package frostfsecdsa import ( "crypto/ecdsa" "crypto/elliptic" "crypto/rand" "crypto/sha512" frostfscrypto "github.com/TrueCloudLab/frostfs-sdk-go/crypto" "github.com/nspcc-dev/neo-go/pkg/crypto/keys" ) // Signer wraps ecdsa.PrivateKey and represents signer based on ECDSA with // SHA-512 hashing. Provides frostfscrypto.Signer interface. // // Instances MUST be initialized from ecdsa.PrivateKey using type conversion. type Signer ecdsa.PrivateKey // Scheme returns frostfscrypto.ECDSA_SHA512. // Implements frostfscrypto.Signer. func (x Signer) Scheme() frostfscrypto.Scheme { return frostfscrypto.ECDSA_SHA512 } // Sign signs data using ECDSA algorithm with SHA-512 hashing. // Implements frostfscrypto.Signer. func (x Signer) Sign(data []byte) ([]byte, error) { h := sha512.Sum512(data) r, s, err := ecdsa.Sign(rand.Reader, (*ecdsa.PrivateKey)(&x), h[:]) if err != nil { return nil, err } params := elliptic.P256().Params() curveOrderByteSize := params.P.BitLen() / 8 buf := make([]byte, 1+curveOrderByteSize*2) buf[0] = 4 _ = r.FillBytes(buf[1 : 1+curveOrderByteSize]) _ = s.FillBytes(buf[1+curveOrderByteSize:]) return buf, nil } // Public initializes PublicKey and returns it as frostfscrypto.PublicKey. // Implements frostfscrypto.Signer. func (x Signer) Public() frostfscrypto.PublicKey { return (*PublicKey)(&x.PublicKey) } // SignerRFC6979 wraps ecdsa.PrivateKey and represents signer based on deterministic // ECDSA with SHA-256 hashing (RFC 6979). Provides frostfscrypto.Signer interface. // // Instances SHOULD be initialized from ecdsa.PrivateKey using type conversion. type SignerRFC6979 ecdsa.PrivateKey // Scheme returns frostfscrypto.ECDSA_DETERMINISTIC_SHA256. // Implements frostfscrypto.Signer. func (x SignerRFC6979) Scheme() frostfscrypto.Scheme { return frostfscrypto.ECDSA_DETERMINISTIC_SHA256 } // Sign signs data using deterministic ECDSA algorithm with SHA-256 hashing. // Implements frostfscrypto.Signer. // // See also RFC 6979. func (x SignerRFC6979) Sign(data []byte) ([]byte, error) { p := keys.PrivateKey{PrivateKey: (ecdsa.PrivateKey)(x)} return p.Sign(data), nil } // Public initializes PublicKeyRFC6979 and returns it as frostfscrypto.PublicKey. // Implements frostfscrypto.Signer. func (x SignerRFC6979) Public() frostfscrypto.PublicKey { return (*PublicKeyRFC6979)(&x.PublicKey) }