Alexander Afanasyev | 181a8b9 | 2013-02-28 13:28:53 -0800 | [diff] [blame] | 1 | var b64map="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
| 2 | var b64pad="="; |
| 3 | |
| 4 | function hex2b64(h) { |
| 5 | var i; |
| 6 | var c; |
| 7 | var ret = ""; |
| 8 | for(i = 0; i+3 <= h.length; i+=3) { |
| 9 | c = parseInt(h.substring(i,i+3),16); |
| 10 | ret += b64map.charAt(c >> 6) + b64map.charAt(c & 63); |
| 11 | } |
| 12 | if(i+1 == h.length) { |
| 13 | c = parseInt(h.substring(i,i+1),16); |
| 14 | ret += b64map.charAt(c << 2); |
| 15 | } |
| 16 | else if(i+2 == h.length) { |
| 17 | c = parseInt(h.substring(i,i+2),16); |
| 18 | ret += b64map.charAt(c >> 2) + b64map.charAt((c & 3) << 4); |
| 19 | } |
| 20 | while((ret.length & 3) > 0) ret += b64pad; |
| 21 | return ret; |
| 22 | } |
| 23 | |
| 24 | // convert a base64 string to hex |
| 25 | function b64tohex(s) { |
| 26 | var ret = "" |
| 27 | var i; |
| 28 | var k = 0; // b64 state, 0-3 |
| 29 | var slop; |
| 30 | for(i = 0; i < s.length; ++i) { |
| 31 | if(s.charAt(i) == b64pad) break; |
| 32 | var v = b64map.indexOf(s.charAt(i)); |
| 33 | if(v < 0) continue; |
| 34 | if(k == 0) { |
| 35 | ret += int2char(v >> 2); |
| 36 | slop = v & 3; |
| 37 | k = 1; |
| 38 | } |
| 39 | else if(k == 1) { |
| 40 | ret += int2char((slop << 2) | (v >> 4)); |
| 41 | slop = v & 0xf; |
| 42 | k = 2; |
| 43 | } |
| 44 | else if(k == 2) { |
| 45 | ret += int2char(slop); |
| 46 | ret += int2char(v >> 2); |
| 47 | slop = v & 3; |
| 48 | k = 3; |
| 49 | } |
| 50 | else { |
| 51 | ret += int2char((slop << 2) | (v >> 4)); |
| 52 | ret += int2char(v & 0xf); |
| 53 | k = 0; |
| 54 | } |
| 55 | } |
| 56 | if(k == 1) |
| 57 | ret += int2char(slop << 2); |
| 58 | return ret; |
| 59 | } |
| 60 | |
| 61 | // convert a base64 string to a byte/number array |
| 62 | function b64toBA(s) { |
| 63 | //piggyback on b64tohex for now, optimize later |
| 64 | var h = b64tohex(s); |
| 65 | var i; |
| 66 | var a = new Array(); |
| 67 | for(i = 0; 2*i < h.length; ++i) { |
| 68 | a[i] = parseInt(h.substring(2*i,2*i+2),16); |
| 69 | } |
| 70 | return a; |
| 71 | } |