1 ecf69ddf 2022-10-20 op /*
  2 ecf69ddf 2022-10-20 op  * Copyright (c) 2022 Omar Polo <op@openbsd.org>
  3 ecf69ddf 2022-10-20 op  *
  4 ecf69ddf 2022-10-20 op  * Permission to use, copy, modify, and distribute this software for any
  5 ecf69ddf 2022-10-20 op  * purpose with or without fee is hereby granted, provided that the above
  6 ecf69ddf 2022-10-20 op  * copyright notice and this permission notice appear in all copies.
  7 ecf69ddf 2022-10-20 op  *
  8 ecf69ddf 2022-10-20 op  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  9 ecf69ddf 2022-10-20 op  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 10 ecf69ddf 2022-10-20 op  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 11 ecf69ddf 2022-10-20 op  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 12 ecf69ddf 2022-10-20 op  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 13 ecf69ddf 2022-10-20 op  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 14 ecf69ddf 2022-10-20 op  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 15 ecf69ddf 2022-10-20 op  */
 16 ecf69ddf 2022-10-20 op 
 17 ecf69ddf 2022-10-20 op #include <ctype.h>
 18 ecf69ddf 2022-10-20 op #include <err.h>
 19 ecf69ddf 2022-10-20 op #include <errno.h>
 20 ecf69ddf 2022-10-20 op #include <stdio.h>
 21 ecf69ddf 2022-10-20 op #include <stdlib.h>
 22 ecf69ddf 2022-10-20 op #include <string.h>
 23 ecf69ddf 2022-10-20 op #include <time.h>
 24 ecf69ddf 2022-10-20 op #include <unistd.h>
 25 ecf69ddf 2022-10-20 op 
 26 ecf69ddf 2022-10-20 op #include <openssl/evp.h>
 27 ecf69ddf 2022-10-20 op #include <openssl/hmac.h>
 28 ecf69ddf 2022-10-20 op 
 29 ecf69ddf 2022-10-20 op #ifndef __OpenBSD__
 30 ecf69ddf 2022-10-20 op # define pledge(a, b) (0)
 31 ecf69ddf 2022-10-20 op #endif
 32 ecf69ddf 2022-10-20 op 
 33 ecf69ddf 2022-10-20 op #ifndef __dead
 34 ecf69ddf 2022-10-20 op # define __dead __attribute__((noreturn))
 35 ecf69ddf 2022-10-20 op #endif
 36 ecf69ddf 2022-10-20 op 
 37 ecf69ddf 2022-10-20 op #if defined(__FreeBSD__)
 38 ecf69ddf 2022-10-20 op # include <sys/endian.h>
 39 ecf69ddf 2022-10-20 op #elif defined(__APPLE__)
 40 ecf69ddf 2022-10-20 op # include <machine/endian.h>
 41 ecf69ddf 2022-10-20 op # include <libkern/OSByteOrder.h>
 42 ecf69ddf 2022-10-20 op # define htobe64(x) OSSwapHostToBigInt64(x)
 43 ecf69ddf 2022-10-20 op # define be32toh(x) OSSwapBigToHostInt32(x)
 44 ecf69ddf 2022-10-20 op #else
 45 ecf69ddf 2022-10-20 op # include <endian.h>
 46 ecf69ddf 2022-10-20 op #endif
 47 ecf69ddf 2022-10-20 op 
 48 ecf69ddf 2022-10-20 op static __dead void
