Talk:Services/Sync/SimplifiedCrypto - Revision history

MarcusWolschon: /* Deriving encryption and HMAC keys from the Sync Key */

2010-12-04T10:58:41Z

Deriving encryption and HMAC keys from the Sync Key

← Older revision		Revision as of 10:58, 4 December 2010
Line 13:		Line 13:
	** [http://hg.mozilla.org/services/fx-sync/file/37150bc0bf62/services/sync/modules/constants.js source]		** [http://hg.mozilla.org/services/fx-sync/file/37150bc0bf62/services/sync/modules/constants.js source]
	** it is the string "Sync-AES_256_CBC-HMAC256"		** it is the string "Sync-AES_256_CBC-HMAC256"

	* what is enc + HMAC_INPUT + u + "\x02"? (enc is a byte array, the others are strings)		* what is enc + HMAC_INPUT + u + "\x02"? (enc is a byte array, the others are strings)
	* \x?? = "The Latin-1 character specified by the two hexadecimal digits dd between 00 and FF. ie, copyright symbol is \xA9."		* \x?? = "The Latin-1 character specified by the two hexadecimal digits dd between 00 and FF. ie, copyright symbol is \xA9."
			** \x01 = SOH = \u0001 in unicode

	== Upgrading existing Sync Keys to the new AES key ==		== Upgrading existing Sync Keys to the new AES key ==

MarcusWolschon: /* Deriving encryption and HMAC keys from the Sync Key */

2010-12-04T10:54:39Z

Deriving encryption and HMAC keys from the Sync Key

← Older revision		Revision as of 10:54, 4 December 2010
Line 14:		Line 14:
	** it is the string "Sync-AES_256_CBC-HMAC256"		** it is the string "Sync-AES_256_CBC-HMAC256"
	* what is enc + HMAC_INPUT + u + "\x02"? (enc is a byte array, the others are strings)		* what is enc + HMAC_INPUT + u + "\x02"? (enc is a byte array, the others are strings)
			* \x?? = "The Latin-1 character specified by the two hexadecimal digits dd between 00 and FF. ie, copyright symbol is \xA9."

	== Upgrading existing Sync Keys to the new AES key ==		== Upgrading existing Sync Keys to the new AES key ==

MarcusWolschon: /* Deriving encryption and HMAC keys from the Sync Key */

2010-12-04T10:47:29Z

Deriving encryption and HMAC keys from the Sync Key

← Older revision		Revision as of 10:47, 4 December 2010
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	* What is the value of HMAC_INPUT?		* What is the value of HMAC_INPUT?
			** [http://hg.mozilla.org/services/fx-sync/file/37150bc0bf62/services/sync/modules/constants.js source]
			** it is the string "Sync-AES_256_CBC-HMAC256"
	* what is enc + HMAC_INPUT + u + "\x02"? (enc is a byte array, the others are strings)		* what is enc + HMAC_INPUT + u + "\x02"? (enc is a byte array, the others are strings)

MarcusWolschon: /* Deriving encryption and HMAC keys from the Sync Key */

2010-12-04T10:32:36Z

Deriving encryption and HMAC keys from the Sync Key

← Older revision		Revision as of 10:32, 4 December 2010
Line 7:		Line 7:
	== Deriving encryption and HMAC keys from the Sync Key ==		== Deriving encryption and HMAC keys from the Sync Key ==

	The hmac used is an SHA-256 HMAC.		The hmac used is an SHA-256 HMAC.<br/>
			* Sourcecode of [http://hg.mozilla.org/services/fx-sync/file/12189166cd01/services/sync/modules/util.js#l571 Utils.makeHMACKey()] Sorry, it's a native method.

	(~~A deep link to Utils.makeHMACKey() would be helpful here.~~)		* What is the value of HMAC_INPUT?
			* what is enc + HMAC_INPUT + u + "\x02"? (enc is a byte array, the others are strings)

	== Upgrading existing Sync Keys to the new AES key ==		== Upgrading existing Sync Keys to the new AES key ==

MarcusWolschon: /* Upgrading existing Sync Keys to the new AES key */

2010-12-04T08:29:08Z

Upgrading existing Sync Keys to the new AES key

← Older revision		Revision as of 08:29, 4 December 2010
Line 12:		Line 12:

	== Upgrading existing Sync Keys to the new AES key ==		== Upgrading existing Sync Keys to the new AES key ==
	PBKDF2 iteration count it 4096, key length 128 bit.		PBKDF2 iteration count it 4096, key length 128 bit.<br/>
			Keep in mind that while everywhere else Base64 is used, this is Base32.

