Submitted By: Robert Connolly (ashes) Date: 2006-01-14 Initial Package Version: 4.0.14 Upstream Status: Not submitted Origin: http://www.openwall.com/crypt/contrib/\ shadow-4.0.3-crypt_blowfish.diff.gz Thanks to Stephen Leaf for update. Description: Adds blowfish passwords to shadow. This depends on a blowfish library. There's a hint for this patch here: http://www.linuxfromscratch.org/hints/downloads/files/blowfish-passwords.txt diff -Naur shadow-4.0.14/etc/login.defs shadow-4.0.14.new/etc/login.defs --- shadow-4.0.14/etc/login.defs 2005-09-03 05:20:20.000000000 -0500 +++ shadow-4.0.14.new/etc/login.defs 2006-01-14 11:07:58.000000000 -0600 @@ -242,13 +242,6 @@ PASS_ALWAYS_WARN yes # -# Number of significant characters in the password for crypt(). -# Default is 8, don't change unless your crypt() is better. -# Ignored if MD5_CRYPT_ENAB set to "yes". -# -#PASS_MAX_LEN 8 - -# # Require password before chfn/chsh can make any changes. # CHFN_AUTH yes @@ -268,15 +261,60 @@ # to use the default which is just "Password: ". #LOGIN_STRING "%s's Password: " -# -# Only works if compiled with MD5_CRYPT defined: -# If set to "yes", new passwords will be encrypted using the MD5-based -# algorithm compatible with the one used by recent releases of FreeBSD. -# It supports passwords of unlimited length and longer salt strings. -# Set to "no" if you need to copy encrypted passwords to other systems -# which don't understand the new algorithm. Default is "no". -# -#MD5_CRYPT_ENAB no +# Each password entry contains a prefix that specifies the hashing algorithm +# used to create the remaining characters/bytes. Use this setting to specify +# which hashing algorithm is used to create new passwords. +# +# The default here is to use the Blowfish-based algorithm, (which currently +# requires you to be running a patched version of glibc). To use the slightly +# more compatible MD5-based algorithm, you would set this to $1$. To be +# completely backwards compatible and use the traditional DES-based hashing, +# you should set this value to an empty string, but be warned, passwords using +# this algorithm offer very little security. +# +CRYPT_PREFIX "$2a$" + +# +# For hashing algorithms that can alter their complexity, use this setting to +# achieve a balance between the security of the password and performance on the +# host system. +# +# This value is interpreted by each algorithm in specific ways. With the +# Blowfish algorithm, it specifies the number of rounds as a base-2 logarithm +# of the actual iteration count, so 12 actually refers to 2^12. Altering the +# value to 11 would therefore halve the number of iterations used to 2^11. +# +# Make sure that if you alter the above setting, this setting is also +# appropriate. For algorithms that have fixed iteration counts, or to +# enforce the use of a low default value, use a setting of 0. +# +CRYPT_ROUNDS 12 + +# All algorithms require varying amounts of random bytes known as salt. For +# example the DES-based algorithm requires only 12-bits, (1 bytes), whereas +# the Blowfish-based algorithm requires 128-bits, (16 bytes). +# +# If an algorithm doesn't receive enough salt, more will be collected from +# /dev/urandom, a byte at a time until it's satisfied. If you know how much +# is enough to satisfy even the most hungry of algorithms locally available, +# setting it here will speed up the generation of passwords. +# +# A maximum is also provided to enforce an upper limit on this to prevent a +# wayward algorithm munching all the randomness unnecessarily. +# +CRYPT_MINSALT 16 +CRYPT_MAXSALT 32 + +# Number of significant characters in the password for crypt(). MD5 can +# effectively cope with unlimited length passwords, but a limit of ~127 is +# reasonable. Blowfish can handle up to 72 characters, and the DES algorithm +# can only handle 8. +# +# This setting is used in some of the obscure checks, and also to inform the +# user on how big their new password should be, so it should be set in +# accordance to the choice of algorithm. +PASS_MAX_LEN 72 + # # List of groups to add to the user's supplementary group set diff -Naur