + printf("Image size (%ld bytes) not aliged to 4 bytes!\n", + img_sz); + return -EBFONT; + } + + /* Generate HASH384 from the image */ + sha384_csum_wd((u8 *)img_addr, img_sz, hash384, CHUNKSZ_PER_WD_RESET); + + cert_hash_ptr = (u8 *)(img_addr + img_sz + VAB_CERT_MAGIC_OFFSET + + VAB_CERT_FIT_SHA384_OFFSET); + + /* + * Compare the SHA384 found in certificate against the SHA384 + * calculated from image + */ + if (memcmp(hash384, cert_hash_ptr, SHA384_SUM_LEN)) { + puts("SHA384 not match!\n"); + return -EKEYREJECTED; + } + + mbox_data_addr = img_addr + img_sz - sizeof(u32); + /* Size in word (32bits) */ + mbox_data_sz = (ALIGN(*p_size - img_sz, sizeof(u32))) >> 2; + + debug("mbox_data_addr = 0x%016llx\n", mbox_data_addr); + debug("mbox_data_sz = %ld words\n", mbox_data_sz); + + /* + * Relocate certificate to first memory block before trigger SMC call + * to send mailbox command because ATF only able to access first + * memory block. + */ + mbox_relocate_data_addr = (u8 *)malloc(mbox_data_sz * sizeof(u32)); + if (!mbox_relocate_data_addr) { + puts("Out of memory for VAB certificate relocation!\n"); + return -ENOMEM; + } + + memcpy(mbox_relocate_data_addr, (u8 *)mbox_data_addr, mbox_data_sz * sizeof(u32)); + *(u32 *)mbox_relocate_data_addr = 0; + + debug("mbox_relocate_data_addr = 0x%p\n", mbox_relocate_data_addr); + + do { + if (!IS_ENABLED(CONFIG_SPL_BUILD) && IS_ENABLED(CONFIG_SPL_ATF)) { + /* Invoke SMC call to ATF to send the VAB certificate to SDM */ + ret = smc_send_mailbox(MBOX_VAB_SRC_CERT, mbox_data_sz, + (u32 *)mbox_relocate_data_addr, 0, &resp_len, + &resp); + } else { + /* Send the VAB certficate to SDM for authentication */ + ret = mbox_send_cmd(MBOX_ID_UBOOT, MBOX_VAB_SRC_CERT, + MBOX_CMD_DIRECT, mbox_data_sz, + (u32 *)mbox_relocate_data_addr, 0, &resp_len, + &resp); + } + /* If SDM is not available, just delay 50ms and retry again */ + if (ret == MBOX_RESP_DEVICE_BUSY) + mdelay(50); + else + break; + } while (--retry_count); + + /* Free the relocate certificate memory space */ + free(mbox_relocate_data_addr); + + /* Exclude the size of the VAB certificate from image size */ + *p_size = img_sz; + + debug("ret = 0x%08x, resp = 0x%08x, resp_len = %d\n", ret, resp, + resp_len); + + if (ret) { + /* + * Unsupported mailbox command or device not in the + * owned/secure state + */ + if (ret == MBOX_RESP_NOT_ALLOWED_UNDER_SECURITY_SETTINGS) { + /* SDM bypass authentication */ + printf("%s 0x%016llx (%ld bytes)\n", + "Image Authentication bypassed at address", + img_addr, img_sz); + return 0; + } + puts("VAB certificate authentication failed in SDM"); + if (ret == MBOX_RESP_DEVICE_BUSY) { + puts(" (SDM busy timeout)\n"); + return -ETIMEDOUT; + } else if (ret == MBOX_RESP_UNKNOWN) { + puts(" (Not supported)\n"); + return -ESRCH; + } + puts("\n"); + return -EKEYREJECTED; + } else { + /* If Certificate Process Status has error */ + if (resp) { + puts("VAB certificate process failed\n"); + return -ENOEXEC; + } + } + + printf("%s 0x%016llx (%ld bytes)\n", + "Image Authentication passed at address", img_addr, img_sz); + + return 0; +} |