From 41714d89d7a2b521b8246506e92957a2d5e4d883 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Groenvall?= <bg@sics.se>
Date: Thu, 22 May 1997 14:41:13 +0000
Subject: [PATCH] MD5 support in crypt(3).

git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@1758 ec53bebd-3082-4978-b11e-865c3cabbd6b
---
 lib/des/fcrypt.c | 154 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 154 insertions(+)

diff --git a/lib/des/fcrypt.c b/lib/des/fcrypt.c
index d5501b8a3..6ee742842 100644
--- a/lib/des/fcrypt.c
+++ b/lib/des/fcrypt.c
@@ -58,6 +58,154 @@
 #define const
 #endif
 
+/* It is really only FreeBSD that still suffers from MD5 based crypts,
+ * for now let all platforms support it. */
+#define MD5_CRYPT_SUPPORT 1
+#if     MD5_CRYPT_SUPPORT
+/*
+ * ----------------------------------------------------------------------------
+ * "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
+ * ----------------------------------------------------------------------------
+ */
+
+#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...
+ */
+
+static
+char *
+crypt_md5(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;
+}
+#endif /* MD5_CRYPT_SUPPORT */
+
 typedef unsigned char des_cblock[8];
 
 typedef struct des_ks_struct
@@ -399,6 +547,7 @@ static int body();
 static int des_set_key();
 #endif
 
+inline
 static int des_set_key(key, schedule)
 des_cblock (*key);
 des_key_schedule schedule;
@@ -567,6 +716,11 @@ char *salt;
 	unsigned char *b=bb;
 	unsigned char c,u;
 
+#if     MD5_CRYPT_SUPPORT
+	if (!strncmp(salt, "$1$", 3))
+		return crypt_md5(buf, salt);
+#endif
+
 	/* eay 25/08/92
 	 * If you call crypt("pwd","*") as often happens when you
 	 * have * as the pwd field in /etc/passwd, the function