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authorH. Peter Anvin <hpa@zytor.com>2007-07-24 22:49:05 -0700
committerH. Peter Anvin <hpa@zytor.com>2007-07-24 22:49:05 -0700
commit61a4936836c3dc8341130b4fa938e0106f8a41bf (patch)
treeb594b7e08ca47794326610cae4018a63686f4e73 /com32/libutil/crypt-md5.c
parent217a9b0c77cdd5df5800c7b250765f543c680477 (diff)
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Add support for Unix-standard MD5 password
Diffstat (limited to 'com32/libutil/crypt-md5.c')
-rw-r--r--com32/libutil/crypt-md5.c169
1 files changed, 169 insertions, 0 deletions
diff --git a/com32/libutil/crypt-md5.c b/com32/libutil/crypt-md5.c
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+++ b/com32/libutil/crypt-md5.c
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+/*-
+ * Copyright (c) 2003 Poul-Henning Kamp
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <inttypes.h>
+#include <md5.h>
+#include <string.h>
+
+/*
+ * UNIX password
+ */
+
+#include "crypt.h"
+
+static char itoa64[] = /* 0 ... 63 => ascii - 64 */
+ "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
+static void
+_crypt_to64(char *s, uint32_t v, int n)
+{
+ while (--n >= 0) {
+ *s++ = itoa64[v&0x3f];
+ v >>= 6;
+ }
+}
+
+char *
+crypt_md5(const char *pw, const char *salt)
+{
+ MD5_CTX ctx,ctx1;
+ unsigned long l;
+ int sl, pl;
+ uint32_t i;
+ uint8_t final[MD5_SIZE];
+ static const char *sp, *ep;
+ static char passwd[120], *p;
+ static const char *magic = "$1$";
+
+ /* 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, (const uint8_t *)pw, strlen(pw));
+
+ /* Then our magic string */
+ MD5Update(&ctx, (const uint8_t *)magic, strlen(magic));
+
+ /* Then the raw salt */
+ MD5Update(&ctx, (const uint8_t *)sp, (uint32_t)sl);
+
+ /* Then just as many characters of the MD5(pw,salt,pw) */
+ MD5Init(&ctx1);
+ MD5Update(&ctx1, (const uint8_t *)pw, strlen(pw));
+ MD5Update(&ctx1, (const uint8_t *)sp, (uint32_t)sl);
+ MD5Update(&ctx1, (const uint8_t *)pw, strlen(pw));
+ MD5Final(final, &ctx1);
+ for(pl = (int)strlen(pw); pl > 0; pl -= MD5_SIZE)
+ MD5Update(&ctx, (const uint8_t *)final,
+ (uint32_t)(pl > MD5_SIZE ? MD5_SIZE : pl));
+
+ /* Don't leave anything around in vm they could use. */
+ memset(final, 0, sizeof(final));
+
+ /* Then something really weird... */
+ for (i = strlen(pw); i; i >>= 1)
+ if(i & 1)
+ MD5Update(&ctx, (const uint8_t *)final, 1);
+ else
+ MD5Update(&ctx, (const uint8_t *)pw, 1);
+
+ /* Now make the output string */
+ strcpy(passwd, magic);
+ strncat(passwd, sp, (uint32_t)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, (const uint8_t *)pw, strlen(pw));
+ else
+ MD5Update(&ctx1, (const uint8_t *)final, MD5_SIZE);
+
+ if(i % 3)
+ MD5Update(&ctx1, (const uint8_t *)sp, (uint32_t)sl);
+
+ if(i % 7)
+ MD5Update(&ctx1, (const uint8_t *)pw, strlen(pw));
+
+ if(i & 1)
+ MD5Update(&ctx1, (const uint8_t *)final, MD5_SIZE);
+ else
+ MD5Update(&ctx1, (const uint8_t *)pw, strlen(pw));
+ MD5Final(final, &ctx1);
+ }
+
+ p = passwd + strlen(passwd);
+
+ l = (final[ 0]<<16) | (final[ 6]<<8) | final[12];
+ _crypt_to64(p, l, 4); p += 4;
+ l = (final[ 1]<<16) | (final[ 7]<<8) | final[13];
+ _crypt_to64(p, l, 4); p += 4;
+ l = (final[ 2]<<16) | (final[ 8]<<8) | final[14];
+ _crypt_to64(p, l, 4); p += 4;
+ l = (final[ 3]<<16) | (final[ 9]<<8) | final[15];
+ _crypt_to64(p, l, 4); p += 4;
+ l = (final[ 4]<<16) | (final[10]<<8) | final[ 5];
+ _crypt_to64(p, l, 4); p += 4;
+ l = final[11];
+ _crypt_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);
+}
+
+#ifdef TEST
+#include <stdio.h>
+
+int main(int argc, char *argv[])
+{
+ puts(crypt_md5(argv[1], argv[2]));
+ return 0;
+}
+
+#endif