Description

Vulnerability: Javascript Attacks
Impact: Attack to Javascript code to achieve our goals.


LOW Security Level

This is the source code of the server:

$page[ 'body' ] .= <<<EOF
<script>

/*
MD5 code from here
https://github.com/blueimp/JavaScript-MD5
*/

!function(n){"use strict";function t(n,t){var r=(65535&n)+(65535&t);return(n>>16)+(t>>16)+(r>>16)<<16|65535&r}function r(n,t){return n<<t|n>>>32-t}function e(n,e,o,u,c,f){return t(r(t(t(e,n),t(u,f)),c),o)}function o(n,t,r,o,u,c,f){return e(t&r|~t&o,n,t,u,c,f)}function u(n,t,r,o,u,c,f){return e(t&o|r&~o,n,t,u,c,f)}function c(n,t,r,o,u,c,f){return e(t^r^o,n,t,u,c,f)}function f(n,t,r,o,u,c,f){return e(r^(t|~o),n,t,u,c,f)}function i(n,r){n[r>>5]|=128<<r%32,n[14+(r+64>>>9<<4)]=r;var e,i,a,d,h,l=1732584193,g=-271733879,v=-1732584194,m=271733878;for(e=0;e<n.length;e+=16)i=l,a=g,d=v,h=m,g=f(g=f(g=f(g=f(g=c(g=c(g=c(g=c(g=u(g=u(g=u(g=u(g=o(g=o(g=o(g=o(g,v=o(v,m=o(m,l=o(l,g,v,m,n[e],7,-680876936),g,v,n[e+1],12,-389564586),l,g,n[e+2],17,606105819),m,l,n[e+3],22,-1044525330),v=o(v,m=o(m,l=o(l,g,v,m,n[e+4],7,-176418897),g,v,n[e+5],12,1200080426),l,g,n[e+6],17,-1473231341),m,l,n[e+7],22,-45705983),v=o(v,m=o(m,l=o(l,g,v,m,n[e+8],7,1770035416),g,v,n[e+9],12,-1958414417),l,g,n[e+10],17,-42063),m,l,n[e+11],22,-1990404162),v=o(v,m=o(m,l=o(l,g,v,m,n[e+12],7,1804603682),g,v,n[e+13],12,-40341101),l,g,n[e+14],17,-1502002290),m,l,n[e+15],22,1236535329),v=u(v,m=u(m,l=u(l,g,v,m,n[e+1],5,-165796510),g,v,n[e+6],9,-1069501632),l,g,n[e+11],14,643717713),m,l,n[e],20,-373897302),v=u(v,m=u(m,l=u(l,g,v,m,n[e+5],5,-701558691),g,v,n[e+10],9,38016083),l,g,n[e+15],14,-660478335),m,l,n[e+4],20,-405537848),v=u(v,m=u(m,l=u(l,g,v,m,n[e+9],5,568446438),g,v,n[e+14],9,-1019803690),l,g,n[e+3],14,-187363961),m,l,n[e+8],20,1163531501),v=u(v,m=u(m,l=u(l,g,v,m,n[e+13],5,-1444681467),g,v,n[e+2],9,-51403784),l,g,n[e+7],14,1735328473),m,l,n[e+12],20,-1926607734),v=c(v,m=c(m,l=c(l,g,v,m,n[e+5],4,-378558),g,v,n[e+8],11,-2022574463),l,g,n[e+11],16,1839030562),m,l,n[e+14],23,-35309556),v=c(v,m=c(m,l=c(l,g,v,m,n[e+1],4,-1530992060),g,v,n[e+4],11,1272893353),l,g,n[e+7],16,-155497632),m,l,n[e+10],23,-1094730640),v=c(v,m=c(m,l=c(l,g,v,m,n[e+13],4,681279174),g,v,n[e],11,-358537222),l,g,n[e+3],16,-722521979),m,l,n[e+6],23,76029189),v=c(v,m=c(m,l=c(l,g,v,m,n[e+9],4,-640364487),g,v,n[e+12],11,-421815835),l,g,n[e+15],16,530742520),m,l,n[e+2],23,-995338651),v=f(v,m=f(m,l=f(l,g,v,m,n[e],6,-198630844),g,v,n[e+7],10,1126891415),l,g,n[e+14],15,-1416354905),m,l,n[e+5],21,-57434055),v=f(v,m=f(m,l=f(l,g,v,m,n[e+12],6,1700485571),g,v,n[e+3],10,-1894986606),l,g,n[e+10],15,-1051523),m,l,n[e+1],21,-2054922799),v=f(v,m=f(m,l=f(l,g,v,m,n[e+8],6,1873313359),g,v,n[e+15],10,-30611744),l,g,n[e+6],15,-1560198380),m,l,n[e+13],21,1309151649),v=f(v,m=f(m,l=f(l,g,v,m,n[e+4],6,-145523070),g,v,n[e+11],10,-1120210379),l,g,n[e+2],15,718787259),m,l,n[e+9],21,-343485551),l=t(l,i),g=t(g,a),v=t(v,d),m=t(m,h);return[l,g,v,m]}function a(n){var t,r="",e=32*n.length;for(t=0;t<e;t+=8)r+=String.fromCharCode(n[t>>5]>>>t%32&255);return r}function d(n){var t,r=[];for(r[(n.length>>2)-1]=void 0,t=0;t<r.length;t+=1)r[t]=0;var e=8*n.length;for(t=0;t<e;t+=8)r[t>>5]|=(255&n.charCodeAt(t/8))<<t%32;return r}function h(n){return a(i(d(n),8*n.length))}function l(n,t){var r,e,o=d(n),u=[],c=[];for(u[15]=c[15]=void 0,o.length>16&&(o=i(o,8*n.length)),r=0;r<16;r+=1)u[r]=909522486^o[r],c[r]=1549556828^o[r];return e=i(u.concat(d(t)),512+8*t.length),a(i(c.concat(e),640))}function g(n){var t,r,e="";for(r=0;r<n.length;r+=1)t=n.charCodeAt(r),e+="0123456789abcdef".charAt(t>>>4&15)+"0123456789abcdef".charAt(15&t);return e}function v(n){return unescape(encodeURIComponent(n))}function m(n){return h(v(n))}function p(n){return g(m(n))}function s(n,t){return l(v(n),v(t))}function C(n,t){return g(s(n,t))}function A(n,t,r){return t?r?s(t,n):C(t,n):r?m(n):p(n)}"function"==typeof define&&define.amd?define(function(){return A}):"object"==typeof module&&module.exports?module.exports=A:n.md5=A}(this);

