d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering#include <gcrypt.h>

6bedfcbb2970e06a4d3280c8fb62083d252ede73Lennart Poettering

6bedfcbb2970e06a4d3280c8fb62083d252ede73Lennart Poettering#include "alloc-util.h"

0b6b6787e3f0ae8906ce0212bd629edbe931b73dKay Sievers#include "dns-domain.h"

07630cea1f3a845c09309f197ac7c4f11edd3b62Lennart Poettering#include "resolved-dns-dnssec.h"

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek#include "resolved-dns-packet.h"

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek#include "string-table.h"

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek#define VERIFY_RRS_MAX 256

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek#define MAX_KEY_SIZE (32*1024)

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek#define SKEW_MAX (1*USEC_PER_HOUR + 10*USEC_PER_MINUTE)

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmekstatic bool dnssec_algorithm_supported(int algorithm) {

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek return IN_SET(algorithm,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek DNSSEC_ALGORITHM_RSASHA1,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek DNSSEC_ALGORITHM_RSASHA256,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek DNSSEC_ALGORITHM_RSASHA512);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek}

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmekstatic bool dnssec_digest_supported(int digest) {

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek return IN_SET(digest,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek DNSSEC_DIGEST_SHA1,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek DNSSEC_DIGEST_SHA256);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek}

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmekuint16_t dnssec_keytag(DnsResourceRecord *dnskey) {

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek const uint8_t *p;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek uint32_t sum;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek size_t i;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek /* The algorithm from RFC 4034, Appendix B. */

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek assert(dnskey);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek assert(dnskey->key->type == DNS_TYPE_DNSKEY);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek sum = (uint32_t) dnskey->dnskey.flags +

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek ((((uint32_t) dnskey->dnskey.protocol) << 8) + (uint32_t) dnskey->dnskey.algorithm);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek p = dnskey->dnskey.key;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek for (i = 0; i < dnskey->dnskey.key_size; i++)

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek sum += (i & 1) == 0 ? (uint32_t) p[i] << 8 : (uint32_t) p[i];

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek sum += (sum >> 16) & UINT32_C(0xFFFF);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek return sum & UINT32_C(0xFFFF);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek}

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmekstatic int rr_compare(const void *a, const void *b) {

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek DnsResourceRecord **x = (DnsResourceRecord**) a, **y = (DnsResourceRecord**) b;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek size_t m;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek int r;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek /* Let's order the RRs according to RFC 4034, Section 6.3 */

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek assert(x);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek assert(*x);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek assert((*x)->wire_format);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek assert(y);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek assert(*y);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek assert((*y)->wire_format);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek m = MIN((*x)->wire_format_size, (*y)->wire_format_size);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek r = memcmp((*x)->wire_format, (*y)->wire_format, m);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek if (r != 0)

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek return r;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek if ((*x)->wire_format_size < (*y)->wire_format_size)

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek return -1;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek else if ((*x)->wire_format_size > (*y)->wire_format_size)

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek return 1;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek return 0;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek}

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmekstatic int dnssec_rsa_verify(

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek const char *hash_algorithm,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek const void *signature, size_t signature_size,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek const void *data, size_t data_size,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek const void *exponent, size_t exponent_size,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek const void *modulus, size_t modulus_size) {

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek gcry_sexp_t public_key_sexp = NULL, data_sexp = NULL, signature_sexp = NULL;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek gcry_mpi_t n = NULL, e = NULL, s = NULL;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek gcry_error_t ge;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek int r;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek assert(hash_algorithm);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak ge = gcry_mpi_scan(&s, GCRYMPI_FMT_USG, signature, signature_size, NULL);

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak if (ge != 0) {

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak r = -EIO;

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak goto finish;

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak }

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak ge = gcry_mpi_scan(&e, GCRYMPI_FMT_USG, exponent, exponent_size, NULL);

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak if (ge != 0) {

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak r = -EIO;

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak goto finish;

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak }

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak ge = gcry_mpi_scan(&n, GCRYMPI_FMT_USG, modulus, modulus_size, NULL);

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak if (ge != 0) {

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak r = -EIO;

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak goto finish;

