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/*
* Copyright (c) 2005, 2006, 2007 Lev Walkin <vlm@lionet.info>.
* All rights reserved.
* Redistribution and modifications are permitted subject to BSD license.
*/
#include <asn_system.h>
#include <asn_internal.h>
#include <per_support.h>
char *
per_data_string(asn_per_data_t *pd) {
static char buf[2][32];
static int n;
n = (n+1) % 2;
snprintf(buf[n], sizeof(buf),
"{m=%d span %+d[%d..%d] (%d)}",
pd->moved,
(((int)pd->buffer) & 0xf),
pd->nboff, pd->nbits,
pd->nbits - pd->nboff);
return buf[n];
}
void
per_get_undo(asn_per_data_t *pd, int nbits) {
if((ssize_t)pd->nboff < nbits) {
assert((ssize_t)pd->nboff < nbits);
} else {
pd->nboff -= nbits;
pd->moved -= nbits;
}
}
/*
* Extract a small number of bits (<= 31) from the specified PER data pointer.
*/
int32_t
per_get_few_bits(asn_per_data_t *pd, int nbits) {
size_t off; /* Next after last bit offset */
ssize_t nleft; /* Number of bits left in this stream */
uint32_t accum;
const uint8_t *buf;
if(nbits < 0)
return -1;
nleft = pd->nbits - pd->nboff;
if(nbits > nleft) {
int32_t tailv, vhead;
if(!pd->refill || nbits > 31) return -1;
/* Accumulate unused bytes before refill */
ASN_DEBUG("Obtain the rest %d bits (want %d)", nleft, nbits);
tailv = per_get_few_bits(pd, nleft);
if(tailv < 0) return -1;
/* Refill (replace pd contents with new data) */
if(pd->refill(pd))
return -1;
nbits -= nleft;
vhead = per_get_few_bits(pd, nbits);
/* Combine the rest of previous pd with the head of new one */
tailv = (tailv << nbits) | vhead; /* Could == -1 */
return tailv;
}
/*
* Normalize position indicator.
*/
if(pd->nboff >= 8) {
pd->buffer += (pd->nboff >> 3);
pd->nbits -= (pd->nboff & ~0x07);
pd->nboff &= 0x07;
}
pd->moved += nbits;
pd->nboff += nbits;
off = pd->nboff;
buf = pd->buffer;
/*
* Extract specified number of bits.
*/
if(off <= 8)
accum = nbits ? (buf[0]) >> (8 - off) : 0;
else if(off <= 16)
accum = ((buf[0] << 8) + buf[1]) >> (16 - off);
else if(off <= 24)
accum = ((buf[0] << 16) + (buf[1] << 8) + buf[2]) >> (24 - off);
else if(off <= 31)
accum = ((buf[0] << 24) + (buf[1] << 16)
+ (buf[2] << 8) + (buf[3])) >> (32 - off);
else if(nbits <= 31) {
asn_per_data_t tpd = *pd;
/* Here are we with our 31-bits limit plus 1..7 bits offset. */
per_get_undo(&tpd, nbits);
/* The number of available bits in the stream allow
* for the following operations to take place without
* invoking the ->refill() function */
accum = per_get_few_bits(&tpd, nbits - 24) << 24;
accum |= per_get_few_bits(&tpd, 24);
} else {
per_get_undo(pd, nbits);
return -1;
}
accum &= (((uint32_t)1 << nbits) - 1);
ASN_DEBUG(" [PER got %2d<=%2d bits => span %d %+d[%d..%d]:%02x (%d) => 0x%x]",
nbits, nleft,
pd->moved,
(((int)pd->buffer) & 0xf),
pd->nboff, pd->nbits,
pd->buffer[0],
pd->nbits - pd->nboff,
(int)accum);
return accum;
}
/*
* Extract a large number of bits from the specified PER data pointer.