 49 ecf69ddf 2022-10-20 op usage(void)
 50 ecf69ddf 2022-10-20 op {
 51 ecf69ddf 2022-10-20 op 	fprintf(stderr, "usage: %s\n", getprogname());
 52 ecf69ddf 2022-10-20 op 	exit(1);
 53 ecf69ddf 2022-10-20 op }
 54 ecf69ddf 2022-10-20 op 
 55 ecf69ddf 2022-10-20 op static int
 56 ecf69ddf 2022-10-20 op b32c(unsigned char c)
 57 ecf69ddf 2022-10-20 op {
 58 ecf69ddf 2022-10-20 op 	if (c >= 'A' && c <= 'Z')
 59 ecf69ddf 2022-10-20 op 		return (c - 'A');
 60 ecf69ddf 2022-10-20 op 	if (c >= '2' && c <= '7')
 61 ecf69ddf 2022-10-20 op 		return (c - '2' + 26);
 62 ecf69ddf 2022-10-20 op 	errno = EINVAL;
 63 ecf69ddf 2022-10-20 op 	return (-1);
 64 ecf69ddf 2022-10-20 op }
 65 ecf69ddf 2022-10-20 op 
 66 ecf69ddf 2022-10-20 op static size_t
 67 cc5f172a 2022-10-25 op b32decode(const char *s, char *q, size_t qlen)
 68 ecf69ddf 2022-10-20 op {
 69 ecf69ddf 2022-10-20 op 	int	 i, val[8];
 70 ecf69ddf 2022-10-20 op 	char	*t = q;
 71 ecf69ddf 2022-10-20 op 
 72 cc5f172a 2022-10-25 op 	while (*s != '\0') {
 73 ecf69ddf 2022-10-20 op 		memset(val, 0, sizeof(val));
 74 ecf69ddf 2022-10-20 op 		for (i = 0; i < 8; ++i) {
 75 cc5f172a 2022-10-25 op 			if (*s == '\0')
 76 ecf69ddf 2022-10-20 op 				break;
 77 ecf69ddf 2022-10-20 op 			if ((val[i] = b32c(*s)) == -1)
 78 ecf69ddf 2022-10-20 op 				return (0);
 79 cc5f172a 2022-10-25 op 			s++;
 80 ecf69ddf 2022-10-20 op 		}
 81 ecf69ddf 2022-10-20 op 
 82 ecf69ddf 2022-10-20 op 		if (qlen < 5) {
 83 ecf69ddf 2022-10-20 op 			errno = ENOSPC;
 84 ecf69ddf 2022-10-20 op 			return (0);
 85 ecf69ddf 2022-10-20 op 		}
 86 ecf69ddf 2022-10-20 op 		qlen -= 5;
 87 ecf69ddf 2022-10-20 op 
 88 ecf69ddf 2022-10-20 op 		*q++ = (val[0] << 3) | (val[1] >> 2);
 89 ecf69ddf 2022-10-20 op 		*q++ = ((val[1] & 0x03) << 6) | (val[2] << 1) | (val[3] >> 4);
 90 ecf69ddf 2022-10-20 op 		*q++ = ((val[3] & 0x0F) << 4) | (val[4] >> 1);
 91 ecf69ddf 2022-10-20 op 		*q++ = ((val[4] & 0x01) << 7) | (val[5] << 2) | (val[6] >> 3);
 92 ecf69ddf 2022-10-20 op 		*q++ = ((val[6] & 0x07) << 5) | val[7];
 93 ecf69ddf 2022-10-20 op 	}
 94 ecf69ddf 2022-10-20 op 
 95 ecf69ddf 2022-10-20 op 	return (q - t);
 96 ecf69ddf 2022-10-20 op }
 97 ecf69ddf 2022-10-20 op 
 98 ecf69ddf 2022-10-20 op int
 99 ecf69ddf 2022-10-20 op main(int argc, char **argv)
100 ecf69ddf 2022-10-20 op {
101 ecf69ddf 2022-10-20 op 	char		 buf[1024];
102 ecf69ddf 2022-10-20 op 	size_t		 buflen;
103 ecf69ddf 2022-10-20 op 	unsigned char	 md[EVP_MAX_MD_SIZE];
104 ecf69ddf 2022-10-20 op 	unsigned int	 mdlen;
105 ecf69ddf 2022-10-20 op 	char		*s, *q, *line = NULL;
