6.1. DES, MD5, ¥H¤Î Crypt

Contributed by Garrett Wollman <wollman@FreeBSD.ORG>
24 September 1995.

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¦b³o´Á¶¡¡ADES-based ±K½X hash ¨ç¦¡¨ÌµM¦b¶i¦æ¤¤¡A­º¥ý¤@­Ó¦b¬ü°ê ¥H¥~µo®iªº`crypt' ¨ç¦¡³Q¿é¤J¡A¦]¦¹¬ü°êª©»P«D¬ü°êª©¦³¤F¤@ ­P©Ê¡CµM«á¡A¥±K¤è­±ªº¨ç¦¡®w³Q­×§ï¨Ã©î¦¨¨â­Ó¡A¤@¬° DES `libcrypt' ¥u¥]§t one-way password hash¡A¥t¤@­Ó¨ç¦¡®w `libcipher' ¥]§t¯u¥¿ªº¥±K¨ç¦¡¡A³o¨Ç¨ç¦¡®w¤§©Ò¥H³Q¤ÀÂ÷¥X¨Ó ¡A¬O¬°¤F¥i¥H®e©öªº¨ú±o½sĶ¨ç¦¡®wªº¥X¤f°õ·Ó¡C

¤F¸Ñ§Aªº `crypt' ¤èªk

¤À¿ì DES-based ©Î MD5-based hash ¨ç¦¡©Ò²£¥Íªº±K½X¦r¦ê¬O«Ü®e©öªº¡C MD5 ±K½X¦r¦êªº±Ò©l¦r¤¸Á`¬O`$1$'. ¦Ó DES±K½X¦r ¦ê«h¨S¦³¥ô¦ó¯S®íªº¦r¤¸¡A¦ý¬O³o¨Ç¦r¦ê¤ñ MD5©Ò²£¥Íªº¸ûµu¡A¦Ó¥B ³Q½s¦¨64­Ó¤£¥]§t`$' ªº¦r¤¸¡A¦]¦¹¤ñ¸ûµu¥B¤£§t¿ú¦r¸¹ ªº¦r¦ê´N«Ü¦³¥i¯à¬O DES ªº±K½X¡C

¦b¤j³¡¤Àµ{¦¡¤¤¡A­n¨M©w§Aªº¨t²Î¬O¨Ï¥Î¨º¤@­Ó¨ç¦¡®w¬O¬Û·í®e©öªº¡C °£¤F¨º¨Ç¹³¬OÀRºA³sµ²ªº`init'((¹ï¨º¨Çµ{¦¡¦Ó¨¥¡A°ß¤@ªº¤èªk ¬O¥Î¤@­Ó¤wª¾ªº±K½X¥h¸Õ¬Ý¬Ý¨Ã¦Û¤v¥h¬Ý)¥Î`crypt' ªºµ{¦¡ ¾a`libcrypt'©Ò³sµ²ªº¡A¨C¤@­Ó¨ç¦¡®w³£³sµ²¨ì¾A·íªº¦a¤è¡C Á|­Ó¨Ò¤l¡A¦b¨Ï¥Î DES ªº¨t²Î¤¤¡G

$ cd /usr/lib
$ ls -l /usr/lib/libcrypt*
lrwxr-xr-x  1 bin  bin  13 Sep  5 12:50 libcrypt.a -> libdescrypt.a
lrwxr-xr-x  1 bin  bin  18 Sep  5 12:50 libcrypt.so.2.0 -> libdescrypt.so.2.0
lrwxr-xr-x  1 bin  bin  15 Sep  5 12:50 libcrypt_p.a -> libdescrypt_p.a

¦b¤@­Ó¨Ï¥Î´Ó°ò©ó MD5 ¨ç¦¡®wªº¨t²Î¡A¤@¼Ë¦³³sµ²¦s¦b¡A¦ý¬O¥¦¬O³s µ²¨ì`libscrypt' ¦Ó¤£¬O`libdescrypt'.