1 | /* |
---|---|
2 | * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. |
3 | * |
4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
5 | * this file except in compliance with the License. You can obtain a copy |
6 | * in the file LICENSE in the source distribution or at |
7 | * https://www.openssl.org/source/license.html |
8 | */ |
9 | |
10 | #include <stdio.h> |
11 | #include <time.h> |
12 | #include "internal/cryptlib.h" |
13 | #include <openssl/bn.h> |
14 | #include "dsa_local.h" |
15 | |
16 | static int dsa_builtin_keygen(DSA *dsa); |
17 | |
18 | int DSA_generate_key(DSA *dsa) |
19 | { |
20 | if (dsa->meth->dsa_keygen) |
21 | return dsa->meth->dsa_keygen(dsa); |
22 | return dsa_builtin_keygen(dsa); |
23 | } |
24 | |
25 | static int dsa_builtin_keygen(DSA *dsa) |
26 | { |
27 | int ok = 0; |
28 | BN_CTX *ctx = NULL; |
29 | BIGNUM *pub_key = NULL, *priv_key = NULL; |
30 | |
31 | if ((ctx = BN_CTX_new()) == NULL) |
32 | goto err; |
33 | |
34 | if (dsa->priv_key == NULL) { |
35 | if ((priv_key = BN_secure_new()) == NULL) |
36 | goto err; |
37 | } else |
38 | priv_key = dsa->priv_key; |
39 | |
40 | do |
41 | if (!BN_priv_rand_range(priv_key, dsa->q)) |
42 | goto err; |
43 | while (BN_is_zero(priv_key)) ; |
44 | |
45 | if (dsa->pub_key == NULL) { |
46 | if ((pub_key = BN_new()) == NULL) |
47 | goto err; |
48 | } else |
49 | pub_key = dsa->pub_key; |
50 | |
51 | { |
52 | BIGNUM *prk = BN_new(); |
53 | |
54 | if (prk == NULL) |
55 | goto err; |
56 | BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME); |
57 | |
58 | if (!BN_mod_exp(pub_key, dsa->g, prk, dsa->p, ctx)) { |
59 | BN_free(prk); |
60 | goto err; |
61 | } |
62 | /* We MUST free prk before any further use of priv_key */ |
63 | BN_free(prk); |
64 | } |
65 | |
66 | dsa->priv_key = priv_key; |
67 | dsa->pub_key = pub_key; |
68 | dsa->dirty_cnt++; |
69 | ok = 1; |
70 | |
71 | err: |
72 | if (pub_key != dsa->pub_key) |
73 | BN_free(pub_key); |
74 | if (priv_key != dsa->priv_key) |
75 | BN_free(priv_key); |
76 | BN_CTX_free(ctx); |
77 | return ok; |
78 | } |
79 |