We were using the "RSA Protected Configuration provider" to encrypt sensitive information in our config files. More info about this on MSDN at - http://msdn.microsoft.com/en-us/library/ms998283.aspx.
In the generated config file there is a triple-DES encrypted key. So that means the config section is actually encrypted/decrypted using this symmetric key.
But this symmetric DES key is actually encrypted/decrypted using the RSA private/public key in the RSA key container. The question I have is whether the public/private RSA keys in the container are also encrypted? If yes, then where is the key for that stored?
If the keys in the container are not encrypted, then why do we need to export the keys to a XML file and them import them in another machine? Why not just copy-paste the RSA container key to all nodes in a web cluster/farm?
They are encrypted using DPAPI.
Related
I've been doing some searching and still do not know if this is possible. What I want is for a message to by encrypted by our system and decrypted by a "master key" and also a 3rd party.
This encrypted message needs to be decrypted by 2 entities
-A 3rd party (which we want the control to shut off their ability to decrypt)
-Our system (which we want to always be able to decrypt no matter what, master key?)
From some research I was doing there is a concept of master key and derived keys
Does this following system exist?:
Master Key - can decrypt anything encrypted by derived keys
DerivedKey1 -> Encrypt data with this key and be able to decrypt with Master Key OR DerivedKey1
DerivedKey2 -> Encrypt data with this key and be able to decrypt with Master Key OR DerivedKey2 but NOT derivedKey1
Any terminology I should be using to search for answers would be helpful, also any crypto systems that do this already would be great to know.
Yes, I mean deny any new messages sent from our system to be decrypted
You can encrypt the content with a random key (data key).
Then you can encrypt the data key for each intended recipient (master key and any 3rd party) using its shared or public key.
According to the documentation the gpgme_op_encrypt method of GPGME is able to perform symmetric encryption tasks:
gpgme_op_encrypt (gpgme_ctx_t ctx, gpgme_key_t recp[], gpgme_encrypt_flags_t flags, gpgme_data_t plain, gpgme_data_t cipher)
If recp is NULL, symmetric rather than public key encryption is
performed. Symmetrically encrypted cipher text can be deciphered with
gpgme_op_decrypt. Note that in this case the crypto backend needs to
retrieve a passphrase from the user. Symmetric encryption is currently
only supported for the OpenPGP crypto backend.
But where does the key used for the symmetric encryption come from? Is it somehow possible to fetch this key and transfer it to another device (where I would like to decrypt the text) ?
The session key for symmetric encryption is derived from a passphrase, which will be queried from the user through one of the pinentry methods. Specifically highlighting a part of the text you already quoted:
If recp is NULL, symmetric rather than public key encryption is performed. Symmetrically encrypted cipher text can be deciphered with gpgme_op_decrypt. Note that in this case the crypto backend needs to retrieve a passphrase from the user. Symmetric encryption is currently only supported for the OpenPGP crypto backend.
I'm not aware you can extract the session key through GPGME, but you don't really need to: all you need to know at the other end is the passphrase used, and the session key can be derived again. You could of course also reimplement the string-to-key-function used for OpenPGP.
I am working on a C# app that encrypts/decrypts messages using PGP implemented by the Bouncy Castle (BC) library. I know PKI but the secret key in PGP throws me off a bit. I looked at the BC examples/source code and the PGP RFC but came away with more questions.
Is Secretkey == Session key?
Is Secretkey == Symmetric key?
Is Secretkey == private key (pub/priv key pairs)? At least the following seems to suggest that the secret key is a private key.
internal static PgpPrivateKey FindSecretKey(PgpSecretKeyRingBundle pgpSec, long keyID, char[] pass)
The RFC says the secretkey contains, among others, information about the publickey or may be the public key itself (at least that's my reading).
Also, somewhere I read the Secretkey is basically a password encrypted privatekey.
When/why would I need a secret key in the PGP protocol? Signing or encrypting?
Thanks
Quoting RFC 4880, OpenPGP, 5.5.1.3. Secret-Key Packet:
A Secret-Key packet contains all the information that is found in a
Public-Key packet, including the public-key material, but also
includes the secret-key material after all the public-key fields.
and 11.2. Transferable Secret Keys:
[...] The format of a transferable
secret key is the same as a transferable public key except that
secret-key and secret-subkey packets are used instead of the public
key and public-subkey packets. Implementations SHOULD include self-
signatures on any user IDs and subkeys, [...]
With other words, the secret key contains the public/private key pair (eg., RSA), but should also contain user IDs and self-signatures. 12.1. Key Structures gives more details on how exported keys are constructed. A helpful tool for understanding the composition of OpenPGP packets are gpg --list-packets [file] or pgpdump [file], which dump the packet structure of their input.
In this case the secret key is a private key. The private key can be used for signing or decryption. Encryption and verification is performed using the public key of the other party. A secret key is nowadays mostly thought of to be a symmetric key, but it can also mean private, especially in older protocols.
There is a lot of this kind of confusion in cryptography, the best thing to do is to look at the context. For instance, if there is a public key, the key cannot be symmetric.
I have old p12 certificate. Can I know what encrypted algorithm used: RSA-1024 or RSA-2048?
PKCS#12 is not a certificate and the key size is not an algorithm. The key within the X5.09 certificate in the PKCS#12 has a public modulus though, and the size of the modulus is equal to the key size. If you use an online decoder, don't give it the entire PKCS#12 key store as it probably includes your private key.
You can check it using one of the cert decoders online such as https://certlogik.com/decoder/
Suppose I would like to encrypt a file with my private key for whatever reason so that only people with my public key can have access to the file. How would I do this?
gpg --sign --armor file
does not work because if you omit the --armor and use
gpg --sign --compress-level 0 file
the plaintext appears in the file.gpg.
gpg --encrypt file
will also not work because that uses public keys. Does anybody know how to do this?
You unfortunately have got some fundamental misconceptions about the cryptography you want use. By definition if you want to asymmetrically encrypt some data you need to use the public key and the encrypted data can only be decrypted with the private key.
If you want to encrypt a message so that only a certain group of people can access it you can asymmetrically encrypt it with all the public keys of each individual in the group or encrypt it symmetrically with a random key and share that key with each individual in the group.
You can encrypt your file symmetrically using your public key, so that everybody with access to your public key can decrypt your file.