| /*- |
| * Copyright (c) 2003 Lev Walkin <vlm@lionet.info>. All rights reserved. |
| * Redistribution and modifications are permitted subject to BSD license. |
| */ |
| #include <INTEGER.h> |
| #include <assert.h> |
| #include <errno.h> |
| |
| /* |
| * INTEGER basic type description. |
| */ |
| static ber_tlv_tag_t asn1_DEF_INTEGER_tags[] = { |
| (ASN_TAG_CLASS_UNIVERSAL | (2 << 2)) |
| }; |
| asn1_TYPE_descriptor_t asn1_DEF_INTEGER = { |
| "INTEGER", |
| asn_generic_no_constraint, |
| INTEGER_decode_ber, |
| INTEGER_encode_der, |
| INTEGER_print, |
| INTEGER_free, |
| 0, /* Use generic outmost tag fetcher */ |
| asn1_DEF_INTEGER_tags, |
| sizeof(asn1_DEF_INTEGER_tags)/sizeof(asn1_DEF_INTEGER_tags[0]), |
| 1, /* Single UNIVERSAL tag may be implicitly overriden */ |
| 0, /* Always in primitive form */ |
| 0, 0, /* No members */ |
| 0 /* No specifics */ |
| }; |
| |
| /* |
| * Decode INTEGER type. |
| */ |
| ber_dec_rval_t |
| INTEGER_decode_ber(asn1_TYPE_descriptor_t *td, |
| void **int_structure, void *buf_ptr, size_t size, int tag_mode) { |
| INTEGER_t *st = (INTEGER_t *)*int_structure; |
| ber_dec_rval_t rval; |
| ber_dec_ctx_t ctx = { 0, 0, 0, 0 }; |
| ber_tlv_len_t length; |
| |
| /* |
| * If the structure is not there, allocate it. |
| */ |
| if(st == NULL) { |
| (void *)st = *int_structure = CALLOC(1, sizeof(*st)); |
| if(st == NULL) { |
| rval.code = RC_FAIL; |
| rval.consumed = 0; |
| return rval; |
| } |
| } |
| |
| ASN_DEBUG("Decoding %s as INTEGER (tm=%d)", |
| td->name, tag_mode); |
| |
| /* |
| * Check tags. |
| */ |
| rval = ber_check_tags(td, &ctx, |
| buf_ptr, size, tag_mode, &length, 0); |
| if(rval.code != RC_OK) |
| return rval; |
| |
| ASN_DEBUG("%s length is %d bytes", td->name, (int)length); |
| |
| /* |
| * Make sure we have this length. |
| */ |
| buf_ptr = ((char *)buf_ptr) + rval.consumed; |
| size -= rval.consumed; |
| if(length > (ber_tlv_len_t)size) { |
| rval.code = RC_WMORE; |
| rval.consumed = 0; |
| return rval; |
| } |
| |
| st->buf = (uint8_t *)MALLOC(length); |
| if(st->buf) { |
| st->size = length; |
| } else { |
| rval.code = RC_FAIL; |
| rval.consumed = 0; |
| return rval; |
| } |
| |
| memcpy(st->buf, buf_ptr, st->size); |
| |
| rval.code = RC_OK; |
| rval.consumed += length; |
| |
| ASN_DEBUG("Took %ld/%ld bytes to encode %s", |
| (long)rval.consumed, |
| (long)length, td->name); |
| |
| return rval; |
| } |
| |
| /* |
| * Encode INTEGER type using DER. |
| */ |
| der_enc_rval_t |
| INTEGER_encode_der(asn1_TYPE_descriptor_t *sd, void *ptr, |
| int tag_mode, ber_tlv_tag_t tag, |
| asn_app_consume_bytes_f *cb, void *app_key) { |
| der_enc_rval_t erval; |
| INTEGER_t *st = (INTEGER_t *)ptr; |
| |
| ASN_DEBUG("%s %s as INTEGER (tm=%d)", |
| cb?"Encoding":"Estimating", sd->name, tag_mode); |
| |
| /* |
| * Canonicalize integer in the buffer. |
| * (Remove too long sign extension, remove some first 0x00 bytes) |
| */ |
| if(st->buf) { |
| uint8_t *buf = st->buf; |
| uint8_t *end1 = buf + st->size - 1; |
| int shift; |
| |
| /* Compute the number of superfluous leading bytes */ |
| for(; buf < end1; buf++) { |
| /* |
| * If the contents octets of an integer value encoding |
| * consist of more than one octet, then the bits of the |
| * first octet and bit 8 of the second octet: |
| * a) shall not all be ones; and |
| * b) shall not all be zero. |
| */ |
| switch(*buf) { |
| case 0x00: if((buf[1] & 0x80) == 0) |
| continue; |
| break; |
| case 0xff: if((buf[1] & 0x80)) |
| continue; |
| break; |
| } |
| break; |
| } |
| |
| /* Remove leading superfluous bytes from the integer */ |
| shift = buf - st->buf; |
| if(shift) { |
| uint8_t *nb = st->buf; |
| uint8_t *end; |
| |
| st->size -= shift; /* New size, minus bad bytes */ |
| end = nb + st->size; |
| |
| for(; nb < end; nb++, buf++) |
| *nb = *buf; |
| } |
| |
| } /* if(1) */ |
| |
| erval.encoded = der_write_tags(sd, st->size, tag_mode, tag, |
| cb, app_key); |
| ASN_DEBUG("INTEGER %s wrote tags %d", sd->name, (int)erval.encoded); |
| if(erval.encoded == -1) { |
| erval.failed_type = sd; |
| erval.structure_ptr = ptr; |
| return erval; |
| } |
| |
