diff options
Diffstat (limited to 'md5_crypt.c')
| -rw-r--r-- | md5_crypt.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/md5_crypt.c b/md5_crypt.c new file mode 100644 index 0000000..7871b45 --- /dev/null +++ b/md5_crypt.c @@ -0,0 +1,149 @@ +/* + * $Id: md5_crypt.c,v 1.1 2002-05-11 14:42:35 cpbotha 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 + * ---------------------------------------------------------------------------- + * + * Origin: Id: crypt.c,v 1.3 1995/05/30 05:42:22 rgrimes Exp + * + */ + +#include <string.h> +#include "md5.h" + +static unsigned char itoa64[] = /* 0 ... 63 => ascii - 64 */ +"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; + +static void to64(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 *MD5Name(crypt_md5)(const char *pw, const char *salt) +{ + const 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; + + MD5Name(MD5Init)(&ctx); + + /* The password first, since that is what is most unknown */ + MD5Name(MD5Update)(&ctx,(unsigned const char *)pw,strlen(pw)); + + /* Then our magic string */ + MD5Name(MD5Update)(&ctx,(unsigned const char *)magic,strlen(magic)); + + /* Then the raw salt */ + MD5Name(MD5Update)(&ctx,(unsigned const char *)sp,sl); + + /* Then just as many characters of the MD5(pw,salt,pw) */ + MD5Name(MD5Init)(&ctx1); + MD5Name(MD5Update)(&ctx1,(unsigned const char *)pw,strlen(pw)); + MD5Name(MD5Update)(&ctx1,(unsigned const char *)sp,sl); + MD5Name(MD5Update)(&ctx1,(unsigned const char *)pw,strlen(pw)); + MD5Name(MD5Final)(final,&ctx1); + for (pl = strlen(pw); pl > 0; pl -= 16) + MD5Name(MD5Update)(&ctx,(unsigned const char *)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) + MD5Name(MD5Update)(&ctx, (unsigned const char *)final+j, 1); + else + MD5Name(MD5Update)(&ctx, (unsigned const char *)pw+j, 1); + + /* Now make the output string */ + strcpy(passwd, magic); + strncat(passwd, sp, sl); + strcat(passwd, "$"); + + MD5Name(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++) { + MD5Name(MD5Init)(&ctx1); + if (i & 1) + MD5Name(MD5Update)(&ctx1,(unsigned const char *)pw,strlen(pw)); + else + MD5Name(MD5Update)(&ctx1,(unsigned const char *)final,16); + + if (i % 3) + MD5Name(MD5Update)(&ctx1,(unsigned const char *)sp,sl); + + if (i % 7) + MD5Name(MD5Update)(&ctx1,(unsigned const char *)pw,strlen(pw)); + + if (i & 1) + MD5Name(MD5Update)(&ctx1,(unsigned const char *)final,16); + else + MD5Name(MD5Update)(&ctx1,(unsigned const char *)pw,strlen(pw)); + MD5Name(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; +} |