Coverage Report

Created: 2025-06-13 06:58

/src/openssl30/crypto/evp/bio_b64.c
Line
Count
Source (jump to first uncovered line)
1
/*
2
 * Copyright 1995-2021 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 <stdio.h>
11
#include <errno.h>
12
#include "internal/cryptlib.h"
13
#include <openssl/buffer.h>
14
#include <openssl/evp.h>
15
#include "internal/bio.h"
16
17
static int b64_write(BIO *h, const char *buf, int num);
18
static int b64_read(BIO *h, char *buf, int size);
19
static int b64_puts(BIO *h, const char *str);
20
static long b64_ctrl(BIO *h, int cmd, long arg1, void *arg2);
21
static int b64_new(BIO *h);
22
static int b64_free(BIO *data);
23
static long b64_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
24
#define B64_BLOCK_SIZE  1024
25
#define B64_BLOCK_SIZE2 768
26
6.36k
#define B64_NONE        0
27
#define B64_ENCODE      1
28
#define B64_DECODE      2
29
30
typedef struct b64_struct {
31
    /*
32
     * BIO *bio; moved to the BIO structure
33
     */
34
    int buf_len;
35
    int buf_off;
36
    int tmp_len;                /* used to find the start when decoding */
37
    int tmp_nl;                 /* If true, scan until '\n' */
38
    int encode;
39
    int start;                  /* have we started decoding yet? */
40
    int cont;                   /* <= 0 when finished */
41
    EVP_ENCODE_CTX *base64;
42
    char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE) + 10];
43
    char tmp[B64_BLOCK_SIZE];
44
} BIO_B64_CTX;
45
46
static const BIO_METHOD methods_b64 = {
47
    BIO_TYPE_BASE64,
48
    "base64 encoding",
49
    bwrite_conv,
50
    b64_write,
51
    bread_conv,
52
    b64_read,
53
    b64_puts,
54
    NULL,                       /* b64_gets, */
55
    b64_ctrl,
56
    b64_new,
57
    b64_free,
58
    b64_callback_ctrl,
59
};
60
61
62
const BIO_METHOD *BIO_f_base64(void)
63
6.09k
{
64
6.09k
    return &methods_b64;
65
6.09k
}
66
67
static int b64_new(BIO *bi)
68
6.09k
{
69
6.09k
    BIO_B64_CTX *ctx;
70
71
6.09k
    if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL) {
72
0
        ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
73
0
        return 0;
74
0
    }
75
76
6.09k
    ctx->cont = 1;
77
6.09k
    ctx->start = 1;
78
6.09k
    ctx->base64 = EVP_ENCODE_CTX_new();
79
6.09k
    if (ctx->base64 == NULL) {
80
0
        OPENSSL_free(ctx);
81
0
        return 0;
82
0
    }
83
84
6.09k
    BIO_set_data(bi, ctx);
85
6.09k
    BIO_set_init(bi, 1);
86
87
6.09k
    return 1;
88
6.09k
}
89
90
static int b64_free(BIO *a)
91
6.09k
{
92
6.09k
    BIO_B64_CTX *ctx;
93
6.09k
    if (a == NULL)
94
0
        return 0;
95
96
6.09k
    ctx = BIO_get_data(a);
97
6.09k
    if (ctx == NULL)
98
0
        return 0;
99
100
6.09k
    EVP_ENCODE_CTX_free(ctx->base64);
101
6.09k
    OPENSSL_free(ctx);
102
6.09k
    BIO_set_data(a, NULL);
103
6.09k
    BIO_set_init(a, 0);
104
105
6.09k
    return 1;
106
6.09k
}
107
108
static int b64_read(BIO *b, char *out, int outl)
109
{
110
    int ret = 0, i, ii, j, k, x, n, num, ret_code = 0;
111
    BIO_B64_CTX *ctx;
112
    unsigned char *p, *q;
113
    BIO *next;
114
115
    if (out == NULL)
116
        return 0;
117
    ctx = (BIO_B64_CTX *)BIO_get_data(b);
118
119
    next = BIO_next(b);
120
    if ((ctx == NULL) || (next == NULL))
121
        return 0;
122
123
    BIO_clear_retry_flags(b);
124
125
    if (ctx->encode != B64_DECODE) {
126
        ctx->encode = B64_DECODE;
127
        ctx->buf_len = 0;
128
        ctx->buf_off = 0;
129
        ctx->tmp_len = 0;
130
        EVP_DecodeInit(ctx->base64);
131
    }
132
133
    /* First check if there are bytes decoded/encoded */
