Skip to content

Commit

Permalink
Switch to NNpsk0
Browse files Browse the repository at this point in the history 
It isn't called that, which I think has something to do with rweather#36, but preshared keys do appear to work correctly.
  • Loading branch information
@bcspragu
bcspragu committed Jul 20, 2023
1 parent a57d5b2 commit 676a9f0
Showing 1 changed file with 49 additions and 11 deletions.
60 changes: 49 additions & 11 deletions src/noise-c.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -20,7 +20,8 @@ static uint8_t message_buffer[MAX_MESSAGE_LEN];
#define ERROR_CODE_NO_GLOBAL_STATE 0x09
#define ERROR_CODE_ENCRYPT_FAILED 0x0A
#define ERROR_CODE_DECRYPT_FAILED 0x0B
// #define ERROR_CODE_IX 0x0C
#define ERROR_CODE_BAD_PSK 0x0C
#define ERROR_CODE_SET_PSK 0x0D

// TODO: Remove this egregious hack, it's just to test the handshake before we have support for serializing/saving handshake data.
static NoiseHandshakeState *global_handshake;
Expand All @@ -44,9 +45,15 @@ typedef struct {
// HandshakeState *hs;
} StartHandshakeResponse;

StartHandshakeResponse *start_handshake() {
StartHandshakeResponse *start_handshake(uint8_t *psk, size_t psk_size, uint8_t *payload, size_t payload_size) {
StartHandshakeResponse *resp = malloc(sizeof(StartHandshakeResponse));

if (psk_size != NOISE_PSK_LEN) {
noise_perror("PSK had wrong length", NOISE_ERROR_INVALID_LENGTH);
resp->error_code = ERROR_CODE_BAD_PSK;
return resp;
}

int err = noise_init();
if (err != NOISE_ERROR_NONE) {
noise_perror("Noise initialization failed", err);
Expand All @@ -55,7 +62,7 @@ StartHandshakeResponse *start_handshake() {
}

NoiseHandshakeState *handshake;
char *protocol = "Noise_NN_25519_ChaChaPoly_BLAKE2s";
char *protocol = "NoisePSK_NN_25519_ChaChaPoly_BLAKE2s";
err = noise_handshakestate_new_by_name
(&handshake, protocol, NOISE_ROLE_INITIATOR);
if (err != NOISE_ERROR_NONE) {
Expand All @@ -72,6 +79,13 @@ StartHandshakeResponse *start_handshake() {
return resp;
}

err = noise_handshakestate_set_pre_shared_key(handshake, psk, psk_size);
if (err != NOISE_ERROR_NONE) {
noise_perror(protocol, err);
resp->error_code = ERROR_CODE_SET_PSK;
return resp;
}

// The NN handshake only uses ephemeral keys, e.g.
// -> e
// <- e, ee
Expand All @@ -94,8 +108,10 @@ StartHandshakeResponse *start_handshake() {

/* Write the next handshake message with a zero-length payload */
NoiseBuffer mbuf;
NoiseBuffer mbuf_payload;
noise_buffer_set_input(mbuf_payload, payload, payload_size);
noise_buffer_set_output(mbuf, message_buffer, sizeof(message_buffer));
err = noise_handshakestate_write_message(handshake, &mbuf, NULL);
err = noise_handshakestate_write_message(handshake, &mbuf, &mbuf_payload);
if (err != NOISE_ERROR_NONE) {
noise_perror("write handshake", err);
resp->error_code = ERROR_CODE_WRITE_MESSAGE;
Expand All @@ -114,13 +130,20 @@ StartHandshakeResponse *start_handshake() {

typedef struct {
uint32_t error_code;

size_t message_size;
uint8_t *message;

// This is actual user message data, not Noise handshake data.
// It's the user info the initiator sent in start_handshake.
size_t payload_size;
uint8_t *payload;