    function rot13(inp) {
        return inp.replace(/[a-zA-Z]/g,function(c){return String.fromCharCode((c<="Z"?90:122)>=(c=c.charCodeAt(0)+13)?c:c-26);});
    }

    function generate_token() {
        var phrase = document.getElementById("phrase").value;
        document.getElementById("token").value = md5(rot13(phrase));
    }

    generate_token();
</script>
EOF;

This code uses MD5 Encrypt and ROT13 to generate a token through generate_token function and it takes the value of element with phrase id, which is the phrase input in the UI.

  1. The challenge requires us to use phrase success so first we have to type success to the input.

Guide image

  1. Open Browser DevTools go to Console and type generate_token() to call the function and generate token.

Guide image

  1. Submit the phrase you should see the Well done message.

Guide image

MEDIUM Security Level

This is the Javascript code:

function do_something(e) {
    for (var t = '', n = e.length - 1; n >= 0; n--) t += e[n];
    return t;
}
setTimeout(function () {
    do_elsesomething('XX');
}, 300);
function do_elsesomething(e) {
    document.getElementById('token').value = do_something(
        e + document.getElementById('phrase').value + 'XX',
    );
}

The do_elsesomething function will set token value based on phrase value with the help of do_something function, and it is called after 300ms the page loads. So to bypass this challenge we can simply change the phrase input to success then open Console tab run do_elsesomething("XX") and submit you will get message Well done

Guide image

HIGH Security Level

The given Javascript code:

var a = [
    'fromCharCode',
    'toString',
    'replace',
    'BeJ',
    '\x5cw+',
    'Lyg',
    'SuR',
    '(w(){\x273M\x203L\x27;q\x201l=\x273K\x203I\x203J\x20T\x27;q\x201R=1c\x202I===\x271n\x27;q\x20Y=1R?2I:{};p(Y.3N){1R=1O}q\x202L=!1R&&1c\x202M===\x271n\x27;q\x202o=!Y.2S&&1c\x202d===\x271n\x27&&2d.2Q&&2d.2Q.3S;p(2o){Y=3R}z\x20p(2L){Y=2M}q\x202G=!Y.3Q&&1c\x202g===\x271n\x27&&2g.X;q\x202s=1c\x202l===\x27w\x27&&2l.3P;q\x201y=!Y.3H&&1c\x20Z!==\x272T\x27;q\x20m=\x273G\x27.3z(\x27\x27);q\x202w=[-3y,3x,3v,3w];q\x20U=[24,16,8,0];q\x20K=[3A,3B,3F,3E,3D,3C,3T,3U,4d,4c,4b,49,4a,4e,4f,4j,4i,4h,3u,48,47,3Z,3Y,3X,3V,3W,40,41,46,45,43,42,4k,3f,38,36,39,37,34,33,2Y,31,2Z,35,3t,3n,3m,3l,3o,3p,3s,3r,3q,3k,3j,3d,3a,3c,3b,3e,3h,3g,3i,4g];q\x201E=[\x271e\x27,\x2727\x27,\x271G\x27,\x272R\x27];q\x20l=[];p(Y.2S||!1z.1K){1z.1K=w(1x){A\x204C.Q.2U.1I(1x)===\x27[1n\x201z]\x27}}p(1y&&(Y.50||!Z.1N)){Z.1N=w(1x){A\x201c\x201x===\x271n\x27&&1x.1w&&1x.1w.1J===Z}}q\x202m=w(1X,x){A\x20w(s){A\x20O\x20N(x,1d).S(s)[1X]()}};q\x202a=w(x){q\x20P=2m(\x271e\x27,x);p(2o){P=2P(P,x)}P.1T=w(){A\x20O\x20N(x)};P.S=w(s){A\x20P.1T().S(s)};1g(q\x20i=0;i<1E.W;++i){q\x20T=1E[i];P[T]=2m(T,x)}A\x20P};q\x202P=w(P,x){q\x201S=2O(\x222N(\x271S\x27)\x22);q\x201Y=2O(\x222N(\x271w\x27).1Y\x22);q\x202n=x?\x271H\x27:\x271q\x27;q\x202z=w(s){p(1c\x20s===\x272p\x27){A\x201S.2x(2n).S(s,\x274S\x27).1G(\x271e\x27)}z{p(s===2q||s===2T){1u\x20O\x201t(1l)}z\x20p(s.1J===Z){s=O\x202r(s)}}p(1z.1K(s)||Z.1N(s)||s.1J===1Y){A\x201S.2x(2n).S(O\x201Y(s)).1G(\x271e\x27)}z{A\x20P(s)}};A\x202z};q\x202k=w(1X,x){A\x20w(G,s){A\x20O\x201P(G,x,1d).S(s)[1X]()}};q\x202f=w(x){q\x20P=2k(\x271e\x27,x);P.1T=w(G){A\x20O\x201P(G,x)};P.S=w(G,s){A\x20P.1T(G).S(s)};1g(q\x20i=0;i<1E.W;++i){q\x20T=1E[i];P[T]=2k(T,x)}A\x20P};w\x20N(x,1v){p(1v){l[0]=l[16]=l[1]=l[2]=l[3]=l[4]=l[5]=l[6]=l[7]=l[8]=l[9]=l[10]=l[11]=l[12]=l[13]=l[14]=l[15]=0;k.l=l}z{k.l=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}p(x){k.C=4I;k.B=4H;k.E=4l;k.F=4U;k.J=4J;k.I=4K;k.H=4L;k.D=4T}z{k.C=4X;k.B=4W;k.E=4Y;k.F=4Z;k.J=4V;k.I=4O;k.H=4F;k.D=4s}k.1C=k.1A=k.L=k.2i=0;k.1U=k.1L=1O;k.2j=1d;k.x=x}N.Q.S=w(s){p(k.1U){A}q\x202h,T=1c\x20s;p(T!