# md4.tcl - Copyright (C) 2003 Pat Thoyts <[email protected]>
#
# This is a Tcl-only implementation of the MD4 hash algorithm as described in
# RFC 1320 ( http://www.ietf.org/rfc/rfc1320.txt )
#
# -------------------------------------------------------------------------
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
# -------------------------------------------------------------------------
package require Tcl 8.2; # tcl minimum version
catch {package require md4c 1.0}; # tcllib critcl alternative
# @mdgen EXCLUDE: md4c.tcl
namespace eval ::md4 {
variable accel
array set accel {critcl 0 cryptkit 0}
namespace export md4 hmac MD4Init MD4Update MD4Final
variable uid
if {![info exists uid]} {
set uid 0
}
}
# -------------------------------------------------------------------------
# MD4Init - create and initialize an MD4 state variable. This will be
# cleaned up when we call MD4Final
#
proc ::md4::MD4Init {} {
variable uid
variable accel
set token [namespace current]::[incr uid]
upvar #0 $token state
# RFC1320:3.3 - Initialize MD4 state structure
array set state \
[list \
A [expr {0x67452301}] \
B [expr {0xefcdab89}] \
C [expr {0x98badcfe}] \
D [expr {0x10325476}] \
n 0 i "" ]
if {$accel(cryptkit)} {
cryptkit::cryptCreateContext state(ckctx) CRYPT_UNUSED CRYPT_ALGO_MD4
}
return $token
}
proc ::md4::MD4Update {token data} {
variable accel
upvar #0 $token state
if {$accel(critcl)} {
if {[info exists state(md4c)]} {
set state(md4c) [md4c $data $state(md4c)]
} else {
set state(md4c) [md4c $data]
}
return
} elseif {[info exists state(ckctx)]} {
if {[string length $data] > 0} {
cryptkit::cryptEncrypt $state(ckctx) $data
}
return
}
# Update the state values
incr state(n) [string length $data]
append state(i) $data
# Calculate the hash for any complete blocks
set len [string length $state(i)]
for {set n 0} {($n + 64) <= $len} {} {
MD4Hash $token [string range $state(i) $n [incr n 64]]
}
# Adjust the state for the blocks completed.
set state(i) [string range $state(i) $n end]
return
}
proc ::md4::MD4Final {token} {
upvar #0 $token state
if {[info exists state(md4c)]} {
set r $state(md4c)
unset state
return $r
} elseif {[info exists state(ckctx)]} {
cryptkit::cryptEncrypt $state(ckctx) ""
cryptkit::cryptGetAttributeString $state(ckctx) \
CRYPT_CTXINFO_HASHVALUE r 16
cryptkit::cryptDestroyContext $state(ckctx)
# If nothing was hashed, we get no r variable set!
if {[info exists r]} {
unset state
return $r
}
}
# RFC1320:3.1 - Padding
#
set len [string length $state(i)]
set pad [expr {56 - ($len % 64)}]
if {$len % 64 > 56} {
incr pad 64
}
if {$pad == 0} {
incr pad 64
}
append state(i) [binary format a$pad \x80]
# RFC1320:3.2 - Append length in bits as little-endian wide int.
append state(i) [binary format ii [expr {8 * $state(n)}] 0]
# Calculate the hash for the remaining block.
set len [string length $state(i)]
for {set n 0} {($n + 64) <= $len} {} {
MD4Hash $token [string range $state(i) $n [incr n 64]]
}
# RFC1320:3.5 - Output
set r [bytes $state(A)][bytes $state(B)][bytes $state(C)][bytes $state(D)]
unset state
return $r
}
# -------------------------------------------------------------------------
# HMAC Hashed Message Authentication (RFC 2104)
#
# hmac = H(K xor opad, H(K xor ipad, text))
#
proc ::md4::HMACInit {K} {
# Key K is adjusted to be 64 bytes long. If K is larger, then use
# the MD4 digest of K and pad this instead.
set len [string length $K]
if {$len > 64} {
set tok [MD4Init]
MD4Update $tok $K
set K [MD4Final $tok]
set len [string length $K]
}
set pad [expr {64 - $len}]
append K [string repeat \0 $pad]
# Cacluate the padding buffers.
set Ki {}
set Ko {}
binary scan $K i16 Ks
foreach k $Ks {
append Ki [binary format i [expr {$k ^ 0x36363636}]]
append Ko [binary format i [expr {$k ^ 0x5c5c5c5c}]]
}
set tok [MD4Init]