134
    if (ctx->buf_len > 0) {
135
        OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
136
        i = ctx->buf_len - ctx->buf_off;
137
        if (i > outl)
138
            i = outl;
139
        OPENSSL_assert(ctx->buf_off + i < (int)sizeof(ctx->buf));
140
        memcpy(out, &(ctx->buf[ctx->buf_off]), i);
141
        ret = i;
142
        out += i;
143
        outl -= i;
144
        ctx->buf_off += i;
145
        if (ctx->buf_len == ctx->buf_off) {
146
            ctx->buf_len = 0;
147
            ctx->buf_off = 0;
148
        }
149
    }
150
151
    /*
152
     * At this point, we have room of outl bytes and an empty buffer, so we
153
     * should read in some more.
154
     */
155
156
    ret_code = 0;
157
    while (outl > 0) {
158
        if (ctx->cont <= 0)
159
            break;
160
161
        i = BIO_read(next, &(ctx->tmp[ctx->tmp_len]),
162
                     B64_BLOCK_SIZE - ctx->tmp_len);
163
164
        if (i <= 0) {
165
            ret_code = i;
166
167
            /* Should we continue next time we are called? */
168
            if (!BIO_should_retry(next)) {
169
                ctx->cont = i;
170
                /* If buffer empty break */
171
                if (ctx->tmp_len == 0)
172
                    break;
173
                /* Fall through and process what we have */
174
                else
175
                    i = 0;
176
            }
177
            /* else we retry and add more data to buffer */
178
            else
179
                break;
180
        }
181
        i += ctx->tmp_len;
182
        ctx->tmp_len = i;
183
184
        /*
185
         * We need to scan, a line at a time until we have a valid line if we
186
         * are starting.
187
         */
188
        if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)) {
189
            /* ctx->start=1; */
190
            ctx->tmp_len = 0;
191
        } else if (ctx->start) {
192
            q = p = (unsigned char *)ctx->tmp;
193
            num = 0;
194
            for (j = 0; j < i; j++) {
195
                if (*(q++) != '\n')
196
                    continue;
197
198
                /*
199
                 * due to a previous very long line, we need to keep on
200
                 * scanning for a '\n' before we even start looking for
201
                 * base64 encoded stuff.
202
                 */
203
                if (ctx->tmp_nl) {
204
                    p = q;
205
                    ctx->tmp_nl = 0;
206
                    continue;
207
                }
208
209
                k = EVP_DecodeUpdate(ctx->base64,
210
                                     (unsigned char *)ctx->buf,
211
                                     &num, p, q - p);
212
                if ((k <= 0) && (num == 0) && (ctx->start))
213
                    EVP_DecodeInit(ctx->base64);
214
                else {
215
                    if (p != (unsigned char *)
216
                        &(ctx->tmp[0])) {
217
                        i -= (p - (unsigned char *)
218
                              &(ctx->tmp[0]));
219
                        for (x = 0; x < i; x++)
220
                            ctx->tmp[x] = p[x];
221
                    }
222
                    EVP_DecodeInit(ctx->base64);
223
                    ctx->start = 0;
224
                    break;
225
                }
226
                p = q;
227
            }
228
229
            /* we fell off the end without starting */
230
            if ((j == i) && (num == 0)) {
231
                /*
232
                 * Is this is one long chunk?, if so, keep on reading until a
233
                 * new line.
