1/*
2 * Copyright 2006-2018 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/*
11 * Experimental ASN1 BIO. When written through the data is converted to an
12 * ASN1 string type: default is OCTET STRING. Additional functions can be
13 * provided to add prefix and suffix data.
14 */
15
16#include <string.h>
17#include "internal/bio.h"
18#include <openssl/asn1.h>
19#include "internal/cryptlib.h"
20
21/* Must be large enough for biggest tag+length */
22#define DEFAULT_ASN1_BUF_SIZE 20
23
24typedef enum {
25 ASN1_STATE_START,
26 ASN1_STATE_PRE_COPY,
27 ASN1_STATE_HEADER,
28 ASN1_STATE_HEADER_COPY,
29 ASN1_STATE_DATA_COPY,
30 ASN1_STATE_POST_COPY,
31 ASN1_STATE_DONE
32} asn1_bio_state_t;
33
34typedef struct BIO_ASN1_EX_FUNCS_st {
35 asn1_ps_func *ex_func;
36 asn1_ps_func *ex_free_func;
37} BIO_ASN1_EX_FUNCS;
38
39typedef struct BIO_ASN1_BUF_CTX_t {
40 /* Internal state */
41 asn1_bio_state_t state;
42 /* Internal buffer */
43 unsigned char *buf;
44 /* Size of buffer */
45 int bufsize;
46 /* Current position in buffer */
47 int bufpos;
48 /* Current buffer length */
49 int buflen;
50 /* Amount of data to copy */
51 int copylen;
52 /* Class and tag to use */
53 int asn1_class, asn1_tag;
54 asn1_ps_func *prefix, *prefix_free, *suffix, *suffix_free;
55 /* Extra buffer for prefix and suffix data */
56 unsigned char *ex_buf;
57 int ex_len;
58 int ex_pos;
59 void *ex_arg;
60} BIO_ASN1_BUF_CTX;
61
62static int asn1_bio_write(BIO *h, const char *buf, int num);
63static int asn1_bio_read(BIO *h, char *buf, int size);
64static int asn1_bio_puts(BIO *h, const char *str);
65static int asn1_bio_gets(BIO *h, char *str, int size);
66static long asn1_bio_ctrl(BIO *h, int cmd, long arg1, void *arg2);
67static int asn1_bio_new(BIO *h);
68static int asn1_bio_free(BIO *data);
69static long asn1_bio_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
70
71static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size);
72static int asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
73 asn1_ps_func *cleanup, asn1_bio_state_t next);
74static int asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
75 asn1_ps_func *setup,
76 asn1_bio_state_t ex_state,
77 asn1_bio_state_t other_state);
78
79static const BIO_METHOD methods_asn1 = {
80 BIO_TYPE_ASN1,
81 "asn1",
82 /* TODO: Convert to new style write function */
83 bwrite_conv,
84 asn1_bio_write,
85 /* TODO: Convert to new style read function */
86 bread_conv,
87 asn1_bio_read,
88 asn1_bio_puts,
89 asn1_bio_gets,
90 asn1_bio_ctrl,
91 asn1_bio_new,
92 asn1_bio_free,
93 asn1_bio_callback_ctrl,
94};
95
96const BIO_METHOD *BIO_f_asn1(void)
97{
98 return &methods_asn1;
99}
100
101static int asn1_bio_new(BIO *b)
102{
103 BIO_ASN1_BUF_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
104
105 if (ctx == NULL)
106 return 0;
107 if (!asn1_bio_init(ctx, DEFAULT_ASN1_BUF_SIZE)) {
108 OPENSSL_free(ctx);
109 return 0;
110 }
111 BIO_set_data(b, ctx);
112 BIO_set_init(b, 1);
113
114 return 1;
115}
116
117static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size)
118{
119 if ((ctx->buf = OPENSSL_malloc(size)) == NULL) {
120 ASN1err(ASN1_F_ASN1_BIO_INIT, ERR_R_MALLOC_FAILURE);
121 return 0;
122 }
123 ctx->bufsize = size;
124 ctx->asn1_class = V_ASN1_UNIVERSAL;
125 ctx->asn1_tag = V_ASN1_OCTET_STRING;
126 ctx->state = ASN1_STATE_START;
127 return 1;
128}
129
130static int asn1_bio_free(BIO *b)
131{
132 BIO_ASN1_BUF_CTX *ctx;
133
