Lev Walkin | cfc16d3 | 2017-08-30 19:15:08 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2017 Lev Walkin <vlm@lionet.info>. |
| 3 | * All rights reserved. |
| 4 | * Redistribution and modifications are permitted subject to BSD license. |
| 5 | */ |
| 6 | #ifndef ASN_DISABLE_OER_SUPPORT |
| 7 | |
| 8 | #include <asn_internal.h> |
| 9 | #include <BIT_STRING.h> |
| 10 | #include <errno.h> |
| 11 | |
| 12 | asn_dec_rval_t |
Lev Walkin | afbf2a9 | 2017-09-12 23:30:27 -0700 | [diff] [blame] | 13 | BIT_STRING_decode_oer(const asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td, |
Lev Walkin | cfc16d3 | 2017-08-30 19:15:08 -0700 | [diff] [blame] | 14 | const asn_oer_constraints_t *constraints, void **sptr, |
| 15 | const void *ptr, size_t size) { |
| 16 | BIT_STRING_t *st = (BIT_STRING_t *)*sptr; |
| 17 | const asn_oer_constraints_t *cts = |
Lev Walkin | a5972be | 2017-09-29 23:15:58 -0700 | [diff] [blame] | 18 | constraints ? constraints : td->encoding_constraints.oer_constraints; |
Lev Walkin | cfc16d3 | 2017-08-30 19:15:08 -0700 | [diff] [blame] | 19 | ssize_t ct_size = cts ? cts->size : -1; |
| 20 | asn_dec_rval_t rval = {RC_OK, 0}; |
| 21 | size_t expected_length = 0; |
| 22 | |
| 23 | (void)opt_codec_ctx; |
| 24 | |
| 25 | if(!st) { |
| 26 | st = (BIT_STRING_t *)(*sptr = CALLOC(1, sizeof(*st))); |
| 27 | if(!st) ASN__DECODE_FAILED; |
| 28 | } |
| 29 | |
| 30 | if(ct_size >= 0) { |
| 31 | expected_length = (ct_size + 7) >> 3; |
| 32 | st->bits_unused = (8 - (ct_size & 7)) & 7; |
| 33 | } else { |
| 34 | /* |
| 35 | * X.696 (08/2015) #13.3.1 |
| 36 | * Encode length determinant as _number of octets_, but only |
| 37 | * if upper bound is not equal to lower bound. |
| 38 | */ |
| 39 | ssize_t len_len = oer_fetch_length(ptr, size, &expected_length); |
| 40 | if(len_len > 0) { |
| 41 | ptr = (const char *)ptr + len_len; |
| 42 | size -= len_len; |
| 43 | } else if(len_len == 0) { |
| 44 | ASN__DECODE_STARVED; |
| 45 | } else if(len_len < 0) { |
| 46 | ASN__DECODE_FAILED; |
| 47 | } |
| 48 | |
| 49 | if(expected_length < 1) { |
Lev Walkin | a5b0288 | 2017-10-01 22:48:44 -0700 | [diff] [blame] | 50 | ASN__DECODE_FAILED; |
| 51 | } else if(expected_length > size) { |
Lev Walkin | cfc16d3 | 2017-08-30 19:15:08 -0700 | [diff] [blame] | 52 | ASN__DECODE_STARVED; |
| 53 | } |
| 54 | |
| 55 | st->bits_unused = ((const uint8_t *)ptr)[0]; |
| 56 | if(st->bits_unused & ~7) { |
| 57 | ASN_DEBUG("%s: unused bits outside of 0..7 range", td->name); |
| 58 | ASN__DECODE_FAILED; |
| 59 | } |
| 60 | ptr = (const char *)ptr + 1; |
| 61 | size--; |
| 62 | expected_length--; |
| 63 | rval.consumed = len_len + 1; |
| 64 | } |
| 65 | |
| 66 | if(size < expected_length) { |
| 67 | ASN__DECODE_STARVED; |
| 68 | } else { |
| 69 | uint8_t *buf = MALLOC(expected_length + 1); |
| 70 | if(buf == NULL) { |
| 71 | ASN__DECODE_FAILED; |
| 72 | } else { |
| 73 | memcpy(buf, ptr, expected_length); |
| 74 | buf[expected_length] = '\0'; |
| 75 | } |
| 76 | FREEMEM(st->buf); |
| 77 | st->buf = buf; |
| 78 | st->size = expected_length; |
| 79 | if(expected_length > 0) { |
| 80 | buf[expected_length - 1] &= (0xff << st->bits_unused); |
| 81 | } |
| 82 | |
| 83 | rval.consumed += expected_length; |
| 84 | return rval; |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | /* |
