2 * Copyright (C) 1994, Index Data I/S
4 * Sebastian Hammer, Adam Dickmeiss
7 * Revision 1.1 1995-02-02 16:21:53 quinn
17 * if p: write tag. return 1 (success) or -1 (error).
20 * if tag && class match up, advance pointer and return 1. set cons.
21 * else leave pointer unchanged. Return 0.
23 int ber_tag(ODR o, const void *p, int class, int tag, int *constructed)
25 static int lclass = -1, ltag, br, lcons; /* save t&c rather than
35 if ((rd = ber_enctag(o->bp, class, tag, *constructed, o->left))
40 fprintf(stderr, "[class=%d,tag=%d,cons=%d]", class, tag,
46 if ((br = ber_dectag(o->bp, &lclass, <ag, &lcons)) <= 0)
48 fprintf(stderr, "[class=%d,tag=%d,cons=%d]", lclass, ltag,
51 if (class == lclass && tag == ltag)
61 case ODR_PRINT: return p != 0;
67 * BER-encode a class/tag/constructed package (identifier octets). Return
68 * number of bytes encoded, or -1 if out of bounds.
70 int ber_enctag(unsigned char *buf, int class, int tag, int constructed, int len)
72 int cons = (constructed ? 1 : 0), n = 0;
73 unsigned char octs[sizeof(int)], *b = buf;
75 *b = (class << 6) & 0XC0;
76 *b |= (cons << 5) & 0X20;
87 octs[n++] = tag & 0X7F;
89 if (n >= len) /* bounds check */
94 *(b++) = octs[n] | ((n > 0) << 7);
100 * Decode BER identifier octets. Return number of bytes read or -1 for error.
102 int ber_dectag(unsigned char *buf, int *class, int *tag, int *constructed)
104 unsigned char *b = buf;
107 *constructed = (*b >> 5) & 0X01;
108 if ((*tag = *b & 0x1F) <= 30)
116 if (b - buf >= 5) /* Precaution */
119 while (*(b++) & 0X80);