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browser/libs/common/src/platform/services/cryptography/encrypt.service.implementation.ts
Matt Gibson 6ef3e9a076 [PM-16831] TS Strict crypto function service (#12737)
* strict types in crypto function services

* Improve aesDecrypt types
2025-01-09 18:58:22 -05:00

313 lines
11 KiB
TypeScript

// FIXME: Update this file to be type safe and remove this and next line
// @ts-strict-ignore
import { Utils } from "../../../platform/misc/utils";
import { CryptoFunctionService } from "../../abstractions/crypto-function.service";
import { EncryptService } from "../../abstractions/encrypt.service";
import { LogService } from "../../abstractions/log.service";
import { EncryptionType, encryptionTypeToString as encryptionTypeName } from "../../enums";
import { Decryptable } from "../../interfaces/decryptable.interface";
import { Encrypted } from "../../interfaces/encrypted";
import { InitializerMetadata } from "../../interfaces/initializer-metadata.interface";
import { EncArrayBuffer } from "../../models/domain/enc-array-buffer";
import { EncString } from "../../models/domain/enc-string";
import { EncryptedObject } from "../../models/domain/encrypted-object";
import { SymmetricCryptoKey } from "../../models/domain/symmetric-crypto-key";
export class EncryptServiceImplementation implements EncryptService {
constructor(
protected cryptoFunctionService: CryptoFunctionService,
protected logService: LogService,
protected logMacFailures: boolean,
) {}
async encrypt(plainValue: string | Uint8Array, key: SymmetricCryptoKey): Promise<EncString> {
if (key == null) {
throw new Error("No encryption key provided.");
}
if (plainValue == null) {
return Promise.resolve(null);
}
let plainBuf: Uint8Array;
if (typeof plainValue === "string") {
plainBuf = Utils.fromUtf8ToArray(plainValue);
} else {
plainBuf = plainValue;
}
const encObj = await this.aesEncrypt(plainBuf, key);
const iv = Utils.fromBufferToB64(encObj.iv);
const data = Utils.fromBufferToB64(encObj.data);
const mac = encObj.mac != null ? Utils.fromBufferToB64(encObj.mac) : null;
return new EncString(encObj.key.encType, data, iv, mac);
}
async encryptToBytes(plainValue: Uint8Array, key: SymmetricCryptoKey): Promise<EncArrayBuffer> {
if (key == null) {
throw new Error("No encryption key provided.");
}
const encValue = await this.aesEncrypt(plainValue, key);
let macLen = 0;
if (encValue.mac != null) {
macLen = encValue.mac.byteLength;
}
const encBytes = new Uint8Array(1 + encValue.iv.byteLength + macLen + encValue.data.byteLength);
encBytes.set([encValue.key.encType]);
encBytes.set(new Uint8Array(encValue.iv), 1);
if (encValue.mac != null) {
encBytes.set(new Uint8Array(encValue.mac), 1 + encValue.iv.byteLength);
}
encBytes.set(new Uint8Array(encValue.data), 1 + encValue.iv.byteLength + macLen);
return new EncArrayBuffer(encBytes);
}
async decryptToUtf8(
encString: EncString,
key: SymmetricCryptoKey,
decryptContext: string = "no context",
): Promise<string> {
if (key == null) {
throw new Error("No key provided for decryption.");
}
key = this.resolveLegacyKey(key, encString);
// DO NOT REMOVE OR MOVE. This prevents downgrade to mac-less CBC, which would compromise integrity and confidentiality.
if (key.macKey != null && encString?.mac == null) {
this.logService.error(
"[Encrypt service] Key has mac key but payload is missing mac bytes. Key type " +
encryptionTypeName(key.encType) +
"Payload type " +
encryptionTypeName(encString.encryptionType),
"Decrypt context: " + decryptContext,
);
return null;
}
if (key.encType !== encString.encryptionType) {
this.logService.error(
"[Encrypt service] Key encryption type does not match payload encryption type. Key type " +
encryptionTypeName(key.encType) +
"Payload type " +
encryptionTypeName(encString.encryptionType),
"Decrypt context: " + decryptContext,
);
return null;
}
const fastParams = this.cryptoFunctionService.aesDecryptFastParameters(
encString.data,
encString.iv,
encString.mac,
key,
);
if (fastParams.macKey != null && fastParams.mac != null) {
const computedMac = await this.cryptoFunctionService.hmacFast(
fastParams.macData,
fastParams.macKey,
"sha256",
);
const macsEqual = await this.cryptoFunctionService.compareFast(fastParams.mac, computedMac);
if (!macsEqual) {
this.logMacFailed(
"[Encrypt service] decryptToUtf8 MAC comparison failed. Key or payload has changed. Key type " +
encryptionTypeName(key.encType) +
"Payload type " +
encryptionTypeName(encString.encryptionType) +
" Decrypt context: " +
decryptContext,
);
return null;
}
}
return await this.cryptoFunctionService.aesDecryptFast({ mode: "cbc", parameters: fastParams });
}
async decryptToBytes(
encThing: Encrypted,
key: SymmetricCryptoKey,
decryptContext: string = "no context",
): Promise<Uint8Array> {
if (key == null) {
throw new Error("No encryption key provided.");
}
if (encThing == null) {
throw new Error("Nothing provided for decryption.");
}
key = this.resolveLegacyKey(key, encThing);
