xref: /third_party/toybox/toys/other/pwgen.c (revision 0f66f451)
1/* pwgen.c - A password generator.
2 *
3 * Copyright 2020 Moritz R�hrich <moritz@ildefons.de>
4
5USE_PWGEN(NEWTOY(pwgen, ">2r(remove):c(capitalize)n(numerals)y(symbols)s(secure)B(ambiguous)h(help)C1vA(no-capitalize)0(no-numerals)[-cA][-n0][-C1]", TOYFLAG_USR|TOYFLAG_BIN))
6
7config PWGEN
8  bool "pwgen"
9  default y
10  help
11    usage: pwgen [-cAn0yrsBhC1v] [LENGTH] [COUNT]
12
13    Generate human-readable random passwords. When output is to tty produces
14    a screenfull to defeat shoulder surfing (pick one and clear the screen).
15
16    -c  --capitalize                  Permit capital letters.
17    -A  --no-capitalize               Don't include capital letters.
18    -n  --numerals                    Permit numbers.
19    -0  --no-numerals                 Don't include numbers.
20    -y  --symbols                     Permit special characters ($#%...).
21    -r <chars>  --remove=<chars>      Don't include the given characters.
22    -s  --secure                      Generate more random passwords.
23    -B  --ambiguous                   Avoid ambiguous characters (e.g. 0, O).
24    -h  --help                        Print this help message.
25    -C                                Print the output in columns.
26    -1                                Print the output one line each.
27    -v                                Don't include vowels.
28*/
29
30#define FOR_pwgen
31#include "toys.h"
32
33GLOBALS(
34  char *r;
35)
36
37void pwgen_main(void)
38{
39  int length = 8, count, ii, jj, c, rand = 0, x = 0;
40  unsigned xx = 80, yy = 24;
41  char randbuf[16];
42
43  if (isatty(1)) terminal_size(&xx, &yy);
44  else toys.optflags |= FLAG_1;
45
46  if (toys.optc && (length = atolx(*toys.optargs))>sizeof(toybuf))
47    error_exit("bad length");
48  if (toys.optc>1) count = atolx(toys.optargs[1]);
49  else count = FLAG(1) ? 1 : (xx/(length+1))*(yy-1);
50
51  for (jj = 0; jj<count; jj++) {
52    for (ii = 0; ii<length;) {
53      // Don't fetch more random than necessary, give each byte 2 tries to fit
54      if (!rand) xgetrandom(randbuf, rand = sizeof(randbuf), 0);
55      c = 33+randbuf[--rand]%93; // remainder 69 makes >102 less likely
56      if (FLAG(s)) randbuf[rand] = 0;
57
58      if (c>='A' && c<='Z') {
59        if (FLAG(A)) continue;
60        // take out half the capital letters to be more human readable
61        else c |= (0x80&randbuf[rand])>>2;
62      }
63      if (FLAG(0) && c>='0' && c<='9') continue;
64      if (FLAG(B) && strchr("0O1lI'`.,", c)) continue;
65      if (FLAG(v) && strchr("aeiou", tolower(c))) continue;
66      if (!FLAG(y) || (0x80&randbuf[rand]))
67        if (c<'0' || (c>'9' && c<'A') || (c>'Z' && c<'a') || c>'z') continue;
68      if (TT.r && strchr(TT.r, c)) continue;
69
70      toybuf[ii++] = c;
71    }
72    if (FLAG(1) || (x += length+1)+length>=xx) x = 0;
73    xprintf("%.*s%c", length, toybuf, x ? ' ' : '\n');
74  }
75  if (x) xputc('\n');
76}
77