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak }

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak ge = gcry_sexp_build(&signature_sexp,

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak NULL,

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak "(sig-val (rsa (s %m)))",

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak s);

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak if (ge != 0) {

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak r = -EIO;

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak goto finish;

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak }

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak ge = gcry_sexp_build(&data_sexp,

3519d230c8bafe834b2dac26ace49fcfba139823Karel Zak NULL,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek "(data (flags pkcs1) (hash %s %b))",

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek hash_algorithm,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek (int) data_size,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek data);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek if (ge != 0) {

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek r = -EIO;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek goto finish;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek }

a75f4e2a02e287294b21ae9e5b1f28b2f8faea39Zbigniew Jędrzejewski-Szmek

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek ge = gcry_sexp_build(&public_key_sexp,

a75f4e2a02e287294b21ae9e5b1f28b2f8faea39Zbigniew Jędrzejewski-Szmek NULL,

a75f4e2a02e287294b21ae9e5b1f28b2f8faea39Zbigniew Jędrzejewski-Szmek "(public-key (rsa (n %m) (e %m)))",

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek n,

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek e);

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek if (ge != 0) {

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek r = -EIO;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek goto finish;

c5e04d51277994cca29234b33a6b8fc90a183cf3Zbigniew Jędrzejewski-Szmek }

c5e04d51277994cca29234b33a6b8fc90a183cf3Zbigniew Jędrzejewski-Szmek

c5e04d51277994cca29234b33a6b8fc90a183cf3Zbigniew Jędrzejewski-Szmek ge = gcry_pk_verify(signature_sexp, data_sexp, public_key_sexp);

a75f4e2a02e287294b21ae9e5b1f28b2f8faea39Zbigniew Jędrzejewski-Szmek if (ge == GPG_ERR_BAD_SIGNATURE)

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek r = 0;

d15d0333be6a1ca7fdd99a1881d967b6be8f387aZbigniew Jędrzejewski-Szmek else if (ge != 0)

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering r = -EIO;

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering else

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering r = 1;

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poetteringfinish:

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering if (e)

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering gcry_mpi_release(e);

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering if (n)

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering gcry_mpi_release(n);

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering if (s)

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering gcry_mpi_release(s);

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering if (public_key_sexp)

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering gcry_sexp_release(public_key_sexp);

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering if (signature_sexp)

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering gcry_sexp_release(signature_sexp);

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering if (data_sexp)

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering gcry_sexp_release(data_sexp);

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering return r;

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering}

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poetteringstatic void md_add_uint8(gcry_md_hd_t md, uint8_t v) {

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering gcry_md_write(md, &v, sizeof(v));

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering}

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poetteringstatic void md_add_uint16(gcry_md_hd_t md, uint16_t v) {

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering v = htobe16(v);

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering gcry_md_write(md, &v, sizeof(v));

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering}

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poetteringstatic void md_add_uint32(gcry_md_hd_t md, uint32_t v) {

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering v = htobe32(v);

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering gcry_md_write(md, &v, sizeof(v));

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering}

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poetteringstatic int dnssec_rrsig_expired(DnsResourceRecord *rrsig, usec_t realtime) {

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering usec_t expiration, inception, skew;

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering assert(rrsig);

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering assert(rrsig->key->type == DNS_TYPE_RRSIG);

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering if (realtime == USEC_INFINITY)

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering realtime = now(CLOCK_REALTIME);

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering expiration = rrsig->rrsig.expiration * USEC_PER_SEC;

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering inception = rrsig->rrsig.inception * USEC_PER_SEC;

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering if (inception > expiration)

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering return -EKEYREJECTED;

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering /* Permit a certain amount of clock skew of 10% of the valid

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering skew = (expiration - inception) / 10;

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering if (skew > SKEW_MAX)

6550203eb471595e41e27f46e5d0a00a4c0e47bbLennart Poettering skew = SKEW_MAX;

if (inception < skew)

inception = 0;

else

inception -= skew;

if (expiration + skew < expiration)

expiration = USEC_INFINITY;

else

expiration += skew;

return realtime < inception || realtime > expiration;

