1 #!/usr/bin/python 2 # 3 # Copyright (c) 2015 The Chromium Authors. All rights reserved. 4 # Use of this source code is governed by a BSD-style license that can be 5 # found in the LICENSE file. 6 7 import os 8 from autotest_lib.client.common_lib import error 9 from autotest_lib.client.bin import test 10 from autotest_lib.client.bin import utils 11 from autotest_lib.client.cros import kernel_config 12 13 import ctypes 14 import hashlib 15 import logging 16 import binascii 17 18 19 AF_ALG = 38 20 SOCK_SEQPACKET = 5 21 22 class sockaddr_alg(ctypes.Structure): 23 """ 24 A python definition of the same struct from <linux/if_alg.h> 25 26 struct sockaddr_alg { 27 __u16 salg_family; 28 __u8 salg_type[14]; 29 __u32 salg_feat; 30 __u32 salg_mask; 31 __u8 salg_name[64]; 32 }; 33 """ 34 _fields_ = [ 35 ('salg_family', ctypes.c_uint16), 36 ('salg_type', ctypes.c_char * 14), 37 ('salg_feat', ctypes.c_uint32), 38 ('salg_mask', ctypes.c_uint32), 39 ('salg_name', ctypes.c_char * 64), 40 ] 41 42 43 def __init__(self, alg_family, alg_type, alg_name, alg_feat=0, alg_mask=0): 44 super(sockaddr_alg, self).__init__(alg_family, alg_type, alg_feat, 45 alg_mask, alg_name) 46 47 48 class kernel_CryptoAPI(test.test): 49 """ 50 Verify that the crypto user API can't be used to load arbitrary modules. 51 Uses the kernel module 'test_module' 52 """ 53 version = 1 54 preserve_srcdir = True 55 56 def initialize(self): 57 self.job.require_gcc() 58 59 60 def setup(self): 61 os.chdir(self.srcdir) 62 utils.make() 63 64 65 def try_load_mod(self, module): 66 """ 67 Try to load a (non-crypto) module using the crypto UAPI 68 @param module: name of the kernel module to try to load 69 """ 70 if utils.module_is_loaded(module): 71 utils.unload_module(module) 72 73 path = os.path.join(self.srcdir, 'crypto_load_mod ') 74 utils.system(path + module) 75 76 if utils.module_is_loaded(module): 77 utils.unload_module(module) 78 raise error.TestFail('Able to load module "%s" using crypto UAPI' % 79 module) 80 81 82 def do_ifalg_digest(self, name, data, outlen): 83 """ 84 Use ctypes to run a digest through one of the available kernel ifalg 85 digest types 86 87 @param name: digest name 88 @param data: string data to digest 89 @param outlen: length of the digest output (e.g., SHA1 is 160-bit, so 90 outlen==20) 91 @param return string containing the output digest, or None if 92 experiencing an error 93 """ 94 libc = ctypes.CDLL("libc.so.6", use_errno=True) 95 96 # If you don't specify the function parameters this way, ctypes may try 97 # to treat pointers as 32-bit (and then later sign-extend them) 98 libc.socket.argtypes = [ ctypes.c_int, ctypes.c_int, ctypes.c_int ] 99 libc.bind.argtypes = [ ctypes.c_int, ctypes.c_void_p, ctypes.c_int ] 100 libc.send.argtypes = [ ctypes.c_int, ctypes.c_void_p, ctypes.c_size_t, 101 ctypes.c_int ] 102 libc.recv.argtypes = [ ctypes.c_int, ctypes.c_void_p, ctypes.c_size_t, 103 ctypes.c_int ] 104 105 sock = libc.socket(AF_ALG, SOCK_SEQPACKET, 0) 106 if sock == -1: 107 libc.perror("socket") 108 return None 109 110 alg = sockaddr_alg(AF_ALG, "hash", name) 111 if libc.bind(sock, ctypes.addressof(alg), ctypes.sizeof(alg)) == -1: 112 libc.perror("bind") 113 return None 114 115 fd = libc.accept(sock, None, 0) 116 if fd == -1: 117 libc.perror("accept") 118 return None 119 120 message = ctypes.create_string_buffer(data, len(data)) 121 if libc.send(fd, ctypes.addressof(message), ctypes.sizeof(message), 0) == -1: 122 libc.perror("send") 123 return None 124 125 out = (ctypes.c_uint8 * outlen)() 126 ret = libc.recv(fd, ctypes.addressof(out), ctypes.sizeof(out), 0) 127 if ret == -1: 128 libc.perror("recv") 129 return None 130 131 h = ctypes.string_at(ctypes.addressof(out), ret) 132 133 libc.close(sock) 134 135 return h 136 137 138 def test_digest(self, name, lib, data): 139 """ 140 Run a digest through both the kernel UAPI and through hashlib, throwing 141 an error if the two don't match 142 143 @param name: name of the digest (according to AF_ALG) 144 @param lib: a hashlib digest object 145 @param data: data to digest 146 """ 147 148 logging.info("Testing digest %s", name) 149 150 h1 = self.do_ifalg_digest(name, data, lib.digestsize) 151 if h1 is None: 152 raise error.TestFail("ifalg digest %s failed", name) 153 154 lib.update(data) 155 h2 = lib.digest() 156 157 if h1 != h2: 158 logging.error("%s: digests do not match", name) 159 logging.error(" hash 1: %s", binascii.hexlify(h1)) 160 logging.error(" hash 2: %s", binascii.hexlify(h2)) 161 raise error.TestFail("digest mismatch (%s)" % name) 162 163 logging.debug("hash 1: %s", binascii.hexlify(h1)) 164 logging.debug("hash 2: %s", binascii.hexlify(h2)) 165 166 167 def test_digests(self, data): 168 """ 169 Test several digests, using both the kernel crypto APIs and python 170 hashlib 171 172 @param data: the data to digest 173 """ 174 175 digests = [ 176 ( "sha1", hashlib.sha1()), 177 ( "md5", hashlib.md5()), 178 ( "sha512", hashlib.sha512()), 179 ] 180 181 for (name, lib) in digests: 182 self.test_digest(name, lib, data) 183 184 185 def test_is_valid(self): 186 """ 187 Check if this test is worth running, based on whether the kernel 188 .config has the right features 189 """ 190 config = kernel_config.KernelConfig() 191 config.initialize() 192 config.is_enabled('CRYPTO_USER_API_HASH') 193 config.is_enabled('CRYPTO_USER_API') 194 return len(config.failures()) == 0 195 196 197 def run_once(self): 198 # crypto tests only work with AF_ALG support 199 if not self.test_is_valid(): 200 raise error.TestNAError("Crypto tests only run with AF_ALG support") 201 202 module = "test_module" 203 self.try_load_mod(module) 204 205 self.test_digests("This is a not-so-secret message") 206
