diff options
Diffstat (limited to 'src/asn1c/per_support.c')
-rw-r--r-- | src/asn1c/per_support.c | 483 |
1 files changed, 483 insertions, 0 deletions
diff --git a/src/asn1c/per_support.c b/src/asn1c/per_support.c new file mode 100644 index 0000000..0d089f4 --- /dev/null +++ b/src/asn1c/per_support.c @@ -0,0 +1,483 @@ +/* + * Copyright (c) 2005-2014 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=%ld span %+ld[%d..%d] (%d)}", + (long)pd->moved, + (((long)pd->buffer) & 0xf), + (int)pd->nboff, (int)pd->nbits, + (int)(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)", + (int)nleft, (int)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 %+ld[%d..%d]:%02x (%d) => 0x%x]", + (int)nbits, (int)nleft, + (int)pd->moved, + (((long)pd->buffer) & 0xf), + (int)pd->nboff, (int)pd->nbits, + pd->buffer[0], + (int)(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", (int)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; +} + +/* + * X.691-11/2008, #11.6 + * Encoding of a normally small non-negative whole number + */ +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); +} + + +/* X.691-2008/11, #11.5.6 -> #11.3 */ +int uper_get_constrained_whole_number(asn_per_data_t *pd, unsigned long *out_value, int nbits) { + unsigned long lhalf; /* Lower half of the number*/ + long half; + + if(nbits <= 31) { + half = per_get_few_bits(pd, nbits); + if(half < 0) return -1; + *out_value = half; + return 0; + } + + if((size_t)nbits > 8 * sizeof(*out_value)) + return -1; /* RANGE */ + + half = per_get_few_bits(pd, 31); + if(half < 0) return -1; + + if(uper_get_constrained_whole_number(pd, &lhalf, nbits - 31)) + return -1; + + *out_value = ((unsigned long)half << (nbits - 31)) | lhalf; + return 0; +} + + +/* X.691-2008/11, #11.5.6 -> #11.3 */ +int uper_put_constrained_whole_number_s(asn_per_outp_t *po, long v, int nbits) { + /* + * Assume signed number can be safely coerced into + * unsigned of the same range. + * The following testing code will likely be optimized out + * by compiler if it is true. + */ + unsigned long uvalue1 = ULONG_MAX; + long svalue = uvalue1; + unsigned long uvalue2 = svalue; + assert(uvalue1 == uvalue2); + return uper_put_constrained_whole_number_u(po, v, nbits); +} + +int uper_put_constrained_whole_number_u(asn_per_outp_t *po, unsigned long v, int nbits) { + if(nbits <= 31) { + return per_put_few_bits(po, v, nbits); + } else { + /* Put higher portion first, followed by lower 31-bit */ + if(uper_put_constrained_whole_number_u(po, v >> 31, nbits - 31)) + return -1; + return per_put_few_bits(po, v, 31); + } +} + +/* + * 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, (int)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 %ld complete + %ld]", + (long)complete_bytes, (long)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, + (int)po->nboff, (int)off, + buf[0], (int)(omsk&0xff), + (int)(buf[0] & omsk)); + + if(off <= 8) /* Completely within 1 byte */ + po->nboff = off, + bits <<= (8 - off), + buf[0] = (buf[0] & omsk) | bits; + else if(off <= 16) + po->nboff = off, + bits <<= (16 - off), + buf[0] = (buf[0] & omsk) | (bits >> 8), + buf[1] = bits; + else if(off <= 24) + po->nboff = off, + bits <<= (24 - off), + buf[0] = (buf[0] & omsk) | (bits >> 16), + buf[1] = bits >> 8, + buf[2] = bits; + else if(off <= 31) + po->nboff = off, + bits <<= (32 - off), + buf[0] = (buf[0] & omsk) | (bits >> 24), + buf[1] = bits >> 16, + buf[2] = bits >> 8, + buf[3] = bits; + else { + per_put_few_bits(po, bits >> (obits - 24), 24); + per_put_few_bits(po, bits, obits - 24); + } + + ASN_DEBUG("[PER out %u/%x => %02x buf+%ld]", + (int)bits, (int)bits, buf[0], + (long)(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; +} + |