1 /* 2 * Copyright (c) 2018 Thomas Pornin <pornin@bolet.org> 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining 5 * a copy of this software and associated documentation files (the 6 * "Software"), to deal in the Software without restriction, including 7 * without limitation the rights to use, copy, modify, merge, publish, 8 * distribute, sublicense, and/or sell copies of the Software, and to 9 * permit persons to whom the Software is furnished to do so, subject to 10 * the following conditions: 11 * 12 * The above copyright notice and this permission notice shall be 13 * included in all copies or substantial portions of the Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 22 * SOFTWARE. 23 */ 24 25 #include "inner.h" 26 27 /* see inner.h */ 28 br_asn1_uint 29 br_asn1_uint_prepare(const void *xdata, size_t xlen) 30 { 31 const unsigned char *x; 32 br_asn1_uint t; 33 34 x = xdata; 35 while (xlen > 0 && *x == 0) { 36 x ++; 37 xlen --; 38 } 39 t.data = x; 40 t.len = xlen; 41 t.asn1len = xlen; 42 if (xlen == 0 || x[0] >= 0x80) { 43 t.asn1len ++; 44 } 45 return t; 46 } 47 48 /* see inner.h */ 49 size_t 50 br_asn1_encode_length(void *dest, size_t len) 51 { 52 unsigned char *buf; 53 size_t z; 54 int i, j; 55 56 buf = dest; 57 if (len < 0x80) { 58 if (buf != NULL) { 59 *buf = len; 60 } 61 return 1; 62 } 63 i = 0; 64 for (z = len; z != 0; z >>= 8) { 65 i ++; 66 } 67 if (buf != NULL) { 68 *buf ++ = 0x80 + i; 69 for (j = i - 1; j >= 0; j --) { 70 *buf ++ = len >> (j << 3); 71 } 72 } 73 return i + 1; 74 } 75 76 /* see inner.h */ 77 size_t 78 br_asn1_encode_uint(void *dest, br_asn1_uint pp) 79 { 80 unsigned char *buf; 81 size_t lenlen; 82 83 if (dest == NULL) { 84 return 1 + br_asn1_encode_length(NULL, pp.asn1len) + pp.asn1len; 85 } 86 buf = dest; 87 *buf ++ = 0x02; 88 lenlen = br_asn1_encode_length(buf, pp.asn1len); 89 buf += lenlen; 90 *buf = 0x00; 91 memcpy(buf + pp.asn1len - pp.len, pp.data, pp.len); 92 return 1 + lenlen + pp.asn1len; 93 } 94