| /* |
| * Copyright 2015 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. |
| */ |
| |
| /* |
| * Some instances of the Chrome OS embedded controller firmware can't do a |
| * normal software sync handshake at boot, but will verify their own RW images |
| * instead. This is typically done by putting a struct vb2_packed_key in the RO |
| * image and a corresponding struct vb21_signature in the RW image. |
| * |
| * This file provides the basic implementation for that approach. |
| */ |
| |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <unistd.h> |
| |
| #include "2sysincludes.h" |
| #include "2common.h" |
| #include "2rsa.h" |
| #include "2sha.h" |
| #include "file_type.h" |
| #include "futility.h" |
| #include "futility_options.h" |
| #include "vb21_common.h" |
| #include "host_common.h" |
| #include "host_key2.h" |
| #include "host_signature2.h" |
| #include "util_misc.h" |
| |
| #define SIGNATURE_RSVD_SIZE 1024 |
| |
| static inline void vb2_print_bytes(const void *ptr, uint32_t len) |
| { |
| const uint8_t *buf = (const uint8_t *)ptr; |
| int i; |
| for (i = 0; i < len; i++) |
| printf("%02x", *buf++); |
| } |
| |
| static void show_sig(const char *name, const struct vb21_signature *sig) |
| { |
| printf("Signature: %s\n", name); |
| printf(" Vboot API: 2.1\n"); |
| printf(" Desc: \"%s\"\n", vb21_common_desc(sig)); |
| printf(" Signature Algorithm: %d %s\n", sig->sig_alg, |
| vb2_get_sig_algorithm_name(sig->sig_alg)); |
| printf(" Hash Algorithm: %d %s\n", sig->hash_alg, |
| vb2_get_hash_algorithm_name(sig->hash_alg)); |
| printf(" Total size: 0x%x (%d)\n", sig->c.total_size, |
| sig->c.total_size); |
| printf(" ID: "); |
| vb2_print_bytes(&sig->id, sizeof(sig->id)); |
| printf("\n"); |
| printf(" Data size: 0x%x (%d)\n", sig->data_size, |
| sig->data_size); |
| } |
| |
| int ft_show_rwsig(const char *name, uint8_t *buf, uint32_t len, void *nuthin) |
| { |
| const struct vb21_signature *sig = 0; |
| struct vb2_public_key key; |
| uint8_t workbuf[VB2_VERIFY_DATA_WORKBUF_BYTES] |
| __attribute__ ((aligned (VB2_WORKBUF_ALIGN))); |
| struct vb2_workbuf wb; |
| uint32_t data_size, sig_size = SIGNATURE_RSVD_SIZE; |
| uint8_t *data; |
| |
| Debug("%s(): name %s\n", __func__, name); |
| Debug("%s(): len 0x%08x (%d)\n", __func__, len, len); |
| |
| /* Am I just looking at a signature file? */ |
| Debug("Looking for signature at 0x0\n"); |
| sig = (const struct vb21_signature *)buf; |
| if (VB2_SUCCESS == vb21_verify_signature(sig, len)) { |
| show_sig(name, sig); |
| if (!show_option.fv) { |
| printf("No data available to verify\n"); |
| return show_option.strict; |
| } |
| data = show_option.fv; |
| data_size = show_option.fv_size; |
| } else { |
| /* Where would it be? */ |
| if (show_option.sig_size) |
| sig_size = show_option.sig_size; |
| |
| Debug("Looking for signature at 0x%x\n", len - sig_size); |
| |
| if (len < sig_size) { |
| Debug("File is too small\n"); |
| return 1; |
| } |
| |
| sig = (const struct vb21_signature *)(buf + len - sig_size); |
| if (VB2_SUCCESS == vb21_verify_signature(sig, sig_size)) { |
| show_sig(name, sig); |
| data = buf; |
| data_size = sig->data_size; |
| } else { |
| return 1; |
| } |
| } |
| |
| if (!show_option.pkey) { |
| printf("No public key available to verify with\n"); |
| return show_option.strict; |
| } |
| |
