diff --git a/lib/include/chiaki/ecdh.h b/lib/include/chiaki/ecdh.h
index 50162ad..af9dc36 100644
--- a/lib/include/chiaki/ecdh.h
+++ b/lib/include/chiaki/ecdh.h
@@ -20,17 +20,22 @@
 
 #include "common.h"
 
+#include <stdlib.h>
+#include <stdint.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 typedef struct chiaki_ecdh_t
 {
-
+	struct ec_group_st *group;
+	struct ec_key_st *key_local;
 } ChiakiECDH;
 
 CHIAKI_EXPORT ChiakiErrorCode chiaki_ecdh_init(ChiakiECDH *ecdh);
 CHIAKI_EXPORT void chiaki_ecdh_fini(ChiakiECDH *ecdh);
+CHIAKI_EXPORT ChiakiErrorCode chiaki_ecdh_get_local_pub_key(ChiakiECDH *ecdh, uint8_t *key_out, size_t *key_out_size, uint8_t *handshake_key, uint8_t *sig_out, size_t *sig_out_size);
 
 #ifdef __cplusplus
 }
diff --git a/lib/include/chiaki/log.h b/lib/include/chiaki/log.h
index 666cacf..c224e4d 100644
--- a/lib/include/chiaki/log.h
+++ b/lib/include/chiaki/log.h
@@ -38,6 +38,7 @@ typedef struct chiaki_log_t
 
 void chiaki_log(ChiakiLog *log, ChiakiLogLevel level, const char *fmt, ...);
 void chiaki_log_hexdump(ChiakiLog *log, ChiakiLogLevel level, const uint8_t *buf, size_t buf_size);
+void chiaki_log_hexdump_raw(ChiakiLog *log, ChiakiLogLevel level, const uint8_t *buf, size_t buf_size);
 
 #define CHIAKI_LOGD(log, ...) do { chiaki_log((log), CHIAKI_LOG_DEBUG, __VA_ARGS__); } while(0)
 #define CHIAKI_LOGI(log, ...) do { chiaki_log((log), CHIAKI_LOG_INFO, __VA_ARGS__); } while(0)
diff --git a/lib/include/chiaki/session.h b/lib/include/chiaki/session.h
index 41dbaca..1a4e7bc 100644
--- a/lib/include/chiaki/session.h
+++ b/lib/include/chiaki/session.h
@@ -25,6 +25,7 @@
 #include "ctrl.h"
 #include "rpcrypt.h"
 #include "takion.h"
+#include "ecdh.h"
 
 #include <stdint.h>
 #include <netdb.h>
@@ -101,6 +102,7 @@ typedef struct chiaki_session_t
 	uint8_t handshake_key[CHIAKI_HANDSHAKE_KEY_SIZE];
 	unsigned int mtu;
 	unsigned int rtt;
+	ChiakiECDH ecdh;
 
 	ChiakiQuitReason quit_reason;
 
diff --git a/lib/src/ecdh.c b/lib/src/ecdh.c
index 0cf366d..9aca9ea 100644
--- a/lib/src/ecdh.c
+++ b/lib/src/ecdh.c
@@ -15,14 +15,55 @@
  * along with Chiaki.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+#include <chiaki/session.h>
 #include <chiaki/ecdh.h>
+#include <chiaki/base64.h>
+
+#include <openssl/evp.h>
+#include <openssl/ec.h>
+#include <openssl/hmac.h>
+
+#include <string.h>
+
+#include <stdio.h>
+
 
 CHIAKI_EXPORT ChiakiErrorCode chiaki_ecdh_init(ChiakiECDH *ecdh)
 {
+	memset(ecdh, 0, sizeof(ChiakiECDH));
+
+#define CHECK(a) if(!(a)) { chiaki_ecdh_fini(ecdh); return CHIAKI_ERR_UNKNOWN; }
+
+	CHECK(ecdh->group = EC_GROUP_new_by_curve_name(NID_secp256k1));
+
+	CHECK(ecdh->key_local = EC_KEY_new());
+	CHECK(EC_KEY_set_group(ecdh->key_local, ecdh->group));
+	CHECK(EC_KEY_generate_key(ecdh->key_local));
+
+#undef CHECK
+
 	return CHIAKI_ERR_SUCCESS;
 }
 