134 if (b == NULL)
135 return 0;
136
137 ctx = BIO_get_data(b);
138 if (ctx == NULL)
139 return 0;
140
141 OPENSSL_free(ctx->buf);
142 OPENSSL_free(ctx);
143 BIO_set_data(b, NULL);
144 BIO_set_init(b, 0);
145
146 return 1;
147}
148
149static int asn1_bio_write(BIO *b, const char *in, int inl)
150{
151 BIO_ASN1_BUF_CTX *ctx;
152 int wrmax, wrlen, ret;
153 unsigned char *p;
154 BIO *next;
155
156 ctx = BIO_get_data(b);
157 next = BIO_next(b);
158 if (in == NULL || inl < 0 || ctx == NULL || next == NULL)
159 return 0;
160
161 wrlen = 0;
162 ret = -1;
163
164 for (;;) {
165 switch (ctx->state) {
166 /* Setup prefix data, call it */
167 case ASN1_STATE_START:
168 if (!asn1_bio_setup_ex(b, ctx, ctx->prefix,
169 ASN1_STATE_PRE_COPY, ASN1_STATE_HEADER))
170 return 0;
171 break;
172
173 /* Copy any pre data first */
174 case ASN1_STATE_PRE_COPY:
175
176 ret = asn1_bio_flush_ex(b, ctx, ctx->prefix_free,
177 ASN1_STATE_HEADER);
178
179 if (ret <= 0)
180 goto done;
181
182 break;
183
184 case ASN1_STATE_HEADER:
185 ctx->buflen = ASN1_object_size(0, inl, ctx->asn1_tag) - inl;
186 if (!ossl_assert(ctx->buflen <= ctx->bufsize))
187 return 0;
188 p = ctx->buf;
189 ASN1_put_object(&p, 0, inl, ctx->asn1_tag, ctx->asn1_class);
190 ctx->copylen = inl;
191 ctx->state = ASN1_STATE_HEADER_COPY;
192
193 break;
194
195 case ASN1_STATE_HEADER_COPY:
196 ret = BIO_write(next, ctx->buf + ctx->bufpos, ctx->buflen);
197 if (ret <= 0)
198 goto done;
199
200 ctx->buflen -= ret;
201 if (ctx->buflen)
202 ctx->bufpos += ret;
203 else {
204 ctx->bufpos = 0;
205 ctx->state = ASN1_STATE_DATA_COPY;
206 }
207
208 break;
209
210 case ASN1_STATE_DATA_COPY:
211
212 if (inl > ctx->copylen)
213 wrmax = ctx->copylen;
214 else
215 wrmax = inl;
216 ret = BIO_write(next, in, wrmax);
217 if (ret <= 0)
218 goto done;
219 wrlen += ret;
220 ctx->copylen -= ret;
221 in += ret;
222 inl -= ret;
223
224 if (ctx->copylen == 0)
225 ctx->state = ASN1_STATE_HEADER;
226
227 if (inl == 0)
228 goto done;
229
230 break;
231
232 case ASN1_STATE_POST_COPY:
233 case ASN1_STATE_DONE:
234 BIO_clear_retry_flags(b);
235 return 0;
236
237 }
238
239 }
240
241 done:
242 BIO_clear_retry_flags(b);
243 BIO_copy_next_retry(b);
244
245 return (wrlen > 0) ? wrlen : ret;
246
247}
248
249static int asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
250 asn1_ps_func *cleanup, asn1_bio_state_t next)
251{
252 int ret;
253
254 if (ctx->ex_len <= 0)
255 return 1;
256 for (;;) {
257 ret = BIO_write(BIO_next(b), ctx->ex_buf + ctx->ex_pos, ctx->ex_len);
258 if (ret <= 0)
259 break;
260 ctx->ex_len -= ret;
261 if (ctx->ex_len > 0)
262 ctx->ex_pos += ret;
263 else {
264 if (cleanup)
265 cleanup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg);
266 ctx->state = next;
267 ctx->ex_pos = 0;
268 break;
269 }
270 }
271 return ret;
272}
273
274static int asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
275 asn1_ps_func *setup,
276 asn1_bio_state_t ex_state,
277 asn1_bio_state_t other_state)
278{
279 if (setup && !setup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg)) {
280 BIO_clear_retry_flags(b);
281 return 0;
282 }
283 if (ctx->ex_len > 0)
284 ctx->state = ex_state;
285 else
286 ctx->state = other_state;
287 return 1;
288}
289
290static int asn1_bio_read(BIO *b, char *in, int inl)
291{
292 BIO *next = BIO_next(b);
293 if (next == NULL)
294 return 0;
295 return BIO_read(next, in, inl);
296}
297
298static int asn1_bio_puts(BIO *b, const char *str)
