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Detect if server closed connection on client and only use one packet for authenticating client on server

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This commit is contained in:
Night Kaly 2024-09-20 17:38:00 +01:00
parent 88602a64b5
commit 79defadf12
Signed by: night0721
GPG key ID: 957D67B8DB7A119B
3 changed files with 22 additions and 17 deletions
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7
lib/packet.c
View file

@ -211,8 +211,13 @@ void free_packet(packet_t *pkt)
*/
int verify_packet(packet_t *pkt, int fd)
{
if (recv_packet(pkt, fd, ZSM_TYP_MESSAGE) != ZSM_STA_SUCCESS) {
int status = recv_packet(pkt, fd, ZSM_TYP_MESSAGE);
if (status != ZSM_STA_SUCCESS) {
close(fd);
if (status == ZSM_STA_CLOSED_CONNECTION) {
error(1, "Server closed connection");
}
return ZSM_STA_ERROR_INTEGRITY;
}

2
src/client/client.c
View file

@ -66,7 +66,7 @@ void *receive_worker(void *arg)
while (1) {
packet_t pkt;
if (verify_packet(&pkt, sockfd) == 0) {
if (verify_packet(&pkt, sockfd) != ZSM_STA_SUCCESS) {
error(0, "Error verifying packet");
}
size_t cipher_len = pkt.length - NONCE_SIZE - MAX_NAME * 2;

28
src/server/server.c
View file

@ -34,43 +34,43 @@ int authenticate_client(int clientfd, uint8_t *username)
/* Sending fake signature as structure requires it */
uint8_t *fake_sig = create_signature(NULL, 0, NULL);
packet_t *auth_pkt = create_packet(1, ZSM_TYP_AUTH, CHALLENGE_SIZE,
packet_t *pkt = create_packet(1, ZSM_TYP_AUTH, CHALLENGE_SIZE,
challenge, fake_sig);
if (send_packet(auth_pkt, clientfd) != ZSM_STA_SUCCESS) {
if (send_packet(pkt, clientfd) != ZSM_STA_SUCCESS) {
error(0, "Could not authenticate client");
goto failure;
}
free(fake_sig);
packet_t client_auth_pkt;
int status;
if ((status = recv_packet(&client_auth_pkt, clientfd, ZSM_TYP_AUTH)
if ((status = recv_packet(pkt, clientfd, ZSM_TYP_AUTH)
!= ZSM_STA_SUCCESS)) {
error(0, "Could not authenticate client");
goto failure;
}
uint8_t pk_bin[PK_RAW_SIZE], pk_username[MAX_NAME];
memcpy(pk_bin, client_auth_pkt.data, PK_RAW_SIZE);
memcpy(pk_username, client_auth_pkt.data + PK_RAW_SIZE, MAX_NAME);
memcpy(pk_bin, pkt->data, PK_RAW_SIZE);
memcpy(pk_username, pkt->data + PK_RAW_SIZE, MAX_NAME);
if (crypto_sign_verify_detached(client_auth_pkt.signature, challenge, CHALLENGE_SIZE, pk_bin) != 0) {
free_packet(auth_pkt);
if (crypto_sign_verify_detached(pkt->signature, challenge, CHALLENGE_SIZE, pk_bin) != 0) {
free_packet(pkt);
error(0, "Incorrect signature, could not authenticate client");
free(client_auth_pkt.data);
goto failure;
} else {
packet_t *ok_pkt = create_packet(ZSM_STA_AUTHORISED, ZSM_TYP_INFO
, 0, NULL, NULL);
send_packet(ok_pkt, clientfd);
free_packet(ok_pkt);
pkt->status = ZSM_STA_AUTHORISED;
pkt->type = ZSM_TYP_INFO;
pkt->length = 0;
pkt->data = NULL;
pkt->signature = NULL;
send_packet(pkt, clientfd);
free_packet(pkt);
strcpy(username, pk_username);
return ZSM_STA_SUCCESS;
}
failure:;
packet_t *error_pkt = create_packet(ZSM_STA_UNAUTHORISED, ZSM_TYP_ERROR,
0, NULL, create_signature(NULL, 0, NULL));
send_packet(error_pkt, clientfd);
free_packet(error_pkt);
close(clientfd);