wxmp-rsa
Version:
兼容小程序环境的rsa加解密库,支持超长文本和中文字符
77 lines (76 loc) • 2.08 kB
JavaScript
import { int2char } from "./util";
var b64map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var b64pad = "=";
export function hex2b64(h) {
var i;
var c;
var ret = "";
for (i = 0; i + 3 <= h.length; i += 3) {
c = parseInt(h.substring(i, i + 3), 16);
ret += b64map.charAt(c >> 6) + b64map.charAt(c & 63);
}
if (i + 1 == h.length) {
c = parseInt(h.substring(i, i + 1), 16);
ret += b64map.charAt(c << 2);
}
else if (i + 2 == h.length) {
c = parseInt(h.substring(i, i + 2), 16);
ret += b64map.charAt(c >> 2) + b64map.charAt((c & 3) << 4);
}
while ((ret.length & 3) > 0) {
ret += b64pad;
}
return ret;
}
// convert a base64 string to hex
export function b64tohex(s) {
var ret = "";
var i;
var k = 0; // b64 state, 0-3
var slop = 0;
for (i = 0; i < s.length; ++i) {
if (s.charAt(i) == b64pad) {
break;
}
var v = b64map.indexOf(s.charAt(i));
if (v < 0) {
continue;
}
if (k == 0) {
ret += int2char(v >> 2);
slop = v & 3;
k = 1;
}
else if (k == 1) {
ret += int2char((slop << 2) | (v >> 4));
slop = v & 0xf;
k = 2;
}
else if (k == 2) {
ret += int2char(slop);
ret += int2char(v >> 2);
slop = v & 3;
k = 3;
}
else {
ret += int2char((slop << 2) | (v >> 4));
ret += int2char(v & 0xf);
k = 0;
}
}
if (k == 1) {
ret += int2char(slop << 2);
}
return ret;
}
// convert a base64 string to a byte/number array
export function b64toBA(s) {
// piggyback on b64tohex for now, optimize later
var h = b64tohex(s);
var i;
var a = [];
for (i = 0; 2 * i < h.length; ++i) {
a[i] = parseInt(h.substring(2 * i, 2 * i + 2), 16);
}
return a;
}