unbound/sldns/keyraw.c

718 lines
16 KiB
C

/*
* keyraw.c - raw key operations and conversions
*
* (c) NLnet Labs, 2004-2008
*
* See the file LICENSE for the license
*/
/**
* \file
* Implementation of raw DNSKEY functions (work on wire rdata).
*/
#include "config.h"
#include "sldns/keyraw.h"
#include "sldns/rrdef.h"
#ifdef HAVE_SSL
#include <openssl/ssl.h>
#include <openssl/evp.h>
#include <openssl/rand.h>
#include <openssl/err.h>
#include <openssl/md5.h>
#ifdef HAVE_OPENSSL_ENGINE_H
# include <openssl/engine.h>
#endif
#ifdef HAVE_OPENSSL_BN_H
#include <openssl/bn.h>
#endif
#ifdef HAVE_OPENSSL_PARAM_BUILD_H
# include <openssl/param_build.h>
#else
# ifdef HAVE_OPENSSL_RSA_H
# include <openssl/rsa.h>
# endif
# ifdef HAVE_OPENSSL_DSA_H
# include <openssl/dsa.h>
# endif
#endif
#endif /* HAVE_SSL */
size_t
sldns_rr_dnskey_key_size_raw(const unsigned char* keydata,
const size_t len, int alg)
{
/* for DSA keys */
uint8_t t;
/* for RSA keys */
uint16_t exp;
uint16_t int16;
switch ((sldns_algorithm)alg) {
case LDNS_DSA:
case LDNS_DSA_NSEC3:
if (len > 0) {
t = keydata[0];
return (64 + t*8)*8;
} else {
return 0;
}
break;
case LDNS_RSAMD5:
case LDNS_RSASHA1:
case LDNS_RSASHA1_NSEC3:
#ifdef USE_SHA2
case LDNS_RSASHA256:
case LDNS_RSASHA512:
#endif
if (len > 0) {
if (keydata[0] == 0) {
/* big exponent */
if (len > 3) {
memmove(&int16, keydata + 1, 2);
exp = ntohs(int16);
return (len - exp - 3)*8;
} else {
return 0;
}
} else {
exp = keydata[0];
return (len-exp-1)*8;
}
} else {
return 0;
}
break;
#ifdef USE_GOST
case LDNS_ECC_GOST:
return 512;
#endif
#ifdef USE_ECDSA
case LDNS_ECDSAP256SHA256:
return 256;
case LDNS_ECDSAP384SHA384:
return 384;
#endif
#ifdef USE_ED25519
case LDNS_ED25519:
return 256;
#endif
#ifdef USE_ED448
case LDNS_ED448:
return 456;
#endif
default:
return 0;
}
}
uint16_t sldns_calc_keytag_raw(uint8_t* key, size_t keysize)
{
if(keysize < 4) {
return 0;
}
/* look at the algorithm field, copied from 2535bis */
if (key[3] == LDNS_RSAMD5) {
uint16_t ac16 = 0;
if (keysize > 4) {
memmove(&ac16, key + keysize - 3, 2);
}
ac16 = ntohs(ac16);
return (uint16_t) ac16;
} else {
size_t i;
uint32_t ac32 = 0;
for (i = 0; i < keysize; ++i) {
ac32 += (i & 1) ? key[i] : key[i] << 8;
}
ac32 += (ac32 >> 16) & 0xFFFF;
return (uint16_t) (ac32 & 0xFFFF);
}
}
#ifdef HAVE_SSL
#ifdef USE_GOST
/** store GOST engine reference loaded into OpenSSL library */
ENGINE* sldns_gost_engine = NULL;
int
sldns_key_EVP_load_gost_id(void)
{
static int gost_id = 0;
const EVP_PKEY_ASN1_METHOD* meth;
ENGINE* e;
if(gost_id) return gost_id;
/* see if configuration loaded gost implementation from other engine*/
meth = EVP_PKEY_asn1_find_str(NULL, "gost2001", -1);
if(meth) {
EVP_PKEY_asn1_get0_info(&gost_id, NULL, NULL, NULL, NULL, meth);
return gost_id;
}
/* see if engine can be loaded already */
e = ENGINE_by_id("gost");
if(!e) {
/* load it ourself, in case statically linked */
ENGINE_load_builtin_engines();
ENGINE_load_dynamic();
