Commit cf7a271f authored by Matt Johnston's avatar Matt Johnston
Browse files

ecc key import function

--HG--
branch : ecc
parent 74cad161
......@@ -678,10 +678,11 @@ void kexecdh_comb_key(struct kex_ecdh_param *param, buffer *pub_them,
// public keys from client and server
ecc_key *Q_C, *Q_S, *Q_them;
// XXX load Q_them
oj // XXX load Q_them
Q_them = buf_get_ecc_key_string()
ses.dh_K = dropbear_ecc_shared_secret();
ses.dh_K = dropbear_ecc_shared_secret()
/* Check that dh_pub_them (dh_e or dh_f) is in the range [1, p-1] */
if (mp_cmp(dh_pub_them, &dh_p) != MP_LT
|| mp_cmp_d(dh_pub_them, 0) != MP_GT) {
......
......@@ -4,9 +4,11 @@
#ifdef DROPBEAR_ECC
// TODO: use raw bytes for the dp rather than the hex strings in libtomcrypt's ecc.c
#ifdef DROPBEAR_ECC_256
const struct ecc_curve_secp256r1 {
.ltc_set = &ltc_ecc_sets[0],
const struct dropbear_ecc_curve ecc_curve_secp256r1 {
.dp = &ltc_ecc_sets[0],
.hash_desc = sha256_desc,
.name = "secp256r1"
};
......@@ -14,23 +16,23 @@ const struct ecc_curve_secp256r1 {
#ifdef DROPBEAR_ECC_384
const struct ecc_curve_secp384r1 {
.ltc_set = &ltc_ecc_sets[1],
const struct dropbear_ecc_curve ecc_curve_secp384r1 {
.dp = &ltc_ecc_sets[1],
.hash_desc = sha384_desc,
.name = "secp384r1"
};
#endif
#ifdef DROPBEAR_ECC_256
const struct ecc_curve_secp256r1 {
.ltc_set = &ltc_ecc_sets[0],
.hash_desc = sha256_desc,
.name = "secp256r1"
#ifdef DROPBEAR_ECC_521
const struct dropbear_ecc_curve ecc_curve_secp521r1 {
.dp = &ltc_ecc_sets[2],
.hash_desc = sha521_desc,
.name = "secp521r1"
};
#endif
void buf_put_ecc_key_string(buffer *buf, ecc_key *key) {
void buf_put_ecc_pubkey_string(buffer *buf, ecc_key *key) {
// XXX point compression
int len = key->dp->size*2 + 1;
buf_putint(len);
......@@ -41,7 +43,62 @@ void buf_put_ecc_key_string(buffer *buf, ecc_key *key) {
buf_incrwritepos(buf, len);
}
int buf_get_ecc_key_string(buffer *buf, ecc_key *key) {
ecc_key * buf_get_ecc_key_string(buffer *buf, const struct dropbear_ecc_curve *curve) {
ecc_key *key = NULL;
int ret = DROPBEAR_FAILURE;
const int size = curve->dp->size;
unsigned int len = buf_get_string(buf);
unsigned char first = buf_get_char(buf);
if (first == 2 || first == 3) {
dropbear_log("Dropbear doesn't support ECC point compression");
return NULL;
}
if (first != 4 || len != 1+2*size) {
return NULL;
}
key = m_malloc(sizeof(*key));
m_mp_init_multi(&key->pubkey.x, &key->pubkey.y, &key->pubkey.z, &key->k, NULL);
if (mp_read_unsigned_bin(&key->pubkey.x, buf_getptr(buf, size), size) != MP_OKAY) {
goto out;
}
buf_incrpos(buf, size);
if (mp_read_unsigned_bin(&key->pubkey.y, buf_getptr(buf, size), size) != MP_OKAY) {
goto out;
}
buf_incrpos(buf, size);
if (mp_set(key->pubkey.z, 1) != MP_OKAY) {
goto out;
}
if (is_point(key) != CRYPT_OK) {
goto out;
}
// SEC1 3.2.3.1 Check that Q != 0
if (mp_cmp_d(key->pubkey.x, 0) == LTC_MP_EQ) {
goto out;
}
if (mp_cmp_d(key->pubkey.y, 0) == LTC_MP_EQ) {
goto out;
}
ret = DROPBEAR_SUCCESS;
out:
if (ret == DROPBEAR_FAILURE) {
if (key) {
mp_free_multi(&key->pubkey.x, &key->pubkey.y, &key->pubkey.z, &key->k, NULL);
m_free(key);
key = NULL;
}
}
return key;
}
// a modified version of libtomcrypt's "ecc_shared_secret" to output
......
......@@ -9,7 +9,7 @@
#ifdef DROPBEAR_ECC
struct dropbear_ecc_curve {
const ltc_ecc_set_type* ltc_set;
const ltc_ecc_set_type *dp; // curve domain parameters
const struct ltc_hash_descriptor *hash_desc;
const char *name;
};
......
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