 CHIAKI_EXPORT void chiaki_ecdh_fini(ChiakiECDH *ecdh)
 {
+	EC_KEY_free(ecdh->key_local);
+	EC_GROUP_free(ecdh->group);
+}
 
+
+CHIAKI_EXPORT ChiakiErrorCode chiaki_ecdh_get_local_pub_key(ChiakiECDH *ecdh, uint8_t *key_out, size_t *key_out_size, uint8_t *handshake_key, uint8_t *sig_out, size_t *sig_out_size)
+{
+	const EC_POINT *point = EC_KEY_get0_public_key(ecdh->key_local);
+	if(!point)
+		return CHIAKI_ERR_UNKNOWN;
+
+	*key_out_size = EC_POINT_point2oct(ecdh->group, point, POINT_CONVERSION_UNCOMPRESSED, key_out, *key_out_size, NULL);
+	if(!(*key_out_size))
+		return CHIAKI_ERR_UNKNOWN;
+
+	if(!HMAC(EVP_sha256(), handshake_key, CHIAKI_HANDSHAKE_KEY_SIZE, key_out, *key_out_size, sig_out, (unsigned int *)sig_out_size))
+		return CHIAKI_ERR_UNKNOWN;
+
+	return CHIAKI_ERR_SUCCESS;
 }
\ No newline at end of file
diff --git a/lib/src/log.c b/lib/src/log.c
index a62b1ca..572cdc6 100644
--- a/lib/src/log.c
+++ b/lib/src/log.c
@@ -112,4 +112,20 @@ void chiaki_log_hexdump(ChiakiLog *log, ChiakiLogLevel level, const uint8_t *buf
 		else
 			break;
 	}
+}
+
+void chiaki_log_hexdump_raw(ChiakiLog *log, ChiakiLogLevel level, const uint8_t *buf, size_t buf_size)
+{
+	char *str = malloc(buf_size * 2 + 1);
+	if(!str)
+		return;
+	for(size_t i=0; i<buf_size; i++)
+	{
+		uint8_t v = buf[i];
+		str[i*2+0] = hex_char[v >> 4];
+		str[i*2+1] = hex_char[v & 0xf];
+	}
+	str[buf_size*2] = 0;
+	chiaki_log(log, level, "%s\n", str);
+	free(str);
 }
\ No newline at end of file
diff --git a/lib/src/nagare.c b/lib/src/nagare.c
index 22b652f..159df20 100644
--- a/lib/src/nagare.c
+++ b/lib/src/nagare.c
@@ -173,13 +173,15 @@ static ChiakiErrorCode nagare_send_big(ChiakiNagare *nagare)
 		char b64[LAUNCH_SPEC_JSON_BUF_SIZE * 2];
 	} launch_spec_buf;
 	ssize_t launch_spec_json_size = chiaki_launchspec_format(launch_spec_buf.json, sizeof(launch_spec_buf.json), &launch_spec);
-	if(launch_spec_json_size != CHIAKI_ERR_SUCCESS)
+	if(launch_spec_json_size < 0)
 	{
 		CHIAKI_LOGE(nagare->log, "Nagare failed to format LaunchSpec json\n");
 		return CHIAKI_ERR_UNKNOWN;
 	}
 	launch_spec_json_size += 1; // we also want the trailing 0
 
+	CHIAKI_LOGD(nagare->log, "LaunchSpec: %s\n", launch_spec_buf.json);
+
 	uint8_t launch_spec_json_enc[LAUNCH_SPEC_JSON_BUF_SIZE];
 	memset(launch_spec_json_enc, 0, (size_t)launch_spec_json_size);
 	ChiakiErrorCode err = chiaki_rpcrypt_encrypt(&session->rpcrypt, 0, launch_spec_json_enc, launch_spec_json_enc,
@@ -198,6 +200,20 @@ static ChiakiErrorCode nagare_send_big(ChiakiNagare *nagare)
 		return err;
 	}
 
