[Ssc-dev] APG for public key crypto

[Nathan Freitas]

Good news - Android Privacy Guard (APG) has all the tools we need for
signing and encrypting data from SSC. I assumed so because this is
already being done with K9Mail, but I hadn't found this specific
documentation until now.

http://code.google.com/p/android-privacy-guard/wiki/UsingApgForDevelopment

Intents
Apg.Intent.ENCRYPT_AND_RETURN

Encrypt data and return the result.

Intent.getData() (Uri), Apg.EXTRA_DATA (byte), Apg.EXTRA_TEXT (String) -
data source
Apg.EXTRA_ASCII_ARMOUR (boolean) - use ASCII armour
true: if EXTRA_DATA or EXTRA_TEXT were used, then the data is returned
with Apg.EXTRA_ENCRYPTED_TEXT
false: EXTRA_DATA or EXTRA_TEXT were used, then the data is returned
with Apg.EXTRA_ENCRYPTED_DATA
Apg.EXTRA_ENCRYPTION_KEY_IDS (long) - the list of encryption keys
Apg.EXTRA_SIGNATURE_KEY_ID (long) - the signature key
returns Apg.EXTRA_ENCRYPTED_DATA (byte) or Apg.EXTRA_ENCRYPTED_TEXT (String)
Apg.Intent.DECRYPT_AND_RETURN


Decrypt data and return the result.
Intent.getData() (Uri), Apg.EXTRA_DATA (byte), Apg.EXTRA_TEXT (String) -
data source
Apg.EXTRA_BINARY (boolean) - return the decrypted data as byte array
true: the data is returned with Apg.EXTRA_DECRYPTED_DATA
false: the data is returned with Apg.EXTRA_DECRYPTED_TEXT
returns Apg.EXTRA_DECRYPTED_DATA (byte) or Apg.EXTRA_DECRYPTED_TEXT (String)
if signed:
returns Apg.EXTRA_SIGNATURE_KEY_ID (long) - the signature key ID
returns Apg.EXTRA_SIGNATURE_USER_ID (String) - the user ID of the signature
returns Apg.EXTRA_SIGNATURE_SUCCESS (boolean) - signature is correct
returns Apg.EXTRA_SIGNATURE_UNKNOWN (boolean) - signature is unknown
Apg.Intent.SELECT_SECRET_KEY

Select a secret key from the list and return its ID.
result returned in Apg.EXTRA_SECRET_KEY (long)
Apg.Intent.SELECT_PUBLIC_KEYS

Select some public keys from the list and return their IDs.
Apg.EXTRA_SELECTION (long) - pass a list of IDs for keys that are
selected already
result returned in Apg.EXTRA_SELECTION (long)