xref: /freebsd/crypto/openssl/apps/enc.c (revision 3cbb4cc200f8a0ad7ed08233425ea54524a21f1c)
1 /*
2  * Copyright 1995-2019 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (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 <stdlib.h>
12 #include <string.h>
13 #include <limits.h>
14 #include "apps.h"
15 #include "progs.h"
16 #include <openssl/bio.h>
17 #include <openssl/err.h>
18 #include <openssl/evp.h>
19 #include <openssl/objects.h>
20 #include <openssl/x509.h>
21 #include <openssl/rand.h>
22 #include <openssl/pem.h>
23 #ifndef OPENSSL_NO_COMP
24 # include <openssl/comp.h>
25 #endif
26 #include <ctype.h>
27 
28 #undef SIZE
29 #undef BSIZE
30 #define SIZE    (512)
31 #define BSIZE   (8*1024)
32 
33 static int set_hex(const char *in, unsigned char *out, int size);
34 static void show_ciphers(const OBJ_NAME *name, void *bio_);
35 
36 struct doall_enc_ciphers {
37     BIO *bio;
38     int n;
39 };
40 
41 typedef enum OPTION_choice {
42     OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
43     OPT_LIST,
44     OPT_E, OPT_IN, OPT_OUT, OPT_PASS, OPT_ENGINE, OPT_D, OPT_P, OPT_V,
45     OPT_NOPAD, OPT_SALT, OPT_NOSALT, OPT_DEBUG, OPT_UPPER_P, OPT_UPPER_A,
46     OPT_A, OPT_Z, OPT_BUFSIZE, OPT_K, OPT_KFILE, OPT_UPPER_K, OPT_NONE,
47     OPT_UPPER_S, OPT_IV, OPT_MD, OPT_ITER, OPT_PBKDF2, OPT_CIPHER,
48     OPT_R_ENUM
49 } OPTION_CHOICE;
50 
51 const OPTIONS enc_options[] = {
52     {"help", OPT_HELP, '-', "Display this summary"},
53     {"list", OPT_LIST, '-', "List ciphers"},
54     {"ciphers", OPT_LIST, '-', "Alias for -list"},
55     {"in", OPT_IN, '<', "Input file"},
56     {"out", OPT_OUT, '>', "Output file"},
57     {"pass", OPT_PASS, 's', "Passphrase source"},
58     {"e", OPT_E, '-', "Encrypt"},
59     {"d", OPT_D, '-', "Decrypt"},
60     {"p", OPT_P, '-', "Print the iv/key"},
61     {"P", OPT_UPPER_P, '-', "Print the iv/key and exit"},
62     {"v", OPT_V, '-', "Verbose output"},
63     {"nopad", OPT_NOPAD, '-', "Disable standard block padding"},
64     {"salt", OPT_SALT, '-', "Use salt in the KDF (default)"},
65     {"nosalt", OPT_NOSALT, '-', "Do not use salt in the KDF"},
66     {"debug", OPT_DEBUG, '-', "Print debug info"},
67     {"a", OPT_A, '-', "Base64 encode/decode, depending on encryption flag"},
68     {"base64", OPT_A, '-', "Same as option -a"},
69     {"A", OPT_UPPER_A, '-',
70      "Used with -[base64|a] to specify base64 buffer as a single line"},
71     {"bufsize", OPT_BUFSIZE, 's', "Buffer size"},
72     {"k", OPT_K, 's', "Passphrase"},
73     {"kfile", OPT_KFILE, '<', "Read passphrase from file"},
74     {"K", OPT_UPPER_K, 's', "Raw key, in hex"},
75     {"S", OPT_UPPER_S, 's', "Salt, in hex"},
76     {"iv", OPT_IV, 's', "IV in hex"},
77     {"md", OPT_MD, 's', "Use specified digest to create a key from the passphrase"},
78     {"iter", OPT_ITER, 'p', "Specify the iteration count and force use of PBKDF2"},
79     {"pbkdf2", OPT_PBKDF2, '-', "Use password-based key derivation function 2"},
80     {"none", OPT_NONE, '-', "Don't encrypt"},
81     {"", OPT_CIPHER, '-', "Any supported cipher"},
82     OPT_R_OPTIONS,
83 #ifdef ZLIB
84     {"z", OPT_Z, '-', "Use zlib as the 'encryption'"},
85 #endif
86 #ifndef OPENSSL_NO_ENGINE
87     {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
88 #endif
89     {NULL}
90 };
91 
92 int enc_main(int argc, char **argv)
93 {
94     static char buf[128];
95     static const char magic[] = "Salted__";
96     ENGINE *e = NULL;
97     BIO *in = NULL, *out = NULL, *b64 = NULL, *benc = NULL, *rbio =
