1 /*
2 * Convert PEM to DER
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19
20 #include "mbedtls/build_info.h"
21
22 #include "mbedtls/platform.h"
23
24 #if defined(MBEDTLS_BASE64_C) && defined(MBEDTLS_FS_IO)
25 #include "mbedtls/error.h"
26 #include "mbedtls/base64.h"
27
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #endif
32
33 #define DFL_FILENAME "file.pem"
34 #define DFL_OUTPUT_FILENAME "file.der"
35
36 #define USAGE \
37 "\n usage: pem2der param=<>...\n" \
38 "\n acceptable parameters:\n" \
39 " filename=%%s default: file.pem\n" \
40 " output_file=%%s default: file.der\n" \
41 "\n"
42
43 #if !defined(MBEDTLS_BASE64_C) || !defined(MBEDTLS_FS_IO)
main(void)44 int main(void)
45 {
46 mbedtls_printf("MBEDTLS_BASE64_C and/or MBEDTLS_FS_IO not defined.\n");
47 mbedtls_exit(0);
48 }
49 #else
50
51
52 /*
53 * global options
54 */
55 struct options {
56 const char *filename; /* filename of the input file */
57 const char *output_file; /* where to store the output */
58 } opt;
59
convert_pem_to_der(const unsigned char * input,size_t ilen,unsigned char * output,size_t * olen)60 int convert_pem_to_der(const unsigned char *input, size_t ilen,
61 unsigned char *output, size_t *olen)
62 {
63 int ret;
64 const unsigned char *s1, *s2, *end = input + ilen;
65 size_t len = 0;
66
67 s1 = (unsigned char *) strstr((const char *) input, "-----BEGIN");
68 if (s1 == NULL) {
69 return -1;
70 }
71
72 s2 = (unsigned char *) strstr((const char *) input, "-----END");
73 if (s2 == NULL) {
74 return -1;
75 }
76
77 s1 += 10;
78 while (s1 < end && *s1 != '-') {
79 s1++;
80 }
81 while (s1 < end && *s1 == '-') {
82 s1++;
83 }
84 if (*s1 == '\r') {
85 s1++;
86 }
87 if (*s1 == '\n') {
88 s1++;
89 }
90
91 if (s2 <= s1 || s2 > end) {
92 return -1;
93 }
94
95 ret = mbedtls_base64_decode(NULL, 0, &len, (const unsigned char *) s1, s2 - s1);
96 if (ret == MBEDTLS_ERR_BASE64_INVALID_CHARACTER) {
97 return ret;
98 }
99
100 if (len > *olen) {
101 return -1;
102 }
103
104 if ((ret = mbedtls_base64_decode(output, len, &len, (const unsigned char *) s1,
105 s2 - s1)) != 0) {
106 return ret;
107 }
108
109 *olen = len;
110
111 return 0;
112 }
113
114 /*
115 * Load all data from a file into a given buffer.
116 */
load_file(const char * path,unsigned char ** buf,size_t * n)117 static int load_file(const char *path, unsigned char **buf, size_t *n)
118 {
119 FILE *f;
120 long size;
121
122 if ((f = fopen(path, "rb")) == NULL) {
123 return -1;
124 }
125
126 fseek(f, 0, SEEK_END);
127 if ((size = ftell(f)) == -1) {
128 fclose(f);
129 return -1;
130 }
131 fseek(f, 0, SEEK_SET);
132
133 *n = (size_t) size;
134
135 if (*n + 1 == 0 ||
136 (*buf = mbedtls_calloc(1, *n + 1)) == NULL) {
137 fclose(f);
138 return -1;
139 }
140
141 if (fread(*buf, 1, *n, f) != *n) {
142 fclose(f);
143 free(*buf);
144 *buf = NULL;
145 return -1;
146 }
147
148 fclose(f);
149
150 (*buf)[*n] = '\0';
151
152 return 0;
153 }
154
155 /*
156 * Write buffer to a file
157 */
write_file(const char * path,unsigned char * buf,size_t n)158 static int write_file(const char *path, unsigned char *buf, size_t n)
159 {
160 FILE *f;
161
162 if ((f = fopen(path, "wb")) == NULL) {
163 return -1;
164 }
165
166 if (fwrite(buf, 1, n, f) != n) {
167 fclose(f);
168 return -1;
169 }
170
171 fclose(f);
172 return 0;
173 }
174
main(int argc,char * argv[])175 int main(int argc, char *argv[])
176 {
177 int ret = 1;
178 int exit_code = MBEDTLS_EXIT_FAILURE;
179 unsigned char *pem_buffer = NULL;
180 unsigned char der_buffer[4096];
181 char buf[1024];
182 size_t pem_size, der_size = sizeof(der_buffer);
183 int i;
184 char *p, *q;
185
186 /*
187 * Set to sane values
188 */
189 memset(buf, 0, sizeof(buf));
190 memset(der_buffer, 0, sizeof(der_buffer));
191
192 if (argc < 2) {
193 usage:
194 mbedtls_printf(USAGE);
195 goto exit;
196 }
197
198 opt.filename = DFL_FILENAME;
199 opt.output_file = DFL_OUTPUT_FILENAME;
200
201 for (i = 1; i < argc; i++) {
202
203 p = argv[i];
204 if ((q = strchr(p, '=')) == NULL) {
205 goto usage;
206 }
207 *q++ = '\0';
208
209 if (strcmp(p, "filename") == 0) {
210 opt.filename = q;
211 } else if (strcmp(p, "output_file") == 0) {
212 opt.output_file = q;
213 } else {
214 goto usage;
215 }
216 }
217
218 /*
219 * 1.1. Load the PEM file
220 */
221 mbedtls_printf("\n . Loading the PEM file ...");
222 fflush(stdout);
223
224 ret = load_file(opt.filename, &pem_buffer, &pem_size);
225
226 if (ret != 0) {
227 #ifdef MBEDTLS_ERROR_C
228 mbedtls_strerror(ret, buf, 1024);
229 #endif
230 mbedtls_printf(" failed\n ! load_file returned %d - %s\n\n", ret, buf);
231 goto exit;
232 }
233
234 mbedtls_printf(" ok\n");
235
236 /*
237 * 1.2. Convert from PEM to DER
238 */
239 mbedtls_printf(" . Converting from PEM to DER ...");
240 fflush(stdout);
241
242 if ((ret = convert_pem_to_der(pem_buffer, pem_size, der_buffer, &der_size)) != 0) {
243 #ifdef MBEDTLS_ERROR_C
244 mbedtls_strerror(ret, buf, 1024);
245 #endif
246 mbedtls_printf(" failed\n ! convert_pem_to_der %d - %s\n\n", ret, buf);
247 goto exit;
248 }
249
250 mbedtls_printf(" ok\n");
251
252 /*
253 * 1.3. Write the DER file
254 */
255 mbedtls_printf(" . Writing the DER file ...");
256 fflush(stdout);
257
258 ret = write_file(opt.output_file, der_buffer, der_size);
259
260 if (ret != 0) {
261 #ifdef MBEDTLS_ERROR_C
262 mbedtls_strerror(ret, buf, 1024);
263 #endif
264 mbedtls_printf(" failed\n ! write_file returned %d - %s\n\n", ret, buf);
265 goto exit;
266 }
267
268 mbedtls_printf(" ok\n");
269
270 exit_code = MBEDTLS_EXIT_SUCCESS;
271
272 exit:
273 free(pem_buffer);
274
275 mbedtls_exit(exit_code);
276 }
277 #endif /* MBEDTLS_BASE64_C && MBEDTLS_FS_IO */
278