age-encryption/dist/stream.js

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import { chacha20poly1305 } from "@noble/ciphers/chacha";
const chacha20poly1305Overhead = 16;
const chunkSize = /* @__PURE__ */ (() => 64 * 1024)();
const chunkSizeWithOverhead = /* @__PURE__ */ (() => chunkSize + chacha20poly1305Overhead)();
export function decryptSTREAM(key, ciphertext) {
    const streamNonce = new Uint8Array(12);
    const incNonce = () => {
        for (let i = streamNonce.length - 2; i >= 0; i--) {
            streamNonce[i]++;
            if (streamNonce[i] !== 0)
                break;
        }
    };
    const chunkCount = Math.ceil(ciphertext.length / chunkSizeWithOverhead);
    const overhead = chunkCount * chacha20poly1305Overhead;
    const plaintext = new Uint8Array(ciphertext.length - overhead);
    let plaintextSlice = plaintext;
    while (ciphertext.length > chunkSizeWithOverhead) {
        const chunk = chacha20poly1305(key, streamNonce).decrypt(ciphertext.subarray(0, chunkSizeWithOverhead));
        plaintextSlice.set(chunk);
        plaintextSlice = plaintextSlice.subarray(chunk.length);
        ciphertext = ciphertext.subarray(chunkSizeWithOverhead);
        incNonce();
    }
    streamNonce[11] = 1; // Last chunk flag.
    const chunk = chacha20poly1305(key, streamNonce).decrypt(ciphertext);
    plaintextSlice.set(chunk);
    if (chunk.length === 0 && plaintext.length !== 0) {
        throw Error("empty final chunk");
    }
    if (plaintextSlice.length !== chunk.length) {
        throw Error("stream: internal error: didn't fill expected plaintext buffer");
    }
    return plaintext;
}
export function encryptSTREAM(key, plaintext) {
    const streamNonce = new Uint8Array(12);
    const incNonce = () => {
        for (let i = streamNonce.length - 2; i >= 0; i--) {
            streamNonce[i]++;
            if (streamNonce[i] !== 0)
                break;
        }
    };
    const chunkCount = plaintext.length === 0 ? 1 : Math.ceil(plaintext.length / chunkSize);
    const overhead = chunkCount * chacha20poly1305Overhead;
    const ciphertext = new Uint8Array(plaintext.length + overhead);
    let ciphertextSlice = ciphertext;
    while (plaintext.length > chunkSize) {
        const chunk = chacha20poly1305(key, streamNonce).encrypt(plaintext.subarray(0, chunkSize));
        ciphertextSlice.set(chunk);
        ciphertextSlice = ciphertextSlice.subarray(chunk.length);
        plaintext = plaintext.subarray(chunkSize);
        incNonce();
    }
    streamNonce[11] = 1; // Last chunk flag.
    const chunk = chacha20poly1305(key, streamNonce).encrypt(plaintext);
    ciphertextSlice.set(chunk);
    if (ciphertextSlice.length !== chunk.length) {
        throw Error("stream: internal error: didn't fill expected ciphertext buffer");
    }
    return ciphertext;
}