98         NULL, *wbio = NULL;
99     EVP_CIPHER_CTX *ctx = NULL;
100     const EVP_CIPHER *cipher = NULL, *c;
101     const EVP_MD *dgst = NULL;
102     char *hkey = NULL, *hiv = NULL, *hsalt = NULL, *p;
103     char *infile = NULL, *outfile = NULL, *prog;
104     char *str = NULL, *passarg = NULL, *pass = NULL, *strbuf = NULL;
105     char mbuf[sizeof(magic) - 1];
106     OPTION_CHOICE o;
107     int bsize = BSIZE, verbose = 0, debug = 0, olb64 = 0, nosalt = 0;
108     int enc = 1, printkey = 0, i, k;
109     int base64 = 0, informat = FORMAT_BINARY, outformat = FORMAT_BINARY;
110     int ret = 1, inl, nopad = 0;
111     unsigned char key[EVP_MAX_KEY_LENGTH], iv[EVP_MAX_IV_LENGTH];
112     unsigned char *buff = NULL, salt[PKCS5_SALT_LEN];
113     int pbkdf2 = 0;
114     int iter = 0;
115     long n;
116     struct doall_enc_ciphers dec;
117 #ifdef ZLIB
118     int do_zlib = 0;
119     BIO *bzl = NULL;
120 #endif
121 
122     /* first check the program name */
123     prog = opt_progname(argv[0]);
124     if (strcmp(prog, "base64") == 0) {
125         base64 = 1;
126 #ifdef ZLIB
127     } else if (strcmp(prog, "zlib") == 0) {
128         do_zlib = 1;
129 #endif
130     } else {
131         cipher = EVP_get_cipherbyname(prog);
132         if (cipher == NULL && strcmp(prog, "enc") != 0) {
133             BIO_printf(bio_err, "%s is not a known cipher\n", prog);
134             goto end;
135         }
136     }
137 
138     prog = opt_init(argc, argv, enc_options);
139     while ((o = opt_next()) != OPT_EOF) {
140         switch (o) {
141         case OPT_EOF:
142         case OPT_ERR:
143  opthelp:
144             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
145             goto end;
146         case OPT_HELP:
147             opt_help(enc_options);
148             ret = 0;
149             goto end;
150         case OPT_LIST:
151             BIO_printf(bio_out, "Supported ciphers:\n");
152             dec.bio = bio_out;
153             dec.n = 0;
154             OBJ_NAME_do_all_sorted(OBJ_NAME_TYPE_CIPHER_METH,
155                                    show_ciphers, &dec);
156             BIO_printf(bio_out, "\n");
157             ret = 0;
158             goto end;
159         case OPT_E:
160             enc = 1;
161             break;
162         case OPT_IN:
163             infile = opt_arg();
164             break;
165         case OPT_OUT:
166             outfile = opt_arg();
167             break;
168         case OPT_PASS:
169             passarg = opt_arg();
170             break;
171         case OPT_ENGINE:
172             e = setup_engine(opt_arg(), 0);
173             break;
174         case OPT_D:
175             enc = 0;
176             break;
177         case OPT_P:
178             printkey = 1;
179             break;
180         case OPT_V:
181             verbose = 1;
182             break;
183         case OPT_NOPAD:
184             nopad = 1;
185             break;
186         case OPT_SALT:
187             nosalt = 0;
188             break;
189         case OPT_NOSALT:
190             nosalt = 1;
191             break;
192         case OPT_DEBUG:
193             debug = 1;
194             break;
195         case OPT_UPPER_P:
196             printkey = 2;
197             break;
198         case OPT_UPPER_A:
199             olb64 = 1;
200             break;
201         case OPT_A:
202             base64 = 1;
203             break;
204         case OPT_Z:
205 #ifdef ZLIB
