ERL_NIF_TERM dh_compute_key_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{/* (OthersPublicKey, MyPrivateKey, DHParams=[P,G]) */
BIGNUM *other_pub_key = NULL,
*dh_p = NULL,
*dh_g = NULL;
DH *dh_priv = DH_new();
/* Check the arguments and get
my private key (dh_priv),
the peer's public key (other_pub_key),
the parameters p & q
*/
{
BIGNUM *dummy_pub_key = NULL,
*priv_key = NULL;
ERL_NIF_TERM head, tail;
if (!get_bn_from_bin(env, argv[0], &other_pub_key)
|| !get_bn_from_bin(env, argv[1], &priv_key)
|| !enif_get_list_cell(env, argv[2], &head, &tail)
|| !get_bn_from_bin(env, head, &dh_p)
|| !enif_get_list_cell(env, tail, &head, &tail)
|| !get_bn_from_bin(env, head, &dh_g)
|| !enif_is_empty_list(env, tail)
/* Note: DH_set0_key() does not allow setting only the
* private key, although DH_compute_key() does not use the
* public key. Work around this limitation by setting
* the public key to a copy of the private key.
*/
|| !(dummy_pub_key = BN_dup(priv_key))
|| !DH_set0_key(dh_priv, dummy_pub_key, priv_key)
|| !DH_set0_pqg(dh_priv, dh_p, NULL, dh_g)
) {
if (dh_p) BN_free(dh_p);
if (dh_g) BN_free(dh_g);
if (other_pub_key) BN_free(other_pub_key);
if (dummy_pub_key) BN_free(dummy_pub_key);
if (priv_key) BN_free(priv_key);
return enif_make_badarg(env);
}
}
{
ErlNifBinary ret_bin;
int size;
enif_alloc_binary(DH_size(dh_priv), &ret_bin);
size = DH_compute_key(ret_bin.data, other_pub_key, dh_priv);
BN_free(other_pub_key);
DH_free(dh_priv);
if (size<=0) {
enif_release_binary(&ret_bin);
return atom_error;
}
if (size != ret_bin.size) enif_realloc_binary(&ret_bin, size);
return enif_make_binary(env, &ret_bin);
}
}
static ERL_NIF_TERM rsa_generate_key(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{/* (ModulusSize, PublicExponent) */
int modulus_bits;
BIGNUM *pub_exp, *three;
RSA *rsa;
int success;
ERL_NIF_TERM result;
BN_GENCB *intr_cb;
#ifndef HAVE_OPAQUE_BN_GENCB
BN_GENCB intr_cb_buf;
#endif
if (!enif_get_int(env, argv[0], &modulus_bits) || modulus_bits < 256) {
return enif_make_badarg(env);
}
if (!get_bn_from_bin(env, argv[1], &pub_exp)) {
return enif_make_badarg(env);
}
/* Make sure the public exponent is large enough (at least 3).
* Without this, RSA_generate_key_ex() can run forever. */
three = BN_new();
BN_set_word(three, 3);
success = BN_cmp(pub_exp, three);
BN_free(three);
if (success < 0) {
BN_free(pub_exp);
return enif_make_badarg(env);
}
/* For large keys, prime generation can take many seconds. Set up
* the callback which we use to test whether the process has been
* interrupted. */
#ifdef HAVE_OPAQUE_BN_GENCB
intr_cb = BN_GENCB_new();
#else
intr_cb = &intr_cb_buf;
#endif
BN_GENCB_set(intr_cb, check_erlang_interrupt, env);
rsa = RSA_new();
success = RSA_generate_key_ex(rsa, modulus_bits, pub_exp, intr_cb);
BN_free(pub_exp);
#ifdef HAVE_OPAQUE_BN_GENCB
BN_GENCB_free(intr_cb);
#endif
if (!success) {
RSA_free(rsa);
return atom_error;
}
result = put_rsa_private_key(env, rsa);
RSA_free(rsa);
return result;
}
int get_rsa_public_key(ErlNifEnv* env, ERL_NIF_TERM key, RSA *rsa)
{
/* key=[E,N] */
ERL_NIF_TERM head, tail;
BIGNUM *e, *n;
if (!enif_get_list_cell(env, key, &head, &tail)
|| !get_bn_from_bin(env, head, &e)
|| !enif_get_list_cell(env, tail, &head, &tail)
|| !get_bn_from_bin(env, head, &n)
|| !enif_is_empty_list(env, tail)) {
return 0;
}
(void) RSA_set0_key(rsa, n, e, NULL);
return 1;
}
ERL_NIF_TERM strong_rand_range_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{/* (Range) */
BIGNUM *bn_range, *bn_rand;
ERL_NIF_TERM ret;
if(!get_bn_from_bin(env, argv[0], &bn_range)) {