==\x272p\x27){p(T===\x271n\x27){p(s===2q){1u\x20O\x201t(1l)}z\x20p(1y&&s.1J===Z){s=O\x202r(s)}z\x20p(!1z.1K(s)){p(!1y||!Z.1N(s)){1u\x20O\x201t(1l)}}}z{1u\x20O\x201t(1l)}2h=1d}q\x20r,M=0,i,W=s.W,l=k.l;4t(M<W){p(k.1L){k.1L=1O;l[0]=k.1C;l[16]=l[1]=l[2]=l[3]=l[4]=l[5]=l[6]=l[7]=l[8]=l[9]=l[10]=l[11]=l[12]=l[13]=l[14]=l[15]=0}p(2h){1g(i=k.1A;M<W&&i<1k;++M){l[i>>2]|=s[M]<<U[i++&3]}}z{1g(i=k.1A;M<W&&i<1k;++M){r=s.1Q(M);p(r<R){l[i>>2]|=r<<U[i++&3]}z\x20p(r<2v){l[i>>2]|=(2t|(r>>6))<<U[i++&3];l[i>>2]|=(R|(r&V))<<U[i++&3]}z\x20p(r<2A||r>=2E){l[i>>2]|=(2D|(r>>12))<<U[i++&3];l[i>>2]|=(R|((r>>6)&V))<<U[i++&3];l[i>>2]|=(R|(r&V))<<U[i++&3]}z{r=2C+(((r&23)<<10)|(s.1Q(++M)&23));l[i>>2]|=(2X|(r>>18))<<U[i++&3];l[i>>2]|=(R|((r>>12)&V))<<U[i++&3];l[i>>2]|=(R|((r>>6)&V))<<U[i++&3];l[i>>2]|=(R|(r&V))<<U[i++&3]}}}k.2u=i;k.L+=i-k.1A;p(i>=1k){k.1C=l[16];k.1A=i-1k;k.1W();k.1L=1d}z{k.1A=i}}p(k.L>4r){k.2i+=k.L/2H<<0;k.L=k.L%2H}A\x20k};N.Q.1s=w(){p(k.1U){A}k.1U=1d;q\x20l=k.l,i=k.2u;l[16]=k.1C;l[i>>2]|=2w[i&3];k.1C=l[16];p(i>=4q){p(!k.1L){k.1W()}l[0]=k.1C;l[16]=l[1]=l[2]=l[3]=l[4]=l[5]=l[6]=l[7]=l[8]=l[9]=l[10]=l[11]=l[12]=l[13]=l[14]=l[15]=0}l[14]=k.2i<<3|k.L>>>29;l[15]=k.L<<3;k.1W()};N.Q.1W=w(){q\x20a=k.C,b=k.B,c=k.E,d=k.F,e=k.J,f=k.I,g=k.H,h=k.D,l=k.l,j,1a,1b,1j,v,1f,1h,1B,1Z,1V,1D;1g(j=16;j<1k;++j){v=l[j-15];1a=((v>>>7)|(v<<25))^((v>>>18)|(v<<14))^(v>>>3);v=l[j-2];1b=((v>>>17)|(v<<15))^((v>>>19)|(v<<13))^(v>>>10);l[j]=l[j-16]+1a+l[j-7]+1b<<0}1D=b&c;1g(j=0;j<1k;j+=4){p(k.2j){p(k.x){1B=4m;v=l[0]-4n;h=v-4o<<0;d=v+4p<<0}z{1B=4v;v=l[0]-4w;h=v-4G<<0;d=v+4D<<0}k.2j=1O}z{1a=((a>>>2)|(a<<30))^((a>>>13)|(a<<19))^((a>>>22)|(a<<10));1b=((e>>>6)|(e<<26))^((e>>>11)|(e<<21))^((e>>>25)|(e<<7));1B=a&b;1j=1B^(a&c)^1D;1h=(e&f)^(~e&g);v=h+1b+1h+K[j]+l[j];1f=1a+1j;h=d+v<<0;d=v+1f<<0}1a=((d>>>2)|(d<<30))^((d>>>13)|(d<<19))^((d>>>22)|(d<<10));1b=((h>>>6)|(h<<26))^((h>>>11)|(h<<21))^((h>>>25)|(h<<7));1Z=d&a;1j=1Z^(d&b)^1B;1h=(h&e)^(~h&f);v=g+1b+1h+K[j+1]+l[j+1];1f=1a+1j;g=c+v<<0;c=v+1f<<0;1a=((c>>>2)|(c<<30))^((c>>>13)|(c<<19))^((c>>>22)|(c<<10));1b=((g>>>6)|(g<<26))^((g>>>11)|(g<<21))^((g>>>25)|(g<<7));1V=c&d;1j=1V^(c&a)^1Z;1h=(g&h)^(~g&e);v=f+1b+1h+K[j+2]+l[j+2];1f=1a+1j;f=b+v<<0;b=v+1f<<0;1a=((b>>>2)|(b<<30))^((b>>>13)|(b<<19))^((b>>>22)|(b<<10));1b=((f>>>6)|(f<<26))^((f>>>11)|(f<<21))^((f>>>25)|(f<<7));1D=b&c;1j=1D^(b&d)^1V;1h=(f&g)^(~f&h);v=e+1b+1h+K[j+3]+l[j+3];1f=1a+1j;e=a+v<<0;a=v+1f<<0}k.C=k.C+a<<0;k.B=k.B+b<<0;k.E=k.E+c<<0;k.F=k.F+d<<0;k.J=k.J+e<<0;k.I