1/*
2 * Copyright 1995-2023 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 <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#define PBKDF2_ITER_DEFAULT     10000
34#define STR(a) XSTR(a)
35#define XSTR(a) #a
36
37static int set_hex(const char *in, unsigned char *out, int size);
38static void show_ciphers(const OBJ_NAME *name, void *bio_);
39
40struct doall_enc_ciphers {
41    BIO *bio;
42    int n;
43};
44
45typedef enum OPTION_choice {
46    OPT_COMMON,
47    OPT_LIST,
48    OPT_E, OPT_IN, OPT_OUT, OPT_PASS, OPT_ENGINE, OPT_D, OPT_P, OPT_V,
49    OPT_NOPAD, OPT_SALT, OPT_NOSALT, OPT_DEBUG, OPT_UPPER_P, OPT_UPPER_A,
50    OPT_A, OPT_Z, OPT_BUFSIZE, OPT_K, OPT_KFILE, OPT_UPPER_K, OPT_NONE,
51    OPT_UPPER_S, OPT_IV, OPT_MD, OPT_ITER, OPT_PBKDF2, OPT_CIPHER,
52    OPT_R_ENUM, OPT_PROV_ENUM
53} OPTION_CHOICE;
54
55const OPTIONS enc_options[] = {
56    OPT_SECTION("General"),
57    {"help", OPT_HELP, '-', "Display this summary"},
58    {"list", OPT_LIST, '-', "List ciphers"},
59#ifndef OPENSSL_NO_DEPRECATED_3_0
60    {"ciphers", OPT_LIST, '-', "Alias for -list"},
61#endif
62    {"e", OPT_E, '-', "Encrypt"},
63    {"d", OPT_D, '-', "Decrypt"},
64    {"p", OPT_P, '-', "Print the iv/key"},
65    {"P", OPT_UPPER_P, '-', "Print the iv/key and exit"},
66#ifndef OPENSSL_NO_ENGINE
67    {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
68#endif
69
70    OPT_SECTION("Input"),
71    {"in", OPT_IN, '<', "Input file"},
72    {"k", OPT_K, 's', "Passphrase"},
73    {"kfile", OPT_KFILE, '<', "Read passphrase from file"},
74
75    OPT_SECTION("Output"),
76    {"out", OPT_OUT, '>', "Output file"},
77    {"pass", OPT_PASS, 's', "Passphrase source"},
78    {"v", OPT_V, '-', "Verbose output"},
79    {"a", OPT_A, '-', "Base64 encode/decode, depending on encryption flag"},
80    {"base64", OPT_A, '-', "Same as option -a"},
81    {"A", OPT_UPPER_A, '-',
82     "Used with -[base64|a] to specify base64 buffer as a single line"},
83
84    OPT_SECTION("Encryption"),
85    {"nopad", OPT_NOPAD, '-', "Disable standard block padding"},
86    {"salt", OPT_SALT, '-', "Use salt in the KDF (default)"},
87    {"nosalt", OPT_NOSALT, '-', "Do not use salt in the KDF"},
88    {"debug", OPT_DEBUG, '-', "Print debug info"},
89
90    {"bufsize", OPT_BUFSIZE, 's', "Buffer size"},
91    {"K", OPT_UPPER_K, 's', "Raw key, in hex"},
92    {"S", OPT_UPPER_S, 's', "Salt, in hex"},
93    {"iv", OPT_IV, 's', "IV in hex"},
94    {"md", OPT_MD, 's', "Use specified digest to create a key from the passphrase"},
95    {"iter", OPT_ITER, 'p',
96     "Specify the iteration count and force the use of PBKDF2"},
97    {OPT_MORE_STR, 0, 0, "Default: " STR(PBKDF2_ITER_DEFAULT)},
98    {"pbkdf2", OPT_PBKDF2, '-',
99     "Use password-based key derivation function 2 (PBKDF2)"},
100    {OPT_MORE_STR, 0, 0,
101     "Use -iter to change the iteration count from " STR(PBKDF2_ITER_DEFAULT)},
102    {"none", OPT_NONE, '-', "Don't encrypt"},
103#ifdef ZLIB
104    {"z", OPT_Z, '-', "Compress or decompress encrypted data using zlib"},
105#endif
106    {"", OPT_CIPHER, '-', "Any supported cipher"},
107
108    OPT_R_OPTIONS,
109    OPT_PROV_OPTIONS,
110    {NULL}
111};
112
113int enc_main(int argc, char **argv)
114{
115    static char buf[128];
116    static const char magic[] = "Salted__";
117    ENGINE *e = NULL;
118    BIO *in = NULL, *out = NULL, *b64 = NULL, *benc = NULL, *rbio =
119        NULL, *wbio = NULL;
120    EVP_CIPHER_CTX *ctx = NULL;
121    EVP_CIPHER *cipher = NULL;
122    EVP_MD *dgst = NULL;
123    const char *digestname = NULL;
