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-rw-r--r--crypto.go47
1 files changed, 0 insertions, 47 deletions
diff --git a/crypto.go b/crypto.go
index 34451cc..546fc0a 100644
--- a/crypto.go
+++ b/crypto.go
@@ -6,55 +6,8 @@ import (
"crypto"
"crypto/rand"
- "crypto/tls"
- "crypto/x509"
-
- "github.com/system-transparency/stfe/x509util"
)
-// buildChainFromDerList builds an X.509 certificate chain from a list of
-// DER-encoded certificates using the log's configured trust anchors, extended
-// key-usages, and maximum chain length (which includes the trust anchor).
-func (lp *LogParameters) buildChainFromDerList(derChain [][]byte) ([]*x509.Certificate, error) {
- certificate, intermediatePool, err := x509util.ParseDerChain(derChain)
- if err != nil {
- return nil, err
- }
- opts := x509.VerifyOptions{
- Roots: lp.AnchorPool,
- Intermediates: intermediatePool,
- KeyUsages: lp.KeyUsage, // no extended key usage passes by default
- }
-
- chains, err := certificate.Verify(opts)
- if err != nil {
- return nil, fmt.Errorf("chain verification failed: %v", err)
- }
- if len(chains) == 0 { // better safe than sorry
- return nil, fmt.Errorf("chain verification failed: no path")
- }
-
- // there might be several valid chains
- for _, chain := range chains {
- if int64(len(chain)) <= lp.MaxChain {
- return chain, nil // just pick the first valid chain
- }
- }
- return nil, fmt.Errorf("bad certificate chain length: too large")
-}
-
-// verifySignature checks if signature is valid for some serialized data. The
-// only supported signature scheme is ed25519(0x0807), see ยง4.2.3 in RFC 8446.
-func (lp *LogParameters) verifySignature(certificate *x509.Certificate, scheme tls.SignatureScheme, serialized, signature []byte) error {
- if scheme != tls.Ed25519 {
- return fmt.Errorf("unsupported signature scheme: %v", scheme)
- }
- if err := certificate.CheckSignature(x509.PureEd25519, serialized, signature); err != nil {
- return fmt.Errorf("invalid signature: %v", err)
- }
- return nil
-}
-
// genV1Sdi issues a new SignedDebugInfoV1 StItem from a serialized leaf value
func (lp *LogParameters) genV1Sdi(serialized []byte) (*StItem, error) {
sig, err := lp.Signer.Sign(rand.Reader, serialized, crypto.Hash(0)) // ed25519