Confirm size of decrypted PMS before using

peterdettman · peterdettman · commit a00b684465b3 · 2017-12-12T08:41:43.000+07:00
diff --git a/tls/src/main/java/org/bouncycastle/tls/crypto/impl/jcajce/JceDefaultTlsCredentialedDecryptor.java b/tls/src/main/java/org/bouncycastle/tls/crypto/impl/jcajce/JceDefaultTlsCredentialedDecryptor.java
@@ -97,7 +97,11 @@ protected TlsSecret safeDecryptPreMasterSecret(TlsCryptoParameters cryptoParams,
         {
             Cipher c = crypto.createRSAEncryptionCipher();
             c.init(Cipher.DECRYPT_MODE, rsaServerPrivateKey);
-            M = c.doFinal(encryptedPreMasterSecret);
+            byte[] m = c.doFinal(encryptedPreMasterSecret);
+            if (m != null && m.length == 48)
+            {
+                M = m;
+            }
         }
         catch (Exception e)
         {

Original file line number	Diff line number	Diff line change
`@@ -97,7 +97,11 @@ protected TlsSecret safeDecryptPreMasterSecret(TlsCryptoParameters cryptoParams,`
`97`	`97`	`{`
`98`	`98`	`Cipher c = crypto.createRSAEncryptionCipher();`
`99`	`99`	`c.init(Cipher.DECRYPT_MODE, rsaServerPrivateKey);`
`100`		`- M = c.doFinal(encryptedPreMasterSecret);`
	`100`	`+ byte[] m = c.doFinal(encryptedPreMasterSecret);`
	`101`	`+ if (m != null && m.length == 48)`
	`102`	`+ {`
	`103`	`+ M = m;`
	`104`	`+ }`
`101`	`105`	`}`
`102`	`106`	`catch (Exception e)`
`103`	`107`	`{`