sss-cli

cli.c

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "sss.h"
int cli_create(int argc, const char* argv[]) {
        if (argc != 4) return 1;
        unsigned long int shares = strtoul(argv[2], NULL, 10);
        unsigned long int required = strtoul(argv[3], NULL, 10);
        if (shares < 1 || shares > 40 || required < 1 || required > shares)
                return 1;
        uint8_t data[sss_MLEN];
        memset(data, 0, sss_MLEN);
        fread(data, 1, sss_MLEN, stdin);
        sss_Share ss_shares[shares];
        sss_create_shares(ss_shares, data, shares, required);
        for(uint8_t idx = 0; idx < shares; idx++) {
                for(uint8_t i = 0; i < sss_SHARE_LEN; i++)
                        printf("%02x", ss_shares[idx][i]);
                printf("\n");
        }
        return 0;
}
int cli_combine(int argc, const char* argv[]) {
        if (argc != 3) return 1;
        unsigned long int shares = strtoul(argv[2], NULL, 10);
        if (shares < 1 || shares > 40) return 1;
        sss_Share ss_shares[shares];
        for(uint8_t idx = 0; idx < shares; idx++) {
                char buffer[sss_SHARE_LEN*2+2];
                fgets(buffer, sizeof(buffer), stdin);
                if (strlen(buffer) < sss_SHARE_LEN*2) {
                        fprintf(stderr, "not enough bytes given for secret\n");
                        return 2;
                }
                for(uint8_t i = 0; i < sss_SHARE_LEN*2; i+=2) {
                        if(sscanf(&buffer[i], "%2x", &ss_shares[idx][i/2]) != 1) {
                                fprintf(stderr, "invalid byte in input\n");
                                return 2;
                        }
                }
        }
        uint8_t restored[sss_MLEN];
        if(!sss_combine_shares(restored, ss_shares, shares)) {
                fwrite(restored, 1, sss_MLEN, stdout);
                return 0;
        } else {
                printf("Corrupted data or not enough shares.\n");
                return 3;
        }
        
        return 0;
}
int main(int argc, const char* argv[]) {
        if (argc < 2) goto usage;
        if (strcmp(argv[1], "create") == 0) {
                if (cli_create(argc, argv) != 0) goto usage;
        } else if (strcmp(argv[1], "combine") == 0) {
                if (cli_combine(argc, argv) != 0) goto usage;
        }
        return 0;
 usage:
        fprintf(stderr,"Usage:\t %s create <shares> <required>\n"
                       "\t %s combine <shares>\n",argv[0], argv[0]);
        return 1;
}