| 89 | * Encode as Canonical OER. |
| 90 | */ |
| 91 | asn_enc_rval_t |
| 92 | BIT_STRING_encode_oer(asn_TYPE_descriptor_t *td, |
| 93 | const asn_oer_constraints_t *constraints, void *sptr, |
| 94 | asn_app_consume_bytes_f *cb, void *app_key) { |
Lev Walkin | fc89b9d | 2017-08-31 00:54:38 -0700 | [diff] [blame] | 95 | BIT_STRING_t *st = (BIT_STRING_t *)sptr; |
| 96 | asn_enc_rval_t erval = {0, 0, 0}; |
| 97 | const asn_oer_constraints_t *cts = |
Lev Walkin | a5972be | 2017-09-29 23:15:58 -0700 | [diff] [blame] | 98 | constraints ? constraints : td->encoding_constraints.oer_constraints; |
Lev Walkin | fc89b9d | 2017-08-31 00:54:38 -0700 | [diff] [blame] | 99 | ssize_t ct_size = cts ? cts->size : -1; |
Lev Walkin | fc89b9d | 2017-08-31 00:54:38 -0700 | [diff] [blame] | 100 | size_t trailing_zeros = 0; |
| 101 | int fix_last_byte = 0; |
| 102 | |
| 103 | if(!st) ASN__ENCODE_FAILED; |
| 104 | |
| 105 | if(st->bits_unused & ~7) { |
| 106 | ASN_DEBUG("BIT STRING unused bits %d out of 0..7 range", |
| 107 | st->bits_unused); |
| 108 | ASN__ENCODE_FAILED; |
| 109 | } |
| 110 | if(st->bits_unused && !(st->size && st->buf)) { |
| 111 | ASN_DEBUG("BIT STRING %s size 0 can't support unused bits %d", td->name, |
| 112 | st->bits_unused); |
| 113 | ASN__ENCODE_FAILED; |
| 114 | } |
| 115 | |
| 116 | if(ct_size >= 0) { |
| 117 | size_t ct_bytes = (ct_size + 7) >> 3; |
| 118 | if(st->size > ct_bytes) { |
| 119 | ASN_DEBUG("More bits in BIT STRING %s (%zd) than constrained %zd", |
| 120 | td->name, 8 * st->size - st->bits_unused, ct_size); |
| 121 | ASN__ENCODE_FAILED; |
| 122 | } |
| 123 | trailing_zeros = ct_bytes - st->size; /* Allow larger constraint */ |
| 124 | } else { |
| 125 | uint8_t ub = st->bits_unused & 7; |
Lev Walkin | 71191ba | 2017-08-31 01:00:00 -0700 | [diff] [blame] | 126 | ssize_t len_len = oer_serialize_length(1 + st->size, cb, app_key); |
Lev Walkin | fc89b9d | 2017-08-31 00:54:38 -0700 | [diff] [blame] | 127 | if(len_len < 0) ASN__ENCODE_FAILED; |
| 128 | if(cb(&ub, 1, app_key) < 0) { |
| 129 | ASN__ENCODE_FAILED; |
| 130 | } |
| 131 | erval.encoded += len_len + 1; |
| 132 | } |
| 133 | |
| 134 | if(st->bits_unused) { |
| 135 | if(st->buf[st->size - 1] & (0xff << st->bits_unused)) { |
| 136 | fix_last_byte = 1; |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | if(cb(st->buf, st->size - fix_last_byte, app_key) < 0) { |
| 141 | ASN__ENCODE_FAILED; |
| 142 | } |
| 143 | |
| 144 | if(fix_last_byte) { |
| 145 | uint8_t b = st->buf[st->size - 1] & (0xff << st->bits_unused); |
| 146 | if(cb(&b, 1, app_key) < 0) { |
| 147 | ASN__ENCODE_FAILED; |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | erval.encoded += st->size; |
| 152 | |
| 153 | if(trailing_zeros) { |
| 154 | static uint8_t zeros[16]; |
| 155 | while(trailing_zeros > 0) { |
| 156 | int ret; |
| 157 | if(trailing_zeros < sizeof(zeros)) { |
| 158 | ret = cb(zeros, trailing_zeros, app_key); |
| 159 | erval.encoded += trailing_zeros; |
| 160 | } else { |
| 161 | ret = cb(zeros, sizeof(zeros), app_key); |
| 162 | erval.encoded += sizeof(zeros); |
| 163 | } |
| 164 | if(ret < 0) ASN__ENCODE_FAILED; |
| 165 | } |
| 166 | } |
| 167 | |
| 168 | return erval; |
Lev Walkin | cfc16d3 | 2017-08-30 19:15:08 -0700 | [diff] [blame] | 169 | } |
| 170 | |
| 171 | |
| 172 | #endif /* ASN_DISABLE_OER_SUPPORT */ |