206             do_zlib = 1;
207 #endif
208             break;
209         case OPT_BUFSIZE:
210             p = opt_arg();
211             i = (int)strlen(p) - 1;
212             k = i >= 1 && p[i] == 'k';
213             if (k)
214                 p[i] = '\0';
215             if (!opt_long(opt_arg(), &n)
216                     || n < 0 || (k && n >= LONG_MAX / 1024))
217                 goto opthelp;
218             if (k)
219                 n *= 1024;
220             bsize = (int)n;
221             break;
222         case OPT_K:
223             str = opt_arg();
224             break;
225         case OPT_KFILE:
226             in = bio_open_default(opt_arg(), 'r', FORMAT_TEXT);
227             if (in == NULL)
228                 goto opthelp;
229             i = BIO_gets(in, buf, sizeof(buf));
230             BIO_free(in);
231             in = NULL;
232             if (i <= 0) {
233                 BIO_printf(bio_err,
234                            "%s Can't read key from %s\n", prog, opt_arg());
235                 goto opthelp;
236             }
237             while (--i > 0 && (buf[i] == '\r' || buf[i] == '\n'))
238                 buf[i] = '\0';
239             if (i <= 0) {
240                 BIO_printf(bio_err, "%s: zero length password\n", prog);
241                 goto opthelp;
242             }
243             str = buf;
244             break;
245         case OPT_UPPER_K:
246             hkey = opt_arg();
247             break;
248         case OPT_UPPER_S:
249             hsalt = opt_arg();
250             break;
251         case OPT_IV:
252             hiv = opt_arg();
253             break;
254         case OPT_MD:
255             if (!opt_md(opt_arg(), &dgst))
256                 goto opthelp;
257             break;
258         case OPT_CIPHER:
259             if (!opt_cipher(opt_unknown(), &c))
260                 goto opthelp;
261             cipher = c;
262             break;
263         case OPT_ITER:
264             if (!opt_int(opt_arg(), &iter))
265                 goto opthelp;
266             pbkdf2 = 1;
267             break;
268         case OPT_PBKDF2:
269             pbkdf2 = 1;
270             if (iter == 0)    /* do not overwrite a chosen value */
271                 iter = 10000;
272             break;
273         case OPT_NONE:
274             cipher = NULL;
275             break;
276         case OPT_R_CASES:
277             if (!opt_rand(o))
278                 goto end;
279             break;
280         }
281     }
282     if (opt_num_rest() != 0) {
283         BIO_printf(bio_err, "Extra arguments given.\n");
284         goto opthelp;
285     }
286 
287     if (cipher && EVP_CIPHER_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) {
288         BIO_printf(bio_err, "%s: AEAD ciphers not supported\n", prog);
289         goto end;
290     }
291 
292     if (cipher && (EVP_CIPHER_mode(cipher) == EVP_CIPH_XTS_MODE)) {
293         BIO_printf(bio_err, "%s XTS ciphers not supported\n", prog);
294         goto end;
295     }
296 
297     if (dgst == NULL)
298         dgst = EVP_sha256();
299 
300     if (iter == 0)
301         iter = 1;
302 
303     /* It must be large enough for a base64 encoded line */
304     if (base64 && bsize < 80)
305         bsize = 80;
306     if (verbose)
307         BIO_printf(bio_err, "bufsize=%d\n", bsize);
308 
309 #ifdef ZLIB
310     if (!do_zlib)
311 #endif
312         if (base64) {
313             if (enc)
314                 outformat = FORMAT_BASE64;
315             else