MD4Update $tok $Ki; # initialize with the inner pad
# preserve the Ko value for the final stage.
# FRINK: nocheck
set [subst $tok](Ko) $Ko
return $tok
}
proc ::md4::HMACUpdate {token data} {
MD4Update $token $data
return
}
proc ::md4::HMACFinal {token} {
# FRINK: nocheck
variable $token
upvar 0 $token state
set tok [MD4Init]; # init the outer hashing function
MD4Update $tok $state(Ko); # prepare with the outer pad.
MD4Update $tok [MD4Final $token]; # hash the inner result
return [MD4Final $tok]
}
# -------------------------------------------------------------------------
set ::md4::MD4Hash_body {
variable $token
upvar 0 $token state
# RFC1320:3.4 - Process Message in 16-Word Blocks
binary scan $msg i* blocks
foreach {X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15} $blocks {
set A $state(A)
set B $state(B)
set C $state(C)
set D $state(D)
# Round 1
# Let [abcd k s] denote the operation
# a = (a + F(b,c,d) + X[k]) <<< s.
# Do the following 16 operations.
# [ABCD 0 3] [DABC 1 7] [CDAB 2 11] [BCDA 3 19]
set A [expr {($A + [F $B $C $D] + $X0) <<< 3}]
set D [expr {($D + [F $A $B $C] + $X1) <<< 7}]
set C [expr {($C + [F $D $A $B] + $X2) <<< 11}]
set B [expr {($B + [F $C $D $A] + $X3) <<< 19}]
# [ABCD 4 3] [DABC 5 7] [CDAB 6 11] [BCDA 7 19]
set A [expr {($A + [F $B $C $D] + $X4) <<< 3}]
set D [expr {($D + [F $A $B $C] + $X5) <<< 7}]
set C [expr {($C + [F $D $A $B] + $X6) <<< 11}]
set B [expr {($B + [F $C $D $A] + $X7) <<< 19}]
# [ABCD 8 3] [DABC 9 7] [CDAB 10 11] [BCDA 11 19]
set A [expr {($A + [F $B $C $D] + $X8) <<< 3}]
set D [expr {($D + [F $A $B $C] + $X9) <<< 7}]
set C [expr {($C + [F $D $A $B] + $X10) <<< 11}]
set B [expr {($B + [F $C $D $A] + $X11) <<< 19}]
# [ABCD 12 3] [DABC 13 7] [CDAB 14 11] [BCDA 15 19]
set A [expr {($A + [F $B $C $D] + $X12) <<< 3}]
set D [expr {($D + [F $A $B $C] + $X13) <<< 7}]
set C [expr {($C + [F $D $A $B] + $X14) <<< 11}]
set B [expr {($B + [F $C $D $A] + $X15) <<< 19}]