106 ecf69ddf 2022-10-20 op 	size_t		 linesize = 0;
107 ecf69ddf 2022-10-20 op 	ssize_t		 linelen;
108 ecf69ddf 2022-10-20 op 	uint64_t	 ct;
109 ecf69ddf 2022-10-20 op 	uint32_t	 hash;
110 ecf69ddf 2022-10-20 op 	uint8_t		 off;
111 ecf69ddf 2022-10-20 op 	int		 ch;
112 ecf69ddf 2022-10-20 op 
113 ecf69ddf 2022-10-20 op 	if (pledge("stdio", NULL) == -1)
114 ecf69ddf 2022-10-20 op 		err(1, "pledge");
115 ecf69ddf 2022-10-20 op 
116 ecf69ddf 2022-10-20 op 	while ((ch = getopt(argc, argv, "")) != -1) {
117 ecf69ddf 2022-10-20 op 		switch (ch) {
118 ecf69ddf 2022-10-20 op 		default:
119 ecf69ddf 2022-10-20 op 			usage();
120 ecf69ddf 2022-10-20 op 		}
121 ecf69ddf 2022-10-20 op 	}
122 ecf69ddf 2022-10-20 op 	argc -= optind;
123 ecf69ddf 2022-10-20 op 	argv += optind;
124 ecf69ddf 2022-10-20 op 
125 ecf69ddf 2022-10-20 op 	if (argc != 0)
126 ecf69ddf 2022-10-20 op 		usage();
127 ecf69ddf 2022-10-20 op 
128 ecf69ddf 2022-10-20 op 	linelen = getline(&line, &linesize, stdin);
129 ecf69ddf 2022-10-20 op 	if (linelen == -1) {
130 ecf69ddf 2022-10-20 op 		if (ferror(stdin))
131 ecf69ddf 2022-10-20 op 			err(1, "getline");
132 ecf69ddf 2022-10-20 op 		errx(1, "no secret provided");
133 ecf69ddf 2022-10-20 op 	}
134 ecf69ddf 2022-10-20 op 	for (s = q = line; *s != '\0'; ++s) {
135 ecf69ddf 2022-10-20 op 		if (isspace((unsigned char)*s)) {
136 ecf69ddf 2022-10-20 op 			linelen--;
137 ecf69ddf 2022-10-20 op 			continue;
138 ecf69ddf 2022-10-20 op 		}
139 ecf69ddf 2022-10-20 op 		*q++ = *s;
140 ecf69ddf 2022-10-20 op 	}
141 ecf69ddf 2022-10-20 op 	*q = '\0';
142 ecf69ddf 2022-10-20 op 	if (linelen < 1)
143 ecf69ddf 2022-10-20 op 		errx(1, "no secret provided");
144 ecf69ddf 2022-10-20 op 
145 cc5f172a 2022-10-25 op 	if ((buflen = b32decode(line, buf, sizeof(buf))) == 0)
146 ecf69ddf 2022-10-20 op 		err(1, "can't base32 decode the secret");
147 ecf69ddf 2022-10-20 op 
148 ecf69ddf 2022-10-20 op 	ct = htobe64(time(NULL) / 30);
149 ecf69ddf 2022-10-20 op 
150 ecf69ddf 2022-10-20 op 	HMAC(EVP_sha1(), buf, buflen, (unsigned char *)&ct, sizeof(ct),
151 ecf69ddf 2022-10-20 op 	    md, &mdlen);
152 ecf69ddf 2022-10-20 op 
153 ecf69ddf 2022-10-20 op 	off = md[mdlen - 1] & 0x0F;
154 ecf69ddf 2022-10-20 op 
155 ecf69ddf 2022-10-20 op 	memcpy(&hash, md + off, sizeof(hash));
156 ecf69ddf 2022-10-20 op 	hash = be32toh(hash);
157 ecf69ddf 2022-10-20 op 	printf("%06d\n", (hash & 0x7FFFFFFF) % 1000000);
158 ecf69ddf 2022-10-20 op 
159 ecf69ddf 2022-10-20 op 	free(line);
160 ecf69ddf 2022-10-20 op 	return (0);
161 ecf69ddf 2022-10-20 op }