+	char ecdh_pub_key[128];
+	ChiakiPBBuf ecdh_pub_key_buf = { sizeof(ecdh_pub_key), ecdh_pub_key };
+	char ecdh_sig[32];
+	ChiakiPBBuf ecdh_sig_buf = { sizeof(ecdh_sig), ecdh_sig };
+	err = chiaki_ecdh_get_local_pub_key(&session->ecdh,
+			ecdh_pub_key, &ecdh_pub_key_buf.size,
+			session->handshake_key,
+			ecdh_sig, &ecdh_sig_buf.size);
+	if(err != CHIAKI_ERR_SUCCESS)
+	{
+		CHIAKI_LOGE(nagare->log, "Nagare failed to get ECDH key and sig\n");
+		return err;
+	}
+
 	tkproto_TakionMessage msg;
 	memset(&msg, 0, sizeof(msg));
 
@@ -209,11 +225,12 @@ static ChiakiErrorCode nagare_send_big(ChiakiNagare *nagare)
 	msg.big_payload.launch_spec.arg = launch_spec_buf.b64;
 	msg.big_payload.launch_spec.funcs.encode = chiaki_pb_encode_string;
 	msg.big_payload.encrypted_key.funcs.encode = chiaki_pb_encode_zero_encrypted_key;
+	msg.big_payload.ecdh_pub_key.arg = &ecdh_pub_key_buf;
+	msg.big_payload.ecdh_pub_key.funcs.encode = chiaki_pb_encode_buf;
+	msg.big_payload.ecdh_sig.arg = &ecdh_sig_buf;
+	msg.big_payload.ecdh_sig.funcs.encode = chiaki_pb_encode_buf;
 
-	// TODO: msg.big_payload.ecdh_pub_key
-	// TODO: msg.big_payload.ecdh_sig
-
-	uint8_t buf[12];
+	uint8_t buf[2048];
 	size_t buf_size;
 
 	pb_ostream_t stream = pb_ostream_from_buffer(buf, sizeof(buf));
diff --git a/lib/src/pb_utils.h b/lib/src/pb_utils.h
index 12381aa..c2aa4a9 100644
--- a/lib/src/pb_utils.h
+++ b/lib/src/pb_utils.h
@@ -30,4 +30,21 @@ static bool chiaki_pb_encode_string(pb_ostream_t *stream, const pb_field_t *fiel
 	return pb_encode_string(stream, (uint8_t*)str, strlen(str));
 }
 
+typedef struct chiaki_pb_buf_t
+{
+	size_t size;
+	uint8_t *buf;
+} ChiakiPBBuf;
+
+static bool chiaki_pb_encode_buf(pb_ostream_t *stream, const pb_field_t *field, void *const *arg)
+{
+	ChiakiPBBuf *buf = *arg;
+
+	if (!pb_encode_tag_for_field(stream, field))
+		return false;
+
+	return pb_encode_string(stream, buf->buf, buf->size);
+}
+
+
 #endif // CHIAKI_PB_UTILS_H
diff --git a/lib/src/session.c b/lib/src/session.c
index d3bf85e..ce8c456 100644
--- a/lib/src/session.c
+++ b/lib/src/session.c
@@ -177,6 +177,13 @@ static void *session_thread_func(void *arg)
 		goto quit_ctrl;
 	}
 
+	err = chiaki_ecdh_init(&session->ecdh);
+	if(err != CHIAKI_ERR_SUCCESS)
+	{
+		CHIAKI_LOGE(&session->log, "Session failed to initialize ECDH\n");
+		goto quit_ctrl;
+	}
+
 	err = chiaki_nagare_run(session);
 	if(err != CHIAKI_ERR_SUCCESS)
 	{