316                 informat = FORMAT_BASE64;
317         }
318 
319     strbuf = app_malloc(SIZE, "strbuf");
320     buff = app_malloc(EVP_ENCODE_LENGTH(bsize), "evp buffer");
321 
322     if (infile == NULL) {
323         in = dup_bio_in(informat);
324     } else {
325         in = bio_open_default(infile, 'r', informat);
326     }
327     if (in == NULL)
328         goto end;
329 
330     if (str == NULL && passarg != NULL) {
331         if (!app_passwd(passarg, NULL, &pass, NULL)) {
332             BIO_printf(bio_err, "Error getting password\n");
333             goto end;
334         }
335         str = pass;
336     }
337 
338     if ((str == NULL) && (cipher != NULL) && (hkey == NULL)) {
339         if (1) {
340 #ifndef OPENSSL_NO_UI_CONSOLE
341             for (;;) {
342                 char prompt[200];
343 
344                 BIO_snprintf(prompt, sizeof(prompt), "enter %s %s password:",
345                         OBJ_nid2ln(EVP_CIPHER_nid(cipher)),
346                         (enc) ? "encryption" : "decryption");
347                 strbuf[0] = '\0';
348                 i = EVP_read_pw_string((char *)strbuf, SIZE, prompt, enc);
349                 if (i == 0) {
350                     if (strbuf[0] == '\0') {
351                         ret = 1;
352                         goto end;
353                     }
354                     str = strbuf;
355                     break;
356                 }
357                 if (i < 0) {
358                     BIO_printf(bio_err, "bad password read\n");
359                     goto end;
360                 }
361             }
362         } else {
363 #endif
364             BIO_printf(bio_err, "password required\n");
365             goto end;
366         }
367     }
368 
369     out = bio_open_default(outfile, 'w', outformat);
370     if (out == NULL)
371         goto end;
372 
373     if (debug) {
374         BIO_set_callback(in, BIO_debug_callback);
375         BIO_set_callback(out, BIO_debug_callback);
376         BIO_set_callback_arg(in, (char *)bio_err);
377         BIO_set_callback_arg(out, (char *)bio_err);
378     }
379 
380     rbio = in;
381     wbio = out;
382 
383 #ifdef ZLIB
384     if (do_zlib) {
385         if ((bzl = BIO_new(BIO_f_zlib())) == NULL)
386             goto end;
387         if (debug) {
388             BIO_set_callback(bzl, BIO_debug_callback);
389             BIO_set_callback_arg(bzl, (char *)bio_err);
390         }
391         if (enc)
392             wbio = BIO_push(bzl, wbio);
393         else
394             rbio = BIO_push(bzl, rbio);
395     }
396 #endif
397 
398     if (base64) {
399         if ((b64 = BIO_new(BIO_f_base64())) == NULL)
400             goto end;
401         if (debug) {
402             BIO_set_callback(b64, BIO_debug_callback);
403             BIO_set_callback_arg(b64, (char *)bio_err);
404         }
405         if (olb64)
406             BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
407         if (enc)
408             wbio = BIO_push(b64, wbio);
409         else
410             rbio = BIO_push(b64, rbio);
411     }
412 
413     if (cipher != NULL) {
414         /*
415          * Note that str is NULL if a key was passed on the command line, so
416          * we get no salt in that case. Is this a bug?
417          */
418         if (str != NULL) {
419             /*
420              * Salt handling: if encrypting generate a salt and write to
421              * output BIO. If decrypting read salt from input BIO.
