summaryrefslogtreecommitdiff
path: root/third_party/heimdal/lib/krb5/pkinit-ec.c
blob: 33bc62c8dcefb23681c85dd369bf7502604e26c6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
/*
 * Copyright (c) 2016 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <config.h>
#include <roken.h>

#ifdef PKINIT

/*
 * As with the other *-ec.c files in Heimdal, this is a bit of a hack.
 *
 * The idea is to use OpenSSL for EC because hcrypto doesn't have the
 * required functionality at this time.  To do this we segregate
 * EC-using code into separate source files and then we arrange for them
 * to get the OpenSSL headers and not the conflicting hcrypto ones.
 *
 * Because of auto-generated *-private.h headers, we end up needing to
 * make sure various types are defined before we include them, thus the
 * strange header include order here.
 */

#ifdef HAVE_HCRYPTO_W_OPENSSL
#include <openssl/ec.h>
#include <openssl/ecdh.h>
#include <openssl/evp.h>
#include <openssl/bn.h>
#define HEIM_NO_CRYPTO_HDRS
#endif

/*
 * NO_HCRYPTO_POLLUTION -> don't refer to hcrypto type/function names
 * that we don't need in this file and which would clash with OpenSSL's
 * in ways that are difficult to address in cleaner ways.
 *
 * In the medium- to long-term what we should do is move all PK in
 * Heimdal to the newer EVP interfaces for PK and then nothing outside
 * lib/hcrypto should ever have to include OpenSSL headers, and -more
 * specifically- the only thing that should ever have to include OpenSSL
 * headers is the OpenSSL backend to hcrypto.
 */
#define NO_HCRYPTO_POLLUTION

#include "krb5_locl.h"
#include <hcrypto/des.h>
#include <cms_asn1.h>
#include <pkcs8_asn1.h>
#include <pkcs9_asn1.h>
#include <pkcs12_asn1.h>
#include <pkinit_asn1.h>
#include <asn1_err.h>

#include <der.h>

krb5_error_code
_krb5_build_authpack_subjectPK_EC(krb5_context context,
                                  krb5_pk_init_ctx ctx,
                                  AuthPack *a)
{
#ifdef HAVE_HCRYPTO_W_OPENSSL
    krb5_error_code ret;
    ECParameters ecp;
    unsigned char *p;
    size_t size;
    int xlen;

    /* copy in public key, XXX find the best curve that the server support or use the clients curve if possible */

    ecp.element = choice_ECParameters_namedCurve;
    ret = der_copy_oid(&asn1_oid_id_ec_group_secp256r1,
                       &ecp.u.namedCurve);
    if (ret)
        return ret;

    ALLOC(a->clientPublicValue->algorithm.parameters, 1);
    if (a->clientPublicValue->algorithm.parameters == NULL) {
        free_ECParameters(&ecp);
        return krb5_enomem(context);
    }
    ASN1_MALLOC_ENCODE(ECParameters, p, xlen, &ecp, &size, ret);
    free_ECParameters(&ecp);
    if (ret)
        return ret;
    if ((int)size != xlen)
        krb5_abortx(context, "asn1 internal error");

    a->clientPublicValue->algorithm.parameters->data = p;
    a->clientPublicValue->algorithm.parameters->length = size;

    /* copy in public key */

    ret = der_copy_oid(&asn1_oid_id_ecPublicKey,
                       &a->clientPublicValue->algorithm.algorithm);
    if (ret)
        return ret;

    ctx->u.eckey = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
    if (ctx->u.eckey == NULL)
        return krb5_enomem(context);

    ret = EC_KEY_generate_key(ctx->u.eckey);
    if (ret != 1)
        return EINVAL;

    xlen = i2o_ECPublicKey(ctx->u.eckey, NULL);
    if (xlen <= 0)
        return EINVAL;

    p = malloc(xlen);
    if (p == NULL)
        return krb5_enomem(context);

    a->clientPublicValue->subjectPublicKey.data = p;

    xlen = i2o_ECPublicKey(ctx->u.eckey, &p);
    if (xlen <= 0) {
        a->clientPublicValue->subjectPublicKey.data = NULL;
        free(p);
        return EINVAL;
    }

    a->clientPublicValue->subjectPublicKey.length = xlen * 8;

    return 0;

    /* XXX verify that this is right with RFC3279 */
#else
    krb5_set_error_message(context, ENOTSUP,
                           N_("PKINIT: ECDH not supported", ""));
    return ENOTSUP;
#endif
}

krb5_error_code
_krb5_pk_rd_pa_reply_ecdh_compute_key(krb5_context context,
                                      krb5_pk_init_ctx ctx,
                                      const unsigned char *in,
                                      size_t in_sz,
                                      unsigned char **out,
                                      int *out_sz)
{
#ifdef HAVE_HCRYPTO_W_OPENSSL
    krb5_error_code ret = 0;
    int dh_gen_keylen;

    const EC_GROUP *group;
    EC_KEY *public = NULL;

    group = EC_KEY_get0_group(ctx->u.eckey);

    public = EC_KEY_new();
    if (public == NULL)
        return krb5_enomem(context);
    if (EC_KEY_set_group(public, group) != 1) {
        EC_KEY_free(public);
        return krb5_enomem(context);
    }

    if (o2i_ECPublicKey(&public, &in, in_sz) == NULL) {
        EC_KEY_free(public);
        ret = KRB5KRB_ERR_GENERIC;
        krb5_set_error_message(context, ret,
                               N_("PKINIT: Can't parse ECDH public key", ""));
        return ret;
    }

    *out_sz = (EC_GROUP_get_degree(group) + 7) / 8;
    if (*out_sz < 0)
        return EOVERFLOW;
    *out = malloc(*out_sz);
    if (*out == NULL) {
        EC_KEY_free(public);
        return krb5_enomem(context);
    }
    dh_gen_keylen = ECDH_compute_key(*out, *out_sz,
                                     EC_KEY_get0_public_key(public),
                                     ctx->u.eckey, NULL);
    EC_KEY_free(public);
    if (dh_gen_keylen <= 0) {
        ret = KRB5KRB_ERR_GENERIC;
        dh_gen_keylen = 0;
        krb5_set_error_message(context, ret,
                               N_("PKINIT: Can't compute ECDH public key", ""));
        free(*out);
        *out = NULL;
        *out_sz = 0;
    }
    *out_sz = dh_gen_keylen;

    return ret;
#else
    krb5_set_error_message(context, ENOTSUP,
                           N_("PKINIT: ECDH not supported", ""));
    return ENOTSUP;
#endif
}

void
_krb5_pk_eckey_free(void *eckey)
{
#ifdef HAVE_HCRYPTO_W_OPENSSL
    EC_KEY_free(eckey);
#endif
}

#else

static char lib_krb5_pkinit_ec_c = '\0';

#endif