new toy: Add pwgen

Add new toy `pwgen`.
A usefule password generation utility.

1 files changed, 130 insertions, 0 deletions

diff --git a/toys/pending/pwgen.c b/toys/pending/pwgen.c
new file mode 100644
index 00000000..c63ebee7
--- /dev/null
+++ b/toys/pending/pwgen.c
@@ -0,0 +1,130 @@
+/* pwgen.c - A password generator.
+ *
+ * Copyright 2020 Moritz Röhrich <moritz@ildefons.de>
+
+USE_PWGEN(NEWTOY(pwgen, ">2?r(remove):c(capitalize)n(numerals)y(symbols)s(secure)B(ambiguous)h(help)C1vA(no-capitalize)0(no-numerals)[-cA][-n0]", TOYFLAG_USR|TOYFLAG_BIN))
+
+config PWGEN
+  bool "pwgen"
+  default n
+  help
+    usage: pwgen [ OPTIONS ] [ length ] [ number ]
+
+    A password generator.
+
+    Options supported by pwgen:
+      -c  --capitalize                  Permit capital letters.
+      -A  --no-capitalize               Don't include capital letters.
+      -n  --numerals                    Permit numbers.
+      -0  --no-numerals                 Don't include numbers.
+      -y  --symbols                     Permit special characters ($#%...).
+      -r <chars>  --remove=<chars>      Don't include the given characters.
+      -s  --secure                      Generate more random passwords.
+      -B  --ambiguous                   Avoid ambiguous characters (e.g. 0, O).
+      -h  --help                        Print this help message.
+      -C                                Print the output in columns.
+      -1                                Print the output one line each.
+      -v                                Don't include vowels.
+*/
+
+#define FOR_pwgen
+#include "toys.h"
+
+GLOBALS(
+  char *r;
+)
+
+// Generate one random printable/typeable ascii character.
+char get_rand_chr() {
+  return (char) (33 + (rand() % 93));
+}
+
+// Uses get_rand_chr to generate a character that conforms the requirements set
+// by the argument flags.
+char get_valid_chr(const char *illegal) {
+  char c = get_rand_chr();
+
+  while (strchr(illegal, c) != NULL)
+    c = get_rand_chr();
+
+  return c;
+}
+
+char * get_illegal_chars() {
+  char* illegal = malloc(94 * sizeof(char));
+  memset(illegal, 0, 94 * sizeof(char));
+  if (toys.optflags & FLAG(A))
+    strcat(illegal, "ABCDEFGHIJKLMNOPQRSTUVWXYZ");
+  if (toys.optflags & FLAG(0))
+    strcat(illegal, "1234567890");
+  if (toys.optflags & FLAG(B))
+    strcat(illegal, "0O1lI'`.,");
+  if (toys.optflags & FLAG(v))
+    strcat(illegal, "ieaouIEAOU");
+  if (!(toys.optflags & FLAG(y)))
+    strcat(illegal, "!@#$%^&*()-_=+`~{}[];:'\",.<>/?\\|");
+  if (TT.r){
+    strcat(illegal, TT.r);
+  }
+  return illegal;
+}
+
+// Generate a new password of length l.
+char * get_pw(const unsigned long l, const char *illegal) {
+  char *pw = malloc((l+1) * sizeof(char));
+  memset(pw, 0, (l+1) * sizeof(char));  // zero out memory for new password.
+  unsigned long i;
+  for (i = 0; i < l; i++){
+    pw[i] = get_valid_chr(illegal);
+  }
+
+  return pw;
+}
+
+void pwgen_main(void)
+{
+  // seed the (pseudo) RNG.
+  time_t t;
+  srand((unsigned) time(&t));
+
+  int length = 8;
+  int count = 160;
+  int num_columns = 8;
+  if (toys.optc > 0) {
+    length = atoi(toys.optargs[0]);
+    num_columns = 80 / (length+1);
+    if (toys.optc > 1) {
+      count = atoi(toys.optargs[1]);
+    } else if (toys.optflags & FLAG(1)) {
+      count = 1;
+    } else {
+      count = 20 * num_columns;
+    }
+  }
+
+  char *illegal = get_illegal_chars();
+  char **passwords = malloc(count * sizeof(char*));
+  int c;
+  for (c = 0; c < count; c++)
+      passwords[c] = get_pw(length, illegal);
+
+  if (toys.optflags & FLAG(1)){
+    for (c = 0; c < count; c++)
+      xprintf("%s\n", passwords[c]);
+  } else {
+    int col;
+    c = 0;
+    while(c < count){
+      for (col = 0; c < count && col < num_columns; col++){
+        xprintf("%s ", passwords[c]);
+        c += 1;
+      }
+      xprintf("\n");
+    }
+  }
+
+  for (c = 0; c < count; c++)
+    free(passwords[c]);
+  free(passwords);
+  free(illegal);
+}