Add logging for decryption failures (#11683)

* Add logging to decryption routines

* Fix case of uknown encryption type

* Remove enum to string mapping

libs/common/src/platform/enums/encryption-type.enum.ts

@@ -8,6 +8,14 @@ export enum EncryptionType {
   Rsa2048_OaepSha1_HmacSha256_B64 = 6,
 }
 
+export function encryptionTypeToString(encryptionType: EncryptionType): string {
+  if (encryptionType in EncryptionType) {
+    return EncryptionType[encryptionType];
+  } else {
+    return "Unknown encryption type " + encryptionType;
+  }
+}
+
 /** The expected number of parts to a serialized EncString of the given encryption type.
  * For example, an EncString of type AesCbc256_B64 will have 2 parts, and an EncString of type
  * AesCbc128_HmacSha256_B64 will have 3 parts.

libs/common/src/platform/services/cryptography/encrypt.service.implementation.ts

@@ -2,7 +2,7 @@ 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 } from "../../enums";
+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";
@@ -70,13 +70,24 @@ export class EncryptServiceImplementation implements EncryptService {
 
     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("MAC required but not provided.");
+      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),
+      );
       return null;
     }
 
     if (key.encType !== encString.encryptionType) {
-      this.logService.error("Key encryption type does not match payload encryption type.");
+      this.logService.error(
+        "[Encrypt service] Key encryption type does not match payload encryption type. Key type " +
+          encryptionTypeName(key.encType) +
+          " Payload type " +
+          encryptionTypeName(encString.encryptionType),
+      );
       return null;
     }
 
@@ -94,7 +105,12 @@ export class EncryptServiceImplementation implements EncryptService {
       );
       const macsEqual = await this.cryptoFunctionService.compareFast(fastParams.mac, computedMac);
       if (!macsEqual) {
-        this.logMacFailed("MAC comparison failed. Key or payload has changed.");
+        this.logMacFailed(
+          "[Encrypt service] MAC comparison failed. Key or payload has changed. Key type " +
+            encryptionTypeName(key.encType) +
+            " Payload type " +
+            encryptionTypeName(encString.encryptionType),
+        );
         return null;
       }
     }
@@ -113,13 +129,24 @@ export class EncryptServiceImplementation implements EncryptService {
 
     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("MAC required but not provided.");
+      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),
+      );
       return null;
     }
 
     if (key.encType !== encThing.encryptionType) {
-      this.logService.error("Key encryption type does not match payload encryption type.");
+      this.logService.error(
+        "[Encrypt service] Key encryption type does not match payload encryption type. Key type " +
+          encryptionTypeName(key.encType) +
+          " Payload type " +
+          encryptionTypeName(encThing.encryptionType),
+      );
       return null;
     }
 
@@ -129,13 +156,25 @@ export class EncryptServiceImplementation implements EncryptService {
       macData.set(new Uint8Array(encThing.dataBytes), encThing.ivBytes.byteLength);
       const computedMac = await this.cryptoFunctionService.hmac(macData, key.macKey, "sha256");
       if (computedMac === null) {
-        this.logMacFailed("Failed to compute MAC.");
+        this.logMacFailed(
+          "[Encrypt service] Failed to compute MAC." +
+            " Key type " +
+            encryptionTypeName(key.encType) +
+            " Payload type " +
+            encryptionTypeName(encThing.encryptionType),
+        );
         return null;
       }
 
       const macsMatch = await this.cryptoFunctionService.compare(encThing.macBytes, computedMac);
       if (!macsMatch) {
-        this.logMacFailed("MAC comparison failed. Key or payload has changed.");
+        this.logMacFailed(
+          "[Encrypt service] MAC comparison failed. Key or payload has changed." +
+            " Key type " +
+            encryptionTypeName(key.encType) +
+            " Payload type " +
+            encryptionTypeName(encThing.encryptionType),
+        );
         return null;
       }
     }
@@ -164,7 +203,7 @@ export class EncryptServiceImplementation implements EncryptService {
 
   async rsaDecrypt(data: EncString, privateKey: Uint8Array): Promise<Uint8Array> {
     if (data == null) {
-      throw new Error("No data provided for decryption.");
+      throw new Error("[Encrypt service] rsaDecrypt: No data provided for decryption.");
     }
 
     let algorithm: "sha1" | "sha256";
@@ -182,7 +221,7 @@ export class EncryptServiceImplementation implements EncryptService {
     }
 
     if (privateKey == null) {
-      throw new Error("No private key provided for decryption.");
+      throw new Error("[Encrypt service] rsaDecrypt: No private key provided for decryption.");
     }
 
     return this.cryptoFunctionService.rsaDecrypt(data.dataBytes, privateKey, algorithm);