1 /*- 2 * Copyright (c) 2019 Stormshield. 3 * Copyright (c) 2019 Semihalf. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 17 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 18 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 19 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 20 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 22 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 23 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 24 * POSSIBILITY OF SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/stat.h> 32 33 #include "libsecureboot-priv.h" 34 #include <verify_file.h> 35 36 /* 37 * Values to pass to kernel by envs. 38 */ 39 static char manifest_path[MAXPATHLEN]; 40 static char manifest_prefix[MAXPATHLEN]; 41 static char manifest_hash[2 * br_sha256_SIZE + 2]; 42 static int manifest_present = 0; 43 44 /* 45 * Verify and pass manifest path and digest to kernel through envs. 46 * The paths in manifest can be either absolute, 47 * or "prefix", if exists will be added to the ones that are not. 48 */ 49 int 50 pass_manifest(const char *path, const char *prefix) 51 { 52 char *content; 53 struct stat st; 54 unsigned char digest[br_sha256_SIZE]; 55 const br_hash_class *md; 56 br_hash_compat_context ctx; 57 int rc; 58 59 content = NULL; 60 md = &br_sha256_vtable; 61 62 if (strnlen(path, MAXPATHLEN) == MAXPATHLEN || 63 strnlen(prefix, MAXPATHLEN) == MAXPATHLEN) 64 return (EINVAL); 65 66 rc = stat(path, &st); 67 if (rc != 0) 68 goto out; 69 70 if (!S_ISREG(st.st_mode)) { 71 rc = EINVAL; 72 goto out; 73 } 74 75 rc = is_verified(&st); 76 77 if (rc != VE_NOT_CHECKED && rc != VE_VERIFIED) { 78 rc = EPERM; 79 goto out; 80 } 81 82 if (rc == VE_VERIFIED) 83 content = read_file(path, NULL); 84 else 85 content = (char *)verify_signed(path, VEF_VERBOSE); 86 87 if (content == NULL) { 88 add_verify_status(&st, VE_FINGERPRINT_WRONG); 89 rc = EIO; 90 goto out; 91 } 92 93 add_verify_status(&st, VE_VERIFIED); 94 95 md->init(&ctx.vtable); 96 md->update(&ctx.vtable, content, st.st_size); 97 md->out(&ctx.vtable, digest); 98 99 if (prefix == NULL) 100 manifest_prefix[0] = '\0'; 101 else 102 strcpy(manifest_prefix, prefix); 103 104 strcpy(manifest_path, path); 105 106 hexdigest(manifest_hash, 2 * br_sha256_SIZE + 2, 107 digest, br_sha256_SIZE); 108 manifest_hash[2*br_sha256_SIZE] = '\0'; 109 110 manifest_present = 1; 111 rc = 0; 112 113 out: 114 if (content != NULL) 115 free(content); 116 117 return (rc); 118 } 119 120 /* 121 * Set appropriate envs to inform kernel about manifest location and digest. 122 * This should be called right before boot so that envs can't be replaced. 123 */ 124 int 125 pass_manifest_export_envs() 126 { 127 int rc; 128 129 /* If we have nothing to pass make sure that envs are empty. */ 130 if (!manifest_present) { 131 unsetenv("veriexec.manifest_path"); 132 unsetenv("veriexec.manifest_hash"); 133 unsetenv("veriexec.manifest_prefix"); 134 return (0); 135 } 136 137 rc = setenv("veriexec.manifest_path", manifest_path, 1); 138 if (rc != 0) 139 return (rc); 140 141 rc = setenv("veriexec.manifest_hash", manifest_hash, 1); 142 if (rc != 0) { 143 unsetenv("veriexec.manifest_path"); 144 return (rc); 145 } 146 147 if (manifest_prefix[0] != '\0') 148 rc = setenv("veriexec.manifest_prefix", manifest_prefix, 1); 149 150 return (rc); 151 } 152 153