234
                 */
235
                if (p == (unsigned char *)&(ctx->tmp[0])) {
236
                    /* Check buffer full */
237
                    if (i == B64_BLOCK_SIZE) {
238
                        ctx->tmp_nl = 1;
239
                        ctx->tmp_len = 0;
240
                    }
241
                } else if (p != q) { /* finished on a '\n' */
242
                    n = q - p;
243
                    for (ii = 0; ii < n; ii++)
244
                        ctx->tmp[ii] = p[ii];
245
                    ctx->tmp_len = n;
246
                }
247
                /* else finished on a '\n' */
248
                continue;
249
            } else {
250
                ctx->tmp_len = 0;
251
            }
252
        } else if ((i < B64_BLOCK_SIZE) && (ctx->cont > 0)) {
253
            /*
254
             * If buffer isn't full and we can retry then restart to read in
255
             * more data.
256
             */
257
            continue;
258
        }
259
260
        if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
261
            int z, jj;
262
263
            jj = i & ~3;        /* process per 4 */
264
            z = EVP_DecodeBlock((unsigned char *)ctx->buf,
265
                                (unsigned char *)ctx->tmp, jj);
266
            if (jj > 2) {
267
                if (ctx->tmp[jj - 1] == '=') {
268
                    z--;
269
                    if (ctx->tmp[jj - 2] == '=')
270
                        z--;
271
                }
272
            }
273
            /*
274
             * z is now number of output bytes and jj is the number consumed
275
             */
276
            if (jj != i) {
277
                memmove(ctx->tmp, &ctx->tmp[jj], i - jj);
278
                ctx->tmp_len = i - jj;
279
            }
280
            ctx->buf_len = 0;
281
            if (z > 0) {
282
                ctx->buf_len = z;
283
            }
284
            i = z;
285
        } else {
286
            i = EVP_DecodeUpdate(ctx->base64,
287
                                 (unsigned char *)ctx->buf, &ctx->buf_len,
288
                                 (unsigned char *)ctx->tmp, i);
289
            ctx->tmp_len = 0;
290
        }
291
        /*
292
         * If eof or an error was signalled, then the condition
293
         * 'ctx->cont <= 0' will prevent b64_read() from reading
294
         * more data on subsequent calls. This assignment was
295
         * deleted accidentally in commit 5562cfaca4f3.
296
         */
297
        ctx->cont = i;
298
299
        ctx->buf_off = 0;
300
        if (i < 0) {
301
            ret_code = 0;
302
            ctx->buf_len = 0;
303
            break;
304
        }
305
306
        if (ctx->buf_len <= outl)
307
            i = ctx->buf_len;
308
        else
309
            i = outl;
310
311
        memcpy(out, ctx->buf, i);
312
        ret += i;
313
        ctx->buf_off = i;
314
        if (ctx->buf_off == ctx->buf_len) {
315
            ctx->buf_len = 0;
316
            ctx->buf_off = 0;
317
        }
318
        outl -= i;
319
        out += i;
320
    }
321
    /* BIO_clear_retry_flags(b); */
322
    BIO_copy_next_retry(b);
323
    return ((ret == 0) ? ret_code : ret);
324
}
325
326
static int b64_write(BIO *b, const char *in, int inl)
327
{
328
    int ret = 0;
329
    int n;
330
    int i;
331
    BIO_B64_CTX *ctx;
332
    BIO *next;
333
334
    ctx = (BIO_B64_CTX *)BIO_get_data(b);
335
    next = BIO_next(b);
336
    if ((ctx == NULL) || (next == NULL))
337
        return 0;
338
339
    BIO_clear_retry_flags(b);
340
341
    if (ctx->encode != B64_ENCODE) {
342
        ctx->encode = B64_ENCODE;
343
        ctx->buf_len = 0;
344
        ctx->buf_off = 0;
345
        ctx->tmp_len = 0;
346
        EVP_EncodeInit(ctx->base64);
