/* $NetBSD: md5crypt.c,v 1.15.2.1 2024/08/23 16:40:48 martin Exp $ */ /* * ---------------------------------------------------------------------------- * "THE BEER-WARE LICENSE" (Revision 42): * 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 * ---------------------------------------------------------------------------- * * from FreeBSD: crypt.c,v 1.5 1996/10/14 08:34:02 phk Exp * via OpenBSD: md5crypt.c,v 1.9 1997/07/23 20:58:27 kstailey Exp * */ #include #if !defined(lint) __RCSID("$NetBSD: md5crypt.c,v 1.15.2.1 2024/08/23 16:40:48 martin Exp $"); #endif /* not lint */ #include #include #include #include #include "crypt.h" #define MD5_MAGIC "$1$" #define MD5_MAGIC_LEN 3 #define INIT(x) MD5Init((x)) #define UPDATE(x, b, l) MD5Update((x), (b), (l)) #define FINAL(v, x) MD5Final((v), (x)) /* * MD5 password encryption. */ crypt_private char * __md5crypt(const char *pw, const char *salt) { static char passwd[120], *p; const char *sp, *ep; unsigned char final[16]; unsigned int i, sl, pwl; MD5_CTX ctx, ctx1; u_int32_t l; int pl; pwl = strlen(pw); /* Refine the salt first */ sp = salt; /* If it starts with the magic string, then skip that */ if (strncmp(sp, MD5_MAGIC, MD5_MAGIC_LEN) == 0) sp += MD5_MAGIC_LEN; /* It stops at the first '$', max 8 chars */ for (ep = sp; *ep != '\0' && *ep != '$' && ep < (sp + 8); ep++) continue; /* get the length of the true salt */ sl = ep - sp; INIT(&ctx); /* The password first, since that is what is most unknown */ UPDATE(&ctx, (const unsigned char *)pw, pwl); /* Then our magic string */ UPDATE(&ctx, (const unsigned char *)MD5_MAGIC, MD5_MAGIC_LEN); /* Then the raw salt */ UPDATE(&ctx, (const unsigned char *)sp, sl); /* Then just as many characters of the MD5(pw,salt,pw) */ INIT(&ctx1); UPDATE(&ctx1, (const unsigned char *)pw, pwl); UPDATE(&ctx1, (const unsigned char *)sp, sl); UPDATE(&ctx1, (const unsigned char *)pw, pwl); FINAL(final, &ctx1); for (pl = pwl; pl > 0; pl -= 16) UPDATE(&ctx, final, (unsigned int)(pl > 16 ? 16 : pl)); /* Don't leave anything around in vm they could use. */ memset(final, 0, sizeof(final)); /* Then something really weird... */ for (i = pwl; i != 0; i >>= 1) if ((i & 1) != 0) UPDATE(&ctx, final, 1); else UPDATE(&ctx, (const unsigned char *)pw, 1); /* Now make the output string */ memcpy(passwd, MD5_MAGIC, MD5_MAGIC_LEN); strlcpy(passwd + MD5_MAGIC_LEN, sp, sl + 1); strlcat(passwd, "$", sizeof(passwd)); FINAL(final, &ctx); /* memset(&ctx, 0, sizeof(ctx)); done by MD5Final() */ /* * 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++) { INIT(&ctx1); if ((i & 1) != 0) UPDATE(&ctx1, (const unsigned char *)pw, pwl); else UPDATE(&ctx1, final, 16); if ((i % 3) != 0) UPDATE(&ctx1, (const unsigned char *)sp, sl); if ((i % 7) != 0) UPDATE(&ctx1, (const unsigned char *)pw, pwl); if ((i & 1) != 0) UPDATE(&ctx1, final, 16); else UPDATE(&ctx1, (const unsigned char *)pw, pwl); FINAL(final, &ctx1); } /* memset(&ctx1, 0, sizeof(ctx1)); done by MD5Final() */ p = passwd + sl + MD5_MAGIC_LEN + 1; 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. */ explicit_memset(final, 0, sizeof(final)); return (passwd); }