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APER: Fix encoding of INTEGER with lower_bound != 0 

When encoding an INTEGER, we need to subtract the lower bound before
encoding the value.  This is specified in Clause 10.5.7.x of X.691.

The decoder already does this correct, but the encoder was wrong.
This commit is contained in:
Harald Welte 2015-12-19 13:37:02 +01:00
parent a37b06d735
commit 667d758c92
1 changed files with 8 additions and 7 deletions
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15
src/INTEGER.c
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@ -972,28 +972,29 @@ INTEGER_encode_aper(asn_TYPE_descriptor_t *td,
/* X.691, #12.2.2 */
if(ct && ct->range_bits >= 0) {
/* #10.5.6 */
ASN_DEBUG("Encoding integer with range %d bits",
ct->range_bits);
ASN_DEBUG("Encoding integer %ld (%lu) with range %d bits",
value, value - ct->lower_bound, ct->range_bits);
unsigned long v = value - ct->lower_bound;
/* #12 <= 8 -> alignment ? */
if (ct->range_bits < 8) {
if(per_put_few_bits(po, 0x00 | value, ct->range_bits))
if(per_put_few_bits(po, 0x00 | v, ct->range_bits))
_ASN_ENCODE_FAILED;
} else if (ct->range_bits == 8) {
if(aper_put_align(po) < 0)
_ASN_ENCODE_FAILED;
if(per_put_few_bits(po, 0x00 | value, ct->range_bits))
if(per_put_few_bits(po, 0x00 | v, ct->range_bits))
_ASN_ENCODE_FAILED;
} else if (ct->range_bits <= 16) {
// Consume the bytes to align on octet
if(aper_put_align(po) < 0)
_ASN_ENCODE_FAILED;
if(per_put_few_bits(po, 0x0000 | value,
if(per_put_few_bits(po, 0x0000 | v,
16))
_ASN_ENCODE_FAILED;
} else {
/* TODO: extend to >64 bits */
int64_t v = value;
int64_t v64 = v;
int i;
/* Putting length - 1 in the minimum number of bits ex: 5 = 3bits */
@ -1005,7 +1006,7 @@ INTEGER_encode_aper(asn_TYPE_descriptor_t *td,
_ASN_ENCODE_FAILED;
/* Put the value */
for (i = 0; i < st->size; i++) {
if(per_put_few_bits(po, (v >> (8 * (st->size - i - 1))) & 0xff, 8)) _ASN_ENCODE_FAILED;
if(per_put_few_bits(po, (v64 >> (8 * (st->size - i - 1))) & 0xff, 8)) _ASN_ENCODE_FAILED;
}
}
_ASN_ENCODED_OK(er);