124    char *hkey = NULL, *hiv = NULL, *hsalt = NULL, *p;
125    char *infile = NULL, *outfile = NULL, *prog;
126    char *str = NULL, *passarg = NULL, *pass = NULL, *strbuf = NULL;
127    const char *ciphername = NULL;
128    char mbuf[sizeof(magic) - 1];
129    OPTION_CHOICE o;
130    int bsize = BSIZE, verbose = 0, debug = 0, olb64 = 0, nosalt = 0;
131    int enc = 1, printkey = 0, i, k;
132    int base64 = 0, informat = FORMAT_BINARY, outformat = FORMAT_BINARY;
133    int ret = 1, inl, nopad = 0;
134    unsigned char key[EVP_MAX_KEY_LENGTH], iv[EVP_MAX_IV_LENGTH];
135    unsigned char *buff = NULL, salt[PKCS5_SALT_LEN];
136    int pbkdf2 = 0;
137    int iter = 0;
138    long n;
139    struct doall_enc_ciphers dec;
140#ifdef ZLIB
141    int do_zlib = 0;
142    BIO *bzl = NULL;
143#endif
144
145    /* first check the command name */
146    if (strcmp(argv[0], "base64") == 0)
147        base64 = 1;
148#ifdef ZLIB
149    else if (strcmp(argv[0], "zlib") == 0)
150        do_zlib = 1;
151#endif
152    else if (strcmp(argv[0], "enc") != 0)
153        ciphername = argv[0];
154
155    prog = opt_init(argc, argv, enc_options);
156    while ((o = opt_next()) != OPT_EOF) {
157        switch (o) {
158        case OPT_EOF:
159        case OPT_ERR:
160 opthelp:
161            BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
162            goto end;
163        case OPT_HELP:
164            opt_help(enc_options);
165            ret = 0;
166            goto end;
167        case OPT_LIST:
168            BIO_printf(bio_out, "Supported ciphers:\n");
169            dec.bio = bio_out;
170            dec.n = 0;
171            OBJ_NAME_do_all_sorted(OBJ_NAME_TYPE_CIPHER_METH,
172                                   show_ciphers, &dec);
173            BIO_printf(bio_out, "\n");
174            ret = 0;
175            goto end;
176        case OPT_E:
177            enc = 1;
178            break;
179        case OPT_IN:
180            infile = opt_arg();
181            break;
182        case OPT_OUT:
183            outfile = opt_arg();
184            break;
185        case OPT_PASS:
186            passarg = opt_arg();
187            break;
188        case OPT_ENGINE:
189            e = setup_engine(opt_arg(), 0);
190            break;
191        case OPT_D:
192            enc = 0;
193            break;
194        case OPT_P:
195            printkey = 1;
196            break;
197        case OPT_V:
198            verbose = 1;
199            break;
200        case OPT_NOPAD:
201            nopad = 1;
202            break;
203        case OPT_SALT:
204            nosalt = 0;
205            break;
206        case OPT_NOSALT:
207            nosalt = 1;
208            break;
209        case OPT_DEBUG:
210            debug = 1;
211            break;
212        case OPT_UPPER_P:
213            printkey = 2;
214            break;
215        case OPT_UPPER_A:
216            olb64 = 1;
217            break;
218        case OPT_A:
219            base64 = 1;
220            break;
221        case OPT_Z:
222#ifdef ZLIB
223            do_zlib = 1;
224#endif
225            break;
226        case OPT_BUFSIZE:
227            p = opt_arg();
228            i = (int)strlen(p) - 1;
229            k = i >= 1 && p[i] == 'k';
230            if (k)
231                p[i] = '\0';
232            if (!opt_long(opt_arg(), &n)
233                    || n < 0 || (k && n >= LONG_MAX / 1024))
234                goto opthelp;
235            if (k)
236                n *= 1024;
237            bsize = (int)n;