| /* We already did this once, so it should work again */ |
| if (vb21_unpack_key(&key, |
| (const uint8_t *)show_option.pkey, |
| show_option.pkey->c.total_size)) { |
| Debug("Can't unpack pubkey\n"); |
| return 1; |
| } |
| |
| /* The sig is destroyed by the verify operation, so make a copy */ |
| { |
| uint8_t sigbuf[sig->c.total_size]; |
| memcpy(sigbuf, sig, sizeof(sigbuf)); |
| |
| vb2_workbuf_init(&wb, workbuf, sizeof(workbuf)); |
| |
| if (vb21_verify_data(data, data_size, |
| (struct vb21_signature *)sigbuf, |
| (const struct vb2_public_key *)&key, |
| &wb)) { |
| printf("Signature verification failed\n"); |
| return 1; |
| } |
| } |
| |
| printf("Signature verification succeeded.\n"); |
| return 0; |
| } |
| |
| int ft_sign_rwsig(const char *name, uint8_t *buf, uint32_t len, void *data) |
| { |
| struct vb21_signature *sig = 0; |
| uint32_t r, data_size = len, sig_size = SIGNATURE_RSVD_SIZE; |
| int retval = 1; |
| |
| Debug("%s(): name %s\n", __func__, name); |
| Debug("%s(): len 0x%08x (%d)\n", __func__, len, len); |
| |
| /* If we don't have a distinct OUTFILE, look for an existing sig */ |
| if (sign_option.inout_file_count < 2) { |
| const struct vb21_signature *old_sig; |
| |
| /* Where would it be? */ |
| if (sign_option.sig_size) |
| sig_size = sign_option.sig_size; |
| |
| Debug("Looking for old signature at 0x%x\n", len - sig_size); |
| |
| if (len < sig_size) { |
| fprintf(stderr, "File is too small\n"); |
| return 1; |
| } |
| |
| /* Take a look */ |
| old_sig = (const struct vb21_signature *)(buf + len - sig_size); |
| if (vb21_verify_signature(old_sig, sig_size)) { |
| fprintf(stderr, "Can't find a valid signature\n"); |
| return 1; |
| } |
| |
| /* Use the same exent again */ |
| data_size = old_sig->data_size; |
| |
| Debug("Found sig: data_size is 0x%x (%d)\n", data_size, |
| data_size); |
| } |
| |
| /* Unless overridden */ |
| if (sign_option.data_size) |
| data_size = sign_option.data_size; |
| |
| /* Sign the blob */ |
| r = vb21_sign_data(&sig, buf, data_size, sign_option.prikey, 0); |
| if (r) { |
| fprintf(stderr, |
| "Unable to sign data (error 0x%08x, if that helps)\n", |
| r); |
| goto done; |
| } |
| |
| if (sign_option.inout_file_count < 2) { |
| /* Overwrite the old signature */ |
| if (sig->c.total_size > sig_size) { |
| fprintf(stderr, "New sig is too large (%d > %d)\n", |
| sig->c.total_size, sig_size); |
| goto done; |
| } |
| memset(buf + len - sig_size, 0xff, sig_size); |
| memcpy(buf + len - sig_size, sig, sig->c.total_size); |
| } else { |
| /* Write the signature to a new file */ |
| r = vb21_write_object(sign_option.outfile, sig); |
| if (r) { |
| fprintf(stderr, "Unable to write sig" |
| " (error 0x%08x, if that helps)\n", r); |
| goto done; |
| } |
| } |
| |
| /* Finally */ |
| retval = 0; |
| done: |
| if (sig) |
| free(sig); |
| if (sign_option.prikey) |
| vb2_private_key_free(sign_option.prikey); |
| |
| return retval; |
| } |
| |
| enum futil_file_type ft_recognize_rwsig(uint8_t *buf, uint32_t len) |
| { |
| if (!vb21_verify_signature((const struct vb21_signature *)buf, len)) |
| return FILE_TYPE_RWSIG; |
| |
| if (len >= SIGNATURE_RSVD_SIZE && |
| !vb21_verify_signature((const struct vb21_signature *) |
| (buf + len - SIGNATURE_RSVD_SIZE), |
| SIGNATURE_RSVD_SIZE)) |
| return FILE_TYPE_RWSIG; |
| |
| return FILE_TYPE_UNKNOWN; |
| } |