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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:24:08 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:24:08 +0000 |
commit | f449f278dd3c70e479a035f50a9bb817a9b433ba (patch) | |
tree | 8ca2bfb785dda9bb4d573acdf9b42aea9cd51383 /src/libknot/rrtype/tsig.c | |
parent | Initial commit. (diff) | |
download | knot-f449f278dd3c70e479a035f50a9bb817a9b433ba.tar.xz knot-f449f278dd3c70e479a035f50a9bb817a9b433ba.zip |
Adding upstream version 3.2.6.upstream/3.2.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/libknot/rrtype/tsig.c | 409 |
1 files changed, 409 insertions, 0 deletions
diff --git a/src/libknot/rrtype/tsig.c b/src/libknot/rrtype/tsig.c new file mode 100644 index 0000000..83f8436 --- /dev/null +++ b/src/libknot/rrtype/tsig.c @@ -0,0 +1,409 @@ +/* Copyright (C) 2021 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 <assert.h> +#include <inttypes.h> +#include <string.h> +#include <stdlib.h> +#include <stdint.h> +#include <time.h> + +#include "libdnssec/tsig.h" +#include "libknot/attribute.h" +#include "libknot/rrtype/tsig.h" +#include "libknot/consts.h" +#include "libknot/dname.h" +#include "libknot/errcode.h" +#include "libknot/rrset.h" +#include "libknot/wire.h" +#include "contrib/wire_ctx.h" + +/*! \brief TSIG field offsets. */ +typedef enum tsig_off_t { + TSIG_ALGNAME_O = 0, + TSIG_TSIGNED_O, + TSIG_FUDGE_O, + TSIG_MACLEN_O, + TSIG_MAC_O, + TSIG_ORIGID_O, + TSIG_ERROR_O, + TSIG_OLEN_O, + TSIG_OTHER_O +} tsig_off_t; + +/* Helpers for RDATA offset calculation. */ +#define TSIG_OFF_MACLEN (4 * sizeof(uint16_t)) +#define TSIG_FIXED_RDLEN (8 * sizeof(uint16_t)) +#define TSIG_OTHER_MAXLEN (3 * sizeof(uint16_t)) + +/*! + * \brief Seek offset of a TSIG RR field. + * + * \param rr TSIG RR. + * \param id Field index. + * \param nb Required number of bytes after the offset (for boundaries check). + * \return pointer to field on wire or NULL. + */ +static uint8_t* rdata_seek(const knot_rrset_t *rr, tsig_off_t id, size_t nb) +{ + const knot_rdata_t *rr_data = knot_rdataset_at(&rr->rrs, 0); + if (!rr_data || rr_data->len == 0) { + return NULL; + } + + wire_ctx_t wire = wire_ctx_init_const(rr_data->data, rr_data->len); + + /* TSIG RR names should be already sanitized on parse. */ + size_t alg_len = knot_dname_size(wire.wire); + + /* Not pretty, but fast. */ + switch (id) { + case TSIG_ALGNAME_O: break; + case TSIG_TSIGNED_O: + wire_ctx_skip(&wire, alg_len); break; + case TSIG_FUDGE_O: + wire_ctx_skip(&wire, alg_len + 3 * sizeof(uint16_t)); + break; + case TSIG_MACLEN_O: + wire_ctx_skip(&wire, alg_len + 4 * sizeof(uint16_t)); + break; + case TSIG_MAC_O: + wire_ctx_skip(&wire, alg_len + 5 * sizeof(uint16_t)); + break; + case TSIG_ORIGID_O: + wire_ctx_skip(&wire, alg_len + 4 * sizeof(uint16_t)); + wire_ctx_skip(&wire, wire_ctx_read_u16(&wire)); + break; + case TSIG_ERROR_O: + wire_ctx_skip(&wire, alg_len + 4 * sizeof(uint16_t)); + wire_ctx_skip(&wire, wire_ctx_read_u16(&wire)); + wire_ctx_skip(&wire, sizeof(uint16_t)); + break; + case TSIG_OLEN_O: + wire_ctx_skip(&wire, alg_len + 4 * sizeof(uint16_t)); + wire_ctx_skip(&wire, wire_ctx_read_u16(&wire)); + wire_ctx_skip(&wire, 2 * sizeof(uint16_t)); + break; + case TSIG_OTHER_O: + wire_ctx_skip(&wire, alg_len + 4 * sizeof(uint16_t)); + wire_ctx_skip(&wire, wire_ctx_read_u16(&wire)); + wire_ctx_skip(&wire, 