299{
300 return asn1_bio_write(b, str, strlen(str));
301}
302
303static int asn1_bio_gets(BIO *b, char *str, int size)
304{
305 BIO *next = BIO_next(b);
306 if (next == NULL)
307 return 0;
308 return BIO_gets(next, str, size);
309}
310
311static long asn1_bio_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
312{
313 BIO *next = BIO_next(b);
314 if (next == NULL)
315 return 0;
316 return BIO_callback_ctrl(next, cmd, fp);
317}
318
319static long asn1_bio_ctrl(BIO *b, int cmd, long arg1, void *arg2)
320{
321 BIO_ASN1_BUF_CTX *ctx;
322 BIO_ASN1_EX_FUNCS *ex_func;
323 long ret = 1;
324 BIO *next;
325
326 ctx = BIO_get_data(b);
327 if (ctx == NULL)
328 return 0;
329 next = BIO_next(b);
330 switch (cmd) {
331
332 case BIO_C_SET_PREFIX:
333 ex_func = arg2;
334 ctx->prefix = ex_func->ex_func;
335 ctx->prefix_free = ex_func->ex_free_func;
336 break;
337
338 case BIO_C_GET_PREFIX:
339 ex_func = arg2;
340 ex_func->ex_func = ctx->prefix;
341 ex_func->ex_free_func = ctx->prefix_free;
342 break;
343
344 case BIO_C_SET_SUFFIX:
345 ex_func = arg2;
346 ctx->suffix = ex_func->ex_func;
347 ctx->suffix_free = ex_func->ex_free_func;
348 break;
349
350 case BIO_C_GET_SUFFIX:
351 ex_func = arg2;
352 ex_func->ex_func = ctx->suffix;
353 ex_func->ex_free_func = ctx->suffix_free;
354 break;
355
356 case BIO_C_SET_EX_ARG:
357 ctx->ex_arg = arg2;
358 break;
359
360 case BIO_C_GET_EX_ARG:
361 *(void **)arg2 = ctx->ex_arg;
362 break;
363
364 case BIO_CTRL_FLUSH:
365 if (next == NULL)
366 return 0;
367
368 /* Call post function if possible */
369 if (ctx->state == ASN1_STATE_HEADER) {
370 if (!asn1_bio_setup_ex(b, ctx, ctx->suffix,
371 ASN1_STATE_POST_COPY, ASN1_STATE_DONE))
372 return 0;
373 }
374
375 if (ctx->state == ASN1_STATE_POST_COPY) {
376 ret = asn1_bio_flush_ex(b, ctx, ctx->suffix_free,
377 ASN1_STATE_DONE);
378 if (ret <= 0)
379 return ret;
380 }
381
382 if (ctx->state == ASN1_STATE_DONE)
383 return BIO_ctrl(next, cmd, arg1, arg2);
384 else {
385 BIO_clear_retry_flags(b);
386 return 0;
387 }
388
389 default:
390 if (next == NULL)
391 return 0;
392 return BIO_ctrl(next, cmd, arg1, arg2);
393
394 }
395
396 return ret;
397}
398
399static int asn1_bio_set_ex(BIO *b, int cmd,
400 asn1_ps_func *ex_func, asn1_ps_func *ex_free_func)
401{
402 BIO_ASN1_EX_FUNCS extmp;
403 extmp.ex_func = ex_func;
404 extmp.ex_free_func = ex_free_func;
405 return BIO_ctrl(b, cmd, 0, &extmp);
406}
407
408static int asn1_bio_get_ex(BIO *b, int cmd,
409 asn1_ps_func **ex_func,
410 asn1_ps_func **ex_free_func)
411{
412 BIO_ASN1_EX_FUNCS extmp;
413 int ret;
414 ret = BIO_ctrl(b, cmd, 0, &extmp);
415 if (ret > 0) {
416 *ex_func = extmp.ex_func;
417 *ex_free_func = extmp.ex_free_func;
418 }
419 return ret;
420}
421
422int BIO_asn1_set_prefix(BIO *b, asn1_ps_func *prefix,
423 asn1_ps_func *prefix_free)
424{
425 return asn1_bio_set_ex(b, BIO_C_SET_PREFIX, prefix, prefix_free);
426}
427
428int BIO_asn1_get_prefix(BIO *b, asn1_ps_func **pprefix,
429 asn1_ps_func **pprefix_free)
430{
431 return asn1_bio_get_ex(b, BIO_C_GET_PREFIX, pprefix, pprefix_free);
432}
433
434int BIO_asn1_set_suffix(BIO *b, asn1_ps_func *suffix,
435 asn1_ps_func *suffix_free)
436{
437 return asn1_bio_set_ex(b, BIO_C_SET_SUFFIX, suffix, suffix_free);
438}
439
440int BIO_asn1_get_suffix(BIO *b, asn1_ps_func **psuffix,
441 asn1_ps_func **psuffix_free)
442{
443 return asn1_bio_get_ex(b, BIO_C_GET_SUFFIX, psuffix, psuffix_free);
444}
445