422              */
423             unsigned char *sptr;
424             size_t str_len = strlen(str);
425 
426             if (nosalt) {
427                 sptr = NULL;
428             } else {
429                 if (enc) {
430                     if (hsalt) {
431                         if (!set_hex(hsalt, salt, sizeof(salt))) {
432                             BIO_printf(bio_err, "invalid hex salt value\n");
433                             goto end;
434                         }
435                     } else if (RAND_bytes(salt, sizeof(salt)) <= 0) {
436                         goto end;
437                     }
438                     /*
439                      * If -P option then don't bother writing
440                      */
441                     if ((printkey != 2)
442                         && (BIO_write(wbio, magic,
443                                       sizeof(magic) - 1) != sizeof(magic) - 1
444                             || BIO_write(wbio,
445                                          (char *)salt,
446                                          sizeof(salt)) != sizeof(salt))) {
447                         BIO_printf(bio_err, "error writing output file\n");
448                         goto end;
449                     }
450                 } else if (BIO_read(rbio, mbuf, sizeof(mbuf)) != sizeof(mbuf)
451                            || BIO_read(rbio,
452                                        (unsigned char *)salt,
453                                        sizeof(salt)) != sizeof(salt)) {
454                     BIO_printf(bio_err, "error reading input file\n");
455                     goto end;
456                 } else if (memcmp(mbuf, magic, sizeof(magic) - 1)) {
457                     BIO_printf(bio_err, "bad magic number\n");
458                     goto end;
459                 }
460                 sptr = salt;
461             }
462 
463             if (pbkdf2 == 1) {
464                 /*
465                 * derive key and default iv
466                 * concatenated into a temporary buffer
467                 */
468                 unsigned char tmpkeyiv[EVP_MAX_KEY_LENGTH + EVP_MAX_IV_LENGTH];
469                 int iklen = EVP_CIPHER_key_length(cipher);
470                 int ivlen = EVP_CIPHER_iv_length(cipher);
471                 /* not needed if HASH_UPDATE() is fixed : */
472                 int islen = (sptr != NULL ? sizeof(salt) : 0);
473                 if (!PKCS5_PBKDF2_HMAC(str, str_len, sptr, islen,
474                                        iter, dgst, iklen+ivlen, tmpkeyiv)) {
475                     BIO_printf(bio_err, "PKCS5_PBKDF2_HMAC failed\n");
476                     goto end;
477                 }
478                 /* split and move data back to global buffer */
479                 memcpy(key, tmpkeyiv, iklen);
480                 memcpy(iv, tmpkeyiv+iklen, ivlen);
481             } else {
482                 BIO_printf(bio_err, "*** WARNING : "
483                                     "deprecated key derivation used.\n"
484                                     "Using -iter or -pbkdf2 would be better.\n");
485                 if (!EVP_BytesToKey(cipher, dgst, sptr,
486                                     (unsigned char *)str, str_len,
487                                     1, key, iv)) {
488                     BIO_printf(bio_err, "EVP_BytesToKey failed\n");
489                     goto end;
490                 }
491             }
492             /*
493              * zero the complete buffer or the string passed from the command
494              * line.
495              */
496             if (str == strbuf)
497                 OPENSSL_cleanse(str, SIZE);
498             else
499                 OPENSSL_cleanse(str, str_len);
500         }
501         if (hiv != NULL) {
502             int siz = EVP_CIPHER_iv_length(cipher);
503             if (siz == 0) {
504                 BIO_printf(bio_err, "warning: iv not used by this cipher\n");
505             } else if (!set_hex(hiv, iv, siz)) {
506                 BIO_printf(bio_err, "invalid hex iv value\n");
507                 goto end;
508             }
509         }
510         if ((hiv == NULL) && (str == NULL)
511             && EVP_CIPHER_iv_length(cipher) != 0) {
512             /*
513              * No IV was explicitly set and no IV was generated.
514              * Hence the IV is undefined, making correct decryption impossible.
515              */
516             BIO_printf(bio_err, "iv undefined\n");
517             goto end;
518         }
519         if (hkey != NULL) {
520             if (!set_hex(hkey, key, EVP_CIPHER_key_length(cipher))) {
521                 BIO_printf(bio_err, "invalid hex key value\n");
522                 goto end;
523             }
524             /* wiping secret data as we no longer need it */
525             OPENSSL_cleanse(hkey, strlen(hkey));
526         }
527 
528         if ((benc = BIO_new(BIO_f_cipher())) == NULL)
529             goto end;
530 
531         /*
532          * Since we may be changing parameters work on the encryption context
533          * rather than calling BIO_set_cipher().
