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-rw-r--r--src/auth/password-scheme-md5crypt.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/src/auth/password-scheme-md5crypt.c b/src/auth/password-scheme-md5crypt.c
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+++ b/src/auth/password-scheme-md5crypt.c
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+/*
+ * ----------------------------------------------------------------------------
+ * "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
+ * ----------------------------------------------------------------------------
+ */
+
+/*
+ * Ported from FreeBSD to Linux, only minimal changes. --marekm
+ */
+
+/*
+ * Adapted from shadow-19990607 by Tudor Bosman, tudorb@jm.nu
+ */
+
+#include "lib.h"
+#include "safe-memset.h"
+#include "str.h"
+#include "md5.h"
+#include "password-scheme.h"
+
+static unsigned char itoa64[] = /* 0 ... 63 => ascii - 64 */
+ "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
+static char magic[] = "$1$"; /*
+ * This string is magic for
+ * this algorithm. Having
+ * it this way, we can get
+ * get better later on
+ */
+
+static void
+to64(string_t *str, unsigned long v, int n)
+{
+ while (--n >= 0) {
+ str_append_c(str, itoa64[v&0x3f]);
+ v >>= 6;
+ }
+}
+
+/*
+ * UNIX password
+ *
+ * Use MD5 for what it is best at...
+ */
+
+const char *password_generate_md5_crypt(const char *pw, const char *salt)
+{
+ const char *sp,*ep;
+ unsigned char final[MD5_RESULTLEN];
+ int sl,pl,i,j;
+ struct md5_context ctx,ctx1;
+ unsigned long l;
+ string_t *passwd;
+ size_t pw_len = strlen(pw);
+
+ /* Refine the Salt first */
+ sp = salt;
+
+ /* If it starts with the magic string, then skip that */
+ if (strncmp(sp, magic, sizeof(magic)-1) == 0)
+ sp += sizeof(magic)-1;
+
+ /* 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;
+
+ md5_init(&ctx);
+
+ /* The password first, since that is what is most unknown */
+ md5_update(&ctx,pw,pw_len);
+
+ /* Then our magic string */
+ md5_update(&ctx,magic,sizeof(magic)-1);
+
+ /* Then the raw salt */
+ md5_update(&ctx,sp,sl);
+
+ /* Then just as many characters of the MD5(pw,salt,pw) */
+ md5_init(&ctx1);
+ md5_update(&ctx1,pw,pw_len);
+ md5_update(&ctx1,sp,sl);
+ md5_update(&ctx1,pw,pw_len);
+ md5_final(&ctx1,final);
+ for(pl = pw_len; pl > 0; pl -= MD5_RESULTLEN)
+ md5_update(&ctx,final,pl>MD5_RESULTLEN ? MD5_RESULTLEN : pl);
+
+ /* Don't leave anything around in vm they could use. */
+ safe_memset(final, 0, sizeof(final));
+
+ /* Then something really weird... */
+ for (j=0,i = pw_len; i != 0; i >>= 1)
+ if ((i&1) != 0)
+ md5_update(&ctx, final+j, 1);
+ else
+ md5_update(&ctx, pw+j, 1);
+
+ /* Now make the output string */
+ passwd = t_str_new(sl + 64);
+ str_append(passwd, magic);
+ str_append_data(passwd, sp, sl);
+ str_append_c(passwd, '$');
+
+ md5_final(&ctx,final);
+
+ /*
+ * 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++) {
+ md5_init(&ctx1);
+ if((i & 1) != 0)
+ md5_update(&ctx1,pw,pw_len);
+ else
+ md5_update(&ctx1,final,MD5_RESULTLEN);
+
+ if((i % 3) != 0)
+ md5_update(&ctx1,sp,sl);
+
+ if((i % 7) != 0)
+ md5_update(&ctx1,pw,pw_len);
+
+ if((i & 1) != 0)
+ md5_update(&ctx1,final,MD5_RESULTLEN);
+ else
+ md5_update(&ctx1,pw,pw_len);
+ md5_final(&ctx1,final);
+ }
+
+ l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; to64(passwd,l,4);
+ l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; to64(passwd,l,4);
+ l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; to64(passwd,l,4);
+ l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; to64(passwd,l,4);
+ l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; to64(passwd,l,4);
+ l = final[11] ; to64(passwd,l,2);
+
+ /* Don't leave anything around in vm they could use. */
+ safe_memset(final, 0, sizeof(final));
+
+ return str_c(passwd);
+}