// TODO: Figure out how to do this correctly.
// HandshakeState *hs;
} ContinueHandshakeResponse;

ContinueHandshakeResponse *continue_handshake(uint8_t *message, size_t message_size, uint8_t *payload, size_t payload_size) {
ContinueHandshakeResponse *continue_handshake(uint8_t *message, size_t message_size, uint8_t *psk, size_t psk_size, uint8_t *payload, size_t payload_size) {
ContinueHandshakeResponse *resp = malloc(sizeof(ContinueHandshakeResponse));

int err = noise_init();
Expand All @@ -131,7 +154,7 @@ ContinueHandshakeResponse *continue_handshake(uint8_t *message, size_t message_s
}

NoiseHandshakeState *handshake;
char *protocol = "Noise_NN_25519_ChaChaPoly_BLAKE2s";
char *protocol = "NoisePSK_NN_25519_ChaChaPoly_BLAKE2s";
err = noise_handshakestate_new_by_name
(&handshake, protocol, NOISE_ROLE_RESPONDER);
if (err != NOISE_ERROR_NONE) {
Expand All @@ -148,6 +171,13 @@ ContinueHandshakeResponse *continue_handshake(uint8_t *message, size_t message_s
return resp;
}

err = noise_handshakestate_set_pre_shared_key(handshake, psk, psk_size);
if (err != NOISE_ERROR_NONE) {
noise_perror(protocol, err);
resp->error_code = ERROR_CODE_SET_PSK;
return resp;
}

// The NN handshake only uses ephemeral keys, e.g.
// -> e
// <- e, ee
Expand All @@ -169,14 +199,21 @@ ContinueHandshakeResponse *continue_handshake(uint8_t *message, size_t message_s
return resp;
}

NoiseBuffer mbuf_payload;
NoiseBuffer mbuf;
noise_buffer_set_input(mbuf, message, message_size);
err = noise_handshakestate_read_message(handshake, &mbuf, NULL);
noise_buffer_set_output(mbuf_payload, message_buffer, sizeof(message_buffer));
err = noise_handshakestate_read_message(handshake, &mbuf, &mbuf_payload);
if (err != NOISE_ERROR_NONE) {
noise_perror("read handshake", err);
resp->error_code = ERROR_CODE_READ_MESSAGE;
return resp;
}

// Copy the payload to something we can return.
size_t out_payload_size = mbuf_payload.size;
uint8_t *out_payload = malloc( sizeof( uint8_t ) * out_payload_size );
memcpy(out_payload, message_buffer, out_payload_size);

// Our second action should be to write our responder's part of the handshake, along with our payload.
action = noise_handshakestate_get_action(handshake);
Expand All @@ -186,7 +223,6 @@ ContinueHandshakeResponse *continue_handshake(uint8_t *message, size_t message_s
return resp;
}

NoiseBuffer mbuf_payload;
noise_buffer_set_input(mbuf_payload, payload, payload_size);
noise_buffer_set_output(mbuf, message_buffer, sizeof(message_buffer));
err = noise_handshakestate_write_message(handshake, &mbuf, &mbuf_payload);
Expand Down Expand Up @@ -215,21 +251,23 @@ ContinueHandshakeResponse *continue_handshake(uint8_t *message, size_t message_s

resp->message_size = mbuf.size;
resp->message = &message_buffer[0];
resp->payload = out_payload;
resp->payload_size = out_payload_size;
resp->error_code = 0;
// resp->handshake = handshake;

return resp;
}

int main() {
start_handshake();
// start_handshake();
}

typedef struct {
uint32_t error_code;

// Unlike previous responses, this is actual user message data, not Noise handshake data.
// It's the user info the responder set back in continue_handshake.
// This is actual user message data, not Noise handshake data.
// It's the user info the responder sent back in continue_handshake.
size_t payload_size;
uint8_t *payload;

Expand Down

0 comments on commit 676a9f0

Please sign in to comment.