/* Copyright 2019 Lenovo */
#include <arpa/inet.h>
#include <crypt.h>
#include <net/if.h>
#include <netdb.h>
#include <sys/socket.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

#define MAXPACKET 1024

static const char cryptalpha[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789./";

unsigned char* genpasswd(int len) {
        unsigned char * passwd;
        int urandom, ret;
        passwd = calloc(len + 1, sizeof(char));
        urandom = open("/dev/urandom", O_RDONLY);
        if (urandom < 0) {
            fprintf(stderr, "Failed reading /dev/urandom\n");
            exit(1);
        }
        ret = read(urandom, passwd, len);
        close(urandom);
        for (urandom = 0; urandom < len; urandom++) {
                passwd[urandom] = cryptalpha[passwd[urandom] >> 2];
        }
        passwd[len] = 0;  // Should be redundant with calloc, but be explicit
        return passwd;

}


int main(int argc, char* argv[]) {
        int sock, ret;
        char slen;
        unsigned char currtype;
        size_t currlen;
        unsigned char* passwd;
        unsigned char* cryptedpass;
        unsigned char* macaddr;
        struct timeval timeout;
        struct addrinfo hints;
        struct addrinfo *addrs;
        struct addrinfo *curr;
        struct sockaddr_in net4bind;
        struct sockaddr_in6 net6bind;
        unsigned char buffer[MAXPACKET];
        memset(&hints, 0, sizeof(struct addrinfo));
        memset(&net4bind, 0, sizeof(struct sockaddr_in));
        memset(&net6bind, 0, sizeof(struct sockaddr_in6));
        memset(&buffer, 0, MAXPACKET);
        memset(&timeout, 0, sizeof(struct timeval));
        timeout.tv_sec = 10;
        net4bind.sin_port = htons(302);
        net4bind.sin_family = AF_INET;
        net6bind.sin6_port = htons(302);
        net6bind.sin6_family = AF_INET6;
        hints.ai_socktype = SOCK_STREAM;
        hints.ai_protocol = IPPROTO_TCP;

        passwd = genpasswd(32);
        memset(buffer, 0, MAXPACKET);
        strncpy(buffer, "$5$", 3);
        cryptedpass = genpasswd(8);
        strncpy(buffer + 3, cryptedpass, 8);
        free(cryptedpass);
        cryptedpass = crypt(passwd, buffer);
        if (argc < 3) {
            fprintf(stderr, "Missing node name and manager\n");
            exit(1);
        }
        sock = getaddrinfo(argv[2], "13001", &hints, &addrs);
        if (sock != 0) {
                fprintf(stderr, "Error trying to resolve %s\n", argv[2]);
                exit(1);
        }
        for (curr = addrs; curr != NULL; curr = curr->ai_next) {
                sock = socket(curr->ai_family, curr->ai_socktype, curr->ai_protocol);
                if (sock < 0) continue;
                if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &(int){1}, sizeof(int)) < 0) {
                    fprintf(stderr, "Failed setting reusaddr\n");
                }
                if (curr->ai_family == AF_INET) {
                    if (bind(sock, (struct sockaddr*)&net4bind, sizeof(struct sockaddr_in)) < 0) {
                        fprintf(stderr, "Unable to bind port 302\n");
                        exit(1);
                    }
                } else if (curr->ai_family == AF_INET6) {
                    if (bind(sock, (struct sockaddr*)&net6bind, sizeof(struct sockaddr_in6)) < 0) {
                        fprintf(stderr, "Unable to bind port 302\n");
                        exit(1);
                    }
                } else {
                        continue;
                }
                if (connect(sock, curr->ai_addr, curr->ai_addrlen) == 0) break;
        }
        if (curr == NULL) {
                fprintf(stderr, "Unable to reach %s\n", argv[2]);
                exit(1);
        }
        if (setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout)) < 0) {
            fprintf(stderr, "Unable to set timeout\n");
        }
        freeaddrinfo(addrs);
        ret = read(sock, buffer, 8);
        if (memcmp(buffer, "\xc2\xd1-\xa8\x80\xd8j\xba", 8) != 0) {
                fprintf(stderr, "Unrecognized server\n");
                exit(1);
        }
        slen = strlen(argv[1]) & 0xff;
        dprintf(sock, "\x01%c%s", slen, argv[1]);
        ret = write(sock, "\x00\x00", 2);
        memset(buffer, 0, MAXPACKET);
        ret = read(sock, buffer, 2);
        while (buffer[0] != 255) {
            currtype = buffer[0];
	    if (currtype & 0b10000000) {
                currlen = buffer[1] << 8;
                while (read(sock, buffer, 1) < 0) {}; 
                currlen |= buffer[0];
            } else {
                currlen = buffer[1];
	    }
            memset(buffer, 0, MAXPACKET);
	    if (currlen > 1000) {
                fprintf(stderr, "Received oversized message\n");
                exit(1);
            }
            if (currlen) {
                ret = read(sock, buffer, currlen);  // Max is 1000, well under MAX_PACKET
                buffer[currlen] = 0;
            }
            if (currtype == 2) {
                dprintf(sock, "\x03%c", (int)currlen);
                ret = write(sock, buffer, currlen);
                slen = strlen(cryptedpass) & 0xff;
                dprintf(sock, "\x04%c%s", slen, cryptedpass);
                ret = write(sock, "\x00\x00", 2);
            } else if (currtype == 128) {
                printf("SEALED:%s", buffer);
                printf("\n");
                exit(0);
            } else if (currtype == 5) {
                printf("%s", passwd);
                printf("\n");
                exit(0);
            }
            buffer[0] = 255;
            ret = read(sock, buffer, 2);
        }
        fprintf(stderr, "Password was not accepted\n");
        exit(1);
}