ct_b64.c revision 1.7 
1/*	$OpenBSD: ct_b64.c,v 1.7 2023/07/08 07:22:58 beck Exp $ */
2/*
3 * Written by Rob Stradling (rob@comodo.com) and Stephen Henson
4 * (steve@openssl.org) for the OpenSSL project 2014.
5 */
6/* ====================================================================
7 * Copyright (c) 2014 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in
18 *    the documentation and/or other materials provided with the
19 *    distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 *    software must display the following acknowledgment:
23 *    "This product includes software developed by the OpenSSL Project
24 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 *    endorse or promote products derived from this software without
28 *    prior written permission. For written permission, please contact
29 *    licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 *    nor may "OpenSSL" appear in their names without prior written
33 *    permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com).  This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59
60#include <limits.h>
61#include <string.h>
62
63#include <openssl/ct.h>
64#include <openssl/err.h>
65#include <openssl/evp.h>
66
67#include "bytestring.h"
68#include "ct_local.h"
69
70/*
71 * Decodes the base64 string |in| into |out|.
72 * A new string will be malloc'd and assigned to |out|. This will be owned by
73 * the caller. Do not provide a pre-allocated string in |out|.
74 */
75static int
76ct_base64_decode(const char *in, unsigned char **out)
77{
78	size_t inlen = strlen(in);
79	int outlen, i;
80	unsigned char *outbuf = NULL;
81
82	if (inlen == 0) {
83		*out = NULL;
84		return 0;
85	}
86
87	outlen = (inlen / 4) * 3;
88	outbuf = malloc(outlen);
89	if (outbuf == NULL) {
90		CTerror(ERR_R_MALLOC_FAILURE);
91		goto err;
92	}
93
94	outlen = EVP_DecodeBlock(outbuf, (unsigned char *)in, inlen);
95	if (outlen < 0) {
96		CTerror(CT_R_BASE64_DECODE_ERROR);
97		goto err;
98	}
99
100	/*
101	 * Subtract padding bytes from |outlen|.
102	 * Any more than 2 is malformed.
103	 */
104	i = 0;
105	while (in[--inlen] == '=') {
106		--outlen;
107		if (++i > 2)
108			goto err;
109	}
110
111	*out = outbuf;
112	return outlen;
113 err:
114	free(outbuf);
115	return -1;
116}
117
118SCT *
119SCT_new_from_base64(unsigned char version, const char *logid_base64,
120    ct_log_entry_type_t entry_type, uint64_t timestamp,
121    const char *extensions_base64, const char *signature_base64)
122{
123	unsigned char *dec = NULL;
124	int declen;
125	SCT *sct;
126	CBS cbs;
127
128	if ((sct = SCT_new()) == NULL) {
129		CTerror(ERR_R_MALLOC_FAILURE);
130		return NULL;
131	}
132
133	/*
134	 * RFC6962 section 4.1 says we "MUST NOT expect this to be 0", but we
135	 * can only construct SCT versions that have been defined.
136	 */
137	if (!SCT_set_version(sct, version)) {
138		CTerror(CT_R_SCT_UNSUPPORTED_VERSION);
139		goto err;
140	}
141
142	declen = ct_base64_decode(logid_base64, &dec);
143	if (declen < 0) {
144		CTerror(X509_R_BASE64_DECODE_ERROR);
145		goto err;
146	}
147	if (!SCT_set0_log_id(sct, dec, declen))
148		goto err;
149	dec = NULL;
150
151	declen = ct_base64_decode(extensions_base64, &dec);
152	if (declen < 0) {
153		CTerror(X509_R_BASE64_DECODE_ERROR);
154		goto err;
155	}
156	SCT_set0_extensions(sct, dec, declen);
157	dec = NULL;
158
159	declen = ct_base64_decode(signature_base64, &dec);
160	if (declen < 0) {
161		CTerror(X509_R_BASE64_DECODE_ERROR);
162		goto err;
163	}
164
165	CBS_init(&cbs, dec, declen);
166	if (!o2i_SCT_signature(sct, &cbs))
167		goto err;
168	free(dec);
169	dec = NULL;
170
171	SCT_set_timestamp(sct, timestamp);
172
173	if (!SCT_set_log_entry_type(sct, entry_type))
174		goto err;
175
176	return sct;
177
178 err:
179	free(dec);
180	SCT_free(sct);
181	return NULL;
182}
183LCRYPTO_ALIAS(SCT_new_from_base64);
184
185/*
186 * Allocate, build and returns a new |ct_log| from input |pkey_base64|
187 * It returns 1 on success,
188 * 0 on decoding failure, or invalid parameter if any
189 * -1 on internal (malloc) failure
190 */
191int
192CTLOG_new_from_base64(CTLOG **ct_log, const char *pkey_base64, const char *name)
193{
194	unsigned char *pkey_der = NULL;
195	int pkey_der_len;
196	const unsigned char *p;
197	EVP_PKEY *pkey = NULL;
198
199	if (ct_log == NULL) {
200	        CTerror(ERR_R_PASSED_NULL_PARAMETER);
201		return 0;
202	}
203
204	pkey_der_len = ct_base64_decode(pkey_base64, &pkey_der);
205	if (pkey_der_len < 0) {
206		CTerror(CT_R_LOG_CONF_INVALID_KEY);
207		return 0;
208	}
209
210	p = pkey_der;
211	pkey = d2i_PUBKEY(NULL, &p, pkey_der_len);
212	free(pkey_der);
213	if (pkey == NULL) {
214		CTerror(CT_R_LOG_CONF_INVALID_KEY);
215		return 0;
216	}
217
218	*ct_log = CTLOG_new(pkey, name);
219	if (*ct_log == NULL) {
220		EVP_PKEY_free(pkey);
221		return 0;
222	}
223
224	return 1;
225}
226LCRYPTO_ALIAS(CTLOG_new_from_base64);
227