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| 1 | +// SPDX-License-Identifier: GPL-2.0-or-later |
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1 | 2 | /* System trusted keyring for trusted public keys |
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2 | 3 | * |
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3 | 4 | * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. |
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4 | 5 | * Written by David Howells (dhowells@redhat.com) |
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5 | | - * |
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6 | | - * This program is free software; you can redistribute it and/or |
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7 | | - * modify it under the terms of the GNU General Public Licence |
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8 | | - * as published by the Free Software Foundation; either version |
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9 | | - * 2 of the Licence, or (at your option) any later version. |
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10 | 6 | */ |
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11 | 7 | |
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12 | 8 | #include <linux/export.h> |
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.. | .. |
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19 | 15 | #include <keys/asymmetric-type.h> |
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20 | 16 | #include <keys/system_keyring.h> |
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21 | 17 | #include <crypto/pkcs7.h> |
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| 18 | +#include "common.h" |
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22 | 19 | |
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23 | 20 | static struct key *builtin_trusted_keys; |
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24 | 21 | #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING |
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25 | 22 | static struct key *secondary_trusted_keys; |
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| 23 | +#endif |
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| 24 | +#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING |
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| 25 | +static struct key *platform_trusted_keys; |
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26 | 26 | #endif |
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27 | 27 | |
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28 | 28 | extern __initconst const u8 system_certificate_list[]; |
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.. | .. |
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137 | 137 | */ |
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138 | 138 | static __init int load_system_certificate_list(void) |
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139 | 139 | { |
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140 | | - key_ref_t key; |
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141 | | - const u8 *p, *end; |
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142 | | - size_t plen; |
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143 | | - |
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144 | 140 | pr_notice("Loading compiled-in X.509 certificates\n"); |
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145 | 141 | |
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146 | | - p = system_certificate_list; |
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147 | | - end = p + system_certificate_list_size; |
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148 | | - while (p < end) { |
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149 | | - /* Each cert begins with an ASN.1 SEQUENCE tag and must be more |
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150 | | - * than 256 bytes in size. |
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151 | | - */ |
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152 | | - if (end - p < 4) |
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153 | | - goto dodgy_cert; |
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154 | | - if (p[0] != 0x30 && |
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155 | | - p[1] != 0x82) |
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156 | | - goto dodgy_cert; |
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157 | | - plen = (p[2] << 8) | p[3]; |
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158 | | - plen += 4; |
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159 | | - if (plen > end - p) |
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160 | | - goto dodgy_cert; |
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161 | | - |
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162 | | - key = key_create_or_update(make_key_ref(builtin_trusted_keys, 1), |
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163 | | - "asymmetric", |
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164 | | - NULL, |
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165 | | - p, |
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166 | | - plen, |
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167 | | - ((KEY_POS_ALL & ~KEY_POS_SETATTR) | |
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168 | | - KEY_USR_VIEW | KEY_USR_READ), |
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169 | | - KEY_ALLOC_NOT_IN_QUOTA | |
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170 | | - KEY_ALLOC_BUILT_IN | |
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171 | | - KEY_ALLOC_BYPASS_RESTRICTION); |
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172 | | - if (IS_ERR(key)) { |
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173 | | - pr_err("Problem loading in-kernel X.509 certificate (%ld)\n", |
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174 | | - PTR_ERR(key)); |
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175 | | - } else { |
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176 | | - pr_notice("Loaded X.509 cert '%s'\n", |
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177 | | - key_ref_to_ptr(key)->description); |
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178 | | - key_ref_put(key); |
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179 | | - } |
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180 | | - p += plen; |
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181 | | - } |
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182 | | - |
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183 | | - return 0; |
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184 | | - |
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185 | | -dodgy_cert: |
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186 | | - pr_err("Problem parsing in-kernel X.509 certificate list\n"); |
