Index: openacs-4/packages/acs-tcl/tcl/base64.tcl =================================================================== RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/Attic/base64.tcl,v diff -u -N --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ openacs-4/packages/acs-tcl/tcl/base64.tcl 28 Aug 2003 09:41:43 -0000 1.2 @@ -0,0 +1,323 @@ +# base64.tcl -- +# +# Encode/Decode base64 for a string +# Stephen Uhler / Brent Welch (c) 1997 Sun Microsystems +# The decoder was done for exmh by Chris Garrigues +# +# Copyright (c) 1998-2000 by Ajuba Solutions. +# See the file "license.terms" for information on usage and redistribution +# of this file, and for a DISCLAIMER OF ALL WARRANTIES. +# +# RCS: @(#) $Id: base64.tcl,v 1.2 2003/08/28 09:41:43 lars Exp $ + +# Version 1.0 implemented Base64_Encode, Bae64_Decode +# Version 2.0 uses the base64 namespace +# Version 2.1 fixes various decode bugs and adds options to encode +# Version 2.2 is much faster, Tcl8.0 compatible +# Version 2.2.1 bugfixes +# Version 2.2.2 bugfixes + +package require Tcl 8.2 +namespace eval ::base64 { + namespace export encode decode +} + +if {![catch {package require Trf 2.0}]} { + # Trf is available, so implement the functionality provided here + # in terms of calls to Trf for speed. + + # ::base64::encode -- + # + # Base64 encode a given string. + # + # Arguments: + # args ?-maxlen maxlen? ?-wrapchar wrapchar? string + # + # If maxlen is 0, the output is not wrapped. + # + # Results: + # A Base64 encoded version of $string, wrapped at $maxlen characters + # by $wrapchar. + + proc ::base64::encode {args} { + # Set the default wrapchar and maximum line length to match the output + # of GNU uuencode 4.2. Various RFC's allow for different wrapping + # characters and wraplengths, so these may be overridden by command line + # options. + set wrapchar "\n" + set maxlen 60 + + if { [llength $args] == 0 } { + error "wrong # args: should be \"[lindex [info level 0] 0]\ + ?-maxlen maxlen? ?-wrapchar wrapchar? string\"" + } + + set optionStrings [list "-maxlen" "-wrapchar"] + for {set i 0} {$i < [llength $args] - 1} {incr i} { + set arg [lindex $args $i] + set index [lsearch -glob $optionStrings "${arg}*"] + if { $index == -1 } { + error "unknown option \"$arg\": must be -maxlen or -wrapchar" + } + incr i + if { $i >= [llength $args] - 1 } { + error "value for \"$arg\" missing" + } + set val [lindex $args $i] + + # The name of the variable to assign the value to is extracted + # from the list of known options, all of which have an + # associated variable of the same name as the option without + # a leading "-". The [string range] command is used to strip + # of the leading "-" from the name of the option. + # + # FRINK: nocheck + set [string range [lindex $optionStrings $index] 1 end] $val + } + + # [string is] requires Tcl8.2; this works with 8.0 too + if {[catch {expr {$maxlen % 2}}]} { + error "expected integer but got \"$maxlen\"" + } + + set string [lindex $args end] + set result [::base64 -mode encode -- $string] + set result [string map [list \n ""] $result] + + if {$maxlen > 0} { + set res "" + set edge [expr {$maxlen - 1}] + while {[string length $result] > $maxlen} { + append res [string range $result 0 $edge]$wrapchar + set result [string range $result $maxlen end] + } + if {[string length $result] > 0} { + append res $result + } + set result $res + } + + return $result + } + + # ::base64::decode -- + # + # Base64 decode a given string. + # + # Arguments: + # string The string to decode. Characters not in the base64 + # alphabet are ignored (e.g., newlines) + # + # Results: + # The decoded value. + + proc ::base64::decode {string} { + ::base64 -mode decode -- $string + } + +} else { + # Without Trf use a pure tcl implementation + + namespace eval base64 { + variable base64 {} + variable base64_en {} + + # We create the auxiliary array base64_tmp, it will be unset later. + + set i 0 + foreach char {A B C D E F G H I J K L M N O P Q R S T U V W X Y Z \ + a b c d e f g h i j k l m n o p q r s t u v w x y z \ + 0 1 2 3 4 5 6 7 8 9 + /} { + set base64_tmp($char) $i + lappend base64_en $char + incr i + } + + # + # Create base64 as list: to code for instance C<->3, specify + # that [lindex $base64 67] be 3 (C is 67 in ascii); non-coded + # ascii chars get a {}. we later use the fact that lindex on a + # non-existing index returns {}, and that [expr {} < 0] is true + # + + # the last ascii char is 'z' + scan z %c len + for {set i 0} {$i <= $len} {incr i} { + set char [format %c $i] + set val {} + if {[info exists base64_tmp($char)]} { + set val $base64_tmp($char) + } else { + set val {} + } + lappend base64 $val + } + + # code the character "=" as -1; used to signal end of message + scan = %c i + set base64 [lreplace $base64 $i $i -1] + + # remove unneeded variables + unset base64_tmp i char len val + + namespace export encode decode + } + + # ::base64::encode -- + # + # Base64 encode a given string. + # + # Arguments: + # args ?