238            break;
239        case OPT_K:
240            str = opt_arg();
241            break;
242        case OPT_KFILE:
243            in = bio_open_default(opt_arg(), 'r', FORMAT_TEXT);
244            if (in == NULL)
245                goto opthelp;
246            i = BIO_gets(in, buf, sizeof(buf));
247            BIO_free(in);
248            in = NULL;
249            if (i <= 0) {
250                BIO_printf(bio_err,
251                           "%s Can't read key from %s\n", prog, opt_arg());
252                goto opthelp;
253            }
254            while (--i > 0 && (buf[i] == '\r' || buf[i] == '\n'))
255                buf[i] = '\0';
256            if (i <= 0) {
257                BIO_printf(bio_err, "%s: zero length password\n", prog);
258                goto opthelp;
259            }
260            str = buf;
261            break;
262        case OPT_UPPER_K:
263            hkey = opt_arg();
264            break;
265        case OPT_UPPER_S:
266            hsalt = opt_arg();
267            break;
268        case OPT_IV:
269            hiv = opt_arg();
270            break;
271        case OPT_MD:
272            digestname = opt_arg();
273            break;
274        case OPT_CIPHER:
275            ciphername = opt_unknown();
276            break;
277        case OPT_ITER:
278            iter = opt_int_arg();
279            pbkdf2 = 1;
280            break;
281        case OPT_PBKDF2:
282            pbkdf2 = 1;
283            if (iter == 0)    /* do not overwrite a chosen value */
284                iter = PBKDF2_ITER_DEFAULT;
285            break;
286        case OPT_NONE:
287            cipher = NULL;
288            break;
289        case OPT_R_CASES:
290            if (!opt_rand(o))
291                goto end;
292            break;
293        case OPT_PROV_CASES:
294            if (!opt_provider(o))
295                goto end;
296            break;
297        }
298    }
299
300    /* No extra arguments. */
301    argc = opt_num_rest();
302    if (argc != 0)
303        goto opthelp;
304    if (!app_RAND_load())
305        goto end;
306
307    /* Get the cipher name, either from progname (if set) or flag. */
308    if (ciphername != NULL) {
309        if (!opt_cipher(ciphername, &cipher))
310            goto opthelp;
311    }
312    if (digestname != NULL) {
313        if (!opt_md(digestname, &dgst))
314            goto opthelp;
315    }
316    if (dgst == NULL)
317        dgst = (EVP_MD *)EVP_sha256();
318
319    if (iter == 0)
320        iter = 1;
321
322    /* It must be large enough for a base64 encoded line */
323    if (base64 && bsize < 80)
324        bsize = 80;
325    if (verbose)
326        BIO_printf(bio_err, "bufsize=%d\n", bsize);
327
328#ifdef ZLIB
329    if (!do_zlib)
330#endif
331        if (base64) {
332            if (enc)
333                outformat = FORMAT_BASE64;
334            else
335                informat = FORMAT_BASE64;
336        }
337
338    strbuf = app_malloc(SIZE, "strbuf");
339    buff = app_malloc(EVP_ENCODE_LENGTH(bsize), "evp buffer");
340
341    if (infile == NULL) {
342        in = dup_bio_in(informat);
343    } else {
344        in = bio_open_default(infile, 'r', informat);
345    }
346    if (in == NULL)
347        goto end;
348
349    if (str == NULL && passarg != NULL) {
350        if (!app_passwd(passarg, NULL, &pass, NULL)) {
351            BIO_printf(bio_err, "Error getting password\n");
352            goto end;
353        }
354        str = pass;
355    }
356
357    if ((str == NULL) && (cipher != NULL) && (hkey == NULL)) {
