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Differential D7306 Diff 18759 lib/libcrypt/crypt-md5.c

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lib/libcrypt/crypt-md5.c

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#include <unistd.h> #include <unistd.h>
#include "crypt.h" #include "crypt.h"
/* /*
* UNIX password * UNIX password
*/ */
char * int
crypt_md5(const char *pw, const char *salt) crypt_md5(const char *pw, const char *salt, char *buffer)
{ {
MD5_CTX ctx,ctx1; MD5_CTX ctx,ctx1;
unsigned long l; unsigned long l;
int sl, pl; int sl, pl;
u_int i; u_int i;
u_char final[MD5_SIZE]; u_char final[MD5_SIZE];
static const char *sp, *ep; const char *ep;
static char passwd[120], *p;
static const char *magic = "$1$"; static const char *magic = "$1$";
/* Refine the Salt first */ /* If the salt starts with the magic string, skip that. */
sp = salt; if (!strncmp(salt, magic, strlen(magic)))
salt += strlen(magic);
/* If it starts with the magic string, then skip that */
if(!strncmp(sp, magic, strlen(magic)))
sp += strlen(magic);
/* It stops at the first '$', max 8 chars */ /* It stops at the first '$', max 8 chars */
for(ep = sp; *ep && *ep != '$' && ep < (sp + 8); ep++) for (ep = salt; *ep && *ep != '$' && ep < salt + 8; ep++)
continue; continue;
/* get the length of the true salt */ /* get the length of the true salt */
sl = ep - sp; sl = ep - salt;
MD5Init(&ctx); MD5Init(&ctx);
/* The password first, since that is what is most unknown */ /* The password first, since that is what is most unknown */
MD5Update(&ctx, (const u_char *)pw, strlen(pw)); MD5Update(&ctx, (const u_char *)pw, strlen(pw));
/* Then our magic string */ /* Then our magic string */
MD5Update(&ctx, (const u_char *)magic, strlen(magic)); MD5Update(&ctx, (const u_char *)magic, strlen(magic));
/* Then the raw salt */ /* Then the raw salt */
MD5Update(&ctx, (const u_char *)sp, (u_int)sl); MD5Update(&ctx, (const u_char *)salt, (u_int)sl);
/* Then just as many characters of the MD5(pw,salt,pw) */ /* Then just as many characters of the MD5(pw,salt,pw) */
MD5Init(&ctx1); MD5Init(&ctx1);
MD5Update(&ctx1, (const u_char *)pw, strlen(pw)); MD5Update(&ctx1, (const u_char *)pw, strlen(pw));
MD5Update(&ctx1, (const u_char *)sp, (u_int)sl); MD5Update(&ctx1, (const u_char *)salt, (u_int)sl);
MD5Update(&ctx1, (const u_char *)pw, strlen(pw)); MD5Update(&ctx1, (const u_char *)pw, strlen(pw));
MD5Final(final, &ctx1); MD5Final(final, &ctx1);
for(pl = (int)strlen(pw); pl > 0; pl -= MD5_SIZE) for(pl = (int)strlen(pw); pl > 0; pl -= MD5_SIZE)
MD5Update(&ctx, (const u_char *)final, MD5Update(&ctx, (const u_char *)final,
(u_int)(pl > MD5_SIZE ? MD5_SIZE : pl)); (u_int)(pl > MD5_SIZE ? MD5_SIZE : pl));
/* Don't leave anything around in vm they could use. */ /* Don't leave anything around in vm they could use. */
memset(final, 0, sizeof(final)); memset(final, 0, sizeof(final));
/* Then something really weird... */ /* Then something really weird... */
for (i = strlen(pw); i; i >>= 1) for (i = strlen(pw); i; i >>= 1)
if(i & 1) if(i & 1)
MD5Update(&ctx, (const u_char *)final, 1); MD5Update(&ctx, (const u_char *)final, 1);
else else
MD5Update(&ctx, (const u_char *)pw, 1); MD5Update(&ctx, (const u_char *)pw, 1);
/* Now make the output string */ /* Now make the output string */
strcpy(passwd, magic); buffer = stpcpy(buffer, magic);
strncat(passwd, sp, (u_int)sl); buffer = stpncpy(buffer, salt, (u_int)sl);
strcat(passwd, "$"); *buffer++ = '$';
MD5Final(final, &ctx); MD5Final(final, &ctx);
/* /*
* and now, just to make sure things don't run too fast * and now, just to make sure things don't run too fast
* On a 60 Mhz Pentium this takes 34 msec, so you would * On a 60 Mhz Pentium this takes 34 msec, so you would
* need 30 seconds to build a 1000 entry dictionary... * need 30 seconds to build a 1000 entry dictionary...
*/ */
for(i = 0; i < 1000; i++) { for(i = 0; i < 1000; i++) {
MD5Init(&ctx1); MD5Init(&ctx1);
if(i & 1) if(i & 1)
MD5Update(&ctx1, (const u_char *)pw, strlen(pw)); MD5Update(&ctx1, (const u_char *)pw, strlen(pw));
else else
MD5Update(&ctx1, (const u_char *)final, MD5_SIZE); MD5Update(&ctx1, (const u_char *)final, MD5_SIZE);
if(i % 3) if(i % 3)
MD5Update(&ctx1, (const u_char *)sp, (u_int)sl); MD5Update(&ctx1, (const u_char *)salt, (u_int)sl);
if(i % 7) if(i % 7)
MD5Update(&ctx1, (const u_char *)pw, strlen(pw)); MD5Update(&ctx1, (const u_char *)pw, strlen(pw));
if(i & 1) if(i & 1)
MD5Update(&ctx1, (const u_char *)final, MD5_SIZE); MD5Update(&ctx1, (const u_char *)final, MD5_SIZE);
else else
MD5Update(&ctx1, (const u_char *)pw, strlen(pw)); MD5Update(&ctx1, (const u_char *)pw, strlen(pw));
MD5Final(final, &ctx1); MD5Final(final, &ctx1);
} }
p = passwd + strlen(passwd);
l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; l = (final[ 0]<<16) | (final[ 6]<<8) | final[12];
_crypt_to64(p, l, 4); p += 4; _crypt_to64(buffer, l, 4); buffer += 4;
l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; l = (final[ 1]<<16) | (final[ 7]<<8) | final[13];
_crypt_to64(p, l, 4); p += 4; _crypt_to64(buffer, l, 4); buffer += 4;
l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; l = (final[ 2]<<16) | (final[ 8]<<8) | final[14];
_crypt_to64(p, l, 4); p += 4; _crypt_to64(buffer, l, 4); buffer += 4;
l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; l = (final[ 3]<<16) | (final[ 9]<<8) | final[15];
_crypt_to64(p, l, 4); p += 4; _crypt_to64(buffer, l, 4); buffer += 4;
l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; l = (final[ 4]<<16) | (final[10]<<8) | final[ 5];
_crypt_to64(p, l, 4); p += 4; _crypt_to64(buffer, l, 4); buffer += 4;
l = final[11]; l = final[11];
_crypt_to64(p, l, 2); p += 2; _crypt_to64(buffer, l, 2); buffer += 2;
*p = '\0'; *buffer = '\0';
/* Don't leave anything around in vm they could use. */ /* Don't leave anything around in vm they could use. */
memset(final, 0, sizeof(final)); memset(final, 0, sizeof(final));
return (passwd); return (0);
} }