2 * sizeof(uint16_t)); + assert(nb == 0); + nb = wire_ctx_read_u16(&wire); + if (wire_ctx_available(&wire) != nb) { + return NULL; + } + break; + } + + if (wire.error != KNOT_EOK) { + return NULL; + } + + /* Check remaining bytes. */ + + if (wire_ctx_available(&wire) < nb){ + return NULL; + } + + return wire.position; +} + +static int rdata_set_tsig_error(knot_rrset_t *tsig, uint16_t tsig_error) +{ + uint8_t *rd = rdata_seek(tsig, TSIG_ERROR_O, sizeof(uint16_t)); + if (!rd) { + return KNOT_ERROR; + } + + knot_wire_write_u16(rd, tsig_error); + return KNOT_EOK; +} + +_public_ +int knot_tsig_create_rdata(knot_rrset_t *rr, const knot_dname_t *alg, + uint16_t maclen, uint16_t tsig_err) +{ + if (rr == NULL || alg == NULL) { + return KNOT_EINVAL; + } + + size_t alg_len = knot_dname_size(alg); + size_t rdlen = alg_len + TSIG_FIXED_RDLEN + maclen; + if (tsig_err == KNOT_RCODE_BADTIME) { + rdlen += TSIG_OTHER_MAXLEN; + } + uint8_t rd[rdlen]; + memset(rd, 0, rdlen); + + /* Copy alg name. */ + knot_dname_to_wire(rd, alg, rdlen); + + /* Set MAC variable length in advance. */ + size_t offset = alg_len + TSIG_OFF_MACLEN; + knot_wire_write_u16(rd + offset, maclen); + + int ret = knot_rrset_add_rdata(rr, rd, rdlen, NULL); + if (ret != KNOT_EOK) { + return ret; + } + + /* Set error. */ + rdata_set_tsig_error(rr, tsig_err); + + return KNOT_EOK; +} + +_public_ +int knot_tsig_rdata_set_time_signed(knot_rrset_t *tsig, uint64_t time) +{ + uint8_t *rd = rdata_seek(tsig, TSIG_TSIGNED_O, 3*sizeof(uint16_t)); + if (!rd) { + return KNOT_ERROR; + } + + knot_wire_write_u48(rd, time); + return KNOT_EOK; +} + +_public_ +int knot_tsig_rdata_set_fudge(knot_rrset_t *tsig, uint16_t fudge) +{ + uint8_t *rd = rdata_seek(tsig, TSIG_FUDGE_O, sizeof(uint16_t)); + if (!rd) { + return KNOT_ERROR; + } + + knot_wire_write_u16(rd, fudge); + return KNOT_EOK; +} + +_public_ +int knot_tsig_rdata_set_mac(knot_rrset_t *tsig, uint16_t length, const uint8_t *mac) +{ + uint8_t *rd = rdata_seek(tsig, TSIG_MAC_O, length); + if (!rd) { + return KNOT_ERROR; + } + + /*! \note Cannot change length, as rdata is already preallocd. */ + + /* Copy the actual MAC. */ + memcpy(rd, mac, length); + return KNOT_EOK; +} + +_public_ +int knot_tsig_rdata_set_orig_id(knot_rrset_t *tsig, uint16_t id) +{ + uint8_t *rd = rdata_seek(tsig, TSIG_ORIGID_O, sizeof(uint16_t)); + if (!rd) { + return KNOT_ERROR; + } + + /* Write the length - 2. */ + knot_wire_write_u16(rd, id); + return KNOT_EOK; +} + +_public_ +int knot_tsig_rdata_set_other_data(knot_rrset_t *tsig, uint16_t len, + const uint8_t *other_data) +{ + if (len > TSIG_OTHER_MAXLEN) { + return KNOT_EINVAL; + } + + uint8_t *rd = rdata_seek(tsig, TSIG_OLEN_O, len + sizeof(uint16_t)); + if (!rd) { + return KNOT_ERROR; + } + + /* Write the length. */ + knot_wire_write_u16(rd, len); + + /* Copy the actual data. */ + if (len > 0) { + memcpy(rd + sizeof(uint16_t), other_data, len); + } + return KNOT_EOK; +} + +_public_ +const knot_dname_t *knot_tsig_rdata_alg_name(const knot_rrset_t *tsig) +{ + return knot_rdataset_at(&tsig->rrs, 0)->data; +} + +_public_ +dnssec_tsig_algorithm_t knot_tsig_rdata_alg(const knot_rrset_t *tsig) +{ + /* Get the algorithm name. */ + const knot_dname_t *alg_name = knot_tsig_rdata_alg_name(tsig); + if (!alg_name) { + return DNSSEC_TSIG_UNKNOWN; + } + + return