358        if (1) {
359#ifndef OPENSSL_NO_UI_CONSOLE
360            for (;;) {
361                char prompt[200];
362
363                BIO_snprintf(prompt, sizeof(prompt), "enter %s %s password:",
364                        EVP_CIPHER_get0_name(cipher),
365                        (enc) ? "encryption" : "decryption");
366                strbuf[0] = '\0';
367                i = EVP_read_pw_string((char *)strbuf, SIZE, prompt, enc);
368                if (i == 0) {
369                    if (strbuf[0] == '\0') {
370                        ret = 1;
371                        goto end;
372                    }
373                    str = strbuf;
374                    break;
375                }
376                if (i < 0) {
377                    BIO_printf(bio_err, "bad password read\n");
378                    goto end;
379                }
380            }
381        } else {
382#endif
383            BIO_printf(bio_err, "password required\n");
384            goto end;
385        }
386    }
387
388    out = bio_open_default(outfile, 'w', outformat);
389    if (out == NULL)
390        goto end;
391
392    if (debug) {
393        BIO_set_callback_ex(in, BIO_debug_callback_ex);
394        BIO_set_callback_ex(out, BIO_debug_callback_ex);
395        BIO_set_callback_arg(in, (char *)bio_err);
396        BIO_set_callback_arg(out, (char *)bio_err);
397    }
398
399    rbio = in;
400    wbio = out;
401
402#ifdef ZLIB
403    if (do_zlib) {
404        if ((bzl = BIO_new(BIO_f_zlib())) == NULL)
405            goto end;
406        if (debug) {
407            BIO_set_callback_ex(bzl, BIO_debug_callback_ex);
408            BIO_set_callback_arg(bzl, (char *)bio_err);
409        }
410        if (enc)
411            wbio = BIO_push(bzl, wbio);
412        else
413            rbio = BIO_push(bzl, rbio);
414    }
415#endif
416
417    if (base64) {
418        if ((b64 = BIO_new(BIO_f_base64())) == NULL)
419            goto end;
420        if (debug) {
421            BIO_set_callback_ex(b64, BIO_debug_callback_ex);
422            BIO_set_callback_arg(b64, (char *)bio_err);
423        }
424        if (olb64)
425            BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
426        if (enc)
427            wbio = BIO_push(b64, wbio);
428        else
429            rbio = BIO_push(b64, rbio);
430    }
431
432    if (cipher != NULL) {
433        if (str != NULL) { /* a passphrase is available */
434            /*
435             * Salt handling: if encrypting generate a salt if not supplied,
436             * and write to output BIO. If decrypting use salt from input BIO
437             * if not given with args
438             */
439            unsigned char *sptr;
440            size_t str_len = strlen(str);
441
442            if (nosalt) {
443                sptr = NULL;
444            } else {
445                if (hsalt != NULL && !set_hex(hsalt, salt, sizeof(salt))) {
446                    BIO_printf(bio_err, "invalid hex salt value\n");
447                    goto end;
448                }
449                if (enc) {  /* encryption */
450                    if (hsalt == NULL) {
451                        if (RAND_bytes(salt, sizeof(salt)) <= 0) {
452                            BIO_printf(bio_err, "RAND_bytes failed\n");
453                            goto end;
454                        }
455                        /*
456                         * If -P option then don't bother writing.
457                         * If salt is given, shouldn't either ?