e = ENGINE_by_id("gost");
}
if(!e) {
/* no gost engine in openssl */
return 0;
}
if(!ENGINE_set_default(e, ENGINE_METHOD_ALL)) {
ENGINE_finish(e);
ENGINE_free(e);
return 0;
}
meth = EVP_PKEY_asn1_find_str(&e, "gost2001", -1);
if(!meth) {
/* algo not found */
ENGINE_finish(e);
ENGINE_free(e);
return 0;
}
/* Note: do not ENGINE_finish and ENGINE_free the acquired engine
* on some platforms this frees up the meth and unloads gost stuff */
sldns_gost_engine = e;
EVP_PKEY_asn1_get0_info(&gost_id, NULL, NULL, NULL, NULL, meth);
return gost_id;
}
void sldns_key_EVP_unload_gost(void)
{
if(sldns_gost_engine) {
ENGINE_finish(sldns_gost_engine);
ENGINE_free(sldns_gost_engine);
sldns_gost_engine = NULL;
}
}
#endif /* USE_GOST */
/* Retrieve params as BIGNUM from raw buffer */
static int
sldns_key_dsa_buf_bignum(unsigned char* key, size_t len, BIGNUM** p,
BIGNUM** q, BIGNUM** g, BIGNUM** y)
{
uint8_t T;
uint16_t length;
uint16_t offset;
if(len == 0)
return 0;
T = (uint8_t)key[0];
length = (64 + T * 8);
offset = 1;
if (T > 8) {
return 0;
}
if(len < (size_t)1 + SHA_DIGEST_LENGTH + 3*length)
return 0;
*q = BN_bin2bn(key+offset, SHA_DIGEST_LENGTH, NULL);
offset += SHA_DIGEST_LENGTH;
*p = BN_bin2bn(key+offset, (int)length, NULL);
offset += length;
*g = BN_bin2bn(key+offset, (int)length, NULL);
offset += length;
*y = BN_bin2bn(key+offset, (int)length, NULL);
if(!*q || !*p || !*g || !*y) {
BN_free(*q);
BN_free(*p);
BN_free(*g);
BN_free(*y);
return 0;
}
return 1;
}
#ifndef HAVE_OSSL_PARAM_BLD_NEW
DSA *
sldns_key_buf2dsa_raw(unsigned char* key, size_t len)
{
DSA *dsa;
BIGNUM *Q=NULL, *P=NULL, *G=NULL, *Y=NULL;
if(!sldns_key_dsa_buf_bignum(key, len, &P, &Q, &G, &Y)) {
return NULL;
}
/* create the key and set its properties */
if(!(dsa = DSA_new())) {
return NULL;
}
#if OPENSSL_VERSION_NUMBER < 0x10100000 || \
(defined(HAVE_LIBRESSL) && LIBRESSL_VERSION_NUMBER < 0x02070000f)
#ifndef S_SPLINT_S
dsa->p = P;
dsa->q = Q;
dsa->g = G;
dsa->pub_key = Y;
#endif /* splint */
#else /* OPENSSL_VERSION_NUMBER */
if (!DSA_set0_pqg(dsa, P, Q, G)) {
/* QPG not yet attached, need to free */
BN_free(Q);
BN_free(P);
BN_free(G);
DSA_free(dsa);
BN_free(Y);
return NULL;
}
if (!DSA_set0_key(dsa, Y, NULL)) {
/* QPG attached, cleaned up by DSA_fre() */
DSA_free(dsa);
BN_free(Y);
return NULL;
}
#endif
return dsa;
}
#endif /* HAVE_OSSL_PARAM_BLD_NEW */
EVP_PKEY *sldns_key_dsa2pkey_raw(unsigned char* key, size_t len)
{
#ifdef HAVE_OSSL_PARAM_BLD_NEW
EVP_PKEY* evp_key = NULL;
EVP_PKEY_CTX* ctx;
BIGNUM *p=NULL, *q=NULL, *g=NULL, *y=NULL;
OSSL_PARAM_BLD* param_bld;
OSSL_PARAM* params = NULL;
if(!sldns_key_dsa_buf_bignum(key, len, &p, &q, &g, &y)) {
return NULL;
}
param_bld = OSSL_PARAM_BLD_new();
if(!param_bld) {
BN_free(p);
BN_free(q);
BN_free(g);
BN_free(y);
return NULL;
}
if(!OSSL_PARAM_BLD_push_BN(param_bld, "p", p) ||
!OSSL_PARAM_BLD_push_BN(param_bld, "g", g) ||
!OSSL_PARAM_BLD_push_BN(param_bld, "q", q) ||
!OSSL_PARAM_BLD_push_BN(param_bld, "pub", y)) {