=k.I+f<<0;k.H=k.H+g<<0;k.D=k.D+h<<0};N.Q.1e=w(){k.1s();q\x20C=k.C,B=k.B,E=k.E,F=k.F,J=k.J,I=k.I,H=k.H,D=k.D;q\x201e=m[(C>>28)&o]+m[(C>>24)&o]+m[(C>>20)&o]+m[(C>>16)&o]+m[(C>>12)&o]+m[(C>>8)&o]+m[(C>>4)&o]+m[C&o]+m[(B>>28)&o]+m[(B>>24)&o]+m[(B>>20)&o]+m[(B>>16)&o]+m[(B>>12)&o]+m[(B>>8)&o]+m[(B>>4)&o]+m[B&o]+m[(E>>28)&o]+m[(E>>24)&o]+m[(E>>20)&o]+m[(E>>16)&o]+m[(E>>12)&o]+m[(E>>8)&o]+m[(E>>4)&o]+m[E&o]+m[(F>>28)&o]+m[(F>>24)&o]+m[(F>>20)&o]+m[(F>>16)&o]+m[(F>>12)&o]+m[(F>>8)&o]+m[(F>>4)&o]+m[F&o]+m[(J>>28)&o]+m[(J>>24)&o]+m[(J>>20)&o]+m[(J>>16)&o]+m[(J>>12)&o]+m[(J>>8)&o]+m[(J>>4)&o]+m[J&o]+m[(I>>28)&o]+m[(I>>24)&o]+m[(I>>20)&o]+m[(I>>16)&o]+m[(I>>12)&o]+m[(I>>8)&o]+m[(I>>4)&o]+m[I&o]+m[(H>>28)&o]+m[(H>>24)&o]+m[(H>>20)&o]+m[(H>>16)&o]+m[(H>>12)&o]+m[(H>>8)&o]+m[(H>>4)&o]+m[H&o];p(!k.x){1e+=m[(D>>28)&o]+m[(D>>24)&o]+m[(D>>20)&o]+m[(D>>16)&o]+m[(D>>12)&o]+m[(D>>8)&o]+m[(D>>4)&o]+m[D&o]}A\x201e};N.Q.2U=N.Q.1e;N.Q.1G=w(){k.1s();q\x20C=k.C,B=k.B,E=k.E,F=k.F,J=k.J,I=k.I,H=k.H,D=k.D;q\x202b=[(C>>24)&u,(C>>16)&u,(C>>8)&u,C&u,(B>>24)&u,(B>>16)&u,(B>>8)&u,B&u,(E>>24)&u,(E>>16)&u,(E>>8)&u,E&u,(F>>24)&u,(F>>16)&u,(F>>8)&u,F&u,(J>>24)&u,(J>>16)&u,(J>>8)&u,J&u,(I>>24)&u,(I>>16)&u,(I>>8)&u,I&u,(H>>24)&u,(H>>16)&u,(H>>8)&u,H&u];p(!k.x){2b.4A((D>>24)&u,(D>>16)&u,(D>>8)&u,D&u)}A\x202b};N.Q.27=N.Q.1G;N.Q.2R=w(){k.1s();q\x201w=O\x20Z(k.x?28:32);q\x201i=O\x204x(1w);1i.1p(0,k.C);1i.1p(4,k.B);1i.1p(8,k.E);1i.1p(12,k.F);1i.1p(16,k.J);1i.1p(20,k.I);1i.1p(24,k.H);p(!k.x){1i.1p(28,k.D)}A\x201w};w\x201P(G,x,1v){q\x20i,T=1c\x20G;p(T===\x272p\x27){q\x20L=[],W=G.W,M=0,r;1g(i=0;i<W;++i){r=G.1Q(i);p(r<R){L[M++]=r}z\x20p(r<2v){L[M++]=(2t|(r>>6));L[M++]=(R|(r&V))}z\x20p(r<2A||r>=2E){L[M++]=(2D|(r>>12));L[M++]=(R|((r>>6)&V));L[M++]=(R|(r&V))}z{r=2C+(((r&23)<<10)|(G.1Q(++i)&23));L[M++]=(2X|(r>>18));L[M++]=(R|((r>>12)&V));L[M++]=(R|((r>>6)&V));L[M++]=(R|(r&V))}}G=L}z{p(T===\x271n\x27){p(G===2q){1u\x20O\x201t(1l)}z\x20p(1y&&G.1J===Z){G=O\x202r(G)}z\x20p(!1z.1K(G)){p(!1y||!Z.1N(G)){1u\x20O\x201t(1l)}}}z{1u\x20O\x201t(1l)}}p(G.W>1k){G=(O\x20N(x,1d)).S(G).27()}q\x201F=[],2e=[];1g(i=0;i<1k;++i){q\x20b=G[i]||0;1F[i]=4z^b;2e[i]=4y^b}N.1I(k,x,1v);k.S(2e);k.1F=1F;k.2c=1d;k.1v=1v}1P.Q=O\x20N();1P.Q.1s=w(){N.Q.1s.1I(k);p(k.2c){k.2c=1O;q\x202W=k.27();N.1I(k,k.x,k.1v);k.S(k.1F);k.S(2W);N.Q.1s.1I(k)}};q\x20X=2a();