*/
int
per_get_many_bits(asn_per_data_t *pd, uint8_t *dst, int alright, int nbits) {
int32_t value;
if(alright && (nbits & 7)) {
/* Perform right alignment of a first few bits */
value = per_get_few_bits(pd, nbits & 0x07);
if(value < 0) return -1;
*dst++ = value; /* value is already right-aligned */
nbits &= ~7;
}
while(nbits) {
if(nbits >= 24) {
value = per_get_few_bits(pd, 24);
if(value < 0) return -1;
*(dst++) = value >> 16;
*(dst++) = value >> 8;
*(dst++) = value;
nbits -= 24;
} else {
value = per_get_few_bits(pd, nbits);
if(value < 0) return -1;
if(nbits & 7) { /* implies left alignment */
value <<= 8 - (nbits & 7),
nbits += 8 - (nbits & 7);
if(nbits > 24)
*dst++ = value >> 24;
}
if(nbits > 16)
*dst++ = value >> 16;
if(nbits > 8)
*dst++ = value >> 8;
*dst++ = value;
break;
}
}
return 0;
}
/*
* Get the length "n" from the stream.
*/
ssize_t
uper_get_length(asn_per_data_t *pd, int ebits, int *repeat) {
ssize_t value;
*repeat = 0;
if(ebits >= 0) return per_get_few_bits(pd, ebits);
value = per_get_few_bits(pd, 8);
if(value < 0) return -1;
if((value & 128) == 0) /* #10.9.3.6 */
return (value & 0x7F);
if((value & 64) == 0) { /* #10.9.3.7 */
value = ((value & 63) << 8) | per_get_few_bits(pd, 8);
if(value < 0) return -1;
return value;
}
value &= 63; /* this is "m" from X.691, #10.9.3.8 */
if(value < 1 || value > 4)
return -1;
*repeat = 1;
return (16384 * value);
}
/*
* Get the normally small length "n".
* This procedure used to decode length of extensions bit-maps
* for SET and SEQUENCE types.
*/
ssize_t
uper_get_nslength(asn_per_data_t *pd) {
ssize_t length;
ASN_DEBUG("Getting normally small length");
if(per_get_few_bits(pd, 1) == 0) {
length = per_get_few_bits(pd, 6) + 1;
if(length <= 0) return -1;
ASN_DEBUG("l=%d", length);
return length;
} else {
int repeat;
length = uper_get_length(pd, -1, &repeat);
if(length >= 0 && !repeat) return length;
return -1; /* Error, or do not support >16K extensions */
}
}
/*
* Get the normally small non-negative whole number.
* X.691, #10.6
*/
ssize_t
uper_get_nsnnwn(asn_per_data_t *pd) {
ssize_t value;
value = per_get_few_bits(pd, 7);
if(value & 64) { /* implicit (value < 0) */
value &= 63;
value <<= 2;
value |= per_get_few_bits(pd, 2);
if(value & 128) /* implicit (value < 0) */
return -1;
if(value == 0)
return 0;
if(value >= 3)
return -1;
value = per_get_few_bits(pd, 8 * value);
return value;
}
return value;
}
/*
* Put the normally small non-negative whole number.
* X.691, #10.6
*/
int
uper_put_nsnnwn(asn_per_outp_t *po, int n) {
int bytes;
if(n <= 63) {
if(n < 0) return -1;
return per_put_few_bits(po, n, 7);
}
if(n < 256)
bytes = 1;
else if(n < 65536)
bytes = 2;
else if(n < 256 * 65536)
bytes = 3;
else
return -1; /* This is not a "normally small" value */
if(per_put_few_bits(po, bytes, 8))
return -1;
return per_put_few_bits(po, n, 8 * bytes);
}
/*
* Put a small number of bits (<= 31).
*/
int
per_put_few_bits(asn_per_outp_t *po, uint32_t bits, int obits) {
size_t off; /* Next after last bit offset */
size_t omsk; /* Existing last byte meaningful bits mask */
uint8_t *buf;
if(obits <= 0 || obits >= 32) return obits ? -1 : 0;
ASN_DEBUG("[PER put %d bits %x to %p+%d bits]",
obits, (int)bits, po->buffer, po->nboff);
/*
* Normalize position indicator.
*/
if(po->nboff >= 8) {
po->buffer += (po->nboff >> 3);
po->nbits -= (po->nboff & ~0x07);
po->nboff &= 0x07;
}
/*
* Flush whole-bytes output, if necessary.