-maxlen maxlen? ?-wrapchar wrapchar? string + # + # If maxlen is 0, the output is not wrapped. + # + # Results: + # A Base64 encoded version of $string, wrapped at $maxlen characters + # by $wrapchar. + + proc ::base64::encode {args} { + set base64_en $::base64::base64_en + + # Set the default wrapchar and maximum line length to match the output + # of GNU uuencode 4.2. Various RFC's allow for different wrapping + # characters and wraplengths, so these may be overridden by command line + # options. + set wrapchar "\n" + set maxlen 60 + + if { [llength $args] == 0 } { + error "wrong # args: should be \"[lindex [info level 0] 0]\ + ?-maxlen maxlen? ?-wrapchar wrapchar? string\"" + } + + set optionStrings [list "-maxlen" "-wrapchar"] + for {set i 0} {$i < [llength $args] - 1} {incr i} { + set arg [lindex $args $i] + set index [lsearch -glob $optionStrings "${arg}*"] + if { $index == -1 } { + error "unknown option \"$arg\": must be -maxlen or -wrapchar" + } + incr i + if { $i >= [llength $args] - 1 } { + error "value for \"$arg\" missing" + } + set val [lindex $args $i] + + # The name of the variable to assign the value to is extracted + # from the list of known options, all of which have an + # associated variable of the same name as the option without + # a leading "-". The [string range] command is used to strip + # of the leading "-" from the name of the option. + # + # FRINK: nocheck + set [string range [lindex $optionStrings $index] 1 end] $val + } + + # [string is] requires Tcl8.2; this works with 8.0 too + if {[catch {expr {$maxlen % 2}}]} { + error "expected integer but got \"$maxlen\"" + } + + set string [lindex $args end] + + set result {} + set state 0 + set length 0 + + + # Process the input bytes 3-by-3 + + binary scan $string c* X + foreach {x y z} $X { + # Do the line length check before appending so that we don't get an + # extra newline if the output is a multiple of $maxlen chars long. + if {$maxlen && $length >= $maxlen} { + append result $wrapchar + set length 0 + } + + append result [lindex $base64_en [expr {($x >>2) & 0x3F}]] + if {$y != {}} { + append result [lindex $base64_en [expr {(($x << 4) & 0x30) | (($y >> 4) & 0xF)}]] + if {$z != {}} { + append result \ + [lindex $base64_en [expr {(($y << 2) & 0x3C) | (($z >> 6) & 0x3)}]] + append result [lindex $base64_en [expr {($z & 0x3F)}]] + } else { + set state 2 + break + } + } else { + set state 1 + break + } + incr length 4 + } + if {$state == 1} { + append result [lindex $base64_en [expr {(($x << 4) & 0x30)}]]== + } elseif {$state == 2} { + append result [lindex $base64_en [expr {(($y << 2) & 0x3C)}]]= + } + return $result + } + + # ::base64::decode -- + # + # Base64 decode a given string. + # + # Arguments: + # string The string to decode. Characters not in the base64 + # alphabet are ignored (e.g., newlines) + # + # Results: + # The decoded value. + + proc ::base64::decode {string} { + if {[string length $string] == 0} {return ""} + + set base64 $::base64::base64 + + binary scan $string c* X + foreach x $X { + set bits [lindex $base64 $x] + if {$bits >= 0} { + if {[llength [lappend nums $bits]] == 4} { + foreach {v w z y} $nums break + set a [expr {($v << 2) | ($w >> 4)}] + set b [expr {(($w & 0xF) << 4) | ($z >> 2)}] + set c [expr {(($z & 0x3) << 6) | $y}] + append output [binary format ccc $a $b $c] + set nums {} + } + } elseif {$bits == -1} { + # = indicates end of data. Output whatever chars are left. + # The encoding algorithm dictates that we can only have 1 or 2 + # padding characters. If x=={}, we have 12 bits of input + # (enough for 1 8-bit output). If x!={}, we have 18 bits of + # input (enough for 2 8-bit outputs). + + foreach {v w z} $nums break + set a [expr {($v << 2) | (($w & 0x30) >> 4)}] + + if {$z == {}} { + append output [binary format c $a ] + } else { + set b [expr {(($w & 0xF) << 4) | (($z & 0x3C) >> 2)}] + append output [binary format cc $a $b] + } + break + } else { + # RFC 2045 says that line breaks and other characters not part + # of the Base64 alphabet must be ignored, and that the decoder + # can optionally emit a warning or reject the message. We opt + # not to do so, but to just ignore the character. + continue + } + } + return $output + } +} + +package provide base64 2.2.2 +