renamed verify.go to crypto.go

Chains and signatures are verified here, but signatures are also
produced.

1 files changed, 0 insertions, 81 deletions

diff --git a/verify.go b/verify.go
deleted file mode 100644
index 47c16bb..0000000
--- a/verify.go
+++ /dev/null
@@ -1,81 +0,0 @@
-package stfe
-
-import (
-	"fmt"
-	"time"
-
-	"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 {
-		return nil, fmt.Errorf("bad certificate chain length: empty")
-	}
-
-	// 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 §4.2.3 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
-	if err != nil {
-		return nil, fmt.Errorf("ed25519 signature failed: %v", err)
-	}
-	lastSdiTimestamp.Set(float64(time.Now().Unix()), lp.id())
-	return NewSignedDebugInfoV1(lp.LogId, []byte("reserved"), sig), nil
-}
-
-// genV1Sth issues a new SignedTreeHeadV1 StItem from a TreeHeadV1 structure
-func (lp *LogParameters) genV1Sth(th *TreeHeadV1) (*StItem, error) {
-	serialized, err := th.Marshal()
-	if err != nil {
-		return nil, fmt.Errorf("failed tls marshaling tree head: %v", err)
-	}
-	sig, err := lp.Signer.Sign(rand.Reader, serialized, crypto.Hash(0)) // ed25519
-	if err != nil {
-		return nil, fmt.Errorf("ed25519 signature failed: %v", err)
-	}
-	lastSthTimestamp.Set(float64(time.Now().Unix()), lp.id())
-	lastSthSize.Set(float64(th.TreeSize), lp.id())
-	return NewSignedTreeHeadV1(th, lp.LogId, sig), nil
-}