/**
* Verifies that the signature from the server matches the computed signature on the data. Returns
* true if the data is correctly signed.
*
* @param publicKey public key associated with the developer account
* @param signedData signed data from server
* @param signature server signature
* @return true if the data and signature match
*/
public static boolean verify(PublicKey publicKey, String signedData, String signature) {
if (StoreConfig.debug) {
Log.i(TAG, "signature: " + signature);
}
Signature sig;
try {
sig = Signature.getInstance(SIGNATURE_ALGORITHM);
sig.initVerify(publicKey);
sig.update(signedData.getBytes());
if (!sig.verify(Base64.decode(signature))) {
Log.e(TAG, "Signature verification failed.");
return false;
}
return true;
} catch (NoSuchAlgorithmException e) {
Log.e(TAG, "NoSuchAlgorithmException.");
} catch (InvalidKeyException e) {
Log.e(TAG, "Invalid key specification.");
} catch (SignatureException e) {
Log.e(TAG, "Signature exception.");
} catch (Base64DecoderException e) {
Log.e(TAG, "Base64 decoding failed.");
}
return false;
}
/**
* Generates a PublicKey instance from a string containing the Base64-encoded public key.
*
* @param encodedPublicKey Base64-encoded public key
* @throws IllegalArgumentException if encodedPublicKey is invalid
*/
public static PublicKey generatePublicKey(String encodedPublicKey) {
try {
byte[] decodedKey = Base64.decode(encodedPublicKey);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_FACTORY_ALGORITHM);
return keyFactory.generatePublic(new X509EncodedKeySpec(decodedKey));
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException(e);
} catch (InvalidKeySpecException e) {
Log.e(TAG, "Invalid key specification.");
throw new IllegalArgumentException(e);
} catch (Base64DecoderException e) {
Log.e(TAG, "Base64 decoding failed.");
throw new IllegalArgumentException(e);
}
}
