aboutsummaryrefslogtreecommitdiff
path: root/libbb/crypt_make_salt.c
diff options
context:
space:
mode:
Diffstat (limited to 'libbb/crypt_make_salt.c')
-rw-r--r--libbb/crypt_make_salt.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/libbb/crypt_make_salt.c b/libbb/crypt_make_salt.c
new file mode 100644
index 0000000..393eba5
--- /dev/null
+++ b/libbb/crypt_make_salt.c
@@ -0,0 +1,45 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * crypt_make_salt
+ *
+ * i64c was also put here, this is the only function that uses it.
+ *
+ * Lifted from loginutils/passwd.c by Thomas Lundquist <thomasez@zelow.no>
+ *
+ */
+
+#include "libbb.h"
+
+static int i64c(int i)
+{
+ i &= 0x3f;
+ if (i == 0)
+ return '.';
+ if (i == 1)
+ return '/';
+ if (i < 12)
+ return ('0' - 2 + i);
+ if (i < 38)
+ return ('A' - 12 + i);
+ return ('a' - 38 + i);
+}
+
+int FAST_FUNC crypt_make_salt(char *p, int cnt, int x)
+{
+ x += getpid() + time(NULL);
+ do {
+ /* x = (x*1664525 + 1013904223) % 2^32 generator is lame
+ * (low-order bit is not "random", etc...),
+ * but for our purposes it is good enough */
+ x = x*1664525 + 1013904223;
+ /* BTW, Park and Miller's "minimal standard generator" is
+ * x = x*16807 % ((2^31)-1)
+ * It has no problem with visibly alternating lowest bit
+ * but is also weak in cryptographic sense + needs div,
+ * which needs more code (and slower) on many CPUs */
+ *p++ = i64c(x >> 16);
+ *p++ = i64c(x >> 22);
+ } while (--cnt);
+ *p = '\0';
+ return x;
+}