Refactored into namespaced packages.

keys/keys.go

@@ -0,0 +1,34 @@
+package keys
+
+import (
+	"encoding/hex"
+	"git.wisehodl.dev/jay/go-roots/errors"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4"
+)
+
+// GeneratePrivateKey generates a new, random secp256k1 private key and returns
+// it as a 64-character, lowercase hexadecimal string.
+func GeneratePrivateKey() (string, error) {
+	sk, err := secp256k1.GeneratePrivateKey()
+	if err != nil {
+		return "", err
+	}
+	skBytes := sk.Serialize()
+	return hex.EncodeToString(skBytes), nil
+}
+
+// GetPublicKey derives the public key from a private key hex string
+// and returns the x-coordinate as 64 lowercase hex characters.
+func GetPublicKey(privateKeyHex string) (string, error) {
+	if len(privateKeyHex) != 64 {
+		return "", errors.MalformedPrivKey
+	}
+	skBytes, err := hex.DecodeString(privateKeyHex)
+	if err != nil {
+		return "", errors.MalformedPrivKey
+	}
+
+	pk := secp256k1.PrivKeyFromBytes(skBytes).PubKey()
+	pkBytes := pk.SerializeCompressed()[1:]
+	return hex.EncodeToString(pkBytes), nil
+}