X.1q=X;X.1H=2a(1d);X.1q.2V=2f();X.1H.2V=2f(1d);p(2G){2g.X=X}z{Y.1q=X.1q;Y.1H=X.1H;p(2s){2l(w(){A\x20X})}}})();w\x202y(e){1g(q\x20t=\x22\x22,n=e.W-1;n>=0;n--)t+=e[n];A\x20t}w\x202J(t,y=\x224B\x22){1m.1o(\x221M\x22).1r=1q(1m.1o(\x221M\x22).1r+y)}w\x202B(e=\x224E\x22){1m.1o(\x221M\x22).1r=1q(e+1m.1o(\x221M\x22).1r)}w\x202K(a,b){1m.1o(\x221M\x22).1r=2y(1m.1o(\x222F\x22).1r)}1m.1o(\x222F\x22).1r=\x22\x22;4u(w(){2B(\x224M\x22)},4N);1m.1o(\x224P\x22).4Q(\x224R\x22,2J);2K(\x223O\x22,44);',
    '||||||||||||||||||||this|blocks|HEX_CHARS||0x0F|if|var|code|message||0xFF|t1|function|is224||else|return|h1|h0|h7|h2|h3|key|h6|h5|h4||bytes|index|Sha256|new|method|prototype|0x80|update|type|SHIFT|0x3f|length|exports|root|ArrayBuffer|||||||||||s0|s1|typeof|true|hex|t2|for|ch|dataView|maj|64|ERROR|document|object|getElementById|setUint32|sha256|value|finalize|Error|throw|sharedMemory|buffer|obj|ARRAY_BUFFER|Array|start|ab|block|bc|OUTPUT_TYPES|oKeyPad|digest|sha224|call|constructor|isArray|hashed|token|isView|false|HmacSha256|charCodeAt|WINDOW|crypto|create|finalized|cd|hash|outputType|Buffer|da||||0x3ff||||array|||createMethod|arr|inner|process|iKeyPad|createHmacMethod|module|notString|hBytes|first|createHmacOutputMethod|define|createOutputMethod|algorithm|NODE_JS|string|null|Uint8Array|AMD|0xc0|lastByteIndex|0x800|EXTRA|createHash|do_something|nodeMethod|0xd800|token_part_2|0x10000|0xe0|0xe000|phrase|COMMON_JS|4294967296|window|token_part_3|token_part_1|WEB_WORKER|self|require|eval|nodeWrap|versions|arrayBuffer|JS_SHA256_NO_NODE_JS|undefined|toString|hmac|innerHash|0xf0|0xa2bfe8a1|0xc24b8b70||0xa81a664b||0x92722c85|0x81c2c92e|0xc76c51a3|0x53380d13|0x766a0abb|0x4d2c6dfc|0x650a7354|0x748f82ee|0x84c87814|0x78a5636f|0x682e6ff3|0x8cc70208|0x2e1b2138|0xa4506ceb|0x90befffa|0xbef9a3f7|0x5b9cca4f|0x4ed8aa4a|0x106aa070|0xf40e3585|0xd6990624|0x19a4c116|0x1e376c08|0x391c0cb3|0x34b0bcb5|0x2748774c|0xd192e819|0x0fc19dc6|32768|128|8388608|2147483648|split|0x428a2f98|0x71374491|0x59f111f1|0x3956c25b|0xe9b5dba5|0xb5c0fbcf|0123456789abcdef|JS_SHA256_NO_ARRAY_BUFFER|is|invalid|input|strict|use|JS_SHA256_NO_WINDOW|ABCD|amd|JS_SHA256_NO_COMMON_JS|global|node|0x923f82a4|0xab1c5ed5|0x983e5152|0xa831c66d|0x76f988da|0x5cb0a9dc|0x4a7484aa|0xb00327c8|0xbf597fc7|0x14292967|0x06ca6351||0xd5a79147|0xc6e00bf3|0x2de92c6f|0x240ca1cc|0x550c7dc3|0x72be5d74|0x243185be|0x12835b01|0xd807aa98|0x80deb1fe|0x9bdc06a7|0xc67178f2|0xefbe4786|0xe49b69c1|0xc19bf174|0x27b70a85|0x3070dd17|300032|1413257819|150054599|24177077|56|4294967295|0x5be0cd19|while|setTimeout|704751109|210244248|DataView|0x36|0x5c|push|ZZ|Object|143694565|YY|0x1f83d9ab|1521486534|0x367cd507|0xc1059ed8|0xffc00b31|0x68581511|0x64f98fa7|XX|300|0x9b05688c|send|addEventListener|click|utf8|0xbefa4fa4|0xf70e5939|0x510e527f|0xbb67ae85|0x6a09e667|0x3c6ef372|0xa54ff53a|JS_SHA256_NO_ARRAY_BUFFER_IS_VIEW',
    'split',
];
(function (c, d) {
    var e = function (f) {
        while (--f) {
            c['push'](c['shift']());
        }
    };
    e(++d);
})(a, 0x1f4);
var b = function (c, d) {
    c = c - 0x0;
    var e = a[c];
    return e;
};
eval(
    (function (d, e, f, g, h, i) {
        h = function (j) {
            return (
                (j < e ? '' : h(parseInt(j / e))) +
                ((j = j % e) > 0x23 ? String[b('0x0')](j + 0x1d) : j[b('0x1')](0x24))
            );
        };
        if (!''[b('0x2')](/^/, String)) {
            while (f--) {
                i[h(f)] = g[f] || h(f);
            }
            g = [
                function (k) {
                    if ('wpA' !== b('0x3')) {
                        return i[k];
                    } else {
                        while (f--) {
                            i[k(f)] = g[f] || k(f);
                        }
                        g = [
                            function (l) {
                                return i[l];
                            },
                        ];
                        k = function () {
                            return b('0x4');
                        };
                        f = 0x1;
                    }
                },
            ];
            h = function () {
                return b('0x4');
            };
            f = 0x1;
        }
        while (f--) {
            if (g[f]) {
                if (b('0x5') === b('0x6')) {
                    return i[h];
                } else {
                    d = d[b('0x2')](new RegExp('\x5cb' + h(f) + '\x5cb', 'g'), g[f]);
                }
            }
        }
        return d;
    })(b('0x7'), 0x3e, 0x137, b('0x8')[b('0x9')]('|'), 0x0, {}),
);

