2 * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 * https://www.openssl.org/source/license.html
8 * or in the file LICENSE in the source distribution.
12 * Confirm that a^b mod c agrees when calculated cleverly vs naively, for
17 #include <openssl/bn.h>
18 #include <openssl/err.h>
22 int FuzzerInitialize(int *argc
, char ***argv
)
24 OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CRYPTO_STRINGS
, NULL
);
30 int FuzzerTestOneInput(const uint8_t *buf
, size_t len
)
33 size_t l1
= 0, l2
= 0, l3
= 0;
49 /* Divide the input into three parts, using the values of the first two
50 * bytes to choose lengths, which generate b1, b2 and b3. Use three bits
51 * of the third byte to choose signs for the three numbers.
55 l1
= (buf
[0] * len
) / 255;
57 l2
= (buf
[0] * (len
- l1
)) / 255;
65 OPENSSL_assert(BN_bin2bn(buf
, l1
, b1
) == b1
);
66 BN_set_negative(b1
, s1
);
67 OPENSSL_assert(BN_bin2bn(buf
+ l1
, l2
, b2
) == b2
);
68 OPENSSL_assert(BN_bin2bn(buf
+ l1
+ l2
, l3
, b3
) == b3
);
69 BN_set_negative(b3
, s3
);
71 /* mod 0 is undefined */
77 OPENSSL_assert(BN_mod_exp(b4
, b1
, b2
, b3
, ctx
));
78 OPENSSL_assert(BN_mod_exp_simple(b5
, b1
, b2
, b3
, ctx
));
80 success
= BN_cmp(b4
, b5
) == 0;
82 BN_print_fp(stdout
, b1
);
84 BN_print_fp(stdout
, b2
);
86 BN_print_fp(stdout
, b3
);
88 BN_print_fp(stdout
, b4
);
90 BN_print_fp(stdout
, b5
);
95 OPENSSL_assert(success
);
107 void FuzzerCleanup(void)