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1d
comment What does the TLS 1.2 client finished message contain?
I'd say: the data to encrypt is 12 bytes, as Dave says, i.e. the truncated output of the PRF-SHA256 output. But GCM being used, means the ciphertext will be longer and include the nonce (12 bytes) and the tag (16 bytes), as to RFC5288. The tag also authenticates the TLS header data (type and length).
1d
comment How to use OpenSSL command line utility to encrypt data with encrypted key from public key?
Also: sizes are stored how? binary, Little-Endian or Big-Endian? All in one continuguous binary file? Length of iv seems superfluous given that we're using AES (so 16 is the only value). Example files (also of PK, see other comment) please!
1d
awarded  Citizen Patrol
1d
comment How to use OpenSSL command line utility to encrypt data with encrypted key from public key?
What's the format of the public key? Could you post one? It's quite doable (using some shell utilities) but the format of the public key matters for the openssl options and possibilities.
Apr
19
answered Deriving 256-bit key from PBKDF2-SHA1
Apr
9
comment Encrypt-then-HMAC implementation - am I doing it right?
But is it C# (and portably so?). I think that would matter to the OP.
Mar
20
comment Finding d given everything else in RSA
@jamie the API might not accept negative numbers, in which case you might need the extended Euclidean algorithm instead
Mar
20
comment Finding d given everything else in RSA
@fgrieu True. I'll delete the comment.
Mar
20
comment Finding d given everything else in RSA
@Jamie take exponent equal to $-1$, modulus to $\phi(n)$.
Mar
20
comment Signing MD5 hashes with RSA?
Collisions and factoring attacks on the hash value etc.
Mar
20
comment I am trying to understand how AES works
Did you look at youtube.com/watch?v=mlzxpkdXP58, e.g.?
Mar
20
comment Signing MD5 hashes with RSA?
Don't use MD5 anymore. Just use SHA256, and a standard algorithm for signing (with padding!), e.g. PKCS1.5 will do fine for this case.
Mar
20
answered Finding d given everything else in RSA
Mar
4
comment Solving for a One-time pad cipher help ; crib dragging doesnt work (no surprise)
@Thrall it's hex encoded, so that's why you only see 16 characters. ASCII bytes xored with random bytes, encoded as hex (2 characters per byte).
Feb
26
revised Why is PuTTYgen-created RSA public exponent(e) not in {3,17,65537}?
typo
Feb
21
answered How to create and validate potential grids when attacking a Playfair cipher?
Feb
9
comment Need CryptDeriveKey AES implementation in C#
Microsoft does document their "CryptDeriveKey" function. Check msdn. It's their own invention, not standard based.
Feb
9
comment Linear cryptanalysis complete key guessing
You guess the other bits as well, after determining the subkeys.
Feb
6
revised How to break Universal Re-Encryption algorithm?
added 5 characters in body
Feb
6
revised How to break Universal Re-Encryption algorithm?
deleted 1 character in body