unbound/sldns/keyraw.c
Florian Obser ff35659d5a Use OpenSSL 1.1 API to access DSA and RSA internals
In LibreSSL 3.5, DSA and RSA internals will become opaque, so they can
no longer be accessed directly and the libunbound build will break. The
required API, DSA_set0_pqg(), DSA_set0_key() as well as RSA_set0_key(),
has been available since LibreSSL 2.7, so this change should not affect
any users.

From Theo Buehler.
2022-01-11 15:34:25 +01:00

715 lines
15 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
#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
#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 */