This commit updates `kMessage` in `test_ecdsa.cpp` function which
verifies the signature generation to be an array of char instead of a
`char *`. This ensures that the use of `sizeof(kMessage)` correctly
gives the length of the message string (which is used during hash
calculation).
This commit updates `VerifyOrQuit()` and `SuccessOrQuit()` macros to
include the failed condition in the error message that is printed on
a failure (in addition to function name and line number where the
error happened). This commit also changes the second parameter
(`aMessage`) to in these macros to be optional.
This commit also updates unit tests to remove the second `aMessage`
string in cases where the failure can be inferred from the condition
itself.
This commit adds a new core header files `common/error.hpp` which
defines `ot::Error` (mirroring `otError`) and `kError{Name}` constants
(mirroring the public `OT_ERROR_{NAME}` definitions). The new (C++
style) definitions are used by core modules. This commit also moves
`otThreadErrorToString()` (from `logging.hpp` to `error.hpp`) and
renames it to `ErrorToString()` which is used as the internal (to
core) function to covert an `Error` to a string.
This commit updates `Sha256` and `HmacSha256` classes adding new
flavors of `Update()` method which inputs bytes from a given buffer,
or from an object, or read from a `Message` for hash calculation.
This commit also updates unit test to add more test-cases (from RFC
4231) for HMAC and adds new set of test-cases for SHA-256. The test
also covers calculating hash over data read directly from a `Message`.
Per Sec 4 of RFC 6605:
"ECDSA public keys consist of a single value, called "Q" in FIPS
186-3. In DNSSEC keys, Q is a simple bit string that represents the
uncompressed form of a curve point, "x | y"."
The bit string of the two curve points (X, Y) should have a fixed
length of 64 bytes and the additional `1` byte prefix should not be
included, because only uncompressed form is allowed.
This commit adds support for ECDSA using NIST P-256 curve and SHA-256
hash. `KeyPair` type is added which represents a set of public and
private keys. It provides methods for generation a new key-pair and
getting a DER format byte sequence representation of the key-pair.
This commit also adds methods to calculate ECDSA signature and verify
a signature for a hashed message. The underlying implementation uses
`mbedtls` APIs.
It also adds a unit-test `test-ecdsa` to cover behavior of the newly
added types and methods. The unit test also verifies the signature
calculation using the test vector example from RFC 6979.