danicoin/external/unbound/ldns/keyraw.c
2014-10-05 23:44:31 +02:00

368 lines
7.7 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 "ldns/keyraw.h"
#include "ldns/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
#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
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 */
DSA *
sldns_key_buf2dsa_raw(unsigned char* key, size_t len)
{
uint8_t T;
uint16_t length;
uint16_t offset;
DSA *dsa;
BIGNUM *Q; BIGNUM *P;
BIGNUM *G; BIGNUM *Y;
if(len == 0)
return NULL;
T = (uint8_t)key[0];
length = (64 + T * 8);
offset = 1;
if (T > 8) {
return NULL;
}
if(len < (size_t)1 + SHA_DIGEST_LENGTH + 3*length)
return NULL;
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);
offset += length;
/* create the key and set its properties */
if(!Q || !P || !G || !Y || !(dsa = DSA_new())) {
BN_free(Q);
BN_free(P);
BN_free(G);
BN_free(Y);
return NULL;
}
#ifndef S_SPLINT_S
dsa->p = P;
dsa->q = Q;
dsa->g = G;
dsa->pub_key = Y;
#endif /* splint */
return dsa;
}
RSA *
sldns_key_buf2rsa_raw(unsigned char* key, size_t len)
{
uint16_t offset;
uint16_t exp;
uint16_t int16;
RSA *rsa;
BIGNUM *modulus;
BIGNUM *exponent;
if (len == 0)
return NULL;
if (key[0] == 0) {
if(len < 3)
return NULL;
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 NULL;
/* Exponent */
exponent = BN_new();
if(!exponent) return NULL;
(void) BN_bin2bn(key+offset, (int)exp, exponent);
offset += exp;
/* Modulus */
modulus = BN_new();
if(!modulus) {
BN_free(exponent);
return NULL;
}
/* length of the buffer must match the key length! */
(void) BN_bin2bn(key+offset, (int)(len - offset), modulus);
rsa = RSA_new();
if(!rsa) {
BN_free(exponent);
BN_free(modulus);
return NULL;
}
#ifndef S_SPLINT_S
rsa->n = modulus;
rsa->e = exponent;
#endif /* splint */
return rsa;
}
#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)
{
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))
return NULL; /* sanity check */
/* 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 /* USE_ECDSA */
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 */