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187 | | - return 0; |
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| 142 | + return load_certificate_list(system_certificate_list, system_certificate_list_size, |
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| 143 | + builtin_trusted_keys); |
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188 | 144 | } |
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189 | 145 | late_initcall(load_system_certificate_list); |
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190 | 146 | |
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191 | 147 | #ifdef CONFIG_SYSTEM_DATA_VERIFICATION |
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| 148 | + |
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| 149 | +/** |
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| 150 | + * verify_pkcs7_message_sig - Verify a PKCS#7-based signature on system data. |
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| 151 | + * @data: The data to be verified (NULL if expecting internal data). |
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| 152 | + * @len: Size of @data. |
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| 153 | + * @pkcs7: The PKCS#7 message that is the signature. |
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| 154 | + * @trusted_keys: Trusted keys to use (NULL for builtin trusted keys only, |
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| 155 | + * (void *)1UL for all trusted keys). |
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| 156 | + * @usage: The use to which the key is being put. |
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| 157 | + * @view_content: Callback to gain access to content. |
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| 158 | + * @ctx: Context for callback. |
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| 159 | + */ |
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| 160 | +int verify_pkcs7_message_sig(const void *data, size_t len, |
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| 161 | + struct pkcs7_message *pkcs7, |
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| 162 | + struct key *trusted_keys, |
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| 163 | + enum key_being_used_for usage, |
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| 164 | + int (*view_content)(void *ctx, |
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| 165 | + const void *data, size_t len, |
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| 166 | + size_t asn1hdrlen), |
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| 167 | + void *ctx) |
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| 168 | +{ |
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| 169 | + int ret; |
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| 170 | + |
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| 171 | + /* The data should be detached - so we need to supply it. */ |
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| 172 | + if (data && pkcs7_supply_detached_data(pkcs7, data, len) < 0) { |
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| 173 | + pr_err("PKCS#7 signature with non-detached data\n"); |
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| 174 | + ret = -EBADMSG; |
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| 175 | + goto error; |
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| 176 | + } |
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| 177 | + |
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| 178 | + ret = pkcs7_verify(pkcs7, usage); |
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| 179 | + if (ret < 0) |
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| 180 | + goto error; |
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| 181 | + |
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| 182 | + if (!trusted_keys) { |
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| 183 | + trusted_keys = builtin_trusted_keys; |
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| 184 | + } else if (trusted_keys == VERIFY_USE_SECONDARY_KEYRING) { |
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| 185 | +#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING |
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| 186 | + trusted_keys = secondary_trusted_keys; |
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| 187 | +#else |
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| 188 | + trusted_keys = builtin_trusted_keys; |
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| 189 | +#endif |
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| 190 | + } else if (trusted_keys == VERIFY_USE_PLATFORM_KEYRING) { |
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| 191 | +#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING |
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| 192 | + trusted_keys = platform_trusted_keys; |
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| 193 | +#else |
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| 194 | + trusted_keys = NULL; |
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| 195 | +#endif |
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| 196 | + if (!trusted_keys) { |
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| 197 | + ret = -ENOKEY; |
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| 198 | + pr_devel("PKCS#7 platform keyring is not available\n"); |
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| 199 | + goto error; |
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| 200 | + } |
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| 201 | + |
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| 202 | + ret = is_key_on_revocation_list(pkcs7); |
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| 203 | + if (ret != -ENOKEY) { |
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| 204 | + pr_devel("PKCS#7 platform key is on revocation list\n"); |
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| 205 | + goto error; |
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| 206 | + } |
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| 207 | + } |
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| 208 | + ret = pkcs7_validate_trust(pkcs7, trusted_keys); |
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| 209 | + if (ret < 0) { |
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| 210 | + if (ret == -ENOKEY) |
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| 211 | + pr_devel("PKCS#7 signature not signed with a trusted key\n"); |
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| 212 | + goto error; |
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| 213 | + } |
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| 214 | + |
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| 215 | + if (view_content) { |
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| 216 | + size_t asn1hdrlen; |
