1 /*
2 * Copyright 2016-2021 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 <limits.h>
11 #include <string.h>
12
13 #include <openssl/ct.h>
14 #include <openssl/err.h>
15 #include <openssl/evp.h>
16
17 #include "ct_local.h"
18
19 /*
20 * Decodes the base64 string |in| into |out|.
21 * A new string will be malloc'd and assigned to |out|. This will be owned by
22 * the caller. Do not provide a pre-allocated string in |out|.
23 */
ct_base64_decode(const char * in,unsigned char ** out)24 static int ct_base64_decode(const char *in, unsigned char **out)
25 {
26 size_t inlen = strlen(in);
27 int outlen, i;
28 unsigned char *outbuf = NULL;
29
30 if (inlen == 0) {
31 *out = NULL;
32 return 0;
33 }
34
35 outlen = (inlen / 4) * 3;
36 outbuf = OPENSSL_malloc(outlen);
37 if (outbuf == NULL)
38 goto err;
39
40 outlen = EVP_DecodeBlock(outbuf, (unsigned char *)in, inlen);
41 if (outlen < 0) {
42 ERR_raise(ERR_LIB_CT, CT_R_BASE64_DECODE_ERROR);
43 goto err;
44 }
45
46 /* Subtract padding bytes from |outlen|. Any more than 2 is malformed. */
47 i = 0;
48 while (in[--inlen] == '=') {
49 --outlen;
50 if (++i > 2)
51 goto err;
52 }
53
54 *out = outbuf;
55 return outlen;
56 err:
57 OPENSSL_free(outbuf);
58 return -1;
59 }
60
SCT_new_from_base64(unsigned char version,const char * logid_base64,ct_log_entry_type_t entry_type,uint64_t timestamp,const char * extensions_base64,const char * signature_base64)61 SCT *SCT_new_from_base64(unsigned char version, const char *logid_base64,
62 ct_log_entry_type_t entry_type, uint64_t timestamp,
63 const char *extensions_base64,
64 const char *signature_base64)
65 {
66 SCT *sct = SCT_new();
67 unsigned char *dec = NULL;
68 const unsigned char* p = NULL;
69 int declen;
70
71 if (sct == NULL) {
72 ERR_raise(ERR_LIB_CT, ERR_R_CT_LIB);
73 return NULL;
74 }
75
76 /*
77 * RFC6962 section 4.1 says we "MUST NOT expect this to be 0", but we
78 * can only construct SCT versions that have been defined.
79 */
80 if (!SCT_set_version(sct, version)) {
81 ERR_raise(ERR_LIB_CT, CT_R_SCT_UNSUPPORTED_VERSION);
82 goto err;
83 }
84
85 declen = ct_base64_decode(logid_base64, &dec);
86 if (declen < 0) {
87 ERR_raise(ERR_LIB_CT, X509_R_BASE64_DECODE_ERROR);
88 goto err;
89 }
90 if (!SCT_set0_log_id(sct, dec, declen))
91 goto err;
92 dec = NULL;
93
94 declen = ct_base64_decode(extensions_base64, &dec);
95 if (declen < 0) {
96 ERR_raise(ERR_LIB_CT, X509_R_BASE64_DECODE_ERROR);
97 goto err;
98 }
99 SCT_set0_extensions(sct, dec, declen);
100 dec = NULL;
101
102 declen = ct_base64_decode(signature_base64, &dec);
103 if (declen < 0) {
104 ERR_raise(ERR_LIB_CT, X509_R_BASE64_DECODE_ERROR);
105 goto err;
106 }
107
108 p = dec;
109 if (o2i_SCT_signature(sct, &p, declen) <= 0)
110 goto err;
111 OPENSSL_free(dec);
112 dec = NULL;
113
114 SCT_set_timestamp(sct, timestamp);
115
116 if (!SCT_set_log_entry_type(sct, entry_type))
117 goto err;
118
119 return sct;
120
121 err:
122 OPENSSL_free(dec);
123 SCT_free(sct);
124 return NULL;
125 }
126
127 /*
128 * Allocate, build and returns a new |ct_log| from input |pkey_base64|
129 * It returns 1 on success,
130 * 0 on decoding failure, or invalid parameter if any
131 * -1 on internal (malloc) failure
132 */
CTLOG_new_from_base64_ex(CTLOG ** ct_log,const char * pkey_base64,const char * name,OSSL_LIB_CTX * libctx,const char * propq)133 int CTLOG_new_from_base64_ex(CTLOG **ct_log, const char *pkey_base64,
134 const char *name, OSSL_LIB_CTX *libctx,
135 const char *propq)
136 {
137 unsigned char *pkey_der = NULL;
138 int pkey_der_len;
139 const unsigned char *p;
140 EVP_PKEY *pkey = NULL;
141
142 if (ct_log == NULL) {
143 ERR_raise(ERR_LIB_CT, ERR_R_PASSED_INVALID_ARGUMENT);
144 return 0;
145 }
146
147 pkey_der_len = ct_base64_decode(pkey_base64, &pkey_der);
148 if (pkey_der_len < 0) {
149 ERR_raise(ERR_LIB_CT, CT_R_LOG_CONF_INVALID_KEY);
150 return 0;
151 }
152
153 p = pkey_der;
154 pkey = d2i_PUBKEY_ex(NULL, &p, pkey_der_len, libctx, propq);
155 OPENSSL_free(pkey_der);
156 if (pkey == NULL) {
157 ERR_raise(ERR_LIB_CT, CT_R_LOG_CONF_INVALID_KEY);
158 return 0;
159 }
160
161 *ct_log = CTLOG_new_ex(pkey, name, libctx, propq);
162 if (*ct_log == NULL) {
163 EVP_PKEY_free(pkey);
164 return 0;
165 }
166
167 return 1;
168 }
169
CTLOG_new_from_base64(CTLOG ** ct_log,const char * pkey_base64,const char * name)170 int CTLOG_new_from_base64(CTLOG **ct_log, const char *pkey_base64,
171 const char *name)
172 {
173 return CTLOG_new_from_base64_ex(ct_log, pkey_base64, name, NULL, NULL);
174 }
175
