Linux kernel mirror (for testing)
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1#!/usr/bin/env python3
2# SPDX-License-Identifier: GPL-2.0-or-later
3#
4# Script that generates test vectors for the given hash function.
5#
6# Copyright 2025 Google LLC
7
8import hashlib
9import hmac
10import sys
11
12DATA_LENS = [0, 1, 2, 3, 16, 32, 48, 49, 63, 64, 65, 127, 128, 129, 256, 511,
13 513, 1000, 3333, 4096, 4128, 4160, 4224, 16384]
14
15# Generate the given number of random bytes, using the length itself as the seed
16# for a simple linear congruential generator (LCG). The C test code uses the
17# same LCG with the same seeding strategy to reconstruct the data, ensuring
18# reproducibility without explicitly storing the data in the test vectors.
19def rand_bytes(length):
20 seed = length
21 out = []
22 for _ in range(length):
23 seed = (seed * 25214903917 + 11) % 2**48
24 out.append((seed >> 16) % 256)
25 return bytes(out)
26
27POLY1305_KEY_SIZE = 32
28
29# A straightforward, unoptimized implementation of Poly1305.
30# Reference: https://cr.yp.to/mac/poly1305-20050329.pdf
31class Poly1305:
32 def __init__(self, key):
33 assert len(key) == POLY1305_KEY_SIZE
34 self.h = 0
35 rclamp = 0x0ffffffc0ffffffc0ffffffc0fffffff
36 self.r = int.from_bytes(key[:16], byteorder='little') & rclamp
37 self.s = int.from_bytes(key[16:], byteorder='little')
38
39 # Note: this supports partial blocks only at the end.
40 def update(self, data):
41 for i in range(0, len(data), 16):
42 chunk = data[i:i+16]
43 c = int.from_bytes(chunk, byteorder='little') + 2**(8 * len(chunk))
44 self.h = ((self.h + c) * self.r) % (2**130 - 5)
45 return self
46
47 # Note: gen_additional_poly1305_testvecs() relies on this being
48 # nondestructive, i.e. not changing any field of self.
49 def digest(self):
50 m = (self.h + self.s) % 2**128
51 return m.to_bytes(16, byteorder='little')
52
53POLYVAL_POLY = sum((1 << i) for i in [128, 127, 126, 121, 0])
54POLYVAL_BLOCK_SIZE = 16
55
56# A straightforward, unoptimized implementation of POLYVAL.
57# Reference: https://datatracker.ietf.org/doc/html/rfc8452
58class Polyval:
59 def __init__(self, key):
60 assert len(key) == 16
61 self.h = int.from_bytes(key, byteorder='little')
62 self.acc = 0
63
64 # Note: this supports partial blocks only at the end.
65 def update(self, data):
66 for i in range(0, len(data), 16):
67 # acc += block
68 self.acc ^= int.from_bytes(data[i:i+16], byteorder='little')
69 # acc = (acc * h * x^-128) mod POLYVAL_POLY
70 product = 0
71 for j in range(128):
72 if (self.h & (1 << j)) != 0:
73 product ^= self.acc << j
74 if (product & (1 << j)) != 0:
75 product ^= POLYVAL_POLY << j
76 self.acc = product >> 128
77 return self
78
79 def digest(self):
80 return self.acc.to_bytes(16, byteorder='little')
81
82def hash_init(alg):
83 if alg == 'poly1305':
84 # Use a fixed random key here, to present Poly1305 as an unkeyed hash.
85 # This allows all the test cases for unkeyed hashes to work on Poly1305.