}

int dnssec_verify_rrset(

DnsAnswer *a,

DnsResourceKey *key,

DnsResourceRecord *rrsig,

DnsResourceRecord *dnskey,

usec_t realtime) {

uint8_t wire_format_name[DNS_WIRE_FOMAT_HOSTNAME_MAX];

size_t exponent_size, modulus_size, hash_size;

void *exponent, *modulus, *hash;

DnsResourceRecord **list, *rr;

gcry_md_hd_t md = NULL;

size_t k, n = 0;

int r;

assert(key);

assert(rrsig);

assert(dnskey);

assert(rrsig->key->type == DNS_TYPE_RRSIG);

assert(dnskey->key->type == DNS_TYPE_DNSKEY);

/* Verifies the the RRSet matching the specified "key" in "a",

if (!dnssec_algorithm_supported(rrsig->rrsig.algorithm))

return -EOPNOTSUPP;

if (a->n_rrs > VERIFY_RRS_MAX)

return -E2BIG;

r = dnssec_rrsig_expired(rrsig, realtime);

if (r < 0)

return r;

if (r > 0)

return DNSSEC_SIGNATURE_EXPIRED;

/* Collect all relevant RRs in a single array, so that we can look at the RRset */

list = newa(DnsResourceRecord *, a->n_rrs);

DNS_ANSWER_FOREACH(rr, a) {

r = dns_resource_key_equal(key, rr->key);

if (r < 0)

return r;

if (r == 0)

continue;

/* We need the wire format for ordering, and digest calculation */

r = dns_resource_record_to_wire_format(rr, true);

if (r < 0)

return r;

list[n++] = rr;

}

if (n <= 0)

return -ENODATA;

/* Bring the RRs into canonical order */

qsort_safe(list, n, sizeof(DnsResourceRecord), rr_compare);

/* OK, the RRs are now in canonical order. Let's calculate the digest */

switch (rrsig->rrsig.algorithm) {

case DNSSEC_ALGORITHM_RSASHA1:

case DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1:

gcry_md_open(&md, GCRY_MD_SHA1, 0);

hash_size = 20;

break;

case DNSSEC_ALGORITHM_RSASHA256:

gcry_md_open(&md, GCRY_MD_SHA256, 0);

hash_size = 32;

break;

case DNSSEC_ALGORITHM_RSASHA512:

gcry_md_open(&md, GCRY_MD_SHA512, 0);

hash_size = 64;

break;

default:

assert_not_reached("Unknown digest");

}

if (!md)

return -EIO;

md_add_uint16(md, rrsig->rrsig.type_covered);

md_add_uint8(md, rrsig->rrsig.algorithm);

md_add_uint8(md, rrsig->rrsig.labels);

md_add_uint32(md, rrsig->rrsig.original_ttl);

md_add_uint32(md, rrsig->rrsig.expiration);

md_add_uint32(md, rrsig->rrsig.inception);

md_add_uint16(md, rrsig->rrsig.key_tag);

r = dns_name_to_wire_format(rrsig->rrsig.signer, wire_format_name, sizeof(wire_format_name), true);

if (r < 0)

goto finish;

gcry_md_write(md, wire_format_name, r);

for (k = 0; k < n; k++) {

size_t l;

rr = list[k];

r = dns_name_to_wire_format(DNS_RESOURCE_KEY_NAME(rr->key), wire_format_name, sizeof(wire_format_name), true);

if (r < 0)

goto finish;

gcry_md_write(md, wire_format_name, r);

md_add_uint16(md, rr->key->type);

md_add_uint16(md, rr->key->class);

md_add_uint32(md, rrsig->rrsig.original_ttl);

assert(rr->wire_format_rdata_offset <= rr->wire_format_size);

l = rr->wire_format_size - rr->wire_format_rdata_offset;

assert(l <= 0xFFFF);

md_add_uint16(md, (uint16_t) l);

gcry_md_write(md, (uint8_t*) rr->wire_format + rr->wire_format_rdata_offset, l);

}

hash = gcry_md_read(md, 0);

if (!hash) {

r = -EIO;

goto finish;

}

if (*(uint8_t*) dnskey->dnskey.key == 0) {

/* exponent is > 255 bytes long */

exponent = (uint8_t*) dnskey->dnskey.key + 3;

exponent_size =

((size_t) (((uint8_t*) dnskey->dnskey.key)[0]) << 8) |

((size_t) ((uint8_t*) dnskey->dnskey.key)[1]);

if (exponent_size < 256) {

r = -EINVAL;

goto finish;

