Better distinguish between keytype and scheme for ECDSA keys #239
Description
Description of issue or feature request:
The key format provided by securesystemslib defines a keytype field and a scheme field. Currently, there is no distinction between these fields for ECDSA keys.
Current behavior:
ECDSA keys have the following format:
{
"keytype" : "ecdsa-sha2-nistp256",
"scheme" : "ecdsa-sha2-nistp256",
"keyval" : {"public" : PUBLIC}
}
As noted in 761aded, ecdsa-sha2-nistp384 is also supported by securesystemslib.
Expected behavior:
Update securesystemslib to use just ecdsa as keytype while retaining the current scheme formats. This also aligns with the key format for RSA keys where we have:
{
"keytype" : "rsa",
"scheme" : "rsassa-pss-sha256",
"keyval" : {"public" : PUBLIC}
}