/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved. * 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 "2sysincludes.h" #include "2api.h" const char *gbb_fname; const char *vblock_fname; const char *body_fname; /** * Local implementation which reads resources from individual files. Could be * more elegant and read from bios.bin, if we understood the fmap. */ int vb2ex_read_resource(struct vb2_context *ctx, 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; } int vb2ex_tpm_clear_owner(struct vb2_context *ctx) { // TODO: implement return VB2_SUCCESS; } /** * Save non-volatile and/or secure data if needed. */ static void save_if_needed(struct vb2_context *ctx) { if (ctx->flags & VB2_CONTEXT_NVDATA_CHANGED) { // TODO: implement ctx->flags &= ~VB2_CONTEXT_NVDATA_CHANGED; } if (ctx->flags & VB2_CONTEXT_SECDATA_CHANGED) { // TODO: implement ctx->flags &= ~VB2_CONTEXT_SECDATA_CHANGED; } } /** * Verify firmware body */ static int hash_body(struct vb2_context *ctx) { uint32_t expect_size; uint8_t block[8192]; uint32_t size; FILE *f; int 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(ctx, VB2_HASH_TAG_FW_BODY, &expect_size); if (rv) { fclose(f); return rv; } printf("Expect %d bytes of body...\n", expect_size); /* Extend over the body */ while (expect_size) { size = sizeof(block); if (size > expect_size) size = expect_size; /* Read next body block */ size = fread(block, 1, size, f); if (size <= 0) break; /* Hash it */ rv = vb2api_extend_hash(ctx, block, size); if (rv) { fclose(f); return rv; } expect_size -= size; } fclose(f); /* Check the result */ rv = vb2api_check_hash(ctx); 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[]) { struct vb2_context ctx; uint8_t workbuf[16384] __attribute__ ((aligned (VB2_WORKBUF_ALIGN))); int rv; if (argc < 4) { print_help(argv[0]); return 1; } /* Save filenames */ gbb_fname = argv[1]; vblock_fname = argv[2]; body_fname = argv[3]; /* Set up context */ memset(&ctx, 0, sizeof(ctx)); ctx.workbuf = workbuf; ctx.workbuf_size = sizeof(workbuf); /* Initialize secure context */ rv = vb2api_secdata_create(&ctx); if (rv) { fprintf(stderr, "error: vb2api_secdata_create() failed (%d)\n", rv); return 1; } // 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"); printf("Workbuf used = %d bytes\n", ctx.workbuf_used); return 0; }