/* Copyright 2011 The ChromiumOS Authors * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. * * Routines for verifying a firmware image's signature. */ #include #include #include #include "2common.h" #include "2misc.h" #include "2secdata.h" #include "2sysincludes.h" const char *gbb_fname; const char *vblock_fname; const char *body_fname; #if defined(ENABLE_HWCRYPTO_RSA_TESTS) bool vb2api_hwcrypto_allowed(struct vb2_context *ctx) { printf("hwcrypto is allowed.\n"); return true; } #endif /** * Local implementation which reads resources from individual files. Could be * more elegant and read from image.bin, if we understood the fmap. */ vb2_error_t vb2ex_read_resource(struct vb2_context *c, enum vb2_resource_index index, uint32_t offset, void *buf, uint32_t size) { const char *fname; FILE *f; int got_size; /* Get the filename for the resource */ switch (index) { case VB2_RES_GBB: fname = gbb_fname; break; case VB2_RES_FW_VBLOCK: fname = vblock_fname; break; default: return VB2_ERROR_UNKNOWN; } /* Open file and seek to the requested offset */ f = fopen(fname, "rb"); if (!f) return VB2_ERROR_UNKNOWN; if (fseek(f, offset, SEEK_SET)) { fclose(f); return VB2_ERROR_UNKNOWN; } /* Read data and close file */ got_size = fread(buf, 1, size, f); fclose(f); /* Return success if we read everything */ return got_size == size ? VB2_SUCCESS : VB2_ERROR_UNKNOWN; } vb2_error_t vb2ex_tpm_clear_owner(struct vb2_context *c) { // TODO: implement return VB2_SUCCESS; } /** * Save non-volatile and/or secure data if needed. */ static void save_if_needed(struct vb2_context *c) { if (c->flags & VB2_CONTEXT_NVDATA_CHANGED) { // TODO: implement c->flags &= ~VB2_CONTEXT_NVDATA_CHANGED; } if (c->flags & VB2_CONTEXT_SECDATA_FIRMWARE_CHANGED) { // TODO: implement c->flags &= ~VB2_CONTEXT_SECDATA_FIRMWARE_CHANGED; } } /** * Verify firmware body */ static vb2_error_t hash_body(struct vb2_context *c) { uint32_t remaining; uint8_t block[8192]; uint32_t size; FILE *f; vb2_error_t rv; /* Open the body data */ f = fopen(body_fname, "rb"); if (!f) return VB2_ERROR_TEST_INPUT_FILE; /* Start the body hash */ rv = vb2api_init_hash(c, VB2_HASH_TAG_FW_BODY); if (rv) { fclose(f); return rv; } remaining = vb2api_get_firmware_size(c); printf("Expect %d bytes of body...\n", remaining); /* Extend over the body */ while (remaining) { size = sizeof(block); if (size > remaining) size = remaining; /* Read next body block */ size = fread(block, 1, size, f); if (size <= 0) break; /* Hash it */ rv = vb2api_extend_hash(c, block, size); if (rv) { fclose(f); return rv; } remaining -= size; } fclose(f); /* Check the result */ rv = vb2api_check_hash(c); if (rv) return rv; return VB2_SUCCESS; } static void print_help(const char *progname) { printf("Usage: %s \n", progname); } int main(int argc, char *argv[]) { uint8_t workbuf[VB2_FIRMWARE_WORKBUF_RECOMMENDED_SIZE] __attribute__((aligned(VB2_WORKBUF_ALIGN))); struct vb2_context *ctx; struct vb2_shared_data *sd; vb2_error_t rv; if (argc < 4) { print_help(argv[0]); return 1; } /* Save filenames */ gbb_fname = argv[1]; vblock_fname = argv[2]; body_fname = argv[3]; /* Intialize workbuf with sentinel value to see how much we'll use. */ uint32_t *ptr = (uint32_t *)workbuf; while ((uint8_t *)ptr + sizeof(*ptr) <= workbuf + sizeof(workbuf)) *ptr++ = 0xbeefdead; /* Set up context */ if (vb2api_init(workbuf, sizeof(workbuf), &ctx)) { printf("Failed to initialize workbuf.\n"); return 1; } sd = vb2_get_sd(ctx); /* Initialize secure context */ vb2api_secdata_firmware_create(ctx); vb2api_secdata_kernel_create(ctx); // TODO: optional args to set contents for nvdata, secdata? /* Do early init */ printf("Phase 1...\n"); rv = vb2api_fw_phase1(ctx); if (rv) { printf("Phase 1 wants recovery mode.\n"); save_if_needed(ctx); return rv; } /* Determine which firmware slot to boot */ printf("Phase 2...\n"); rv = vb2api_fw_phase2(ctx); if (rv) { printf("Phase 2 wants reboot.\n"); save_if_needed(ctx); return rv; } /* Try that slot */ printf("Phase 3...\n"); rv = vb2api_fw_phase3(ctx); if (rv) { printf("Phase 3 wants reboot.\n"); save_if_needed(ctx); return rv; } /* Verify body */ printf("Hash body...\n"); rv = hash_body(ctx); save_if_needed(ctx); if (rv) { printf("Phase 4 wants reboot.\n"); return rv; } printf("Yaay!\n"); while ((uint8_t *)ptr > workbuf && *--ptr == 0xbeefdead) /* find last used workbuf offset */; printf("Workbuf used = %d bytes, high watermark = %zu bytes\n", sd->workbuf_used, (uint8_t *)ptr + sizeof(*ptr) - workbuf); return 0; }