dnssec_tsig_algorithm_from_dname(alg_name); +} + +_public_ +uint64_t knot_tsig_rdata_time_signed(const knot_rrset_t *tsig) +{ + /*! \todo How to return invalid value? */ + uint8_t *rd = rdata_seek(tsig, TSIG_TSIGNED_O, 3*sizeof(uint16_t)); + if (!rd) { + return 0; + } + return knot_wire_read_u48(rd); +} + +_public_ +uint16_t knot_tsig_rdata_fudge(const knot_rrset_t *tsig) +{ + uint8_t *rd = rdata_seek(tsig, TSIG_FUDGE_O, sizeof(uint16_t)); + if (!rd) { + return 0; + } + return knot_wire_read_u16(rd); +} + +_public_ +const uint8_t *knot_tsig_rdata_mac(const knot_rrset_t *tsig) +{ + uint8_t *rd = rdata_seek(tsig, TSIG_MAC_O, 0); + if (!rd) { + return NULL; + } + return rd; +} + +_public_ +size_t knot_tsig_rdata_mac_length(const knot_rrset_t *tsig) +{ + uint8_t *rd = rdata_seek(tsig, TSIG_MACLEN_O, sizeof(uint16_t)); + if (!rd) { + return 0; + } + return knot_wire_read_u16(rd); +} + +_public_ +uint16_t knot_tsig_rdata_orig_id(const knot_rrset_t *tsig) +{ + uint8_t *rd = rdata_seek(tsig, TSIG_ORIGID_O, sizeof(uint16_t)); + if (!rd) { + return 0; + } + return knot_wire_read_u16(rd); +} + +_public_ +uint16_t knot_tsig_rdata_error(const knot_rrset_t *tsig) +{ + uint8_t *rd = rdata_seek(tsig, TSIG_ERROR_O, sizeof(uint16_t)); + if (!rd) { + return 0; + } + return knot_wire_read_u16(rd); +} + +_public_ +const uint8_t *knot_tsig_rdata_other_data(const knot_rrset_t *tsig) +{ + uint8_t *rd = rdata_seek(tsig, TSIG_OTHER_O, 0); + if (!rd) { + return NULL; + } + return rd; +} + +_public_ +uint16_t knot_tsig_rdata_other_data_length(const knot_rrset_t *tsig) +{ + uint8_t *rd = rdata_seek(tsig, TSIG_OLEN_O, sizeof(uint16_t)); + if (!rd) { + return 0; + } + return knot_wire_read_u16(rd); +} + +_public_ +size_t knot_tsig_rdata_tsig_variables_length(const knot_rrset_t *tsig) +{ + if (tsig == NULL) { + return 0; + } + /* Key name, Algorithm name and Other data have variable lengths. */ + const knot_dname_t *key_name = tsig->owner; + if (!key_name) { + return 0; + } + + const knot_dname_t *alg_name = knot_tsig_rdata_alg_name(tsig); + if (!alg_name) { + return 0; + } + + uint16_t other_data_length = knot_tsig_rdata_other_data_length(tsig); + + return knot_dname_size(key_name) + knot_dname_size(alg_name) + + other_data_length + KNOT_TSIG_VARIABLES_LENGTH; +} + +_public_ +size_t knot_tsig_rdata_tsig_timers_length(void) +{ + /*! \todo Cleanup */ + return KNOT_TSIG_TIMERS_LENGTH; +} + +_public_ +size_t knot_tsig_wire_size(const knot_tsig_key_t *key) +{ + if (key == NULL || key->name == NULL) { + return 0; + } + + return knot_dname_size(key->name) + TSIG_FIXED_RDLEN + + sizeof(uint16_t) + /* TYPE */ + sizeof(uint16_t) + /* CLASS */ + sizeof(uint32_t) + /* TTL */ + sizeof(uint16_t) + /* RDATA length. */ + knot_dname_size(dnssec_tsig_algorithm_to_dname(key->algorithm)) + + dnssec_tsig_algorithm_size(key->algorithm); /* MAC length. */ +} + +_public_ +size_t knot_tsig_wire_maxsize(const knot_tsig_key_t *key) +{ + size_t size = knot_tsig_wire_size(key); + if (size == 0) { + return 0; + } + + /* In case of BADTIME other data. */ + return size + TSIG_OTHER_MAXLEN; +} + +_public_ +bool knot_tsig_rdata_is_ok(const knot_rrset_t *tsig) +{ + return (tsig != NULL + && knot_rdataset_at(&tsig->rrs, 0) != NULL + && rdata_seek(tsig, TSIG_OTHER_O, 0) != NULL + && knot_tsig_rdata_alg_name(tsig) != NULL); +} |