return enif_make_badarg(env);
}
bn_rand = BN_new();
if (BN_rand_range(bn_rand, bn_range) != 1) {
ret = atom_false;
}
else {
ret = bin_from_bn(env, bn_rand);
}
BN_free(bn_rand);
BN_free(bn_range);
return ret;
}
int get_rsa_private_key(ErlNifEnv* env, ERL_NIF_TERM key, RSA *rsa)
{
/* key=[E,N,D]|[E,N,D,P1,P2,E1,E2,C] */
ERL_NIF_TERM head, tail;
BIGNUM *e, *n, *d;
BIGNUM *p, *q;
BIGNUM *dmp1, *dmq1, *iqmp;
if (!enif_get_list_cell(env, key, &head, &tail)
|| !get_bn_from_bin(env, head, &e)
|| !enif_get_list_cell(env, tail, &head, &tail)
|| !get_bn_from_bin(env, head, &n)
|| !enif_get_list_cell(env, tail, &head, &tail)
|| !get_bn_from_bin(env, head, &d)) {
return 0;
}
(void) RSA_set0_key(rsa, n, e, d);
if (enif_is_empty_list(env, tail)) {
return 1;
}
if (!enif_get_list_cell(env, tail, &head, &tail)
|| !get_bn_from_bin(env, head, &p)
|| !enif_get_list_cell(env, tail, &head, &tail)
|| !get_bn_from_bin(env, head, &q)
|| !enif_get_list_cell(env, tail, &head, &tail)
|| !get_bn_from_bin(env, head, &dmp1)
|| !enif_get_list_cell(env, tail, &head, &tail)
|| !get_bn_from_bin(env, head, &dmq1)
|| !enif_get_list_cell(env, tail, &head, &tail)
|| !get_bn_from_bin(env, head, &iqmp)
|| !enif_is_empty_list(env, tail)) {
return 0;
}
(void) RSA_set0_factors(rsa, p, q);
(void) RSA_set0_crt_params(rsa, dmp1, dmq1, iqmp);
return 1;
}
ERL_NIF_TERM mod_exp_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{/* (Base,Exponent,Modulo,bin_hdr) */
BIGNUM *bn_base = NULL, *bn_exponent = NULL, *bn_modulo = NULL, *bn_result = NULL;
BN_CTX *bn_ctx = NULL;
unsigned char* ptr;
int dlen;
unsigned bin_hdr; /* return type: 0=plain binary, 4: mpint */
unsigned extra_byte;
ERL_NIF_TERM ret;
ASSERT(argc == 4);
if (!get_bn_from_bin(env, argv[0], &bn_base))
goto bad_arg;
if (!get_bn_from_bin(env, argv[1], &bn_exponent))
goto bad_arg;
if (!get_bn_from_bin(env, argv[2], &bn_modulo))
goto bad_arg;
if (!enif_get_uint(env, argv[3], &bin_hdr))
goto bad_arg;
if (bin_hdr != 0 && bin_hdr != 4)
goto bad_arg;
if ((bn_result = BN_new()) == NULL)
goto err;
if ((bn_ctx = BN_CTX_new()) == NULL)
goto err;
if (!BN_mod_exp(bn_result, bn_base, bn_exponent, bn_modulo, bn_ctx))
goto err;
dlen = BN_num_bytes(bn_result);
if (dlen < 0 || dlen > INT_MAX / 8)
goto bad_arg;
extra_byte = bin_hdr && BN_is_bit_set(bn_result, dlen * 8 - 1);
if ((ptr = enif_make_new_binary(env, bin_hdr + extra_byte + (unsigned int)dlen, &ret)) == NULL)
goto err;
if (bin_hdr) {
put_uint32(ptr, extra_byte + (unsigned int)dlen);
ptr[4] = 0; /* extra zeroed byte to ensure a positive mpint */
ptr += bin_hdr + extra_byte;
}
BN_bn2bin(bn_result, ptr);
goto done;
bad_arg:
err:
ret = enif_make_badarg(env);
done:
if (bn_base)
BN_free(bn_base);
if (bn_exponent)
BN_free(bn_exponent);
if (bn_modulo)
BN_free(bn_modulo);
if (bn_result)
BN_free(bn_result);
if (bn_ctx)
BN_CTX_free(bn_ctx);
return ret;
}
ERL_NIF_TERM dh_generate_key_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{/* (PrivKey|undefined, DHParams=[P,G], Mpint, Len|0) */
DH *dh_params = NULL;
int mpint; /* 0 or 4 */
{
ERL_NIF_TERM head, tail;
BIGNUM
*dh_p = NULL,
*dh_g = NULL,
*priv_key_in = NULL;
unsigned long
len = 0;
if (!(get_bn_from_bin(env, argv[0], &priv_key_in)
|| argv[0] == atom_undefined)
|| !enif_get_list_cell(env, argv[1], &head, &tail)
|| !get_bn_from_bin(env, head, &dh_p)
|| !enif_get_list_cell(env, tail, &head, &tail)
|| !get_bn_from_bin(env, head, &dh_g)
|| !enif_is_empty_list(env, tail)
|| !enif_get_int(env, argv[2], &mpint) || (mpint & ~4)
|| !enif_get_ulong(env, argv[3], &len)
/* Load dh_params with values to use by the generator.
