/* * Copyright (c) 2005, 2006 Lev Walkin . All rights reserved. * Redistribution and modifications are permitted subject to BSD license. */ #include #include #include /* * 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 */ uint32_t accum; const uint8_t *buf; if(nbits < 0 || pd->nboff + nbits > pd->nbits) return -1; ASN_DEBUG("[PER get %d bits from %p+%d bits]", nbits, pd->buffer, pd->nboff); /* * Normalize position indicator. */ if(pd->nboff >= 8) { pd->buffer += (pd->nboff >> 3); pd->nbits -= (pd->nboff & ~0x07); pd->nboff &= 0x07; } off = (pd->nboff += nbits); 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. */ tpd.nboff -= nbits; accum = per_get_few_bits(&tpd, nbits - 24) << 24; accum |= per_get_few_bits(&tpd, 24); } else { pd->nboff -= nbits; /* Oops, revert back */ return -1; } return (accum & (((uint32_t)1 << nbits) - 1)); } /* * 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 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 to %p+%d bits]", obits, 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); if(po->outper(po->buffer, 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, bits, 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]", bits, 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); }