534          */
535 
536         BIO_get_cipher_ctx(benc, &ctx);
537 
538         if (!EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, enc)) {
539             BIO_printf(bio_err, "Error setting cipher %s\n",
540                        EVP_CIPHER_name(cipher));
541             ERR_print_errors(bio_err);
542             goto end;
543         }
544 
545         if (nopad)
546             EVP_CIPHER_CTX_set_padding(ctx, 0);
547 
548         if (!EVP_CipherInit_ex(ctx, NULL, NULL, key, iv, enc)) {
549             BIO_printf(bio_err, "Error setting cipher %s\n",
550                        EVP_CIPHER_name(cipher));
551             ERR_print_errors(bio_err);
552             goto end;
553         }
554 
555         if (debug) {
556             BIO_set_callback(benc, BIO_debug_callback);
557             BIO_set_callback_arg(benc, (char *)bio_err);
558         }
559 
560         if (printkey) {
561             if (!nosalt) {
562                 printf("salt=");
563                 for (i = 0; i < (int)sizeof(salt); i++)
564                     printf("%02X", salt[i]);
565                 printf("\n");
566             }
567             if (EVP_CIPHER_key_length(cipher) > 0) {
568                 printf("key=");
569                 for (i = 0; i < EVP_CIPHER_key_length(cipher); i++)
570                     printf("%02X", key[i]);
571                 printf("\n");
572             }
573             if (EVP_CIPHER_iv_length(cipher) > 0) {
574                 printf("iv =");
575                 for (i = 0; i < EVP_CIPHER_iv_length(cipher); i++)
576                     printf("%02X", iv[i]);
577                 printf("\n");
578             }
579             if (printkey == 2) {
580                 ret = 0;
581                 goto end;
582             }
583         }
584     }
585 
586     /* Only encrypt/decrypt as we write the file */
587     if (benc != NULL)
588         wbio = BIO_push(benc, wbio);
589 
590     while (BIO_pending(rbio) || !BIO_eof(rbio)) {
591         inl = BIO_read(rbio, (char *)buff, bsize);
592         if (inl <= 0)
593             break;
594         if (BIO_write(wbio, (char *)buff, inl) != inl) {
595             BIO_printf(bio_err, "error writing output file\n");
596             goto end;
597         }
598     }
599     if (!BIO_flush(wbio)) {
600         BIO_printf(bio_err, "bad decrypt\n");
601         goto end;
602     }
603 
604     ret = 0;
605     if (verbose) {
606         BIO_printf(bio_err, "bytes read   : %8ju\n", BIO_number_read(in));
607         BIO_printf(bio_err, "bytes written: %8ju\n", BIO_number_written(out));
608     }
609  end:
610     ERR_print_errors(bio_err);
611     OPENSSL_free(strbuf);
612     OPENSSL_free(buff);
613     BIO_free(in);
614     BIO_free_all(out);
615     BIO_free(benc);
616     BIO_free(b64);
617 #ifdef ZLIB
618     BIO_free(bzl);
619 #endif
620     release_engine(e);
621     OPENSSL_free(pass);
622     return ret;
623 }
624 
625 static void show_ciphers(const OBJ_NAME *name, void *arg)
626 {
627     struct doall_enc_ciphers *dec = (struct doall_enc_ciphers *)arg;
628     const EVP_CIPHER *cipher;
629 
630     if (!islower((unsigned char)*name->name))
631         return;
632 
633     /* Filter out ciphers that we cannot use */
634     cipher = EVP_get_cipherbyname(name->name);
635     if (cipher == NULL ||
636             (EVP_CIPHER_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) != 0 ||
637             EVP_CIPHER_mode(cipher) == EVP_CIPH_XTS_MODE)
638         return;
639 
640     BIO_printf(dec->bio, "-%-25s", name->name);
641     if (++dec->n == 3) {
642         BIO_printf(dec->bio, "\n");
643         dec->n = 0;
644     } else
645         BIO_printf(dec->bio, " ");
646 }
647 
648 static int set_hex(const char *in, unsigned char *out, int size)
649 {
650     int i, n;
651     unsigned char j;
652 
653     i = size * 2;
654     n = strlen(in);
655     if (n > i) {
656         BIO_printf(bio_err, "hex string is too long, ignoring excess\n");
657         n = i; /* ignore exceeding part */
658     } else if (n < i) {
659         BIO_printf(bio_err, "hex string is too short, padding with zero bytes to length\n");
660     }
661 
662     memset(out, 0, size);
663     for (i = 0; i < n; i++) {
664         j = (unsigned char)*in++;
665         if (!isxdigit(j)) {
666             BIO_printf(bio_err, "non-hex digit\n");
667             return 0;
668         }
669         j = (unsigned char)OPENSSL_hexchar2int(j);
670         if (i & 1)
671             out[i / 2] |= j;
672         else
673             out[i / 2] = (j << 4);
674     }
675     return 1;
676 }
677