Home | History | Annotate | Download | only in utctime 
      1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
      2  *
      3  * LibTomCrypt is a library that provides various cryptographic
      4  * algorithms in a highly modular and flexible manner.
      5  *
      6  * The library is free for all purposes without any express
      7  * guarantee it works.
      8  *
      9  * Tom St Denis, tomstdenis (at) gmail.com, http://libtomcrypt.com
     10  */
     11 #include "tomcrypt.h"
     12 
     13 /**
     14   @file der_encode_utctime.c
     15   ASN.1 DER, encode a  UTCTIME, Tom St Denis
     16 */
     17 
     18 #ifdef LTC_DER
     19 
     20 static const char *baseten = "0123456789";
     21 
     22 #define STORE_V(y) \
     23     out[x++] = der_ia5_char_encode(baseten[(y/10) % 10]); \
     24     out[x++] = der_ia5_char_encode(baseten[y % 10]);
     25 
     26 /**
     27   Encodes a UTC time structure in DER format
     28   @param utctime      The UTC time structure to encode
     29   @param out          The destination of the DER encoding of the UTC time structure
     30   @param outlen       [in/out] The length of the DER encoding
     31   @return CRYPT_OK if successful
     32 */
     33 int der_encode_utctime(ltc_utctime *utctime,
     34                        unsigned char *out,   unsigned long *outlen)
     35 {
     36     unsigned long x, tmplen;
     37     int           err;
     38 
     39     LTC_ARGCHK(utctime != NULL);
     40     LTC_ARGCHK(out     != NULL);
     41     LTC_ARGCHK(outlen  != NULL);
     42 
     43     if ((err = der_length_utctime(utctime, &tmplen)) != CRYPT_OK) {
     44        return err;
     45     }
     46     if (tmplen > *outlen) {
     47         *outlen = tmplen;
     48         return CRYPT_BUFFER_OVERFLOW;
     49     }
     50 
     51     /* store header */
     52     out[0] = 0x17;
     53 
     54     /* store values */
     55     x = 2;
     56     STORE_V(utctime->YY);
     57     STORE_V(utctime->MM);
     58     STORE_V(utctime->DD);
     59     STORE_V(utctime->hh);
     60     STORE_V(utctime->mm);
     61     STORE_V(utctime->ss);
     62 
     63     if (utctime->off_mm || utctime->off_hh) {
     64        out[x++] = der_ia5_char_encode(utctime->off_dir ? '-' : '+');
     65        STORE_V(utctime->off_hh);
     66        STORE_V(utctime->off_mm);
     67     } else {
     68        out[x++] = der_ia5_char_encode('Z');
     69     }
     70 
     71     /* store length */
     72     out[1] = (unsigned char)(x - 2);
     73 
     74     /* all good let's return */
     75     *outlen = x;
     76     return CRYPT_OK;
     77 }
     78 
     79 #endif
     80 
     81 /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/utctime/der_encode_utctime.c,v $ */
     82 /* $Revision: 1.9 $ */
     83 /* $Date: 2006/12/04 21:34:03 $ */
     84