# Round 2.
# Let [abcd k s] denote the operation
# a = (a + G(b,c,d) + X[k] + 5A827999) <<< s
# Do the following 16 operations.
# [ABCD 0 3] [DABC 4 5] [CDAB 8 9] [BCDA 12 13]
set A [expr {($A + [G $B $C $D] + $X0 + 0x5a827999) <<< 3}]
set D [expr {($D + [G $A $B $C] + $X4 + 0x5a827999) <<< 5}]
set C [expr {($C + [G $D $A $B] + $X8 + 0x5a827999) <<< 9}]
set B [expr {($B + [G $C $D $A] + $X12 + 0x5a827999) <<< 13}]
# [ABCD 1 3] [DABC 5 5] [CDAB 9 9] [BCDA 13 13]
set A [expr {($A + [G $B $C $D] + $X1 + 0x5a827999) <<< 3}]
set D [expr {($D + [G $A $B $C] + $X5 + 0x5a827999) <<< 5}]
set C [expr {($C + [G $D $A $B] + $X9 + 0x5a827999) <<< 9}]
set B [expr {($B + [G $C $D $A] + $X13 + 0x5a827999) <<< 13}]
# [ABCD 2 3] [DABC 6 5] [CDAB 10 9] [BCDA 14 13]
set A [expr {($A + [G $B $C $D] + $X2 + 0x5a827999) <<< 3}]
set D [expr {($D + [G $A $B $C] + $X6 + 0x5a827999) <<< 5}]
set C [expr {($C + [G $D $A $B] + $X10 + 0x5a827999) <<< 9}]
set B [expr {($B + [G $C $D $A] + $X14 + 0x5a827999) <<< 13}]
# [ABCD 3 3] [DABC 7 5] [CDAB 11 9] [BCDA 15 13]
set A [expr {($A + [G $B $C $D] + $X3 + 0x5a827999) <<< 3}]
set D [expr {($D + [G $A $B $C] + $X7 + 0x5a827999) <<< 5}]
set C [expr {($C + [G $D $A $B] + $X11 + 0x5a827999) <<< 9}]
set B [expr {($B + [G $C $D $A] + $X15 + 0x5a827999) <<< 13}]
# Round 3.
# Let [abcd k s] denote the operation
# a = (a + H(b,c,d) + X[k] + 6ED9EBA1) <<< s.
# Do the following 16 operations.
# [ABCD 0 3] [DABC 8 9] [CDAB 4 11] [BCDA 12 15]
set A [expr {($A + [H $B $C $D] + $X0 + 0x6ed9eba1) <<< 3}]
set D [expr {($D + [H $A $B $C] + $X8 + 0x6ed9eba1) <<< 9}]
set C [expr {($C + [H $D $A $B] + $X4 + 0x6ed9eba1) <<< 11}]
set B [expr {($B + [H $C $D $A] + $X12 + 0x6ed9eba1) <<< 15}]
# [ABCD 2 3] [DABC 10 9] [CDAB 6 11] [BCDA 14 15]
set A [expr {($A + [H $B $C $D] + $X2 + 0x6ed9eba1) <<< 3}]
set D [expr {($D + [H $A $B $C] + $X10 + 0x6ed9eba1) <<< 9}]
set C [expr {($C + [H $D $A $B] + $X6 + 0x6ed9eba1) <<< 11}]
set B [expr {($B + [H $C $D $A] + $X14 + 0x6ed9eba1) <<< 15}]
# [ABCD 1 3] [DABC 9 9] [CDAB 5 11] [BCDA 13 15]
set A [expr {($A + [H $B $C $D] + $X1 + 0x6ed9eba1) <<< 3}]
set D [expr {($D + [H $A $B $C] + $X9 + 0x6ed9eba1) <<< 9}]
set C [expr {($C + [H $D $A $B] + $X5 + 0x6ed9eba1) <<< 11}]
set B [expr {($B + [H $C $D $A] + $X13 + 0x6ed9eba1) <<< 15}]
# [ABCD 3 3] [DABC 11 9] [CDAB 7 11] [BCDA 15 15]
set A [expr {($A + [H $B $C $D] + $X3 + 0x6ed9eba1) <<< 3}]
set D [expr {($D + [H $A $B $C] + $X11 + 0x6ed9eba1) <<< 9}]
set C [expr {($C + [H $D $A $B] + $X7 + 0x6ed9eba1) <<< 11}]
set B [expr {($B + [H $C $D $A] + $X15 + 0x6ed9eba1) <<< 15}]