347
    }
348
349
    OPENSSL_assert(ctx->buf_off < (int)sizeof(ctx->buf));
350
    OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
351
    OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
352
    n = ctx->buf_len - ctx->buf_off;
353
    while (n > 0) {
354
        i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
355
        if (i <= 0) {
356
            BIO_copy_next_retry(b);
357
            return i;
358
        }
359
        OPENSSL_assert(i <= n);
360
        ctx->buf_off += i;
361
        OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
362
        OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
363
        n -= i;
364
    }
365
    /* at this point all pending data has been written */
366
    ctx->buf_off = 0;
367
    ctx->buf_len = 0;
368
369
    if ((in == NULL) || (inl <= 0))
370
        return 0;
371
372
    while (inl > 0) {
373
        n = (inl > B64_BLOCK_SIZE) ? B64_BLOCK_SIZE : inl;
374
375
        if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
376
            if (ctx->tmp_len > 0) {
377
                OPENSSL_assert(ctx->tmp_len <= 3);
378
                n = 3 - ctx->tmp_len;
379
                /*
380
                 * There's a theoretical possibility for this
381
                 */
382
                if (n > inl)
383
                    n = inl;
384
                memcpy(&(ctx->tmp[ctx->tmp_len]), in, n);
385
                ctx->tmp_len += n;
386
                ret += n;
387
                if (ctx->tmp_len < 3)
388
                    break;
389
                ctx->buf_len =
390
                    EVP_EncodeBlock((unsigned char *)ctx->buf,
391
                                    (unsigned char *)ctx->tmp, ctx->tmp_len);
392
                OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
393
                OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
394
                /*
395
                 * Since we're now done using the temporary buffer, the
396
                 * length should be 0'd
397
                 */
398
                ctx->tmp_len = 0;
399
            } else {
400
                if (n < 3) {
401
                    memcpy(ctx->tmp, in, n);
402
                    ctx->tmp_len = n;
403
                    ret += n;
404
                    break;
405
                }
406
                n -= n % 3;
407
                ctx->buf_len =
408
                    EVP_EncodeBlock((unsigned char *)ctx->buf,
409
                                    (const unsigned char *)in, n);
410
                OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
411
                OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
412
                ret += n;
413
            }
414
        } else {
415
            if (!EVP_EncodeUpdate(ctx->base64,
416
                                 (unsigned char *)ctx->buf, &ctx->buf_len,
417
                                 (unsigned char *)in, n))
418
                return ((ret == 0) ? -1 : ret);
419
            OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
420
            OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
421
            ret += n;
422
        }
423
        inl -= n;
424
        in += n;
425
426
        ctx->buf_off = 0;
427
        n = ctx->buf_len;
428
        while (n > 0) {
429
            i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
430
            if (i <= 0) {
431
                BIO_copy_next_retry(b);
432
                return ((ret == 0) ? i : ret);
433
            }
434
            OPENSSL_assert(i <= n);
435
            n -= i;
436
            ctx->buf_off += i;
437
            OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
438
            OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
439
        }
440
        ctx->buf_len = 0;
441
        ctx->buf_off = 0;
442
    }
443
    return ret;
444
}
445
446
static long b64_ctrl(BIO *b, int cmd, long num, void *ptr)
447
8.97k
{
448
8.97k
    BIO_B64_CTX *ctx;
449
8.97k
    long ret = 1;
450
8.97k
    int i;
451
8.97k
    BIO *next;
452
453
8.97k
    ctx = (BIO_B64_CTX *)BIO_get_data(b);
454
8.97k
    next = BIO_next(b);
455
8.97k
    if ((ctx == NULL) || (next == NULL))
456
0
        return 0;
457
458
8.97k
    switch (cmd) {
459
0
    case BIO_CTRL_RESET:
460
0
        ctx->cont = 1;
461
0
        ctx->start = 1;
462
0
        ctx->encode = B64_NONE;
463
0
        ret = BIO_ctrl(next, cmd, num, ptr);
464
0
        break;
465
0
    case BIO_CTRL_EOF:         /* More to read */
466
0
        if (ctx->cont <= 0)
467
0
            ret = 1;
468
0
        else
469
0
            ret = BIO_ctrl(next, cmd, num, ptr);
470
0
        break;
471
0
    case BIO_CTRL_WPENDING:    /* More to write in buffer */
472
0
        OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
473
0
        ret = ctx->buf_len - ctx->buf_off;
474
0
        if ((ret == 0) && (ctx->encode != B64_NONE)
475
0
            && (EVP_ENCODE_CTX_num(ctx->base64) != 0))
476
0
            ret = 1;
477
0
        else if (ret <= 0)
478
0
            ret = BIO_ctrl(next, cmd, num, ptr);
479
0
        break;
480
0
    case BIO_CTRL_PENDING:     /* More to read in buffer */
481
0
        OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
482
0
        ret = ctx->buf_len - ctx->buf_off;
483
0
        if (ret <= 0)
484
0
            ret = BIO_ctrl(next, cmd, num, ptr);
485
0
        break;
486
2.99k
    case BIO_CTRL_FLUSH:
487
        /* do a final write */
488
3.18k
 again:
489
4.67k
        while (ctx->buf_len != ctx->buf_off) {
490
1.49k
            i = b64_write(b, NULL, 0);
491
1.49k
            if (i < 0)
492
0
                return i;
493
1.49k
        }
494
3.18k
        if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
495
0
            if (ctx->tmp_len != 0) {
496
0
                ctx->buf_len = EVP_EncodeBlock((unsigned char *)ctx->buf,
497
0
                                               (unsigned char *)ctx->tmp,
498
0
                                               ctx->tmp_len);
499
0
                ctx->buf_off = 0;
500
0
                ctx->tmp_len = 0;
501
0
                goto again;
502
0
            }
503
3.18k
        } else if (ctx->encode != B64_NONE
504
3.18k
                   && EVP_ENCODE_CTX_num(ctx->base64) != 0) {
505
193
            ctx->buf_off = 0;
506
193
            EVP_EncodeFinal(ctx->base64,
507
193
                            (unsigned char *)ctx->buf, &(ctx->buf_len));
508
            /* push out the bytes */
509
193
            goto again;
510
193
        }
511
        /* Finally flush the underlying BIO */
512
2.99k
        ret = BIO_ctrl(next, cmd, num, ptr);
513
2.99k
        break;
514
515
0
    case BIO_C_DO_STATE_MACHINE:
516
0
        BIO_clear_retry_flags(b);
517
0
        ret = BIO_ctrl(next, cmd, num, ptr);
518
0
        BIO_copy_next_retry(b);
519
0
        break;
520
521
0
    case BIO_CTRL_DUP:
522
0
        break;
523
0
    case BIO_CTRL_INFO:
524
0
    case BIO_CTRL_GET:
525
0
    case BIO_CTRL_SET:
526
5.98k
    default:
527
5.98k
        ret = BIO_ctrl(next, cmd, num, ptr);
528
5.98k
        break;
529
8.97k
    }
530
8.97k
    return ret;
531
8.97k
}
532
533
static long b64_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
534
0
{
535
0
    BIO *next = BIO_next(b);
536
537
0
    if (next == NULL)
538
0
        return 0;
539
540
0
    return BIO_callback_ctrl(next, cmd, fp);
541
0
}
542
543
static int b64_puts(BIO *b, const char *str)
544
0
{
545
0
    return b64_write(b, str, strlen(str));
546
0
}