{"version":3,"file":"Base64Decode.js","sources":["../../src/encode/Base64Decode.ts"],"sourcesContent":["/*\n * Copyright (c) Microsoft Corporation. All rights reserved.\n * Licensed under the MIT License.\n */\n\nimport { Constants } from \"@azure/msal-common\";\nimport { BrowserStringUtils } from \"../utils/BrowserStringUtils\";\n\n/**\n * Class which exposes APIs to decode base64 strings to plaintext. See here for implementation details:\n * https://developer.mozilla.org/en-US/docs/Web/API/WindowBase64/Base64_encoding_and_decoding#Solution_2_%E2%80%93_JavaScript's_UTF-16_%3E_UTF-8_%3E_base64\n */\nexport class Base64Decode {\n\n    /**\n     * Returns a URL-safe plaintext decoded string from b64 encoded input.\n     * @param input \n     */\n    decode(input: string): string {\n        let encodedString = input.replace(/-/g, \"+\").replace(/_/g, \"/\");\n        switch (encodedString.length % 4) {\n            case 0:\n                break;\n            case 2:\n                encodedString += \"==\";\n                break;\n            case 3:\n                encodedString += \"=\";\n                break;\n            default:\n                throw new Error(\"Invalid base64 string\");\n        }\n\n        const inputUtf8Arr = this.base64DecToArr(encodedString);\n        return BrowserStringUtils.utf8ArrToString(inputUtf8Arr);\n    }\n\n    /**\n     * Decodes base64 into Uint8Array\n     * @param base64String \n     * @param nBlockSize \n     */\n    private base64DecToArr(base64String: string, nBlockSize?: number): Uint8Array {\n        const sB64Enc = base64String.replace(/[^A-Za-z0-9\\+\\/]/g, Constants.EMPTY_STRING);\n        const nInLen = sB64Enc.length;\n        const nOutLen = nBlockSize ? Math.ceil((nInLen * 3 + 1 >>> 2) / nBlockSize) * nBlockSize : nInLen * 3 + 1 >>> 2;\n        const aBytes = new Uint8Array(nOutLen);\n\n        for (let nMod3, nMod4, nUint24 = 0, nOutIdx = 0, nInIdx = 0; nInIdx < nInLen; nInIdx++) {\n            nMod4 = nInIdx & 3;\n            nUint24 |= this.b64ToUint6(sB64Enc.charCodeAt(nInIdx)) << 18 - 6 * nMod4;\n            if (nMod4 === 3 || nInLen - nInIdx === 1) {\n                for (nMod3 = 0; nMod3 < 3 && nOutIdx < nOutLen; nMod3++, nOutIdx++) {\n                    aBytes[nOutIdx] = nUint24 >>> (16 >>> nMod3 & 24) & 255;\n                }\n                nUint24 = 0;\n            }\n        }\n\n        return aBytes;\n    }\n\n    /**\n     * Base64 string to array decoding helper\n     * @param charNum \n     */\n    private b64ToUint6(charNum: number): number {\n        return charNum > 64 && charNum < 91 ?