dkim-verifier/canonicalization.js

DKIM Signature Verifier in TypeScript

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.relaxedNewLineAndSpace = exports.simpleBody = exports.relaxedBody = exports.simpleHeaders = exports.relaxedHeader = exports.relaxedHeaders = exports.canonicalize = exports.canonicalizationToStr = exports.newCanonicalization = void 0;
const header_1 = require("./header");
const signature_1 = require("./signature");
var Canonicalization;
(function (Canonicalization) {
    Canonicalization["Simple"] = "simple";
    Canonicalization["Relaxed"] = "relaxed";
})(Canonicalization || (Canonicalization = {}));
const newCanonicalization = (c) => {
    if (!c) {
        return [Canonicalization.Relaxed, Canonicalization.Relaxed];
    }
    else if (c.includes("/")) {
        const [headerCanon, bodyCanon] = c.split("/");
        return [
            headerCanon === "simple"
                ? Canonicalization.Simple
                : Canonicalization.Relaxed,
            bodyCanon === "simple"
                ? Canonicalization.Simple
                : Canonicalization.Relaxed,
        ];
    }
    else {
        return [
            c === "simple" ? Canonicalization.Simple : Canonicalization.Relaxed,
            Canonicalization.Simple,
        ];
    }
};
exports.newCanonicalization = newCanonicalization;
const canonicalizationToStr = (c) => {
    return `${c[0]}/${c[1]}`;
};
exports.canonicalizationToStr = canonicalizationToStr;
const canonicalize = (c, dkim, headers, body) => {
    return [
        c[0] === Canonicalization.Simple
            ? (0, exports.simpleHeaders)(dkim, headers)
            : (0, exports.relaxedHeaders)(dkim, headers),
        c[1] === Canonicalization.Simple ? (0, exports.simpleBody)(body) : (0, exports.relaxedBody)(body),
    ];
};
exports.canonicalize = canonicalize;
const relaxedHeaders = (dkim, headers) => {
    const { h } = dkim;
    const signingHeaders = (0, signature_1.selectSigningHeaders)(h, headers);
    let header = "";
    for (const { key, value } of signingHeaders) {
        header += key.toLowerCase();
        header += ":";
        header += (0, exports.relaxedHeader)(value);
        header += "\r\n";
    }
    const nonSignatureDkim = (0, header_1.getNonSignatureDkim)(headers);
    header += nonSignatureDkim;
    return header;
};
exports.relaxedHeaders = relaxedHeaders;
const relaxedHeader = (header) => {
    header = header.replace(/\t/g, " ");
    header = (0, exports.relaxedNewLineAndSpace)(header);
    while (header.endsWith(" ")) {
        header = header.slice(0, -1);
    }
    while (header.startsWith(" ")) {
        header = header.slice(1);
    }
    return header;
};
exports.relaxedHeader = relaxedHeader;
// https://tools.ietf.org/html/rfc6376#section-3.4.2
const simpleHeaders = (dkim, headers) => {
    const { h } = dkim;
    const signingHeaders = (0, signature_1.selectSigningHeaders)(h, headers);
    let header = "";
    for (const { key, value } of signingHeaders) {
        header += key;
        header += ": ";
        header += value;
        header += "\r\n";
    }
    const nonSignatureDkim = (0, header_1.getNonSignatureDkim)(headers);
    header += nonSignatureDkim;
    return header;
};
exports.simpleHeaders = simpleHeaders;
// https://tools.ietf.org/html/rfc6376#section-3.4.4
const relaxedBody = (body) => {
    body = body.replace(/\t/g, " ");
    body = body.replace(/ +/g, " ");
    body = body.replace(/ +\r\n/g, "\r\n");
    while (body.endsWith("\r\n\r\n")) {
        body = body.slice(0, -2);
    }
    if (body.length > 0 && !body.endsWith("\r\n")) {
        body += "\r\n";
    }
    return body;
};
exports.relaxedBody = relaxedBody;
const simpleBody = (body) => {
    if (body.length === 0) {
        return "\r\n";
    }
    while (body.endsWith("\r\n\r\n")) {
        body = body.slice(0, -2);
    }
    return body.replace(/\s+/g, " ").trim();
};
exports.simpleBody = simpleBody;
const relaxedNewLineAndSpace = (str) => {
    return str.replace(/ +/g, " ").replace(/\r\n/g, "");
};
exports.relaxedNewLineAndSpace = relaxedNewLineAndSpace;
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