}

if (3 + exponent_size >= dnskey->dnskey.key_size) {

r = -EINVAL;

goto finish;

}

modulus = (uint8_t*) dnskey->dnskey.key + 3 + exponent_size;

modulus_size = dnskey->dnskey.key_size - 3 - exponent_size;

} else {

/* exponent is <= 255 bytes long */

exponent = (uint8_t*) dnskey->dnskey.key + 1;

exponent_size = (size_t) ((uint8_t*) dnskey->dnskey.key)[0];

if (exponent_size <= 0) {

r = -EINVAL;

goto finish;

}

if (1 + exponent_size >= dnskey->dnskey.key_size) {

r = -EINVAL;

goto finish;

}

modulus = (uint8_t*) dnskey->dnskey.key + 1 + exponent_size;

modulus_size = dnskey->dnskey.key_size - 1 - exponent_size;

}

r = dnssec_rsa_verify(

gcry_md_algo_name(gcry_md_get_algo(md)),

rrsig->rrsig.signature, rrsig->rrsig.signature_size,

hash, hash_size,

exponent, exponent_size,

modulus, modulus_size);

if (r < 0)

goto finish;

r = r ? DNSSEC_VERIFIED : DNSSEC_INVALID;

finish:

gcry_md_close(md);

return r;

}

int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnskey) {

assert(rrsig);

assert(dnskey);

/* Checks if the specified DNSKEY RR matches the key used for

if (rrsig->key->type != DNS_TYPE_RRSIG)

return -EINVAL;

if (dnskey->key->type != DNS_TYPE_DNSKEY)

return 0;

if (dnskey->key->class != rrsig->key->class)

return 0;

if ((dnskey->dnskey.flags & DNSKEY_FLAG_ZONE_KEY) == 0)

return 0;

if (dnskey->dnskey.protocol != 3)

return 0;

if (dnskey->dnskey.algorithm != rrsig->rrsig.algorithm)

return 0;

if (dnssec_keytag(dnskey) != rrsig->rrsig.key_tag)

return 0;

return dns_name_equal(DNS_RESOURCE_KEY_NAME(dnskey->key), DNS_RESOURCE_KEY_NAME(rrsig->key));

}

int dnssec_key_match_rrsig(DnsResourceKey *key, DnsResourceRecord *rrsig) {

assert(key);

assert(rrsig);

/* Checks if the specified RRSIG RR protects the RRSet of the specified RR key. */

if (rrsig->key->type != DNS_TYPE_RRSIG)

return 0;

if (rrsig->key->class != key->class)

return 0;

if (rrsig->rrsig.type_covered != key->type)

return 0;

return dns_name_equal(DNS_RESOURCE_KEY_NAME(rrsig->key), DNS_RESOURCE_KEY_NAME(key));

}

int dnssec_verify_rrset_search(

DnsAnswer *a,

DnsResourceKey *key,

DnsAnswer *validated_dnskeys,

usec_t realtime) {

bool found_rrsig = false, found_dnskey = false;

DnsResourceRecord *rrsig;

int r;

assert(key);

/* Verifies all RRs from "a" that match the key "key", against DNSKEY RRs in "validated_dnskeys" */

if (!a || a->n_rrs <= 0)

return -ENODATA;

/* Iterate through each RRSIG RR. */

DNS_ANSWER_FOREACH(rrsig, a) {

DnsResourceRecord *dnskey;

r = dnssec_key_match_rrsig(key, rrsig);

if (r < 0)

return r;

if (r == 0)

continue;

found_rrsig = true;

DNS_ANSWER_FOREACH(dnskey, validated_dnskeys) {

r = dnssec_rrsig_match_dnskey(rrsig, dnskey);

if (r < 0)

return r;

if (r == 0)

continue;

found_dnskey = true;

/* Take the time here, if it isn't set yet, so

if (realtime == USEC_INFINITY)

realtime = now(CLOCK_REALTIME);

/* Yay, we found a matching RRSIG with a matching

r = dnssec_verify_rrset(a, key, rrsig, dnskey, realtime);

if (r < 0 && r != EOPNOTSUPP)

return r;

if (r == DNSSEC_VERIFIED)

return DNSSEC_VERIFIED;