458                         */
459                        if ((printkey != 2)
460                            && (BIO_write(wbio, magic,
461                                          sizeof(magic) - 1) != sizeof(magic) - 1
462                                || BIO_write(wbio,
463                                             (char *)salt,
464                                             sizeof(salt)) != sizeof(salt))) {
465                            BIO_printf(bio_err, "error writing output file\n");
466                            goto end;
467                        }
468                    }
469                } else {    /* decryption */
470                    if (hsalt == NULL) {
471                        if (BIO_read(rbio, mbuf, sizeof(mbuf)) != sizeof(mbuf)) {
472                            BIO_printf(bio_err, "error reading input file\n");
473                            goto end;
474                        }
475                        if (memcmp(mbuf, magic, sizeof(mbuf)) == 0) { /* file IS salted */
476                            if (BIO_read(rbio, salt,
477                                         sizeof(salt)) != sizeof(salt)) {
478                                BIO_printf(bio_err, "error reading input file\n");
479                                goto end;
480                            }
481                        } else { /* file is NOT salted, NO salt available */
482                            BIO_printf(bio_err, "bad magic number\n");
483                            goto end;
484                        }
485                    }
486                }
487                sptr = salt;
488            }
489
490            if (pbkdf2 == 1) {
491                /*
492                * derive key and default iv
493                * concatenated into a temporary buffer
494                */
495                unsigned char tmpkeyiv[EVP_MAX_KEY_LENGTH + EVP_MAX_IV_LENGTH];
496                int iklen = EVP_CIPHER_get_key_length(cipher);
497                int ivlen = EVP_CIPHER_get_iv_length(cipher);
498                /* not needed if HASH_UPDATE() is fixed : */
499                int islen = (sptr != NULL ? sizeof(salt) : 0);
500                if (!PKCS5_PBKDF2_HMAC(str, str_len, sptr, islen,
501                                       iter, dgst, iklen+ivlen, tmpkeyiv)) {
502                    BIO_printf(bio_err, "PKCS5_PBKDF2_HMAC failed\n");
503                    goto end;
504                }
505                /* split and move data back to global buffer */
506                memcpy(key, tmpkeyiv, iklen);
507                memcpy(iv, tmpkeyiv+iklen, ivlen);
508            } else {
509                BIO_printf(bio_err, "*** WARNING : "
510                                    "deprecated key derivation used.\n"
511                                    "Using -iter or -pbkdf2 would be better.\n");
512                if (!EVP_BytesToKey(cipher, dgst, sptr,
513                                    (unsigned char *)str, str_len,
514                                    1, key, iv)) {
515                    BIO_printf(bio_err, "EVP_BytesToKey failed\n");
516                    goto end;
517                }
518            }
519            /*
520             * zero the complete buffer or the string passed from the command
521             * line.
522             */
523            if (str == strbuf)
524                OPENSSL_cleanse(str, SIZE);
525            else
526                OPENSSL_cleanse(str, str_len);
527        }
528        if (hiv != NULL) {
529            int siz = EVP_CIPHER_get_iv_length(cipher);
530            if (siz == 0) {
531                BIO_printf(bio_err, "warning: iv not used by this cipher\n");
532            } else if (!set_hex(hiv, iv, siz)) {
533                BIO_printf(bio_err, "invalid hex iv value\n");
534                goto end;
535            }
536        }
537        if ((hiv == NULL) && (str == NULL)
538            && EVP_CIPHER_get_iv_length(cipher) != 0) {
539            /*
540             * No IV was explicitly set and no IV was generated.
541             * Hence the IV is undefined, making correct decryption impossible.
542             */
543            BIO_printf(bio_err, "iv undefined\n");
544            goto end;
545        }
546        if (hkey != NULL) {
547            if (!set_hex(hkey, key, EVP_CIPHER_get_key_length(cipher))) {
548                BIO_printf(bio_err, "invalid hex key value\n");
549                goto end;
550            }
551            /* wiping secret data as we no longer need it */
552            cleanse(hkey);
553        }
554
555        if ((benc = BIO_new(BIO_f_cipher())) == NULL)
556            goto end;
557
558        /*
559         * Since we may be changing parameters work on the encryption context
560         * rather than calling BIO_set_cipher().
