diff options
Diffstat (limited to 'usr.sbin/xntpd/lib/a_md5decrypt.c')
-rw-r--r-- | usr.sbin/xntpd/lib/a_md5decrypt.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/usr.sbin/xntpd/lib/a_md5decrypt.c b/usr.sbin/xntpd/lib/a_md5decrypt.c new file mode 100644 index 0000000..892e52e --- /dev/null +++ b/usr.sbin/xntpd/lib/a_md5decrypt.c @@ -0,0 +1,58 @@ +/* authmd5decrypt.c,v 3.1 1993/07/06 01:07:53 jbj Exp + * md5crypt - MD5 based authentication routines + */ + +#include "ntp_types.h" +#include "ntp_string.h" +#include "md5.h" +#include "ntp_stdlib.h" + +extern U_LONG cache_keyid; +extern char *cache_key; +extern int cache_keylen; + +/* + * Stat counters, imported from data base module + */ +extern U_LONG authencryptions; +extern U_LONG authdecryptions; +extern U_LONG authkeyuncached; +extern U_LONG authdecryptok; +extern U_LONG authnokey; + +/* + * For our purposes an NTP packet looks like: + * + * a variable amount of encrypted data, multiple of 8 bytes, followed by: + * NOCRYPT_OCTETS worth of unencrypted data, followed by: + * BLOCK_OCTETS worth of ciphered checksum. + */ +#define NOCRYPT_OCTETS 4 +#define BLOCK_OCTETS 16 + +#define NOCRYPT_LONGS ((NOCRYPT_OCTETS)/sizeof(U_LONG)) +#define BLOCK_LONGS ((BLOCK_OCTETS)/sizeof(U_LONG)) + +int +MD5authdecrypt(keyno, pkt, length) + U_LONG keyno; + const U_LONG *pkt; + int length; /* length of variable data in octets */ +{ + MD5_CTX ctx; + + authdecryptions++; + + if (keyno != cache_keyid) { + authkeyuncached++; + if (!authhavekey(keyno)) + return 0; + } + + MD5Init(&ctx); + MD5Update(&ctx, cache_key, cache_keylen); + MD5Update(&ctx, (char *)pkt, length); + MD5Final(&ctx); + + return (0 == bcmp((char *)ctx.digest, (char *)pkt + length + 4, BLOCK_OCTETS)); +} |