OSSL_PARAM_BLD_free(param_bld);
BN_free(p);
BN_free(q);
BN_free(g);
BN_free(y);
return NULL;
}
params = OSSL_PARAM_BLD_to_param(param_bld);
OSSL_PARAM_BLD_free(param_bld);
ctx = EVP_PKEY_CTX_new_from_name(NULL, "DSA", NULL);
if(!ctx) {
OSSL_PARAM_free(params);
BN_free(p);
BN_free(q);
BN_free(g);
BN_free(y);
return NULL;
}
if(EVP_PKEY_fromdata_init(ctx) <= 0) {
EVP_PKEY_CTX_free(ctx);
OSSL_PARAM_free(params);
BN_free(p);
BN_free(q);
BN_free(g);
BN_free(y);
return NULL;
}
if(EVP_PKEY_fromdata(ctx, &evp_key, EVP_PKEY_PUBLIC_KEY, params) <= 0) {
EVP_PKEY_CTX_free(ctx);
OSSL_PARAM_free(params);
BN_free(p);
BN_free(q);
BN_free(g);
BN_free(y);
return NULL;
}
EVP_PKEY_CTX_free(ctx);
OSSL_PARAM_free(params);
BN_free(p);
BN_free(q);
BN_free(g);
BN_free(y);
return evp_key;
#else
DSA* dsa;
EVP_PKEY* evp_key = EVP_PKEY_new();
if(!evp_key) {
return NULL;
}
dsa = sldns_key_buf2dsa_raw(key, len);
if(!dsa) {
EVP_PKEY_free(evp_key);
return NULL;
}
if(EVP_PKEY_assign_DSA(evp_key, dsa) == 0) {
DSA_free(dsa);
EVP_PKEY_free(evp_key);
return NULL;
}
return evp_key;
#endif
}
/* Retrieve params as BIGNUM from raw buffer, n is modulus, e is exponent */
static int
sldns_key_rsa_buf_bignum(unsigned char* key, size_t len, BIGNUM** n,
BIGNUM** e)
{
uint16_t offset;
uint16_t exp;
uint16_t int16;
if (len == 0)
return 0;
if (key[0] == 0) {
if(len < 3)
return 0;
memmove(&int16, key+1, 2);
exp = ntohs(int16);
offset = 3;
} else {
exp = key[0];
offset = 1;
}
/* key length at least one */
if(len < (size_t)offset + exp + 1)
return 0;
/* Exponent */
*e = BN_new();
if(!*e) return 0;
(void) BN_bin2bn(key+offset, (int)exp, *e);
offset += exp;
/* Modulus */
*n = BN_new();
if(!*n) {
BN_free(*e);
return 0;
}
/* length of the buffer must match the key length! */
(void) BN_bin2bn(key+offset, (int)(len - offset), *n);
return 1;
}
#ifndef HAVE_OSSL_PARAM_BLD_NEW
RSA *
sldns_key_buf2rsa_raw(unsigned char* key, size_t len)
{
BIGNUM* modulus = NULL;
BIGNUM* exponent = NULL;
RSA *rsa;
if(!sldns_key_rsa_buf_bignum(key, len, &modulus, &exponent))
return NULL;
rsa = RSA_new();
if(!rsa) {
BN_free(exponent);
BN_free(modulus);
return NULL;
}
#if OPENSSL_VERSION_NUMBER < 0x10100000 || \
(defined(HAVE_LIBRESSL) && LIBRESSL_VERSION_NUMBER < 0x02070000f)
#ifndef S_SPLINT_S
rsa->n = modulus;
rsa->e = exponent;
#endif /* splint */
#else /* OPENSSL_VERSION_NUMBER */
if (!RSA_set0_key(rsa, modulus, exponent, NULL)) {
BN_free(exponent);
BN_free(modulus);
RSA_free(rsa);
return NULL;
}
#endif
return rsa;
}
#endif /* HAVE_OSSL_PARAM_BLD_NEW */
EVP_PKEY* sldns_key_rsa2pkey_raw(unsigned char* key, size_t len)
{
#ifdef HAVE_OSSL_PARAM_BLD_NEW
EVP_PKEY* evp_key = NULL;
EVP_PKEY_CTX* ctx;
BIGNUM *n=NULL, *e=NULL;
OSSL_PARAM_BLD* param_bld;
OSSL_PARAM* params = NULL;
if(!sldns_key_rsa_buf_bignum(key, len, &n, &e)) {
return NULL;
}
param_bld = OSSL_PARAM_BLD_new();
if(!param_bld) {
BN_free(n);
BN_free(e);
return NULL;
}
if(!OSSL_PARAM_BLD_push_BN(param_bld, "n", n)) {