# Then perform the following additions. (That is, increment each
# of the four registers by the value it had before this block
# was started.)
incr state(A) $A
incr state(B) $B
incr state(C) $C
incr state(D) $D
}
return
}
proc ::md4::byte {n v} {expr {((0xFF << (8 * $n)) & $v) >> (8 * $n)}}
proc ::md4::bytes {v} {
#format %c%c%c%c [byte 0 $v] [byte 1 $v] [byte 2 $v] [byte 3 $v]
format %c%c%c%c \
[expr {0xFF & $v}] \
[expr {(0xFF00 & $v) >> 8}] \
[expr {(0xFF0000 & $v) >> 16}] \
[expr {((0xFF000000 & $v) >> 24) & 0xFF}]
}
# 32bit rotate-left
proc ::md4::<<< {v n} {
return [expr {((($v << $n) \
| (($v >> (32 - $n)) \
& (0x7FFFFFFF >> (31 - $n))))) \
& 0xFFFFFFFF}]
}
# Convert our <<< pseudo-operator into a procedure call.
regsub -all -line \
{\[expr {(.*) <<< (\d+)}\]} \
$::md4::MD4Hash_body \
{[<<< [expr {\1}] \2]} \
::md4::MD4Hash_body
# RFC1320:3.4 - function F
proc ::md4::F {X Y Z} {
return [expr {($X & $Y) | ((~$X) & $Z)}]
}
# Inline the F function
regsub -all -line \
{\[F (\$[ABCD]) (\$[ABCD]) (\$[ABCD])\]} \
$::md4::MD4Hash_body \
{( (\1 \& \2) | ((~\1) \& \3) )} \
::md4::MD4Hash_body
# RFC1320:3.4 - function G
proc ::md4::G {X Y Z} {
return [expr {($X & $Y) | ($X & $Z) | ($Y & $Z)}]
}
# Inline the G function
regsub -all -line \
{\[G (\$[ABCD]) (\$[ABCD]) (\$[ABCD])\]} \
$::md4::MD4Hash_body \
{((\1 \& \2) | (\1 \& \3) | (\2 \& \3))} \
::md4::MD4Hash_body
# RFC1320:3.4 - function H
proc ::md4::H {X Y Z} {
return [expr {$X ^ $Y ^ $Z}]
}
# Inline the H function
regsub -all -line \
{\[H (\$[ABCD]) (\$[ABCD]) (\$[ABCD])\]} \
$::md4::MD4Hash_body \
{(\1 ^ \2 ^ \3)} \
::md4::MD4Hash_body
# Define the MD4 hashing procedure with inline functions.
proc ::md4::MD4Hash {token msg} $::md4::MD4Hash_body
unset ::md4::MD4Hash_body
# -------------------------------------------------------------------------
if {[package provide Trf] != {}} {
interp alias {} ::md4::Hex {} ::hex -mode encode --
} else {
proc ::md4::Hex {data} {
binary scan $data H* result
return [string toupper $result]
}
}
# -------------------------------------------------------------------------
# LoadAccelerator --
#
# This package can make use of a number of compiled extensions to
# accelerate the digest computation. This procedure manages the
# use of these extensions within the package. During normal usage
# this should not be called, but the test package manipulates the
# list of enabled accelerators.
#
proc ::md4::LoadAccelerator {name} {
variable accel
set r 0
switch -exact -- $name {
critcl {
if {![catch {package require tcllibc}]
|| ![catch {package require md4c}]} {
set r [expr {[info commands ::md4::md4c] != {}}]
}
}
cryptkit {
if {![catch {package require cryptkit}]} {
set r [expr {![catch {cryptkit::cryptInit}]}]
}
}
#trf {
# if {![catch {package require Trf}]} {
# set r [expr {![catch {::md4 aa} msg]}]
# }
#}
default {
return -code error "invalid accelerator package:\
must be one of [join [array names accel] {, }]"
}
}
set accel($name) $r
}
# -------------------------------------------------------------------------
# Description:
# Pop the nth element off a list. Used in options processing.
#
proc ::md4::Pop {varname {nth 0}} {
upvar $varname args
set r [lindex $args $nth]
set args [lreplace $args $nth $nth]
