root/genpasswd/trunk/genpasswd.c

#define _XOPEN_SOURCE
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <ctype.h>

#define VERSION  "0.1.13"

char *get_range(char const *input);
void usage(char const *name);
void make_salt(char *salt, int size);

int main(int argc, char **argv) {
char *input = "-0-9a-zA-Z`=[]\\;',./~_+{}|:\"<>?", *buffer = 0, *exclude = 0, *excludeinput = 0;
int len, i, pwlen = 16, md5 = 0, cryptit = 0, showplain = 1, quiet = 0;
char *password = NULL;

        if (argc > 1)
                for (i = 1; i < argc; i++)
                        /* options */
                        if (argv[i][0] == '-') {
                        int j = 1;

                                while (argv[i][j]) {
                                        switch (argv[i][j]) {
                                                /* numeric size */
                                                case '0' : case '1' : case '2' : case '3' :
                                                case '4' : case '5' : case '6' : case '7' :
                                                case '8' : case '9' :
                                                        pwlen = atoi(argv[i] + j);
                                                        while (argv[i][j] && isdigit(argv[i][j])) j++;
                                                        j--;
                                                break;
                                                /* md5 */
                                                case 'm' :
                                                        md5 = 1;
                                                break;
                                                case 'v' :
                                                        printf("%s\n", VERSION);
                                                        return 0;
                                                break;
                                                // crypt
                                                case 'c' :
                                                        cryptit = 1;
                                                break;
                                                case 'n' :
                                                        input = "0-9";
                                                break;
                                                case 'q' :
                                                        quiet = 1;
                                                break;
                                                // exclude
                                                case 'e' :
                                                        excludeinput = argv[i] + j;
                                                        while (argv[i][j]) ++j;
                                                        --j;
                                                break;
                                                case 'a' :
                                                        input = "a-zA-Z";
                                                break;
                                                case 'A' :
                                                        input = "A-Za-z0-9";
                                                break;
                                                case 'p' :
                                                {
                                                int i;
                                                char comp[64];

                                                        for (i = 0; i < 2; i++) {
                                                                showplain = 0;
                                                                system("stty -echo");
                                                                if (i == 1)
                                                                        password = (char*)malloc(64);
                                                                else
                                                                        password = comp;
                                                                if (!quiet) printf("Password: ");
                                                                fflush(stdout);
                                                                fgets(password, 64, stdin);
                                                                password[strlen(password) - 1] = 0;
                                                                system("stty echo");
                                                                if (!quiet) printf("\n");
                                                                fflush(stdout);
                                                        }
                                                        if (strcmp(password, comp)) {
                                                                fprintf(stderr, "error: passwords do not match\n");
                                                                return 1;
                                                        }
                                                }
                                                break;
                                                case 'P' :
                                                        password = argv[i] + j + 1;
                                                        while (argv[i][j]) ++j;
                                                        --j;
                                                break;
                                                default :
                                                        usage(argv[0]);
                                                break;
                                        }
                                        j++;
                                }
                        } else /* specify range of characters to use */
                                input = argv[i];
                
        srand48(getpid() + time(0));

        if ((buffer = get_range(input)) == NULL) {
                printf("%s: error, too many characters in password character pool (>255)\n", argv[0]);
                return 1;
        }

        if (excludeinput) {
        char *new =  (char*)malloc(strlen(buffer) + 1);
        int j = 0;

                if ((exclude = get_range(excludeinput)) == NULL) {
                        printf("%s: error, too many characters in exclude pool (>255)\n", argv[0]);
                        return 1;
                }
                for (i = 0; i < strlen(buffer); i++)
                        if (!strchr(exclude, buffer[i]))
                                new[j++] = buffer[i];
                new[j] = 0;
                free(buffer);
                buffer = new;
        }

        len = strlen(buffer);

        if (password == NULL) {
                password = (char*)malloc(pwlen + 1);
                for (i = 0; i < pwlen; i++)
                        password[i] = buffer[(int)(drand48() * len)];
                password[i] = 0;
        }

        if (showplain) {
                if (!quiet) printf("Password: ");
                printf("%s\n", password);
        }

        if (md5) {
        char salt[13];
                
                strcpy(salt, "$1$");
                make_salt(salt + 3, 9);
                if (!quiet) printf("MD5: ");
                printf("%s\n", crypt(password, salt));
        }

        if (cryptit) {
        char salt[3];

                make_salt(salt, 2);
                if (!quiet) printf("Crypt: ");
                printf("%s\n", crypt(password, salt));
        }
        return 0;
}

char *get_range(char const *input) {
char *out = (char*)malloc(257), *p = out;
        
        if (*input == '-') {
                *p++ = '-';
                input++;
        }
        /* return zero-terminated buffer */
        while (*input) {

                if (p - out >= 254) return NULL;
                if (input[1] == '-') {
                int i;

                        if (input[2] == 0)
                                *p++ = '-';
                        else {
                                for (i = input[0]; i <= input[2]; ++i) {
                                        if (p - out >= 254) return NULL;
                                        *p++ = i;
                                }
                        }
                        input += 3;
                } else {
                        *p++ = *input;
                        ++input;
                }
        }
        *p = 0;
        return out;
}

void usage(char const *name) {
        printf("usage: %s [-<length>] [-m] [-n] [-a] [-A] [<range>]\n"
"  -<length>    specify the length of the password\n"
"  -m           generate the MD5 sum of the resultant password\n"
"  -c           generate crypt of resultant password\n"
"  -n           use numeric characters for password character pool\n"
"  -a           use alpha characters for password character pool\n"
"  -A           use alpha-numeric characters for password character pool\n"
"  -e<string>   exclude the given characters from the password\n"
"  -p           prompt the user for the password\n"
"  -P<string>   use the specified string as the password\n"
"  -q           do not display prompts or field descriptions\n"
"  <range>      specify characters to use for password, ala '[]' regexp\n"
"  -v           show version number\n"
"\n"
"eg. %s -64m A-Za-z0-9\n"
, name, name);
        exit(1);
}

void make_salt(char *salt, int size) {
char *randomchars = get_range("a-zA-Z0-9./");
int i;

        for (i = 0; i < size; i++)
                salt[i] = randomchars[(int)(drand48() * strlen(randomchars))];
        salt[size] = 0;
        free((void*)randomchars);
}