OSSL_PARAM_BLD_free(param_bld);
BN_free(n);
BN_free(e);
return NULL;
}
if(!OSSL_PARAM_BLD_push_BN(param_bld, "e", e)) {
OSSL_PARAM_BLD_free(param_bld);
BN_free(n);
BN_free(e);
return NULL;
}
params = OSSL_PARAM_BLD_to_param(param_bld);
OSSL_PARAM_BLD_free(param_bld);
ctx = EVP_PKEY_CTX_new_from_name(NULL, "RSA", NULL);
if(!ctx) {
OSSL_PARAM_free(params);
BN_free(n);
BN_free(e);
return NULL;
}
if(EVP_PKEY_fromdata_init(ctx) <= 0) {
EVP_PKEY_CTX_free(ctx);
OSSL_PARAM_free(params);
BN_free(n);
BN_free(e);
return NULL;
}
if(EVP_PKEY_fromdata(ctx, &evp_key, EVP_PKEY_PUBLIC_KEY, params) <= 0) {
EVP_PKEY_CTX_free(ctx);
OSSL_PARAM_free(params);
BN_free(n);
BN_free(e);
return NULL;
}
EVP_PKEY_CTX_free(ctx);
OSSL_PARAM_free(params);
BN_free(n);
BN_free(e);
return evp_key;
#else
RSA* rsa;
EVP_PKEY *evp_key = EVP_PKEY_new();
if(!evp_key) {
return NULL;
}
rsa = sldns_key_buf2rsa_raw(key, len);
if(!rsa) {
EVP_PKEY_free(evp_key);
return NULL;
}
if(EVP_PKEY_assign_RSA(evp_key, rsa) == 0) {
RSA_free(rsa);
EVP_PKEY_free(evp_key);
return NULL;
}
return evp_key;
#endif
}
#ifdef USE_GOST
EVP_PKEY*
sldns_gost2pkey_raw(unsigned char* key, size_t keylen)
{
/* prefix header for X509 encoding */
uint8_t asn[37] = { 0x30, 0x63, 0x30, 0x1c, 0x06, 0x06, 0x2a, 0x85,
0x03, 0x02, 0x02, 0x13, 0x30, 0x12, 0x06, 0x07, 0x2a, 0x85,
0x03, 0x02, 0x02, 0x23, 0x01, 0x06, 0x07, 0x2a, 0x85, 0x03,
0x02, 0x02, 0x1e, 0x01, 0x03, 0x43, 0x00, 0x04, 0x40};
unsigned char encoded[37+64];
const unsigned char* pp;
if(keylen != 64) {
/* key wrong size */
return NULL;
}
/* create evp_key */
memmove(encoded, asn, 37);
memmove(encoded+37, key, 64);
pp = (unsigned char*)&encoded[0];
return d2i_PUBKEY(NULL, &pp, (int)sizeof(encoded));
}
#endif /* USE_GOST */
#ifdef USE_ECDSA
EVP_PKEY*
sldns_ecdsa2pkey_raw(unsigned char* key, size_t keylen, uint8_t algo)
{
#ifdef HAVE_OSSL_PARAM_BLD_NEW
unsigned char buf[256+2]; /* sufficient for 2*384/8+1 */
EVP_PKEY *evp_key = NULL;
EVP_PKEY_CTX* ctx;
OSSL_PARAM_BLD* param_bld;
OSSL_PARAM* params = NULL;
char* group = NULL;
/* check length, which uncompressed must be 2 bignums */
if(algo == LDNS_ECDSAP256SHA256) {
if(keylen != 2*256/8) return NULL;
group = "prime256v1";
} else if(algo == LDNS_ECDSAP384SHA384) {
if(keylen != 2*384/8) return NULL;
group = "P-384";
} else {
return NULL;
}
if(keylen+1 > sizeof(buf)) { /* sanity check */
return NULL;
}
/* prepend the 0x04 for uncompressed format */
buf[0] = POINT_CONVERSION_UNCOMPRESSED;
memmove(buf+1, key, keylen);
param_bld = OSSL_PARAM_BLD_new();
if(!param_bld) {
return NULL;
}
if(!OSSL_PARAM_BLD_push_utf8_string(param_bld, "group", group, 0) ||
!OSSL_PARAM_BLD_push_octet_string(param_bld, "pub", buf, keylen+1)) {
OSSL_PARAM_BLD_free(param_bld);
return NULL;
}
params = OSSL_PARAM_BLD_to_param(param_bld);
OSSL_PARAM_BLD_free(param_bld);
ctx = EVP_PKEY_CTX_new_from_name(NULL, "EC", NULL);
if(!ctx) {
OSSL_PARAM_free(params);
return NULL;
}
if(EVP_PKEY_fromdata_init(ctx) <= 0) {
