key.c revision 1.6 
1/*	$Id: key.c,v 1.6 2022/02/22 13:45:09 tb Exp $ */
2/*
3 * Copyright (c) 2019 Renaud Allard <renaud@allard.it>
4 * Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <err.h>
20#include <stdlib.h>
21#include <unistd.h>
22
23#include <openssl/evp.h>
24#include <openssl/pem.h>
25#include <openssl/rsa.h>
26#include <openssl/ecdsa.h>
27#include <openssl/ec.h>
28#include <openssl/obj_mac.h>
29
30#include "key.h"
31
32/*
33 * Default number of bits when creating a new RSA key.
34 */
35#define	KBITS 4096
36#define ECCTYPE NID_secp384r1
37
38/*
39 * Create an RSA key with the default KBITS number of bits.
40 */
41EVP_PKEY *
42rsa_key_create(FILE *f, const char *fname)
43{
44	EVP_PKEY_CTX	*ctx = NULL;
45	EVP_PKEY	*pkey = NULL;
46
47	/* First, create the context and the key. */
48
49	if ((ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_RSA, NULL)) == NULL) {
50		warnx("EVP_PKEY_CTX_new_id");
51		goto err;
52	} else if (EVP_PKEY_keygen_init(ctx) <= 0) {
53		warnx("EVP_PKEY_keygen_init");
54		goto err;
55	} else if (EVP_PKEY_CTX_set_rsa_keygen_bits(ctx, KBITS) <= 0) {
56		warnx("EVP_PKEY_set_rsa_keygen_bits");
57		goto err;
58	} else if (EVP_PKEY_keygen(ctx, &pkey) <= 0) {
59		warnx("EVP_PKEY_keygen");
60		goto err;
61	}
62
63	/* Serialise the key to the disc. */
64
65	if (PEM_write_PrivateKey(f, pkey, NULL, NULL, 0, NULL, NULL))
66		goto out;
67
68	warnx("%s: PEM_write_PrivateKey", fname);
69
70err:
71	EVP_PKEY_free(pkey);
72	pkey = NULL;
73out:
74	EVP_PKEY_CTX_free(ctx);
75	return pkey;
76}
77
78EVP_PKEY *
79ec_key_create(FILE *f, const char *fname)
80{
81	EC_KEY		*eckey = NULL;
82	EVP_PKEY	*pkey = NULL;
83
84	if ((eckey = EC_KEY_new_by_curve_name(ECCTYPE)) == NULL ) {
85		warnx("EC_KEY_new_by_curve_name");
86		goto err;
87	}
88
89	if (!EC_KEY_generate_key(eckey)) {
90		warnx("EC_KEY_generate_key");
91		goto err;
92	}
93
94	/* set OPENSSL_EC_NAMED_CURVE to be able to load the key */
95
96	EC_KEY_set_asn1_flag(eckey, OPENSSL_EC_NAMED_CURVE);
97
98	/* Serialise the key to the disc in EC format */
99
100	if (!PEM_write_ECPrivateKey(f, eckey, NULL, NULL, 0, NULL, NULL)) {
101		warnx("%s: PEM_write_ECPrivateKey", fname);
102		goto err;
103	}
104
105	/* Convert the EC key into a PKEY structure */
106
107	if ((pkey = EVP_PKEY_new()) == NULL) {
108		warnx("EVP_PKEY_new");
109		goto err;
110	}
111	if (!EVP_PKEY_set1_EC_KEY(pkey, eckey)) {
112		warnx("EVP_PKEY_assign_EC_KEY");
113		goto err;
114	}
115
116	goto out;
117
118err:
119	EVP_PKEY_free(pkey);
120	pkey = NULL;
121out:
122	EC_KEY_free(eckey);
123	return pkey;
124}
125
126
127
128EVP_PKEY *
129key_load(FILE *f, const char *fname)
130{
131	EVP_PKEY	*pkey;
132
133	pkey = PEM_read_PrivateKey(f, NULL, NULL, NULL);
134	if (pkey == NULL) {
135		warnx("%s: PEM_read_PrivateKey", fname);
136		return NULL;
137	}
138	if (EVP_PKEY_base_id(pkey) == EVP_PKEY_RSA ||
139	    EVP_PKEY_base_id(pkey) == EVP_PKEY_EC)
140		return pkey;
141
142	warnx("%s: unsupported key type", fname);
143	EVP_PKEY_free(pkey);
144	return NULL;
145}
146