diff options
Diffstat (limited to 'main.c')
| -rw-r--r-- | main.c | 29 |
1 files changed, 19 insertions, 10 deletions
@@ -50,6 +50,7 @@ static bool strtol_safe(long *, const char *); static bool totp(struct totp_config, uint32_t *); static uint32_t pow32(uint32_t, uint32_t); static bool uri_parse(struct totp_config *, const char *); +static bool big_endian(void); void usage(void) @@ -191,9 +192,9 @@ totp(struct totp_config conf, uint32_t *code) char *enc_sec; uchar *mac; time_t epoch; - size_t keylen, enc_sec_len, old; - uint8_t buf[sizeof(time_t)]; /* Enough for a 64bit num */ + uint8_t buf[sizeof(time_t)]; uint32_t binc; + size_t keylen, enc_sec_len, old; /* conf.enc_sec needs to be ‘=’ padded to a multiple of 8 */ old = enc_sec_len = strlen(conf.enc_sec); @@ -219,14 +220,12 @@ totp(struct totp_config conf, uint32_t *code) epoch /= conf.p; - buf[0] = (epoch >> 56) & 0xFF; - buf[1] = (epoch >> 48) & 0xFF; - buf[2] = (epoch >> 40) & 0xFF; - buf[3] = (epoch >> 32) & 0xFF; - buf[4] = (epoch >> 24) & 0xFF; - buf[5] = (epoch >> 16) & 0xFF; - buf[6] = (epoch >> 8) & 0xFF; - buf[7] = (epoch >> 0) & 0xFF; + if (big_endian()) + memcpy(buf, &epoch, sizeof(time_t)); + else { + for (size_t i = 0; i < sizeof(buf); i++) + buf[i] = (epoch >> (8 * (sizeof(buf) - 1 - i))) & 0xFF; + } mac = HMAC(EVP_sha1(), key, keylen, buf, sizeof(buf), NULL, NULL); if (mac == NULL) @@ -234,6 +233,7 @@ totp(struct totp_config conf, uint32_t *code) /* SHA1 hashes are 20 bytes long */ off = mac[19] & 0x0F; + printf("%d\n", off); binc = (mac[off + 0] & 0x7F) << 24 | (mac[off + 1] & 0xFF) << 16 | (mac[off + 2] & 0xFF) << 8 @@ -265,3 +265,12 @@ pow32(uint32_t x, uint32_t y) x *= n; return x; } + +bool +big_endian(void) +{ + unsigned n = 0x01020304; + uchar *ptr = (uchar *)&n; + + return *ptr == 1; +} |