Pass the group order (if known/specified) to crypto_dh_derive_secret()
(and also to OpenSSL DH_generate_key() in case of Group 5) and verify
that the public key received from the peer meets 1 < pubkey < p and
pubkey^q == 1 mod p conditions.
While all these use cases were using only ephemeral DH keys, it is
better to use more explicit checks while deriving the shared secret to
avoid unexpected behavior.
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
The patch offers alternate implementations of some functions using the
abstract cryptographic API.
This work was done in preparation for the changes to allow hostap to be
compiled with the wolfSSL cryptography and TLS library.
Signed-off-by: Sean Parkinson <sean@wolfssl.com>
It was possible for some NFC DH generation error paths to leak memory
since the old private/public key was not freed if an allocation failed.
Signed-off-by: Jouni Malinen <j@w1.fi>
By analysing objdump output some read only structures were found in
.data section. To help compiler further optimize code declare these
as const.
Signed-off-by: Mikael Kanstrup <mikael.kanstrup@sonymobile.com>
The groups 22, 23, and 24 are not based on a safe prime and generate a
prime order subgroup. As such, struct dh_group is also extended to
include the order for previously defined groups (q=(p-1)/2 since these
were based on a safe prime).
Signed-hostap: Jouni Malinen <j@w1.fi>
This commit adds a new wrapper, random_get_bytes(), that is currently
defined to use os_get_random() as is. The places using
random_get_bytes() depend on the returned value being strong random
number, i.e., something that is infeasible for external device to
figure out. These values are used either directly as a key or as
nonces/challenges that are used as input for key derivation or
authentication.
The remaining direct uses of os_get_random() do not need as strong
random numbers to function correctly.
The returned buffer length was hardcoded to be the prime length
which resulted in shorter results being padded in the end. However,
the results from DH code are supposed to be unpadded (and when used
with WPS, the padding is done in WPS code and it is added to the
beginning of the buffer). This fixes WPS key derivation errors
in about 1/256 of runs ("WPS: Incorrect Authenticator") when using
the internal crypto code.
Jouni Malinen