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| 217 | + |
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| 218 | + ret = pkcs7_get_content_data(pkcs7, &data, &len, &asn1hdrlen); |
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| 219 | + if (ret < 0) { |
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| 220 | + if (ret == -ENODATA) |
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| 221 | + pr_devel("PKCS#7 message does not contain data\n"); |
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| 222 | + goto error; |
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| 223 | + } |
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| 224 | + |
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| 225 | + ret = view_content(ctx, data, len, asn1hdrlen); |
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| 226 | + } |
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| 227 | + |
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| 228 | +error: |
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| 229 | + pr_devel("<==%s() = %d\n", __func__, ret); |
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| 230 | + return ret; |
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| 231 | +} |
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192 | 232 | |
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193 | 233 | /** |
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194 | 234 | * verify_pkcs7_signature - Verify a PKCS#7-based signature on system data. |
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.. | .. |
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218 | 258 | if (IS_ERR(pkcs7)) |
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219 | 259 | return PTR_ERR(pkcs7); |
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220 | 260 | |
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221 | | - /* The data should be detached - so we need to supply it. */ |
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222 | | - if (data && pkcs7_supply_detached_data(pkcs7, data, len) < 0) { |
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223 | | - pr_err("PKCS#7 signature with non-detached data\n"); |
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224 | | - ret = -EBADMSG; |
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225 | | - goto error; |
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226 | | - } |
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| 261 | + ret = verify_pkcs7_message_sig(data, len, pkcs7, trusted_keys, usage, |
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| 262 | + view_content, ctx); |
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227 | 263 | |
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228 | | - ret = pkcs7_verify(pkcs7, usage); |
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229 | | - if (ret < 0) |
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230 | | - goto error; |
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231 | | - |
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232 | | - if (!trusted_keys) { |
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233 | | - trusted_keys = builtin_trusted_keys; |
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234 | | - } else if (trusted_keys == VERIFY_USE_SECONDARY_KEYRING) { |
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235 | | -#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING |
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236 | | - trusted_keys = secondary_trusted_keys; |
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237 | | -#else |
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238 | | - trusted_keys = builtin_trusted_keys; |
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239 | | -#endif |
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240 | | - } |
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241 | | - ret = pkcs7_validate_trust(pkcs7, trusted_keys); |
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242 | | - if (ret < 0) { |
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243 | | - if (ret == -ENOKEY) |
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244 | | - pr_err("PKCS#7 signature not signed with a trusted key\n"); |
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245 | | - goto error; |
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246 | | - } |
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247 | | - |
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248 | | - if (view_content) { |
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249 | | - size_t asn1hdrlen; |
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250 | | - |
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251 | | - ret = pkcs7_get_content_data(pkcs7, &data, &len, &asn1hdrlen); |
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252 | | - if (ret < 0) { |
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253 | | - if (ret == -ENODATA) |
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254 | | - pr_devel("PKCS#7 message does not contain data\n"); |
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255 | | - goto error; |
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256 | | - } |
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257 | | - |
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258 | | - ret = view_content(ctx, data, len, asn1hdrlen); |
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259 | | - } |
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260 | | - |
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261 | | -error: |
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262 | 264 | pkcs7_free_message(pkcs7); |
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263 | 265 | pr_devel("<==%s() = %d\n", __func__, ret); |
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264 | 266 | return ret; |
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.. | .. |
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266 | 268 | EXPORT_SYMBOL_GPL(verify_pkcs7_signature); |
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267 | 269 | |
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268 | 270 | #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ |
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| 271 | + |
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| 272 | +#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING |
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| 273 | +void __init set_platform_trusted_keys(struct key *keyring) |
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| 274 | +{ |
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| 275 | + platform_trusted_keys = keyring; |
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| 276 | +} |
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| 277 | +#endif |
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