	Example (Java):		Example (Java):

MarcusWolschon: /* Upgrading existing Sync Keys to the new AES key */

2010-12-04T08:28:34Z

Upgrading existing Sync Keys to the new AES key

← Older revision		Revision as of 08:28, 4 December 2010
Line 12:		Line 12:

	== Upgrading existing Sync Keys to the new AES key ==		== Upgrading existing Sync Keys to the new AES key ==
			PBKDF2 iteration count it 4096, key length 128 bit.

	~~example~~:		Example (Java):
	<pre>		<pre>
	/**		/**

MarcusWolschon: /* Deriving encryption and HMAC keys from the Sync Key */

2010-12-04T08:26:49Z

Deriving encryption and HMAC keys from the Sync Key

← Older revision		Revision as of 08:26, 4 December 2010
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	(A deep link to Utils.makeHMACKey() would be helpful here.)		(A deep link to Utils.makeHMACKey() would be helpful here.)

			== Upgrading existing Sync Keys to the new AES key ==

			example:
			<pre>
			/**
			* See https://wiki.mozilla.org/Services/Sync/SimplifiedCrypto#Upgrading_existing_Sync_Keys_to_the_new_AES_key
			* for details on the algorithm.
			* @param aV3Passphrase
			* @return the v4 syncKey (serves the same purpose as the passphrase before)
			* @throws Exception see {@link #passwordToSymmetricKey(char[], byte[])}
			* @throws UnsupportedEncodingException should not happen (ASCII)
			*/
			public String upgradeV3PassphraseToV4SyncKey(final String aV3Passphrase) throws UnsupportedEncodingException, Exception {
			String salt = mSyncID;
			KeySpec ks = new PBEKeySpec(aV3Passphrase.toCharArray(), salt.getBytes("ASCII"), 4096, 128);
			PBKDF2HmacSHA1Factory f = new PBKDF2HmacSHA1Factory();
			SecretKey s = f.engineGenerateSecret(ks);

			String base32 = biz.wolschon.android.codec.binary.Base32.encode(s.getEncoded()).toLowerCase();
			String syncKey = base32.replace('l', '8').replace('o', '9');

			syncKey = syncKey.charAt(0)
			+ "-" + syncKey.substring(1, 6)
			+ "-" + syncKey.substring(6, 11)
			+ "-" + syncKey.substring(11, 16)
			+ "-" + syncKey.substring(16, 21)
			+ "-" + syncKey.substring(21, 26);
			Log.d(LOG_TAG, "upgraded passphrase to syncKey \"" + syncKey + "\"");
			return syncKey;
			}

			</pre>

MarcusWolschon: /* Deriving encryption and HMAC keys from the Sync Key */

2010-12-04T07:42:18Z

Deriving encryption and HMAC keys from the Sync Key

← Older revision		Revision as of 07:42, 4 December 2010
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			== sync key representation ==

			The sync key is represented to the user as:

			X-XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

	== Deriving encryption and HMAC keys from the Sync Key ==		== Deriving encryption and HMAC keys from the Sync Key ==

MarcusWolschon: Created page with "== Deriving encryption and HMAC keys from the Sync Key == The hmac used is an SHA-256 HMAC. (A deep link to Utils.makeHMACKey() would be helpful here.)"

2010-12-04T07:18:47Z

Created page with "== Deriving encryption and HMAC keys from the Sync Key == The hmac used is an SHA-256 HMAC. (A deep link to Utils.makeHMACKey() would be helpful here.)"

New page

== Deriving encryption and HMAC keys from the Sync Key ==

The hmac used is an SHA-256 HMAC.

(A deep link to Utils.makeHMACKey() would be helpful here.)