38 lines
1.5 KiB
TypeScript
38 lines
1.5 KiB
TypeScript
// Note: avoid Node's crypto to support runtimes where it's unavailable (e.g., edge/browsers)
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export interface PiiHasher {
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hash(input: string): string;
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}
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export class Md5PiiHasher implements PiiHasher {
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constructor(private readonly salt: string) {}
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hash(input: string) {
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// FNV-1a 32-bit using Math.imul, repeated 4 times with variant salt to get 128-bit hex
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const fnv1a32 = (str: string) => {
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// Convert to UTF-8 bytes without relying on TextEncoder/Buffer
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const data = unescape(encodeURIComponent(str));
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let hash = 0x811c9dc5; // offset basis (2166136261)
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for (let i = 0; i < data.length; i++) {
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hash = Math.imul(hash ^ data.charCodeAt(i), 0x01000193); // 16777619
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}
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return hash >>> 0; // unsigned 32-bit
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};
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// Four independent 32-bit hashes to produce a stable 128-bit hex string
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const h1 = fnv1a32(`${this.salt}::1::${input}`);
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const h2 = fnv1a32(`${this.salt}::2::${input}`);
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const h3 = fnv1a32(`${this.salt}::3::${input}`);
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const h4 = fnv1a32(`${this.salt}::4::${input}`);
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const toHex8 = (n: number) => n.toString(16).padStart(8, "0");
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return `${toHex8(h1)}${toHex8(h2)}${toHex8(h3)}${toHex8(h4)}`;
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}
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}
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export const piiHasher: PiiHasher = new Md5PiiHasher(process.env.CALENDSO_ENCRYPTION_KEY ?? "");
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export const hashEmail = (email: string, hasher: PiiHasher = piiHasher): string => {
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const [localPart, domain] = email.split("@");
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// Simple hash function for email, can be replaced with a more complex one if needed
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return `${hasher.hash(localPart)}@${domain}`;
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};
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