Mem mgmnt transfered from dh_p etc to dh_params */
|| !(dh_params = DH_new())
|| (priv_key_in && !DH_set0_key(dh_params, NULL, priv_key_in))
|| !DH_set0_pqg(dh_params, dh_p, NULL, dh_g)
) {
if (priv_key_in) BN_free(priv_key_in);
if (dh_p) BN_free(dh_p);
if (dh_g) BN_free(dh_g);
if (dh_params) DH_free(dh_params);
return enif_make_badarg(env);
}
if (len) {
if (len < BN_num_bits(dh_p))
DH_set_length(dh_params, len);
else {
if (priv_key_in) BN_free(priv_key_in);
if (dh_p) BN_free(dh_p);
if (dh_g) BN_free(dh_g);
if (dh_params) DH_free(dh_params);
return enif_make_badarg(env);
}
}
}
#ifdef HAS_EVP_PKEY_CTX
{
EVP_PKEY_CTX *ctx;
EVP_PKEY *dhkey, *params;
int success;
params = EVP_PKEY_new();
success = EVP_PKEY_set1_DH(params, dh_params); /* set the key referenced by params to dh_params... */
DH_free(dh_params); /* ...dh_params (and params) must be freed */
if (!success) return atom_error;
ctx = EVP_PKEY_CTX_new(params, NULL);
EVP_PKEY_free(params);
if (!ctx) {
return atom_error;
}
if (!EVP_PKEY_keygen_init(ctx)) {
/* EVP_PKEY_CTX_free(ctx); */
return atom_error;
}
dhkey = EVP_PKEY_new();
if (!EVP_PKEY_keygen(ctx, &dhkey)) { /* "performs a key generation operation, the ... */
/*... generated key is written to ppkey." (=last arg) */
/* EVP_PKEY_CTX_free(ctx); */
/* EVP_PKEY_free(dhkey); */
return atom_error;
}
dh_params = EVP_PKEY_get1_DH(dhkey); /* return the referenced key. dh_params and dhkey must be freed */
EVP_PKEY_free(dhkey);
if (!dh_params) {
/* EVP_PKEY_CTX_free(ctx); */
return atom_error;
}
EVP_PKEY_CTX_free(ctx);
}
#else
if (!DH_generate_key(dh_params)) return atom_error;
#endif
{
unsigned char *pub_ptr, *prv_ptr;
int pub_len, prv_len;
ERL_NIF_TERM ret_pub, ret_prv;
const BIGNUM *pub_key_gen, *priv_key_gen;
DH_get0_key(dh_params,
&pub_key_gen, &priv_key_gen); /* Get pub_key_gen and priv_key_gen.
"The values point to the internal representation of
the public key and private key values. This memory
should not be freed directly." says man */
pub_len = BN_num_bytes(pub_key_gen);
prv_len = BN_num_bytes(priv_key_gen);
pub_ptr = enif_make_new_binary(env, pub_len+mpint, &ret_pub);
prv_ptr = enif_make_new_binary(env, prv_len+mpint, &ret_prv);
if (mpint) {
put_int32(pub_ptr, pub_len); pub_ptr += 4;
put_int32(prv_ptr, prv_len); prv_ptr += 4;
}
BN_bn2bin(pub_key_gen, pub_ptr);
BN_bn2bin(priv_key_gen, prv_ptr);
ERL_VALGRIND_MAKE_MEM_DEFINED(pub_ptr, pub_len);
ERL_VALGRIND_MAKE_MEM_DEFINED(prv_ptr, prv_len);
DH_free(dh_params);
return enif_make_tuple2(env, ret_pub, ret_prv);
}
}