EVP_PKEY_CTX_free(ctx);
OSSL_PARAM_free(params);
return NULL;
}
if(EVP_PKEY_fromdata(ctx, &evp_key, EVP_PKEY_PUBLIC_KEY, params) <= 0) {
EVP_PKEY_CTX_free(ctx);
OSSL_PARAM_free(params);
return NULL;
}
EVP_PKEY_CTX_free(ctx);
OSSL_PARAM_free(params);
return evp_key;
#else
unsigned char buf[256+2]; /* sufficient for 2*384/8+1 */
const unsigned char* pp = buf;
EVP_PKEY *evp_key;
EC_KEY *ec;
/* check length, which uncompressed must be 2 bignums */
if(algo == LDNS_ECDSAP256SHA256) {
if(keylen != 2*256/8) return NULL;
ec = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
} else if(algo == LDNS_ECDSAP384SHA384) {
if(keylen != 2*384/8) return NULL;
ec = EC_KEY_new_by_curve_name(NID_secp384r1);
} else ec = NULL;
if(!ec) return NULL;
if(keylen+1 > sizeof(buf)) { /* sanity check */
EC_KEY_free(ec);
return NULL;
}
/* prepend the 0x02 (from docs) (or actually 0x04 from implementation
* of openssl) for uncompressed data */
buf[0] = POINT_CONVERSION_UNCOMPRESSED;
memmove(buf+1, key, keylen);
if(!o2i_ECPublicKey(&ec, &pp, (int)keylen+1)) {
EC_KEY_free(ec);
return NULL;
}
evp_key = EVP_PKEY_new();
if(!evp_key) {
EC_KEY_free(ec);
return NULL;
}
if (!EVP_PKEY_assign_EC_KEY(evp_key, ec)) {
EVP_PKEY_free(evp_key);
EC_KEY_free(ec);
return NULL;
}
return evp_key;
#endif /* HAVE_OSSL_PARAM_BLD_NEW */
}
#endif /* USE_ECDSA */
#ifdef USE_ED25519
EVP_PKEY*
sldns_ed255192pkey_raw(const unsigned char* key, size_t keylen)
{
/* ASN1 for ED25519 is 302a300506032b6570032100 <32byteskey> */
uint8_t pre[] = {0x30, 0x2a, 0x30, 0x05, 0x06, 0x03, 0x2b, 0x65,
0x70, 0x03, 0x21, 0x00};
int pre_len = 12;
uint8_t buf[256];
EVP_PKEY *evp_key;
/* pp gets modified by d2i() */
const unsigned char* pp = (unsigned char*)buf;
if(keylen != 32 || keylen + pre_len > sizeof(buf))
return NULL; /* wrong length */
memmove(buf, pre, pre_len);
memmove(buf+pre_len, key, keylen);
evp_key = d2i_PUBKEY(NULL, &pp, (int)(pre_len+keylen));
return evp_key;
}
#endif /* USE_ED25519 */
#ifdef USE_ED448
EVP_PKEY*
sldns_ed4482pkey_raw(const unsigned char* key, size_t keylen)
{
/* ASN1 for ED448 is 3043300506032b6571033a00 <57byteskey> */
uint8_t pre[] = {0x30, 0x43, 0x30, 0x05, 0x06, 0x03, 0x2b, 0x65,
0x71, 0x03, 0x3a, 0x00};
int pre_len = 12;
uint8_t buf[256];
EVP_PKEY *evp_key;
/* pp gets modified by d2i() */
const unsigned char* pp = (unsigned char*)buf;
if(keylen != 57 || keylen + pre_len > sizeof(buf))
return NULL; /* wrong length */
memmove(buf, pre, pre_len);
memmove(buf+pre_len, key, keylen);
evp_key = d2i_PUBKEY(NULL, &pp, (int)(pre_len+keylen));
return evp_key;
}
#endif /* USE_ED448 */
int
sldns_digest_evp(unsigned char* data, unsigned int len, unsigned char* dest,
const EVP_MD* md)
{
EVP_MD_CTX* ctx;
ctx = EVP_MD_CTX_create();
if(!ctx)
return 0;
if(!EVP_DigestInit_ex(ctx, md, NULL) ||
!EVP_DigestUpdate(ctx, data, len) ||
!EVP_DigestFinal_ex(ctx, dest, NULL)) {
EVP_MD_CTX_destroy(ctx);
return 0;
}
EVP_MD_CTX_destroy(ctx);
return 1;
}
#endif /* HAVE_SSL */