561         */
562
563        BIO_get_cipher_ctx(benc, &ctx);
564
565        if (!EVP_CipherInit_ex(ctx, cipher, e, NULL, NULL, enc)) {
566            BIO_printf(bio_err, "Error setting cipher %s\n",
567                       EVP_CIPHER_get0_name(cipher));
568            ERR_print_errors(bio_err);
569            goto end;
570        }
571
572        if (nopad)
573            EVP_CIPHER_CTX_set_padding(ctx, 0);
574
575        if (!EVP_CipherInit_ex(ctx, NULL, NULL, key, iv, enc)) {
576            BIO_printf(bio_err, "Error setting cipher %s\n",
577                       EVP_CIPHER_get0_name(cipher));
578            ERR_print_errors(bio_err);
579            goto end;
580        }
581
582        if (debug) {
583            BIO_set_callback_ex(benc, BIO_debug_callback_ex);
584            BIO_set_callback_arg(benc, (char *)bio_err);
585        }
586
587        if (printkey) {
588            if (!nosalt) {
589                printf("salt=");
590                for (i = 0; i < (int)sizeof(salt); i++)
591                    printf("%02X", salt[i]);
592                printf("\n");
593            }
594            if (EVP_CIPHER_get_key_length(cipher) > 0) {
595                printf("key=");
596                for (i = 0; i < EVP_CIPHER_get_key_length(cipher); i++)
597                    printf("%02X", key[i]);
598                printf("\n");
599            }
600            if (EVP_CIPHER_get_iv_length(cipher) > 0) {
601                printf("iv =");
602                for (i = 0; i < EVP_CIPHER_get_iv_length(cipher); i++)
603                    printf("%02X", iv[i]);
604                printf("\n");
605            }
606            if (printkey == 2) {
607                ret = 0;
608                goto end;
609            }
610        }
611    }
612
613    /* Only encrypt/decrypt as we write the file */
614    if (benc != NULL)
615        wbio = BIO_push(benc, wbio);
616
617    while (BIO_pending(rbio) || !BIO_eof(rbio)) {
618        inl = BIO_read(rbio, (char *)buff, bsize);
619        if (inl <= 0)
620            break;
621        if (BIO_write(wbio, (char *)buff, inl) != inl) {
622            BIO_printf(bio_err, "error writing output file\n");
623            goto end;
624        }
625    }
626    if (!BIO_flush(wbio)) {
627        if (enc)
628            BIO_printf(bio_err, "bad encrypt\n");
629        else
630            BIO_printf(bio_err, "bad decrypt\n");
631        goto end;
632    }
633
634    ret = 0;
635    if (verbose) {
636        BIO_printf(bio_err, "bytes read   : %8ju\n", BIO_number_read(in));
637        BIO_printf(bio_err, "bytes written: %8ju\n", BIO_number_written(out));
638    }
639 end:
640    ERR_print_errors(bio_err);
641    OPENSSL_free(strbuf);
642    OPENSSL_free(buff);
643    BIO_free(in);
644    BIO_free_all(out);
645    BIO_free(benc);
646    BIO_free(b64);
647    EVP_MD_free(dgst);
648    EVP_CIPHER_free(cipher);
649#ifdef ZLIB
650    BIO_free(bzl);
651#endif
652    release_engine(e);
653    OPENSSL_free(pass);
654    return ret;
655}
656
657static void show_ciphers(const OBJ_NAME *name, void *arg)
658{
659    struct doall_enc_ciphers *dec = (struct doall_enc_ciphers *)arg;
660    const EVP_CIPHER *cipher;
661
662    if (!islower((unsigned char)*name->name))
663        return;
664
665    /* Filter out ciphers that we cannot use */
666    cipher = EVP_get_cipherbyname(name->name);
667    if (cipher == NULL
668            || (EVP_CIPHER_get_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) != 0
669            || EVP_CIPHER_get_mode(cipher) == EVP_CIPH_XTS_MODE)
670        return;
671
672    BIO_printf(dec->bio, "-%-25s", name->name);
673    if (++dec->n == 3) {
674        BIO_printf(dec->bio, "\n");
675        dec->n = 0;
676    } else
677        BIO_printf(dec->bio, " ");
678}
679
680static int set_hex(const char *in, unsigned char *out, int size)
681{
682    int i, n;
683    unsigned char j;
684
685    i = size * 2;
686    n = strlen(in);
687    if (n > i) {
688        BIO_printf(bio_err, "hex string is too long, ignoring excess\n");
689        n = i; /* ignore exceeding part */
690    } else if (n < i) {
691        BIO_printf(bio_err, "hex string is too short, padding with zero bytes to length\n");
692    }
693
694    memset(out, 0, size);
695    for (i = 0; i < n; i++) {
696        j = (unsigned char)*in++;
697        if (!isxdigit(j)) {
698            BIO_printf(bio_err, "non-hex digit\n");
699            return 0;
700        }
701        j = (unsigned char)OPENSSL_hexchar2int(j);
702        if (i & 1)
703            out[i / 2] |= j;
704        else
705            out[i / 2] = (j << 4);
706    }
707    return 1;
708}
709