| /* Copyright (c) 2014 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. |
| * |
| * Key unpacking functions |
| */ |
| |
| #include "2sysincludes.h" |
| #include "2common.h" |
| #include "2rsa.h" |
| #include "vb2_common.h" |
| |
| int vb2_unpack_key_data(struct vb2_public_key *key, |
| const uint8_t *key_data, |
| uint32_t key_size) |
| { |
| const uint32_t *buf32 = (const uint32_t *)key_data; |
| uint32_t expected_key_size = vb2_packed_key_size(key->sig_alg); |
| |
| /* Make sure buffer is the correct length */ |
| if (!expected_key_size || expected_key_size != key_size) { |
| VB2_DEBUG("Wrong key size for algorithm\n"); |
| return VB2_ERROR_UNPACK_KEY_SIZE; |
| } |
| |
| /* Check for alignment */ |
| if (!vb2_aligned(buf32, sizeof(uint32_t))) |
| return VB2_ERROR_UNPACK_KEY_ALIGN; |
| |
| key->arrsize = buf32[0]; |
| |
| /* Sanity check key array size */ |
| if (key->arrsize * sizeof(uint32_t) != vb2_rsa_sig_size(key->sig_alg)) |
| return VB2_ERROR_UNPACK_KEY_ARRAY_SIZE; |
| |
| key->n0inv = buf32[1]; |
| |
| /* Arrays point inside the key data */ |
| key->n = buf32 + 2; |
| key->rr = buf32 + 2 + key->arrsize; |
| |
| return VB2_SUCCESS; |
| } |
| |
| int vb2_unpack_key(struct vb2_public_key *key, |
| const uint8_t *buf, |
| uint32_t size) |
| { |
| const struct vb2_packed_key *pkey = |
| (const struct vb2_packed_key *)buf; |
| uint32_t sig_size; |
| uint32_t min_offset = 0; |
| int rv; |
| |
| /* Check magic number */ |
| if (pkey->c.magic != VB2_MAGIC_PACKED_KEY) |
| return VB2_ERROR_UNPACK_KEY_MAGIC; |
| |
| rv = vb2_verify_common_header(buf, size); |
| if (rv) |
| return rv; |
| |
| /* Make sure key data is inside */ |
| rv = vb2_verify_common_member(pkey, &min_offset, |
| pkey->key_offset, pkey->key_size); |
| if (rv) |
| return rv; |
| |
| /* |
| * Check for compatible version. No need to check minor version, since |
| * that's compatible across readers matching the major version, and we |
| * haven't added any new fields. |
| */ |
| if (pkey->c.struct_version_major != VB2_PACKED_KEY_VERSION_MAJOR) |
| return VB2_ERROR_UNPACK_KEY_STRUCT_VERSION; |
| |
| /* Copy key algorithms */ |
| key->hash_alg = pkey->hash_alg; |
| if (!vb2_digest_size(key->hash_alg)) |
| return VB2_ERROR_UNPACK_KEY_HASH_ALGORITHM; |
| |
| key->sig_alg = pkey->sig_alg; |
| if (key->sig_alg != VB2_SIG_NONE) { |
| sig_size = vb2_rsa_sig_size(key->sig_alg); |
| if (!sig_size) |
| return VB2_ERROR_UNPACK_KEY_SIG_ALGORITHM; |
| rv = vb2_unpack_key_data( |
| key, |
| (const uint8_t *)pkey + pkey->key_offset, |
| pkey->key_size); |
| if (rv) |
| return rv; |
| } |
| |
| /* Key description */ |
| key->desc = vb2_common_desc(pkey); |
| key->version = pkey->key_version; |
| key->id = &pkey->id; |
| |
| return VB2_SUCCESS; |
| } |