The code is heavily obfuscated so we have to examine the code. You can copy the entire Javscript code to Console tab of browser but change eval to console.log to see the readable Javascript code. After that, you should see a really long readable Javascript code but these lines are worth to examine:

function do_something(e) {
    for (var t = '', n = e.length - 1; n >= 0; n--) t += e[n];
    return t;
}

function token_part_3(t, y = 'ZZ') {
    document.getElementById('token').value = sha256(document.getElementById('token').value + y);
}

function token_part_2(e = 'YY') {
    document.getElementById('token').value = sha256(e + document.getElementById('token').value);
}

function token_part_1(a, b) {
    document.getElementById('token').value = do_something(document.getElementById('phrase').value);
}

document.getElementById('phrase').value = '';

setTimeout(function () {
    token_part_2('XX');
}, 300);

document.getElementById('send').addEventListener('click', token_part_3);

token_part_1('ABCD', 44);

It has 3 functions to create token token_part_1, token_part_2 and token_part_3 so we can step-by-step do this:

  1. Change phrase input to success and run token_part_1("ABCD", 44) in the Console tab. The token now:
sseccus
  1. Run token_part_2("XX") in Console tab. The token now becomes:
7f1bfaaf829f785ba5801d5bf68c1ecaf95ce04545462c8b8f311dfc9014068a
  1. Now click Submit the token_part_3 function will automatically execute through the eventListener. Final token:
ec7ef8687050b6fe803867ea696734c67b541dfafb286a0b1239f42ac5b0aa84

Guide image

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