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88c4c60 | 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 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 52 53 54 55 56 | /**
* Qoder body encoding ported from qoder2api's QoderEncoding.java (via the
* CLIProxyAPIPlus qoder-provider branch).
*
* Algorithm:
* 1. base64-encode the plaintext bytes (standard alphabet).
* 2. Rearrange: split into thirds, reorder as [tail][mid][head].
* 3. Substitute each character via a custom alphabet mapping.
*
* The encoded body must be sent with `&Encode=1` appended to the URL so the
* server decodes in reverse. The obfuscation prevents Alibaba Cloud WAF from
* pattern-matching the plaintext request body.
*/
const QODER_STD_ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
const QODER_CUSTOM_ALPHABET = "_doRTgHZBKcGVjlvpC,@aFSx#DPuNJme&i*MzLOEn)sUrthbf%Y^w.(kIQyXqWA!";
const QODER_S2C = (() => {
const table = new Int16Array(128).fill(-1);
for (let i = 0; i < 64; i++) {
table[QODER_STD_ALPHABET.charCodeAt(i)] = QODER_CUSTOM_ALPHABET.charCodeAt(i);
}
table["=".charCodeAt(0)] = "$".charCodeAt(0);
return table;
})();
/**
* Encode plaintext bytes/string using Qoder's WAF-bypass scheme.
* @param {Buffer|Uint8Array|string} plaintext
* @returns {string} encoded string
*/
export function qoderEncodeBody(plaintext) {
const buf = Buffer.isBuffer(plaintext)
? plaintext
: typeof plaintext === "string"
? Buffer.from(plaintext, "utf8")
: Buffer.from(plaintext);
const std = buf.toString("base64");
const n = std.length;
const a = Math.floor(n / 3);
// [tail][mid][head]
const rearranged = std.slice(n - a) + std.slice(a, n - a) + std.slice(0, a);
const out = Buffer.alloc(n);
for (let i = 0; i < n; i++) {
const c = rearranged.charCodeAt(i);
if (c < 128 && QODER_S2C[c] >= 0) {
out[i] = QODER_S2C[c];
} else {
out[i] = c;
}
}
return out.toString("latin1");
}
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