Js base64 加密解密介绍_javascript技巧

复制代码 代码如下: var base64encodechars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; var base64decodechars = new Array( -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1); function base64encode(str) { var out, i, len; var c1, c2, c3; len = str.length; i = 0; out = ""; while (i c1 = str.charCodeAt(i++) & 0xff; if (i == len) { out += base64encodechars.charAt(c1 >> 2); out += base64encodechars.charAt((c1 & 0x3) out += "=="; break; } c2 = str.charCodeAt(i++); if (i == len) { out += base64encodechars.charAt(c1 >> 2); out += base64encodechars.charAt(((c1 & 0x3) > 4)); out += base64encodechars.charAt((c2 & 0xf) out += "="; break; } c3 = str.charCodeAt(i++); out += base64encodechars.charAt(c1 >> 2); out += base64encodechars.charAt(((c1 & 0x3) > 4)); out += base64encodechars.charAt(((c2 & 0xf) > 6)); out += base64encodechars.charAt(c3 & 0x3f); } return out; } function base64decode(str) { var c1, c2, c3, c4; var i, len, out; len = str.length; i = 0; out = ""; while (i do { c1 = base64decodechars[str.charCodeAt(i++) & 0xff]; } while (i if (c1 == -1) break; do { c2 = base64decodechars[str.charCodeAt(i++) & 0xff]; } while (i if (c2 == -1) break; out += String.fromCharCode((c1 > 4)); do { c3 = str.charCodeAt(i++) & 0xff; if (c3 == 61) return out; c3 = base64decodechars[c3]; } while (i if (c3 == -1) break; out += String.fromCharCode(((c2 & 0xf) > 2)); do { c4 = str.charCodeAt(i++) & 0xff; if (c4 == 61) return out; c4 = base64decodechars[c4]; } while (i if (c4 == -1) break; out += String.fromCharCode(((c3 & 0x03) } return out; }

Js base64 加密解密介绍_javascript技巧

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