\n            charNum - 65\n            : charNum > 96 && charNum < 123 ? \n                charNum - 71\n                : charNum > 47 && charNum < 58 ?\n                    charNum + 4\n                    : charNum === 43 ?\n                        62\n                        : charNum === 47 ?\n                            63\n                            :\n                            0;\n    }\n}\n"],"names":[],"mappings":";;;;;AAAA;;;;AAQA;;;;;IAIA;KAoEC;;;;;IA9DG,6BAAM,GAAN,UAAO,KAAa;QAChB,IAAI,aAAa,GAAG,KAAK,CAAC,OAAO,CAAC,IAAI,EAAE,GAAG,CAAC,CAAC,OAAO,CAAC,IAAI,EAAE,GAAG,CAAC,CAAC;QAChE,QAAQ,aAAa,CAAC,MAAM,GAAG,CAAC;YAC5B,KAAK,CAAC;gBACF,MAAM;YACV,KAAK,CAAC;gBACF,aAAa,IAAI,IAAI,CAAC;gBACtB,MAAM;YACV,KAAK,CAAC;gBACF,aAAa,IAAI,GAAG,CAAC;gBACrB,MAAM;YACV;gBACI,MAAM,IAAI,KAAK,CAAC,uBAAuB,CAAC,CAAC;SAChD;QAED,IAAM,YAAY,GAAG,IAAI,CAAC,cAAc,CAAC,aAAa,CAAC,CAAC;QACxD,OAAO,kBAAkB,CAAC,eAAe,CAAC,YAAY,CAAC,CAAC;KAC3D;;;;;;IAOO,qCAAc,GAAtB,UAAuB,YAAoB,EAAE,UAAmB;QAC5D,IAAM,OAAO,GAAG,YAAY,CAAC,OAAO,CAAC,mBAAmB,EAAE,SAAS,CAAC,YAAY,CAAC,CAAC;QAClF,IAAM,MAAM,GAAG,OAAO,CAAC,MAAM,CAAC;QAC9B,IAAM,OAAO,GAAG,UAAU,GAAG,IAAI,CAAC,IAAI,CAAC,CAAC,MAAM,GAAG,CAAC,GAAG,CAAC,KAAK,CAAC,IAAI,UAAU,CAAC,GAAG,UAAU,GAAG,MAAM,GAAG,CAAC,GAAG,CAAC,KAAK,CAAC,CAAC;QAChH,IAAM,MAAM,GAAG,IAAI,UAAU,CAAC,OAAO,CAAC,CAAC;QAEvC,KAAK,IAAI,KAAK,SAAA,EAAE,KAAK,SAAA,EAAE,OAAO,GAAG,CAAC,EAAE,OAAO,GAAG,CAAC,EAAE,MAAM,GAAG,CAAC,EAAE,MAAM,GAAG,MAAM,EAAE,MAAM,EAAE,EAAE;YACpF,KAAK,GAAG,MAAM,GAAG,CAAC,CAAC;YACnB,OAAO,IAAI,IAAI,CAAC,UAAU,CAAC,OAAO,CAAC,UAAU,CAAC,MAAM,CAAC,CAAC,IAAI,EAAE,GAAG,CAAC,GAAG,KAAK,CAAC;YACzE,IAAI,KAAK,KAAK,CAAC,IAAI,MAAM,GAAG,MAAM,KAAK,CAAC,EAAE;gBACtC,KAAK,KAAK,GAAG,CAAC,EAAE,KAAK,GAAG,CAAC,IAAI,OAAO,GAAG,OAAO,EAAE,KAAK,EAAE,EAAE,OAAO,EAAE,EAAE;oBAChE,MAAM,CAAC,OAAO,CAAC,GAAG,OAAO,MAAM,EAAE,KAAK,KAAK,GAAG,EAAE,CAAC,GAAG,GAAG,CAAC;iBAC3D;gBACD,OAAO,GAAG,CAAC,CAAC;aACf;SACJ;QAED,OAAO,MAAM,CAAC;KACjB;;;;;IAMO,iCAAU,GAAlB,UAAmB,OAAe;QAC9B,OAAO,OAAO,GAAG,EAAE,IAAI,OAAO,GAAG,EAAE;YAC/B,OAAO,GAAG,EAAE;cACV,OAAO,GAAG,EAAE,IAAI,OAAO,GAAG,GAAG;gBAC3B,OAAO,GAAG,EAAE;kBACV,OAAO,GAAG,EAAE,IAAI,OAAO,GAAG,EAAE;oBAC1B,OAAO,GAAG,CAAC;sBACT,OAAO,KAAK,EAAE;wBACZ,EAAE;0BACA,OAAO,KAAK,EAAE;4BACZ,EAAE;;gCAEF,CAAC,CAAC;KACzB;IACL,mBAAC;AAAD,CAAC;;;;"}