add md5crypt()

1 files changed, 151 insertions, 0 deletions

diff --git a/lib/libc/crypt/md5crypt.c b/lib/libc/crypt/md5crypt.c
new file mode 100644
index 00000000000..7872c368597
--- /dev/null
+++ b/lib/libc/crypt/md5crypt.c
@@ -0,0 +1,151 @@
+/*	$OpenBSD: md5crypt.c,v 1.1 1996/05/30 02:36:33 deraadt Exp $ */
+
+/*
+ * ----------------------------------------------------------------------------
+ * "THE BEER-WARE LICENSE" (Revision 42):
+ * <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
+ * can do whatever you want with this stuff. If we meet some day, and you think
+ * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
+ * ----------------------------------------------------------------------------
+ *
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char rcsid[] = "$OpenBSD: md5crypt.c,v 1.1 1996/05/30 02:36:33 deraadt Exp $";
+#endif /* LIBC_SCCS and not lint */
+
+#include <unistd.h>
+#include <stdio.h>
+#include "md5.h"
+
+static unsigned char itoa64[] =		/* 0 ... 63 => ascii - 64 */
+	"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
+static void
+to64(s, v, n)
+	char *s;
+	unsigned long v;
+	int n;
+{
+	while (--n >= 0) {
+		*s++ = itoa64[v&0x3f];
+		v >>= 6;
+	}
+}
+
+/*
+ * UNIX password
+ *
+ * Use MD5 for what it is best at...
+ */
+
+char *
+md5crypt(pw, salt)
+	register const char *pw;
+	register const char *salt;
+{
+	static char	*magic = "$1$";	/*
+						 * This string is magic for
+						 * this algorithm.  Having
+						 * it this way, we can get
+						 * get better later on
+						 */
+	static char     passwd[120], *p;
+	static const char *sp,*ep;
+	unsigned char	final[16];
+	int sl,pl,i,j;
+	MD5_CTX	ctx,ctx1;
+	unsigned long l;
+
+	/* Refine the Salt first */
+	sp = salt;
+
+	/* If it starts with the magic string, then skip that */
+	if(!strncmp(sp,magic,strlen(magic)))
+		sp += strlen(magic);
+
+	/* It stops at the first '$', max 8 chars */
+	for(ep=sp;*ep && *ep != '$' && ep < (sp+8);ep++)
+		continue;
+
+	/* get the length of the true salt */
+	sl = ep - sp;
+
+	MD5Init(&ctx);
+
+	/* The password first, since that is what is most unknown */
+	MD5Update(&ctx,pw,strlen(pw));
+
+	/* Then our magic string */
+	MD5Update(&ctx,magic,strlen(magic));
+
+	/* Then the raw salt */
+	MD5Update(&ctx,sp,sl);
+
+	/* Then just as many characters of the MD5(pw,salt,pw) */
+	MD5Init(&ctx1);
+	MD5Update(&ctx1,pw,strlen(pw));
+	MD5Update(&ctx1,sp,sl);
+	MD5Update(&ctx1,pw,strlen(pw));
+	MD5Final(final,&ctx1);
+	for(pl = strlen(pw); pl > 0; pl -= 16)
+		MD5Update(&ctx,final,pl>16 ? 16 : pl);
+
+	/* Don't leave anything around in vm they could use. */
+	memset(final,0,sizeof final);
+
+	/* Then something really weird... */
+	for (j=0,i = strlen(pw); i ; i >>= 1)
+		if(i&1)
+		    MD5Update(&ctx, final+j, 1);
+		else
+		    MD5Update(&ctx, pw+j, 1);
+
+	/* Now make the output string */
+	strcpy(passwd,magic);
+	strncat(passwd,sp,sl);
+	strcat(passwd,"$");
+
+	MD5Final(final,&ctx);
+
+	/*
+	 * and now, just to make sure things don't run too fast
+	 * On a 60 Mhz Pentium this takes 34 msec, so you would
+	 * need 30 seconds to build a 1000 entry dictionary...
+	 */
+	for(i=0;i<1000;i++) {
+		MD5Init(&ctx1);
+		if(i & 1)
+			MD5Update(&ctx1,pw,strlen(pw));
+		else
+			MD5Update(&ctx1,final,16);
+
+		if(i % 3)
+			MD5Update(&ctx1,sp,sl);
+
+		if(i % 7)
+			MD5Update(&ctx1,pw,strlen(pw));
+
+		if(i & 1)
+			MD5Update(&ctx1,final,16);
+		else
+			MD5Update(&ctx1,pw,strlen(pw));
+		MD5Final(final,&ctx1);
+	}
+
+	p = passwd + strlen(passwd);
+
+	l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; to64(p,l,4); p += 4;
+	l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; to64(p,l,4); p += 4;
+	l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; to64(p,l,4); p += 4;
+	l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; to64(p,l,4); p += 4;
+	l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; to64(p,l,4); p += 4;
+	l =                    final[11]                ; to64(p,l,2); p += 2;
+	*p = '\0';
+
+	/* Don't leave anything around in vm they could use. */
+	memset(final,0,sizeof final);
+
+	return passwd;
+}
+