Reorganize ssl_parse_encrypted_pms so that it first prepares the
ciphertext to decrypt, then decrypts it, then returns either the
decrypted premaster secret or random data in an appropriate manner.
This is in preparation for allowing the private key operation to be
offloaded to an external cryptographic module which can operate
asynchronously. The refactored code no longer calculates state before
the decryption that needs to be saved until after the decryption,
which allows the decryption to be started and later resumed.
Use the public key to extract metadata rather than the public key.
Don't abort early if there is no private key.
This is in preparation for allowing the private key operation to be
offloaded to an external cryptographic module.
Add test cases for SSL asynchronous signature to ssl-opt.sh:
* Delay=0,1 to test the sequences of calls to f_async_resume
* Test fallback when the async callbacks don't support that key
* Test error injection at each stage
* Test renegotiation
Implement SSL asynchronous private operation for the case of a
signature operation in a server.
This is a first implementation. It is functional, but the code is not
clean, with heavy reliance on goto.
The pk layer can infer the hash length from the hash type. Calculate
it explicitly here anyway because it's needed for debugging purposes,
and it's needed for the upcoming feature allowing the signature
operation to be offloaded to an external cryptographic processor, as
the offloading code will need to know what length hash to copy.
New options in ssl_server2 to use the asynchronous private key
operation feature.
Features: resume delay to call resume more than once; error injection
at each stage; renegotiation support.
New compile-time option MBEDTLS_SSL_ASYNC_PRIVATE_C, enabling
callbacks to replace private key operations. These callbacks allow the
SSL stack to make an asynchronous call to an external cryptographic
module instead of calling the cryptography layer inside the library.
The call is asynchronous in that it may return the new status code
MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS, in which case the SSL stack returns
and can be later called where it left off.
This commit introduces the configuration option. Later commits will
implement the feature proper.
This function is declared in ssl_internal.h, so this is not a public
API change.
This is in preparation for mbedtls_ssl_handshake_free needing to call
methods from the config structure.
In SSL, don't use mbedtls_pk_ec or mbedtls_pk_rsa on a private
signature or decryption key (as opposed to a public key or a key used
for DH/ECDH). Extract the data (it's the same data) from the public
key object instead. This way the code works even if the private key is
opaque or if there is no private key object at all.
Specifically, with an EC key, when checking whether the curve in a
server key matches the handshake parameters, rely only on the offered
certificate and not on the metadata of the private key.