*/
if(po->nboff + obits > po->nbits) {
int complete_bytes = (po->buffer - po->tmpspace);
ASN_DEBUG("[PER output %d complete + %d]",
complete_bytes, po->flushed_bytes);
if(po->outper(po->tmpspace, complete_bytes, po->op_key) < 0)
return -1;
if(po->nboff)
po->tmpspace[0] = po->buffer[0];
po->buffer = po->tmpspace;
po->nbits = 8 * sizeof(po->tmpspace);
po->flushed_bytes += complete_bytes;
}
/*
* Now, due to sizeof(tmpspace), we are guaranteed large enough space.
*/
buf = po->buffer;
omsk = ~((1 << (8 - po->nboff)) - 1);
off = (po->nboff += obits);
/* Clear data of debris before meaningful bits */
bits &= (((uint32_t)1 << obits) - 1);
ASN_DEBUG("[PER out %d %u/%x (t=%d,o=%d) %x&%x=%x]", obits,
(int)bits, (int)bits,
po->nboff - obits, off, buf[0], omsk&0xff, buf[0] & omsk);
if(off <= 8) /* Completely within 1 byte */
bits <<= (8 - off),
buf[0] = (buf[0] & omsk) | bits;
else if(off <= 16)
bits <<= (16 - off),
buf[0] = (buf[0] & omsk) | (bits >> 8),
buf[1] = bits;
else if(off <= 24)
bits <<= (24 - off),
buf[0] = (buf[0] & omsk) | (bits >> 16),
buf[1] = bits >> 8,
buf[2] = bits;
else if(off <= 31)
bits <<= (32 - off),
buf[0] = (buf[0] & omsk) | (bits >> 24),
buf[1] = bits >> 16,
buf[2] = bits >> 8,
buf[3] = bits;
else {
ASN_DEBUG("->[PER out split %d]", obits);
per_put_few_bits(po, bits >> 8, 24);
per_put_few_bits(po, bits, obits - 24);
ASN_DEBUG("<-[PER out split %d]", obits);
}
ASN_DEBUG("[PER out %u/%x => %02x buf+%d]",
(int)bits, (int)bits, buf[0], po->buffer - po->tmpspace);
return 0;
}
/*
* Output a large number of bits.
*/
int
per_put_many_bits(asn_per_outp_t *po, const uint8_t *src, int nbits) {
while(nbits) {
uint32_t value;
if(nbits >= 24) {
value = (src[0] << 16) | (src[1] << 8) | src[2];
src += 3;
nbits -= 24;
if(per_put_few_bits(po, value, 24))
return -1;
} else {
value = src[0];
if(nbits > 8)
value = (value << 8) | src[1];
if(nbits > 16)
value = (value << 8) | src[2];
if(nbits & 0x07)
value >>= (8 - (nbits & 0x07));
if(per_put_few_bits(po, value, nbits))
return -1;
break;
}
}
return 0;
}
/*
* Put the length "n" (or part of it) into the stream.
*/
ssize_t
uper_put_length(asn_per_outp_t *po, size_t length) {
if(length <= 127) /* #10.9.3.6 */
return per_put_few_bits(po, length, 8)
? -1 : (ssize_t)length;
else if(length < 16384) /* #10.9.3.7 */
return per_put_few_bits(po, length|0x8000, 16)
? -1 : (ssize_t)length;
length >>= 14;
if(length > 4) length = 4;
return per_put_few_bits(po, 0xC0 | length, 8)
? -1 : (ssize_t)(length << 14);
}
/*
* Put the normally small length "n" into the stream.
* This procedure used to encode length of extensions bit-maps
* for SET and SEQUENCE types.
*/
int
uper_put_nslength(asn_per_outp_t *po, size_t length) {
if(length <= 64) {
/* #10.9.3.4 */
if(length == 0) return -1;
return per_put_few_bits(po, length-1, 7) ? -1 : 0;
} else {
if(uper_put_length(po, length) != (ssize_t)length) {
/* This might happen in case of >16K extensions */
return -1;
}
}
return 0;
}
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