PlatformId from CSR

[flihp]

For PkiPaths we provide a TryFrom in the PlatformId type to walk the PkiPath and extract the PlatformId string. The dice-mfg command does the same thing for CSRs as a way to ensure that the platform being manufactured generated a CSR with a subject field in the expected form & with the expected content (

dice-util/dice-mfg/src/lib.rs

Line 107 in 10952e8

for dn in csr.info.subject.0 {

). For the sake of consistency we should provide a TryFrom<CertReq> impl.