/* If the signature is invalid, or done using

}

}

if (found_dnskey)

return DNSSEC_INVALID;

if (found_rrsig)

return DNSSEC_MISSING_KEY;

return DNSSEC_NO_SIGNATURE;

}

int dnssec_canonicalize(const char *n, char *buffer, size_t buffer_max) {

_cleanup_free_ char *s = NULL;

size_t c = 0;

int r;

/* Converts the specified hostname into DNSSEC canonicalized

if (buffer_max < 2)

return -ENOBUFS;

for (;;) {

size_t i;

r = dns_label_unescape(&n, buffer, buffer_max);

if (r < 0)

return r;

if (r == 0)

break;

if (r > 0) {

int k;

/* DNSSEC validation is always done on the ASCII version of the label */

k = dns_label_apply_idna(buffer, r, buffer, buffer_max);

if (k < 0)

return k;

if (k > 0)

r = k;

}

if (buffer_max < (size_t) r + 2)

return -ENOBUFS;

/* The DNSSEC canonical form is not clear on what to

if (memchr(buffer, '.', r))

return -EINVAL;

for (i = 0; i < (size_t) r; i ++) {

if (buffer[i] >= 'A' && buffer[i] <= 'Z')

buffer[i] = buffer[i] - 'A' + 'a';

}

buffer[r] = '.';

buffer += r + 1;

c += r + 1;

buffer_max -= r + 1;

}

if (c <= 0) {

/* Not even a single label: this is the root domain name */

assert(buffer_max > 2);

buffer[0] = '.';

buffer[1] = 0;

return 1;

}

return (int) c;

}

int dnssec_verify_dnskey(DnsResourceRecord *dnskey, DnsResourceRecord *ds) {

gcry_md_hd_t md = NULL;

char owner_name[DNSSEC_CANONICAL_HOSTNAME_MAX];

void *result;

int r;

assert(dnskey);

assert(ds);

/* Implements DNSKEY verification by a DS, according to RFC 4035, section 5.2 */

if (dnskey->key->type != DNS_TYPE_DNSKEY)

return -EINVAL;

if (ds->key->type != DNS_TYPE_DS)

return -EINVAL;

if ((dnskey->dnskey.flags & DNSKEY_FLAG_ZONE_KEY) == 0)

return -EKEYREJECTED;

if (dnskey->dnskey.protocol != 3)

return -EKEYREJECTED;

if (!dnssec_algorithm_supported(dnskey->dnskey.algorithm))

return -EOPNOTSUPP;

if (!dnssec_digest_supported(ds->ds.digest_type))

return -EOPNOTSUPP;

if (dnskey->dnskey.algorithm != ds->ds.algorithm)

return 0;

if (dnssec_keytag(dnskey) != ds->ds.key_tag)

return 0;

switch (ds->ds.digest_type) {

case DNSSEC_DIGEST_SHA1:

if (ds->ds.digest_size != 20)

return 0;

gcry_md_open(&md, GCRY_MD_SHA1, 0);

break;

case DNSSEC_DIGEST_SHA256:

if (ds->ds.digest_size != 32)

return 0;

gcry_md_open(&md, GCRY_MD_SHA256, 0);

break;

default:

assert_not_reached("Unknown digest");

}

if (!md)

return -EIO;

r = dnssec_canonicalize(DNS_RESOURCE_KEY_NAME(dnskey->key), owner_name, sizeof(owner_name));

if (r < 0)

goto finish;

gcry_md_write(md, owner_name, r);

md_add_uint16(md, dnskey->dnskey.flags);

md_add_uint8(md, dnskey->dnskey.protocol);

md_add_uint8(md, dnskey->dnskey.algorithm);

gcry_md_write(md, dnskey->dnskey.key, dnskey->dnskey.key_size);

result = gcry_md_read(md, 0);

if (!result) {

r = -EIO;

goto finish;

}

r = memcmp(result, ds->ds.digest, ds->ds.digest_size) != 0;

finish:

gcry_md_close(md);

return r;

}

static const char* const dnssec_mode_table[_DNSSEC_MODE_MAX] = {

[DNSSEC_NO] = "no",

[DNSSEC_TRUST] = "trust",

[DNSSEC_YES] = "yes",

};

DEFINE_STRING_TABLE_LOOKUP(dnssec_mode, DnssecMode);