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November 3, 2019 22:28
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| # g_base64.tcl - Base64 encoding/decoding routines | |
| # (c) 2013 Mantas Mikulėnas <grawity@gmail.com> | |
| # Released under the MIT Expat License. | |
| if {![catch {package require Tcl 8.6}]} { | |
| proc b64:encode {input} { | |
| binary encode base64 $input | |
| } | |
| proc b64:decode {input} { | |
| binary decode base64 $input | |
| } | |
| } elseif {![catch {package require base64}]} { | |
| proc b64:encode {input} { | |
| ::base64::encode -wrapchar "" $input | |
| } | |
| proc b64:decode {input} { | |
| ::base64::decode $input | |
| } | |
| } else { | |
| set b64map {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 + / =} | |
| proc b64:encode {input} { | |
| global b64map | |
| set str {} | |
| set pad 0 | |
| binary scan $input c* X | |
| foreach {x y z} $X { | |
| if {$y == {}} {set y 0; incr pad} | |
| if {$z == {}} {set z 0; incr pad} | |
| set n [expr {($x << 16) | ($y << 8) | $z}] | |
| set a [expr {($n >> 18) & 63}] | |
| set b [expr {($n >> 12) & 63}] | |
| set c [expr {($n >> 6) & 63}] | |
| set d [expr {$n & 63}] | |
| append str \ | |
| [lindex $b64map $a] \ | |
| [lindex $b64map $b] \ | |
| [lindex $b64map [expr {$pad >= 2 ? 64 : $c}]] \ | |
| [lindex $b64map [expr {$pad >= 1 ? 64 : $d}]] | |
| } | |
| return $str | |
| } | |
| proc b64:decode {input} { | |
| set str {} | |
| set pos 0 | |
| set pad 0 | |
| set n 0 | |
| binary scan $input c* X | |
| foreach x $X { | |
| if {$x >= 65 && $x <= 90} { set x [expr {$x - 65}] }\ | |
| elseif {$x >= 97 && $x <= 122} { set x [expr {$x - 71}] }\ | |
| elseif {$x >= 48 && $x <= 57} { set x [expr {$x + 4}] }\ | |
| elseif {$x == 61} { set x 0; incr pad }\ | |
| else { continue } | |
| set o [expr {18 - 6 * ($pos % 4)}] | |
| set n [expr {$n | ($x << $o)}] | |
| if {$o == 0} { | |
| set a [expr {($n >> 16) & 255}] | |
| set b [expr {($n >> 8) & 255}] | |
| set c [expr {$n & 255}] | |
| set n 0 | |
| if {$pad == 2} { | |
| append str [binary format c $a] | |
| break | |
| } elseif {$pad == 1} { | |
| append str [binary format cc $a $b] | |
| break | |
| } else { | |
| append str [binary format ccc $a $b $c] | |
| } | |
| } | |
| incr pos | |
| } | |
| return $str | |
| } | |
| } |
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