shadow-4.0.14/lib/getdef.c shadow-4.0.14.new/lib/getdef.c --- shadow-4.0.14/lib/getdef.c 2005-12-02 17:23:34.000000000 -0600 +++ shadow-4.0.14.new/lib/getdef.c 2006-01-14 11:19:15.000000000 -0600 @@ -51,6 +51,10 @@ {"CONSOLE_GROUPS", NULL}, {"CONSOLE", NULL}, {"CREATE_HOME", NULL}, + {"CRYPT_MAXSALT", NULL }, + {"CRYPT_MINSALT", NULL }, + {"CRYPT_PREFIX", NULL }, + {"CRYPT_ROUNDS", NULL }, {"DEFAULT_HOME", NULL}, {"ENV_PATH", NULL}, {"ENV_SUPATH", NULL}, @@ -68,7 +72,9 @@ {"LOG_UNKFAIL_ENAB", NULL}, {"MAIL_DIR", NULL}, {"MAIL_FILE", NULL}, +#if 0 {"MD5_CRYPT_ENAB", NULL}, +#endif {"PASS_MAX_DAYS", NULL}, {"PASS_MIN_DAYS", NULL}, {"PASS_WARN_AGE", NULL}, diff -Naur shadow-4.0.14/libmisc/obscure.c shadow-4.0.14.new/libmisc/obscure.c --- shadow-4.0.14/libmisc/obscure.c 2005-08-31 12:24:57.000000000 -0500 +++ shadow-4.0.14.new/libmisc/obscure.c 2006-01-14 11:07:58.000000000 -0600 @@ -233,8 +233,10 @@ Example: "password$%^&*123". So check it again, this time truncated to the maximum length. Idea from npasswd. --marekm */ +#if 0 if (getdef_bool ("MD5_CRYPT_ENAB")) return NULL; /* unlimited password length */ +#endif maxlen = getdef_num ("PASS_MAX_LEN", 8); if (oldlen <= maxlen && newlen <= maxlen) diff -Naur shadow-4.0.14/libmisc/salt.c shadow-4.0.14.new/libmisc/salt.c --- shadow-4.0.14/libmisc/salt.c 2005-08-31 12:24:58.000000000 -0500 +++ shadow-4.0.14.new/libmisc/salt.c 2006-01-14 11:07:58.000000000 -0600 @@ -20,6 +20,7 @@ * (magic) and pw_encrypt() will execute the MD5-based FreeBSD-compatible * version of crypt() instead of the standard one. */ +#if 0 char *crypt_make_salt (void) { struct timeval tv; @@ -44,3 +45,93 @@ return result; } +#endif + +/* Soopa-doopa salt generation function. There isn't anything algorithm + * specific in here, although it does require the Openwall-patched glibc to + * provide the crypt_gensalt() function, as well as make use of Blowfish-based + * hashing. + * + * All parameters can be customised from the /etc/login.defs file + * + * Written by Matt Dainty + */ +#include +#include +#include +#include +#include + +#define RANDOM_FILE "/dev/random" + +char * +crypt_make_salt(void) +{ + char *result, *salt; + int fd, offset, minsalt, maxsalt, count; + + minsalt = getdef_num( "CRYPT_MINSALT", 16 ); + maxsalt = getdef_num( "CRYPT_MAXSALT", 32 ); + + if( minsalt > maxsalt ) { + fprintf( stderr, "Check the CRYPT_MINSALT and CRYPT_MAXSALT settings!\n" ); + exit(1); + } + + if( ( salt = ( char * ) malloc( maxsalt ) ) == NULL ) { + fprintf( stderr, "Can't allocate %d bytes of memory\n", maxsalt ); + exit(1); + } + + if( ( fd = open( RANDOM_FILE, O_RDONLY ) ) < 0 ) { + fprintf( stderr, "Can't open %s for reading\n", RANDOM_FILE ); + free( salt ); + exit(1); + } + + offset = 0; + result = NULL; + + while( !result ) { + while( offset < minsalt ) { + count = read( fd, &salt[offset], minsalt - offset ); + if( count <= 0 ) { + if( errno == EINTR ) + continue; + goto finish; + } + offset += count; + } + result = crypt_gensalt( getdef_str( "CRYPT_PREFIX" ), + getdef_num( "CRYPT_ROUNDS", 0 ), + salt, minsalt ); + + if( !result && errno == EINVAL ) { + if( minsalt < maxsalt ) { + minsalt++; + } else { + fprintf( stderr, "CRYPT_PREFIX or CRYPT_ROUNDS is set incorrectly\n" ); + goto finish; + } + } + } + +finish: + if( salt ) + free( salt ); + if( fd ) + close( fd ); + + /* XXX If we return the salt string as NULL, crypt will currently + * segfault, so if have we a NULL salt string, exit here. + * Otherwise, every invocation of crypt_make_salt() will have to + * check for a NULL return value. + * + * This way, I don't muck up any more code! :-) + */ + if( result ) + return result; + + exit(1); +} + diff -Naur shadow-4.0.14/src/passwd.c shadow-4.0.14.new/src/passwd.c --- shadow-4.0.14/src/passwd.c 2005-12-06 15:25:00.000000000 -0600 +++ shadow-4.0.14.new/src/passwd.c 2006-01-14 11:07:58.000000000 -0600 @@ -236,9 +236,11 @@ * for strength, unless it is the root user. This provides an escape * for initial login passwords. */ +#if 0 if (getdef_bool ("MD5_CRYPT_ENAB")) pass_max_len = 127; else +#endif pass_max_len = getdef_num ("PASS_MAX_LEN", 8); if (!qflg)