| // SPDX-License-Identifier: BSD-2-Clause |
| /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
| * |
| * LibTomCrypt is a library that provides various cryptographic |
| * algorithms in a highly modular and flexible manner. |
| * |
| * The library is free for all purposes without any express |
| * guarantee it works. |
| */ |
| #include "tomcrypt_private.h" |
| |
| /** |
| @file der_decode_utctime.c |
| ASN.1 DER, decode a UTCTIME, Tom St Denis |
| */ |
| |
| #ifdef LTC_DER |
| |
| static int _char_to_int(unsigned char x) |
| { |
| switch (x) { |
| case '0': return 0; |
| case '1': return 1; |
| case '2': return 2; |
| case '3': return 3; |
| case '4': return 4; |
| case '5': return 5; |
| case '6': return 6; |
| case '7': return 7; |
| case '8': return 8; |
| case '9': return 9; |
| default: return 100; |
| } |
| } |
| |
| #define DECODE_V(y, max) \ |
| y = _char_to_int(buf[x])*10 + _char_to_int(buf[x+1]); \ |
| if (y >= max) return CRYPT_INVALID_PACKET; \ |
| x += 2; |
| |
| /** |
| Decodes a UTC time structure in DER format (reads all 6 valid encoding formats) |
| @param in Input buffer |
| @param inlen Length of input buffer in octets |
| @param out [out] Destination of UTC time structure |
| @return CRYPT_OK if successful |
| */ |
| int der_decode_utctime(const unsigned char *in, unsigned long *inlen, |
| ltc_utctime *out) |
| { |
| unsigned char buf[32] = { 0 }; /* initialize as all zeroes */ |
| unsigned long x; |
| int y; |
| |
| LTC_ARGCHK(in != NULL); |
| LTC_ARGCHK(inlen != NULL); |
| LTC_ARGCHK(out != NULL); |
| |
| /* check header */ |
| if (*inlen < 2UL || (in[1] >= sizeof(buf)) || ((in[1] + 2UL) > *inlen)) { |
| return CRYPT_INVALID_PACKET; |
| } |
| |
| /* decode the string */ |
| for (x = 0; x < in[1]; x++) { |
| y = der_ia5_value_decode(in[x+2]); |
| if (y == -1) { |
| return CRYPT_INVALID_PACKET; |
| } |
| buf[x] = y; |
| } |
| *inlen = 2 + x; |
| |
| |
| /* possible encodings are |
| YYMMDDhhmmZ |
| YYMMDDhhmm+hh'mm' |
| YYMMDDhhmm-hh'mm' |
| YYMMDDhhmmssZ |
| YYMMDDhhmmss+hh'mm' |
| YYMMDDhhmmss-hh'mm' |
| |
| So let's do a trivial decode upto [including] mm |
| */ |
| |
| x = 0; |
| DECODE_V(out->YY, 100); |
| DECODE_V(out->MM, 13); |
| DECODE_V(out->DD, 32); |
| DECODE_V(out->hh, 24); |
| DECODE_V(out->mm, 60); |
| |
| /* clear timezone and seconds info */ |
| out->off_dir = out->off_hh = out->off_mm = out->ss = 0; |
| |
| /* now is it Z, +, - or 0-9 */ |
| if (buf[x] == 'Z') { |
| return CRYPT_OK; |
| } |
| if (buf[x] == '+' || buf[x] == '-') { |
| out->off_dir = (buf[x++] == '+') ? 0 : 1; |
| DECODE_V(out->off_hh, 24); |
| DECODE_V(out->off_mm, 60); |
| return CRYPT_OK; |
| } |
| |
| /* decode seconds */ |
| DECODE_V(out->ss, 60); |
| |
| /* now is it Z, +, - */ |
| if (buf[x] == 'Z') { |
| return CRYPT_OK; |
| } |
| if (buf[x] == '+' || buf[x] == '-') { |
| out->off_dir = (buf[x++] == '+') ? 0 : 1; |
| DECODE_V(out->off_hh, 24); |
| DECODE_V(out->off_mm, 60); |
| return CRYPT_OK; |
| } |
| return CRYPT_INVALID_PACKET; |
| } |
| |
| #endif |
| |
| /* ref: $Format:%D$ */ |
| /* git commit: $Format:%H$ */ |
| /* commit time: $Format:%ai$ */ |