| if(cb && st->buf) { |
| ssize_t ret; |
| |
| ret = cb(st->buf, st->size, app_key); |
| if(ret == -1) { |
| erval.encoded = -1; |
| erval.failed_type = sd; |
| erval.structure_ptr = ptr; |
| return erval; |
| } |
| } else { |
| assert(st->buf || st->size == 0); |
| } |
| |
| erval.encoded += st->size; |
| |
| return erval; |
| } |
| |
| /* |
| * INTEGER specific human-readable output. |
| */ |
| int |
| INTEGER_print(asn1_TYPE_descriptor_t *td, const void *sptr, int ilevel, |
| asn_app_consume_bytes_f *cb, void *app_key) { |
| char scratch[32]; /* Enough for 64-bit integer */ |
| const INTEGER_t *st = (const INTEGER_t *)sptr; |
| uint8_t *buf = st->buf; |
| uint8_t *buf_end = st->buf + st->size; |
| signed long accum; |
| char *p; |
| int ret; |
| |
| (void)td; /* Unused argument */ |
| (void)ilevel; /* Unused argument */ |
| |
| if(!st && !st->buf) return cb("<absent>", 8, app_key); |
| |
| if(st->size == 0) |
| return cb("0", 1, app_key); |
| |
| /* |
| * Advance buf pointer until the start of the value's body. |
| * This will make us able to process large integers using simple case, |
| * when the actual value is small |
| * (0x0000000000abcdef would yield a fine 0x00abcdef) |
| */ |
| /* Skip the insignificant leading bytes */ |
| for(; buf < buf_end-1; buf++) { |
| switch(*buf) { |
| case 0x00: if((buf[1] & 0x80) == 0) continue; break; |
| case 0xff: if((buf[1] & 0x80) != 0) continue; break; |
| } |
| break; |
| } |
| |
| /* Simple case: the integer size is small */ |
| if((size_t)(buf_end - buf) <= sizeof(accum)) { |
| accum = (*buf & 0x80) ? -1 : 0; |
| for(; buf < buf_end; buf++) |
| accum = (accum << 8) | *buf; |
| ret = snprintf(scratch, sizeof(scratch), "%ld", accum); |
| assert(ret > 0 && ret < (int)sizeof(scratch)); |
| return cb(scratch, ret, app_key); |
| } |
| |
| /* Output in the long xx:yy:zz... format */ |
| /* TODO: replace with generic algorithm (Knuth TAOCP Vol 2, 4.3.1) */ |
| for(p = scratch; buf < buf_end; buf++) { |
| static const char *h2c = "0123456789ABCDEF"; |
| if((p - scratch) >= (ssize_t)(sizeof(scratch) - 4)) { |
| /* Flush buffer */ |
| if(cb(scratch, p - scratch, app_key)) |
| return -1; |
| p = scratch; |
| } |
| *p++ = h2c[*buf >> 4]; |
| *p++ = h2c[*buf & 0x0F]; |
| *p++ = ':'; |
| } |
| if(p != scratch) |
| p--; /* Remove the last ':' */ |
| |
| return cb(scratch, p - scratch, app_key); |
| } |
| |
| void |
| INTEGER_free(asn1_TYPE_descriptor_t *td, void *ptr, int contents_only) { |
| INTEGER_t *st = (INTEGER_t *)ptr; |
| |
| if(!td || !st) |
| return; |
| |
| ASN_DEBUG("Freeing %s as INTEGER (%d, %p, %p)", |
| td->name, contents_only, st, st->buf); |
| |
| if(st->buf) { |
| FREEMEM(st->buf); |
| } |
| |
| if(!contents_only) { |
| FREEMEM(st); |
| } |
| } |
| |
| int |
| asn1_INTEGER2long(const INTEGER_t *iptr, long *lptr) { |
| uint8_t *b, *end; |
| size_t size; |
| long l; |
| |
| /* Sanity checking */ |
| if(!iptr || !iptr->buf || !lptr) { |
| errno = EINVAL; |
| return -1; |
| } |
| |
| /* Cache the begin/end of the buffer */ |
| b = iptr->buf; /* Start of the INTEGER buffer */ |
| size = iptr->size; |
| end = b + size; /* Where to stop */ |
| |
| if(size > sizeof(long)) { |
| uint8_t *end1 = end - 1; |
| /* |
| * Slightly more advanced processing, |
| * able to >sizeof(long) bytes, |
| * when the actual value is small |
| * (0x0000000000abcdef would yield a fine 0x00abcdef) |
| */ |
| /* Skip out the insignificant leading bytes */ |
| for(; b < end1; b++) { |
| switch(*b) { |
| case 0x00: if((b[1] & 0x80) == 0) continue; break; |
| case 0xff: if((b[1] & 0x80) != 0) continue; break; |
| } |
| break; |
| } |
| |
| size = end - b; |
| if(size > sizeof(long)) { |
| /* Still cannot fit the long */ |
| errno = ERANGE; |
| return -1; |
| } |
| } |
| |
| /* Shortcut processing of a corner case */ |
| if(end == b) { |
| *lptr = 0; |
| return 0; |
| } |
| |
| /* Perform the sign initialization */ |
| /* Actually l = -(*b >> 7); gains nothing, yet unreadable! */ |
| if((*b >> 7)) l = -1; else l = 0; |
| |
| /* Conversion engine */ |
| for(; b < end; b++) |
| l = (l << 8) | *b; |
| |
| *lptr = l; |
| return 0; |
| } |