1 /*
2  * Copyright (c) 2022-2023 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 #include "hvb_footer.h"
16 #include "hvb_util.h"
17 #include "hvb_cert.h"
18 #include "hvb_sysdeps.h"
19 
_footer_parser(struct hvb_footer * footer,struct hvb_buf * footer_buf)20 static enum hvb_errno _footer_parser(struct hvb_footer *footer, struct hvb_buf *footer_buf)
21 {
22     uint64_t size;
23 
24     if (footer_buf->size < sizeof(*footer)) {
25         hvb_print("footer src size error.\n");
26         return HVB_ERROR_INVALID_FOOTER_FORMAT;
27     }
28     if (hvb_memcpy_s(footer, sizeof(*footer), footer_buf->addr, sizeof(*footer)) != 0) {
29         hvb_print("error, copy footer.\n");
30         return HVB_ERROR_OOM;
31     }
32 
33     /* Check that magic is correct. */
34     if (hvb_memcmp(footer->magic, HVB_FOOTER_MAGIC, sizeof(footer->magic)) != 0) {
35         hvb_print("Footer magic is incorrect.\n");
36         return HVB_ERROR_INVALID_FOOTER_FORMAT;
37     }
38 
39     /* check these size is correct */
40     if (footer->partition_size > HVB_MAX_PARTITION_SIZE ||
41         footer->partition_size < HVB_MIN_PARTITION_SIZE) {
42         hvb_print("Invalid partition_size in footer.\n");
43         return HVB_ERROR_INVALID_FOOTER_FORMAT;
44     }
45 
46     size = footer->image_size + footer->cert_size + HVB_FOOTER_SIZE;
47     if (footer->image_size >= footer->partition_size ||
48         size < footer->image_size + HVB_FOOTER_SIZE ||
49         size > footer->partition_size) {
50         hvb_print("Invalid image_size in footer.\n");
51         return HVB_ERROR_INVALID_FOOTER_FORMAT;
52     }
53 
54     size = footer->cert_offset + footer->cert_size + HVB_FOOTER_SIZE;
55     if (footer->cert_offset < footer->image_size ||
56         size < footer->cert_offset + HVB_FOOTER_SIZE ||
57         size > footer->partition_size) {
58         hvb_print("Invalid cert info in footer.\n");
59         return HVB_ERROR_INVALID_FOOTER_FORMAT;
60     }
61 
62     return HVB_OK;
63 }
64 
_load_and_parse_footer(struct hvb_ops * ops,struct hvb_footer * footer,const char * ptn)65 static enum hvb_errno _load_and_parse_footer(struct hvb_ops *ops, struct hvb_footer *footer, const char *ptn)
66 {
67     enum hvb_errno ret = HVB_OK;
68     uint64_t read_bytes = 0;
69     enum hvb_io_errno io_ret = HVB_IO_OK;
70     uint8_t buf[HVB_FOOTER_SIZE] = {0};
71     struct hvb_buf footer_buf = {&buf[0], sizeof(buf)};
72 
73     io_ret = ops->read_partition(ops, ptn, -HVB_FOOTER_SIZE, HVB_FOOTER_SIZE, footer_buf.addr, &read_bytes);
74     if (io_ret != HVB_IO_OK) {
75         hvb_printv(ptn, ": error, loading data.\n", NULL);
76         return HVB_ERROR_IO;
77     }
78 
79     if (read_bytes != footer_buf.size) {
80         hvb_printv(ptn, ": Read incorrect number of bytes.\n", NULL);
81         return HVB_ERROR_IO;
82     }
83 
84     ret = _footer_parser(footer, &footer_buf);
85     if (ret != HVB_OK) {
86         hvb_printv(ptn, ": No footer detected,.\n", NULL);
87         return ret;
88     }
89 
90     return HVB_OK;
91 }
92 
_load_cert(struct hvb_ops * ops,struct hvb_buf * cert,const char * ptn,struct hvb_footer * footer)93 static enum hvb_errno _load_cert(struct hvb_ops *ops, struct hvb_buf *cert, const char *ptn, struct hvb_footer *footer)
94 {
95     enum hvb_io_errno io_ret = HVB_IO_OK;
96     uint64_t read_bytes = 0;
97     uint64_t offset = footer->cert_offset;
98 
99     io_ret = ops->read_partition(ops, ptn, offset, cert->size, cert->addr, &read_bytes);
100     if (io_ret != HVB_IO_OK) {
101         hvb_printv(ptn, ": error loading signature data.\n", NULL);
102         return HVB_ERROR_IO;
103     }
104 
105     if (cert->size != read_bytes) {
106         hvb_printv(ptn, ": Read incorrect number of bytes from.\n", NULL);
107         return HVB_ERROR_IO;
108     }
109 
110     return HVB_OK;
111 }
112 
footer_init_desc(struct hvb_ops * ops,const char * ptn,const char * const * hash_ptn_list,struct hvb_buf * out_pubk,struct hvb_verified_data * vd)113 enum hvb_errno footer_init_desc(struct hvb_ops *ops, const char *ptn, const char *const *hash_ptn_list,
114                                 struct hvb_buf *out_pubk, struct hvb_verified_data *vd)
115 {
116     hvb_return_hvb_err_if_null(ops);
117     hvb_return_hvb_err_if_null(ptn);
118     hvb_return_hvb_err_if_null(out_pubk);
119     hvb_return_hvb_err_if_null(vd);
120 
121     enum hvb_errno ret = HVB_OK;
122     struct hvb_buf cert_buf = {NULL, 0};
123     struct hvb_footer footer = {0};
124     struct hvb_cert_data *cert_info = NULL;
125 
126     ret = _load_and_parse_footer(ops, &footer, ptn);
127     if (ret != HVB_OK)
128         return ret;
129 
130     cert_buf.size = footer.cert_size;
131     cert_buf.addr = hvb_malloc(cert_buf.size);
132     if (!cert_buf.addr) {
133         hvb_print("error, alloc cert buf\n");
134         return HVB_ERROR_OOM;
135     }
136 
137     ret = _load_cert(ops, &cert_buf, ptn, &footer);
138     if (ret != HVB_OK)
139         goto out;
140 
141     ret = cert_init_desc(ops, ptn, &cert_buf, hash_ptn_list, out_pubk, vd);
142     if (ret != HVB_OK)
143         goto out;
144 
145     if (vd->num_loaded_certs >= HVB_MAX_NUMBER_OF_LOADED_CERTS) {
146         hvb_print("error, too many certs\n");
147         ret = HVB_ERROR_OOM;
148         goto out;
149     }
150 
151     cert_info = &vd->certs[vd->num_loaded_certs++];
152     cert_info->partition_name = hvb_strdup(ptn);
153     cert_info->data = cert_buf;
154     cert_info->verify_result = ret;
155 
156     return ret;
157 
158 out:
159     if (cert_buf.addr != NULL)
160         hvb_free(cert_buf.addr);
161 
162     return ret;
163 }
164