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Diffstat (limited to 'src/libdnssec/nsec/nsec.c')
| -rw-r--r-- | src/libdnssec/nsec/nsec.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/src/libdnssec/nsec/nsec.c b/src/libdnssec/nsec/nsec.c new file mode 100644 index 0000000..2e71598 --- /dev/null +++ b/src/libdnssec/nsec/nsec.c @@ -0,0 +1,130 @@ +/* Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include "libdnssec/nsec.h" +#include "libdnssec/shared/shared.h" +#include "libdnssec/shared/binary_wire.h" + +#include "libdnssec/binary.h" +#include "libdnssec/error.h" + +/*! + * Free NSEC3 parameters. + */ +_public_ +void dnssec_nsec3_params_free(dnssec_nsec3_params_t *params) +{ + if (!params) { + return; + } + + dnssec_binary_free(¶ms->salt); + clear_struct(params); +} + +/*! + * Parse NSEC3 parameters from NSEC3PARAM RDATA. + * + * \see RFC 5155 (section 4.2) + */ +_public_ +int dnssec_nsec3_params_from_rdata(dnssec_nsec3_params_t *params, + const dnssec_binary_t *rdata) +{ + if (!params || !rdata || !rdata->data) { + return DNSSEC_EINVAL; + } + + dnssec_nsec3_params_t new_params = { 0 }; + + wire_ctx_t wire = binary_init(rdata); + + if (wire_ctx_available(&wire) < 5) { + return DNSSEC_MALFORMED_DATA; + } + + new_params.algorithm = wire_ctx_read_u8(&wire); + new_params.flags = wire_ctx_read_u8(&wire); + new_params.iterations = wire_ctx_read_u16(&wire); + new_params.salt.size = wire_ctx_read_u8(&wire); + + if (wire_ctx_available(&wire) != new_params.salt.size) { + return DNSSEC_MALFORMED_DATA; + } + + new_params.salt.data = malloc(new_params.salt.size); + if (new_params.salt.data == NULL) { + return DNSSEC_ENOMEM; + } + + binary_read(&wire, &new_params.salt); + assert(wire_ctx_offset(&wire) == rdata->size); + + *params = new_params; + + return DNSSEC_EOK; +} + +_public_ +bool dnssec_nsec_bitmap_contains(const uint8_t *bitmap, uint16_t size, uint16_t type) +{ + if (!bitmap || size == 0) { + return false; + } + + const uint8_t type_hi = (type >> 8); // Which window block contains type. + const uint8_t type_lo = (type & 0xff); + const uint8_t bitmap_idx = (type_lo >> 3); // Which byte in the window block contains type. + const uint8_t bit_mask = 1 << (7 - (type_lo & 0x07)); // Which bit in the byte represents type. + + size_t bitmap_pos = 0; + while (bitmap_pos + 3 <= size) { + uint8_t block_idx = bitmap[bitmap_pos++]; // Skip window block No. + uint8_t block_size = bitmap[bitmap_pos++]; // Skip window block size. + + // Size checks. + if (block_size == 0 || bitmap_pos + block_size > size) { + return false; + } + + // Check whether we found the correct window block. + if (block_idx == type_hi) { + if (bitmap_idx < block_size) { + // Check if the bit for type is set. + return bitmap[bitmap_pos + bitmap_idx] & bit_mask; + } + return false; + } else { + bitmap_pos += block_size; + } + } + + return false; +} + +_public_ +bool dnssec_nsec3_params_match(const dnssec_nsec3_params_t *params1, + const dnssec_nsec3_params_t *params2) +{ + if (params1 != NULL && params2 != NULL) { + return (params1->algorithm == params2->algorithm && + params1->flags == params2->flags && + params1->iterations == params2->iterations && + dnssec_binary_cmp(¶ms1->salt, ¶ms2->salt) == 0); + } else { + return (params1 == NULL && params2 == NULL); + } +} |