86 return Poly1305(rand_bytes(POLY1305_KEY_SIZE))
87 if alg == 'polyval':
88 return Polyval(rand_bytes(POLYVAL_BLOCK_SIZE))
89 return hashlib.new(alg)
90
91def hash_update(ctx, data):
92 ctx.update(data)
93
94def hash_final(ctx):
95 return ctx.digest()
96
97def compute_hash(alg, data):
98 ctx = hash_init(alg)
99 hash_update(ctx, data)
100 return hash_final(ctx)
101
102def print_bytes(prefix, value, bytes_per_line):
103 for i in range(0, len(value), bytes_per_line):
104 line = prefix + ''.join(f'0x{b:02x}, ' for b in value[i:i+bytes_per_line])
105 print(f'{line.rstrip()}')
106
107def print_static_u8_array_definition(name, value):
108 print('')
109 print(f'static const u8 {name} = {{')
110 print_bytes('\t', value, 8)
111 print('};')
112
113def print_c_struct_u8_array_field(name, value):
114 print(f'\t\t.{name} = {{')
115 print_bytes('\t\t\t', value, 8)
116 print('\t\t},')
117
118def alg_digest_size_const(alg):
119 if alg.startswith('blake2'):
120 return f'{alg.upper()}_HASH_SIZE'
121 return f"{alg.upper().replace('-', '_')}_DIGEST_SIZE"
122
123def gen_unkeyed_testvecs(alg):
124 print('')
125 print('static const struct {')
126 print('\tsize_t data_len;')
127 print(f'\tu8 digest[{alg_digest_size_const(alg)}];')
128 print('} hash_testvecs[] = {')
129 for data_len in DATA_LENS:
130 data = rand_bytes(data_len)
131 print('\t{')
132 print(f'\t\t.data_len = {data_len},')
133 print_c_struct_u8_array_field('digest', compute_hash(alg, data))
134 print('\t},')
135 print('};')
136
137 data = rand_bytes(4096)
138 ctx = hash_init(alg)
139 for data_len in range(len(data) + 1):
140 hash_update(ctx, compute_hash(alg, data[:data_len]))
141 print_static_u8_array_definition(
142 f'hash_testvec_consolidated[{alg_digest_size_const(alg)}]',
143 hash_final(ctx))
144
145def gen_additional_sha3_testvecs():
146 max_len = 4096
147 in_data = rand_bytes(max_len)
148 for alg in ['shake128', 'shake256']:
149 ctx = hashlib.new('sha3-256')
150 for in_len in range(max_len + 1):
151 out_len = (in_len * 293) % (max_len + 1)
152 out = hashlib.new(alg, data=in_data[:in_len]).digest(out_len)
153 ctx.update(out)
154 print_static_u8_array_definition(f'{alg}_testvec_consolidated[SHA3_256_DIGEST_SIZE]',
155 ctx.digest())
156
157def gen_hmac_testvecs(alg):
158 ctx = hmac.new(rand_bytes(32), digestmod=alg)
159 data = rand_bytes(4096)
160 for data_len in range(len(data) + 1):
161 ctx.update(data[:data_len])
162 key_len = data_len % 293
163 key = rand_bytes(key_len)
164 mac = hmac.digest(key, data[:data_len], alg)
165 ctx.update(mac)
166 print_static_u8_array_definition(
167 f'hmac_testvec_consolidated[{alg.upper()}_DIGEST_SIZE]',
168 ctx.digest())
169
170def gen_additional_blake2_testvecs(alg):
171 if alg == 'blake2s':
172 (max_key_size, max_hash_size) = (32, 32)
173 elif alg == 'blake2b':
174 (max_key_size, max_hash_size) = (64, 64)
175 else:
176 raise ValueError(f'Unsupported alg: {alg}')
177 hashes = b''
178 for key_len in range(max_key_size + 1):
179 for out_len in range(1, max_hash_size + 1):
180 h = hashlib.new(alg, digest_size=out_len, key=rand_bytes(key_len))
181 h.update(rand_bytes(100))
182 hashes += h.digest()
183 print_static_u8_array_definition(
184 f'{alg}_keyed_testvec_consolidated[{alg_digest_size_const(alg)}]',
185 compute_hash(alg, hashes))
186
187def gen_additional_poly1305_testvecs():
188 key = b'\xff' * POLY1305_KEY_SIZE
189 data = b''
190 ctx = Poly1305(key)
191 for _ in range(32):
192 for j in range(0, 4097, 16):
193 ctx.update(b'\xff' * j)
194 data += ctx.digest()
195 print_static_u8_array_definition(
196 'poly1305_allones_macofmacs[POLY1305_DIGEST_SIZE]',
197 Poly1305(key).update(data).digest())
198
199def gen_additional_polyval_testvecs():
200 key = b'\xff' * POLYVAL_BLOCK_SIZE
201 hashes = b''
202 for data_len in range(0, 4097, 16):
203 hashes += Polyval(key).update(b'\xff' * data_len).digest()
204 print_static_u8_array_definition(
205 'polyval_allones_hashofhashes[POLYVAL_DIGEST_SIZE]',
206 Polyval(key).update(hashes).digest())
207
208if len(sys.argv) != 2:
209 sys.stderr.write('Usage: gen-hash-testvecs.py ALGORITHM\n')
210 sys.stderr.write('ALGORITHM may be any supported by Python hashlib; or poly1305, polyval, or sha3.\n')
211 sys.stderr.write('Example: gen-hash-testvecs.py sha512\n')
212 sys.exit(1)
213
214alg = sys.argv[1]
215print('/* SPDX-License-Identifier: GPL-2.0-or-later */')
216print(f'/* This file was generated by: {sys.argv[0]} {" ".join(sys.argv[1:])} */')
217if alg.startswith('blake2'):
218 gen_unkeyed_testvecs(alg)
219 gen_additional_blake2_testvecs(alg)
220elif alg == 'poly1305':
221 gen_unkeyed_testvecs(alg)
222 gen_additional_poly1305_testvecs()
223elif alg == 'polyval':
224 gen_unkeyed_testvecs(alg)
225 gen_additional_polyval_testvecs()
226elif alg == 'sha3':
227 print()
228 print('/* SHA3-256 test vectors */')
229 gen_unkeyed_testvecs('sha3-256')
230 print()
231 print('/* SHAKE test vectors */')
232 gen_additional_sha3_testvecs()
233else:
234 gen_unkeyed_testvecs(alg)
235 gen_hmac_testvecs(alg)