return $r
}
# -------------------------------------------------------------------------
# fileevent handler for chunked file hashing.
#
proc ::md4::Chunk {token channel {chunksize 4096}} {
# FRINK: nocheck
variable $token
upvar 0 $token state
if {[eof $channel]} {
fileevent $channel readable {}
set state(reading) 0
}
MD4Update $token [read $channel $chunksize]
}
# -------------------------------------------------------------------------
proc ::md4::md4 {args} {
array set opts {-hex 0 -filename {} -channel {} -chunksize 4096}
while {[string match -* [set option [lindex $args 0]]]} {
switch -glob -- $option {
-hex { set opts(-hex) 1 }
-file* { set opts(-filename) [Pop args 1] }
-channel { set opts(-channel) [Pop args 1] }
-chunksize { set opts(-chunksize) [Pop args 1] }
default {
if {[llength $args] == 1} { break }
if {[string compare $option "--"] == 0 } { Pop args; break }
set err [join [lsort [array names opts]] ", "]
return -code error "bad option $option:\
must be one of $err"
}
}
Pop args
}
if {$opts(-filename) != {}} {
set opts(-channel) [open $opts(-filename) r]
fconfigure $opts(-channel) -translation binary
}
if {$opts(-channel) == {}} {
if {[llength $args] != 1} {
return -code error "wrong # args:\
should be \"md4 ?-hex? -filename file | string\""
}
set tok [MD4Init]
MD4Update $tok [lindex $args 0]
set r [MD4Final $tok]
} else {
set tok [MD4Init]
# FRINK: nocheck
set [subst $tok](reading) 1
fileevent $opts(-channel) readable \
[list [namespace origin Chunk] \
$tok $opts(-channel) $opts(-chunksize)]
vwait [subst $tok](reading)
set r [MD4Final $tok]
# If we opened the channel - we should close it too.
if {$opts(-filename) != {}} {
close $opts(-channel)
}
}
if {$opts(-hex)} {
set r [Hex $r]
}
return $r
}
# -------------------------------------------------------------------------
proc ::md4::hmac {args} {
array set opts {-hex 0 -filename {} -channel {} -chunksize 4096}
while {[string match -* [set option [lindex $args 0]]]} {
switch -glob -- $option {
-key { set opts(-key) [Pop args 1] }
-hex { set opts(-hex) 1 }
-file* { set opts(-filename) [Pop args 1] }
-channel { set opts(-channel) [Pop args 1] }
-chunksize { set opts(-chunksize) [Pop args 1] }
default {
if {[llength $args] == 1} { break }
if {[string compare $option "--"] == 0 } { Pop args; break }
set err [join [lsort [array names opts]] ", "]
return -code error "bad option $option:\
must be one of $err"
}
}
Pop args
}
if {![info exists opts(-key)]} {
return -code error "wrong # args:\
should be \"hmac ?-hex? -key key -filename file | string\""
}
if {$opts(-filename) != {}} {
set opts(-channel) [open $opts(-filename) r]
fconfigure $opts(-channel) -translation binary
}
if {$opts(-channel) == {}} {
if {[llength $args] != 1} {
return -code error "wrong # args:\
should be \"hmac ?-hex? -key key -filename file | string\""
}
set tok [HMACInit $opts(-key)]
HMACUpdate $tok [lindex $args 0]
set r [HMACFinal $tok]
} else {
set tok [HMACInit $opts(-key)]
# FRINK: nocheck
set [subst $tok](reading) 1
fileevent $opts(-channel) readable \
[list [namespace origin Chunk] \
$tok $opts(-channel) $opts(-chunksize)]
vwait [subst $tok](reading)
set r [HMACFinal $tok]
# If we opened the channel - we should close it too.
if {$opts(-filename) != {}} {
close $opts(-channel)
}
}
if {$opts(-hex)} {
set r [Hex $r]
}
return $r
}
# -------------------------------------------------------------------------
# Try and load a compiled extension to help.
namespace eval ::md4 {
variable e {}
foreach e {critcl cryptkit} { if {[LoadAccelerator $e]} { break } }
unset e
}
package provide md4 1.0.6
# -------------------------------------------------------------------------
# Local Variables:
# mode: tcl
# indent-tabs-mode: nil
# End:
