summaryrefslogtreecommitdiffstats
path: root/third_party/heimdal/lib/roken/base32.c
blob: 9eb999a871a999688b5d9e6750bf8719bc9ec1ec (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
/*
 * Copyright (c) 2020 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <config.h>

#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#ifdef TEST
#include <stdio.h>
#include <getarg.h>
#include <err.h>
#endif
#include "base32.h"
#include "roken.h"

static const unsigned char base32_chars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
static const unsigned char base32op_chars[] = "0123456789ABCDEFGHIJKLMNOPQRSTUV";

ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
rk_base32_encode(const void *data, int size, char **str, enum rk_base32_flags flags)
{
    const unsigned char *chars =
        (flags & RK_BASE32_FLAG_PRESERVE_ORDER) ? base32op_chars :
                                                  base32_chars;
    uint64_t c;
    char *s, *p;
    int i;
    const unsigned char *q;

    if (size > INT_MAX/8 || size < 0) {
	*str = NULL;
        errno = ERANGE;
	return -1;
    }

    p = s = malloc(((size + 5 - 1) / 5) * 8 + 1);
    if (p == NULL) {
        *str = NULL;
	return -1;
    }
    q = (const unsigned char *) data;

    for (i = 0; i < size;) {
        /* 5 bytes of input will give us 8 output bytes' worth of bits */
	c = q[i++];
	c <<= 8;
	if (i < size)
	    c += q[i];
	i++;
	c <<= 8;
	if (i < size)
	    c += q[i];
	i++;
	c <<= 8;
	if (i < size)
	    c += q[i];
	i++;
	c <<= 8;
	if (i < size)
	    c += q[i];
	i++;
	p[0] = chars[(c & 0x000000f800000000ULL) >> 35];
	p[1] = chars[(c & 0x00000007c0000000ULL) >> 30];
	p[2] = chars[(c & 0x000000003e000000ULL) >> 25];
	p[3] = chars[(c & 0x0000000001f00000ULL) >> 20];
	p[4] = chars[(c & 0x00000000000f8000ULL) >> 15];
	p[5] = chars[(c & 0x0000000000007c00ULL) >> 10];
	p[6] = chars[(c & 0x00000000000003e0ULL) >> 5];
	p[7] = chars[(c & 0x000000000000001fULL) >> 0];
        switch (i - size) {
        case 4: p[2] = p[3] = '=';  HEIM_FALLTHROUGH;
        case 3: p[4] = '=';         HEIM_FALLTHROUGH;
        case 2: p[5] = p[6] = '=';  HEIM_FALLTHROUGH;
        case 1: p[7] = '=';         HEIM_FALLTHROUGH;
        default:                    break;
        }
	p += 8;
    }
    *p = 0;
    *str = s;
    return (int) strlen(s);
}

#define DECODE_ERROR ((uint64_t)-1)

static int
pos(char c, int preserve_order)
{
    /* EBCDIC need not apply */
    if (preserve_order) {
        if (c >= '0' && c <= '9')
            return c - '0';
        if (c >= 'A' && c <= 'V')
            return c - 'A' + ('9' - '0') + 1;
    } else {
        if (c >= 'A' && c <= 'Z')
            return c - 'A';
        if (c >= '2' && c <= '7')
            return c - '2' + ('Z' - 'A') + 1;
    }
    return -1;
}

static uint64_t
token_decode(const char *token, enum rk_base32_flags flags)
{
    uint64_t marker = 0;
    uint64_t val = 0;
    int preserve_order = !!(flags & RK_BASE32_FLAG_PRESERVE_ORDER);
    int i, c;

    for (i = 0; i < 8 && token[i] != '\0'; i++) {
	val <<= 5;
	if (token[i] == '=')
	    marker++;
	else if (marker)
	    return DECODE_ERROR;
	else if ((c = pos(token[i], preserve_order)) == -1 &&
            (flags & RK_BASE32_FLAG_STOP_ON_GARBAGE))
            break;
        else if (c == -1)
            return DECODE_ERROR;
        else
            val |= c;
    }
    if (i < 8 || marker > 6)
	return DECODE_ERROR;
    return (marker << 40) | val;
}

ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
rk_base32_decode(const char *str, void *data, enum rk_base32_flags flags)
{
    const char *p;
    unsigned char *q;
    int preserve_order = !!(flags & RK_BASE32_FLAG_PRESERVE_ORDER);

    q = data;
    for (p = str; *p && (*p == '=' || pos(*p, preserve_order) != -1); p += 8) {
	uint64_t val = token_decode(p, flags);
	uint64_t marker = (val >> 40) & 0xffULL;

	if (val == DECODE_ERROR) {
            errno = EINVAL;
	    return -1;
        }
	*q++ = (val >> 32) & 0xffULL;
	if (marker < 6)
	    *q++ = (val >> 24) & 0xffULL;
	if (marker < 4)
	    *q++ = (val >> 16) & 0xffULL;
	if (marker < 3)
	    *q++ = (val >> 8) & 0xffULL;
	if (marker < 1)
	    *q++ = val & 0xffULL;
        if (marker && !(flags & RK_BASE32_FLAG_INTERIOR_PADDING_OK))
            break;
    }
    if (q - (unsigned char *) data > INT_MAX) {
        errno = EOVERFLOW;
        return -1;
    }
    return q - (unsigned char *) data;
}

#ifdef TEST
static int interior_padding_ok;
static int preserve_order_flag;
static int stop_on_garbage;
static int decode_flag;
static int help_flag;

/*
 * The short options are compatible with a subset of the FreeBSD contrib
 * vis(1).  Heimdal additions have long option names only.
 */
static struct getargs args[] = {
    { "preserve-order", 'P', arg_flag, &preserve_order_flag,
        "Use order-preserving alphabet", NULL },
    { "interior-padding-ok", 'O', arg_flag, &interior_padding_ok,
        "Decode concatenated padded base32 strings as one", NULL },
    { "stop-on-garbage", 'G', arg_flag, &stop_on_garbage,
        "Do not error on garbage", NULL },
    { "decode", 'd', arg_flag, &decode_flag, "Decode", NULL },
    { "help", 'h', arg_flag, &help_flag, "Print help message", NULL },
};
static size_t num_args = sizeof(args)/sizeof(args[0]);

int
main(int argc, char **argv)
{
    enum rk_base32_flags flags = 0;
    unsigned char *buf = NULL;
    size_t buflen = 0;
    size_t bufsz = 0;
    int goptind = 0;
    int ret;

    setprogname("rkbase32");
    if (getarg(args, num_args, argc, argv, &goptind) || help_flag) {
        arg_printusage(args, num_args, NULL, "FILE | -");
        return help_flag ? 0 : 1;
    }

    argc -= goptind;
    argv += goptind;

    flags |= preserve_order_flag ? RK_BASE32_FLAG_PRESERVE_ORDER : 0;
    flags |= interior_padding_ok ? RK_BASE32_FLAG_INTERIOR_PADDING_OK : 0;
    flags |= stop_on_garbage ? RK_BASE32_FLAG_STOP_ON_GARBAGE : 0;

    if (help_flag)
        return arg_printusage(args, num_args, NULL, "FILE | -- -"), 0;
    if (argc != 1)
        return arg_printusage(args, num_args, NULL, "FILE | -- -"), 1;

    if (strcmp(argv[0], "-") == 0) {
        unsigned char *tmp;
        unsigned char d[4096];
        size_t bytes;

        while (!feof(stdin) && !ferror(stdin)) {
            bytes = fread(d, 1, sizeof(d), stdin);
            if (bytes == 0)
                continue;
            if (buflen + bytes > bufsz) {
                if ((tmp = realloc(buf, bufsz + (bufsz >> 2) + sizeof(d))) == NULL)
                    err(1, "Could not read stdin");
                buf = tmp;
                bufsz = bufsz + (bufsz >> 2) + sizeof(d);
            }
            memcpy(buf + buflen, d, bytes);
            buflen += bytes;
        }
        if (ferror(stdin))
            err(1, "Could not read stdin");
    } else {
        void *d;

        if ((errno = rk_undumpdata(argv[0], &d, &bufsz)))
            err(1, "Could not read %s", argv[0]);
        buflen = bufsz;
        buf = d;
    }

    if (decode_flag) {
        unsigned char *d;

        if (buflen == bufsz) {
            unsigned char *tmp;

            if ((tmp = realloc(buf, bufsz + 1)) == NULL)
                err(1, "Could not decode data");
            buf = tmp;
            bufsz++;
        }
        buf[buflen] = '\0';

        if ((d = malloc(buflen * 5 / 8 + 4)) == NULL)
            err(1, "Could not decode data");

        if ((ret = rk_base32_decode((const char *)buf, d, flags)) < 0)
            err(1, "Could not decode data");
        if (fwrite(d, ret, 1, stdout) != 1)
            err(1, "Could not write decoded data");
        free(d);
    } else if (buf) { /* buf can be NULL if we read from an empty file */
        char *e;

        if ((ret = rk_base32_encode(buf, buflen, &e, flags)) < 0)
            err(1, "Could not encode data");
        if (fwrite(e, ret, 1, stdout) != 1)
            err(1, "Could not write decoded data");
        free(e);
        if (fwrite("\n", 1, 1, stdout) != 1)
            err(1, "Could not write decoded data");
    }
    free(buf);
    return 0;
}
#endif