tetatet/src/main.c

// #include "audio.h"
#include "crypt.h"
#include "net.h"

#define CHANNELS 1
#define SAMPLE_RATE 48000
#define FRAMES_PER_BUFFFER 960
#define AUDIO_BUF_SIZE (FRAMES_PER_BUFFFER * CHANNELS)

#define NET_BUF_SIZE 1024

int client_handshake(net_t *const n, crypt_session_t *const s, crypt_key_t *const ok, crypt_key_t *const rk);
int server_handshake(net_t *const n, crypt_session_t *const s, crypt_key_t *const ok, crypt_key_t *const rk);

void usage(void) {
    fprintf(stderr, "tetatet c|s ADDR PORT\n");
}

int main(int argc, char **argv) {
    int ret = 0;

    if (argc < 4) {
        usage();
        return -1;
    }

    if (sodium_init() == -1) {
        return -1;
    }

    // if (audio_init_soundsystem() == -1)
    //     return -1;

    char direction = argv[1][0];
    char *addr = argv[2];
    char *port = argv[3];

    net_t n;
    crypt_session_t s;
    crypt_key_t ok, rk;

    if (crypt_key_gen(&ok) == -1) {
        ret = -1;
        goto cleanup;
    }

    if (direction == 'c') {
        if (net_client_init(&n, addr, port) == -1) {
            ret = -1;
            goto cleanup;
        }

        int res = client_handshake(&n, &s, &ok, &rk);

        if (res != 0) {
            ret = res;
            goto cleanup;
        }
    } else if (direction == 's') {
        if (net_server_init(&n, addr, port) == -1) {
            ret = -1;
            goto cleanup;
        }

        int res = server_handshake(&n, &s, &ok, &rk);

        if (res != 0) {
            ret = -1;
            goto cleanup;
        }
    } else {
        usage();
    }

    fprintf(stderr, "A connection established!\n");

cleanup:

    net_destroy(&n);
    crypt_session_destroy(&s);
    crypt_key_destroy(&ok);
    crypt_key_destroy(&rk);

    // if (audio_terminate_soundsystem() == -1)
    //     return -1;

    return ret;
}

int client_handshake(net_t *const n, crypt_session_t *const s, crypt_key_t *const ok, crypt_key_t *const rk) {
    char buffer[NET_BUF_SIZE];
    ssize_t bytes = 0;
    unsigned char *hello = NULL;
    unsigned char *nonce = NULL;

    if ((hello = crypt_hello(ok)) == NULL)
        return -1;

    if (net_send(n, (char *)hello, CRYPT_HELLO_LEN) == -1) {
        free(hello);
        return -1;
    }

    if ((bytes = net_recv(n, buffer, NET_BUF_SIZE)) == -1) {
        free(hello);
        return -1;
    }

    if (CRYPT_HELLO_LEN != bytes) {
        free(hello);
        return -1;
    }

    if (crypt_key_from_hex_public(rk, buffer) == -1) {
        free(hello);
        return -1;
    }

    if (crypt_hello_verify((unsigned char *)buffer, rk) == -1) {
        free(hello);
        return -2;
    }

    if ((nonce = crypt_hello_get_nonce(hello, (unsigned char *)buffer, true)) == NULL) {
        free(hello);
        return -1;
    }

    free(hello);

    if (crypt_session_init(s, ok, rk, nonce, true) == -1) {
        free(nonce);
        return -3;
    }

    free(nonce);

    return 0;
}

int server_handshake(net_t *const n, crypt_session_t *const s, crypt_key_t *const ok, crypt_key_t *const rk) {
    char buffer[NET_BUF_SIZE];
    ssize_t bytes = 0;
    unsigned char *hello = NULL;
    unsigned char *nonce = NULL;

    if ((bytes = net_recv(n, buffer, NET_BUF_SIZE)) == -1)
        return -1;

    if (CRYPT_HELLO_LEN != bytes)
        return -1;

    if (crypt_key_from_hex_public(rk, buffer) == -1)
        return -1;

    if (crypt_hello_verify((unsigned char *)buffer, rk) == -1)
        return -2;

    if ((hello = crypt_hello(ok)) == NULL)
        return -1;

    if ((nonce = crypt_hello_get_nonce(hello, (unsigned char *)buffer, false)) == NULL) {
        free(hello);
        return -1;
    }

    if (crypt_session_init(s, ok, rk, nonce, false) == -1) {
        free(nonce);
        return -3;
    }

    n->raddr = n->inaddr;
    n->raddr_len = n->inaddr_len;

    if (net_send(n, (char *)hello, CRYPT_HELLO_LEN) == -1) {
        free(hello);
        return -1;
    }

    free(hello);
    free(nonce);

    return 0;
}