// DO NOT REMOVE OR MOVE. This prevents downgrade to mac-less CBC, which would compromise integrity and confidentiality.
if (key.macKey != null && encThing.macBytes == null) {
this.logService.error(
"[Encrypt service] Key has mac key but payload is missing mac bytes. Key type " +
encryptionTypeName(key.encType) +
" Payload type " +
encryptionTypeName(encThing.encryptionType) +
" Decrypt context: " +
decryptContext,
);
return null;
}
if (key.encType !== encThing.encryptionType) {
this.logService.error(
"[Encrypt service] Key encryption type does not match payload encryption type. Key type " +
encryptionTypeName(key.encType) +
" Payload type " +
encryptionTypeName(encThing.encryptionType) +
" Decrypt context: " +
decryptContext,
);
return null;
}
if (key.macKey != null && encThing.macBytes != null) {
const macData = new Uint8Array(encThing.ivBytes.byteLength + encThing.dataBytes.byteLength);
macData.set(new Uint8Array(encThing.ivBytes), 0);
macData.set(new Uint8Array(encThing.dataBytes), encThing.ivBytes.byteLength);
const computedMac = await this.cryptoFunctionService.hmac(macData, key.macKey, "sha256");
if (computedMac === null) {
this.logMacFailed(
"[Encrypt service#decryptToBytes] Failed to compute MAC." +
" Key type " +
encryptionTypeName(key.encType) +
" Payload type " +
encryptionTypeName(encThing.encryptionType) +
" Decrypt context: " +
decryptContext,
);
return null;
}
const macsMatch = await this.cryptoFunctionService.compare(encThing.macBytes, computedMac);
if (!macsMatch) {
this.logMacFailed(
"[Encrypt service#decryptToBytes]: MAC comparison failed. Key or payload has changed." +
" Key type " +
encryptionTypeName(key.encType) +
" Payload type " +
encryptionTypeName(encThing.encryptionType) +
" Decrypt context: " +
decryptContext,
);
return null;
}
}
const result = await this.cryptoFunctionService.aesDecrypt(
encThing.dataBytes,
encThing.ivBytes,
key.encKey,
"cbc",
);
return result ?? null;
}
async rsaEncrypt(data: Uint8Array, publicKey: Uint8Array): Promise<EncString> {
if (data == null) {
throw new Error("No data provided for encryption.");
}
if (publicKey == null) {
throw new Error("No public key provided for encryption.");
}
const encrypted = await this.cryptoFunctionService.rsaEncrypt(data, publicKey, "sha1");
return new EncString(EncryptionType.Rsa2048_OaepSha1_B64, Utils.fromBufferToB64(encrypted));
}
async rsaDecrypt(data: EncString, privateKey: Uint8Array): Promise<Uint8Array> {
if (data == null) {
throw new Error("[Encrypt service] rsaDecrypt: No data provided for decryption.");
}
let algorithm: "sha1" | "sha256";
switch (data.encryptionType) {
case EncryptionType.Rsa2048_OaepSha1_B64:
case EncryptionType.Rsa2048_OaepSha1_HmacSha256_B64:
algorithm = "sha1";
break;
case EncryptionType.Rsa2048_OaepSha256_B64:
case EncryptionType.Rsa2048_OaepSha256_HmacSha256_B64:
algorithm = "sha256";
break;
default:
throw new Error("Invalid encryption type.");
}
if (privateKey == null) {
throw new Error("[Encrypt service] rsaDecrypt: No private key provided for decryption.");
}
return this.cryptoFunctionService.rsaDecrypt(data.dataBytes, privateKey, algorithm);
}
/**
* @deprecated Replaced by BulkEncryptService (PM-4154)
*/
async decryptItems<T extends InitializerMetadata>(
items: Decryptable<T>[],
key: SymmetricCryptoKey,
): Promise<T[]> {
if (items == null || items.length < 1) {
return [];
}
// don't use promise.all because this task is not io bound
const results = [];
for (let i = 0; i < items.length; i++) {
results.push(await items[i].decrypt(key));
}
return results;
}
async hash(value: string | Uint8Array, algorithm: "sha1" | "sha256" | "sha512"): Promise<string> {
const hashArray = await this.cryptoFunctionService.hash(value, algorithm);
return Utils.fromBufferToB64(hashArray);
}
private async aesEncrypt(data: Uint8Array, key: SymmetricCryptoKey): Promise<EncryptedObject> {
const obj = new EncryptedObject();
obj.key = key;
obj.iv = await this.cryptoFunctionService.randomBytes(16);
obj.data = await this.cryptoFunctionService.aesEncrypt(data, obj.iv, obj.key.encKey);
if (obj.key.macKey != null) {
const macData = new Uint8Array(obj.iv.byteLength + obj.data.byteLength);
macData.set(new Uint8Array(obj.iv), 0);
macData.set(new Uint8Array(obj.data), obj.iv.byteLength);
obj.mac = await this.cryptoFunctionService.hmac(macData, obj.key.macKey, "sha256");
}
return obj;
}
private logMacFailed(msg: string) {
if (this.logMacFailures) {
this.logService.error(msg);
}
}
/**
* Transform into new key for the old encrypt-then-mac scheme if required, otherwise return the current key unchanged
* @param encThing The encrypted object (e.g. encString or encArrayBuffer) that you want to decrypt
*/
resolveLegacyKey(key: SymmetricCryptoKey, encThing: Encrypted): SymmetricCryptoKey {
if (
encThing.encryptionType === EncryptionType.AesCbc128_HmacSha256_B64 &&
key.encType === EncryptionType.AesCbc256_B64
) {
return new SymmetricCryptoKey(key.key, EncryptionType.AesCbc128_HmacSha256_B64);
}
return key;
}
}