Define accepted log public keys

GoogleChrome / CertificateTransparency

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Define accepted log public keys #25

Open sleevi opened 4 years ago

sleevi commented 4 years ago

The Chromium implementation of CT is limited in support of public keys to the set of public keys it accepts for the Web PKI:

RSA (nominally, 2048, 3072, 4096)
ECC using NIST P-256, P-384

The Chromium implementation does not explicitly support Curve25519, although it could, and does not support other forms of EC keys.

devonobrien commented 4 years ago

We also need to check what key algs our compliance monitoring infrastructure supports to provide the minimal set of supportable key types.

devonobrien commented 4 years ago

Also, of note is Section 2.1.4 of RFC 6962 which states:

Various data structures are signed. A log MUST use either elliptic curve signatures using the NIST P-256 curve (Section D.1.2.3 of the Digital Signature Standard [DSS]) or RSA signatures (RSASSA-PKCS1- V1_5 with SHA-256, Section 8.2 of [RFC3447]) using a key of at least 2048 bits.