diff options
| -rw-r--r-- | ecdsa.go | 27 |
1 files changed, 17 insertions, 10 deletions
@@ -12,9 +12,8 @@ import ( "math/big" ) -const ( - PemLabelEcdsa = "EC PRIVATE KEY" -) +// This label is used as the type in the pem encoding of ECDSA private keys. +const PemLabelEcdsa = "EC PRIVATE KEY" type ( // This type handles the function calls to the ecdsa private key by @@ -23,16 +22,20 @@ type ( private_key *ecdsa.PrivateKey } + // EcdsaPublicKey is the specific public key type for ecdsa. It implements the + // the PublicKey interface. EcdsaPublicKey struct { public_key *ecdsa.PublicKey } + // This struct is used to marshal and parse the ecdsa signature. signatureEcdsa struct { R, S *big.Int } ) // Create a new ECDSA private key using the specified curve. +// For available curves, please take a look at the crypto/elliptic package. func NewPrivateKeyEcdsa(curve elliptic.Curve) (*EcdsaPrivateKey, error) { key, err := ecdsa.GenerateKey(curve, rand.Reader) if err != nil { return nil, err } @@ -46,12 +49,12 @@ func LoadPrivateKeyEcdsa(raw []byte) (*EcdsaPrivateKey, error) { return &EcdsaPrivateKey{key}, nil } -// derive a public key from the private key +// Create a new public key from the private key. func (pr EcdsaPrivateKey) Public() PublicKey { return &EcdsaPublicKey{pr.private_key.Public().(*ecdsa.PublicKey)} } -// sign a message with the private key +// Sign a message using the private key and the provided hash function. func (pr EcdsaPrivateKey) Sign(message []byte, hash crypto.Hash) ([]byte, error) { empty := make([]byte, 0) if !hash.Available() { @@ -62,12 +65,13 @@ func (pr EcdsaPrivateKey) Sign(message []byte, hash crypto.Hash) ([]byte, error) return pr.private_key.Sign(rand.Reader, hashed_message.Sum(nil), hash) } -// get the private key +// This function returns the crypto.PrivateKey structure of the ECDSA key. func (pr EcdsaPrivateKey) PrivateKey() crypto.PrivateKey { return pr.private_key } -// implement Pemmer interface +// This function implements the Pemmer interface to marshal the private key +// into a pem block. func (pr EcdsaPrivateKey) MarshalPem() (marshalledPemBlock, error) { asn1, err := x509.MarshalECPrivateKey(pr.private_key) if err != nil { return nil, err } @@ -75,7 +79,7 @@ func (pr EcdsaPrivateKey) MarshalPem() (marshalledPemBlock, error) { return pem.EncodeToMemory(&pem_block), nil } -// load an ecdsa public key +// This functoin loads an ecdsa public key from the asn.1 representation. func LoadPublicKeyEcdsa(raw []byte) (*EcdsaPublicKey, error) { raw_pub, err := x509.ParsePKIXPublicKey(raw) if err != nil { return nil, err } @@ -85,7 +89,8 @@ func LoadPublicKeyEcdsa(raw []byte) (*EcdsaPublicKey, error) { return &EcdsaPublicKey{pub}, nil } -// marshal the public key to a pem block +// This function implements the Pemmer interface to marshal the public key into +// a pem block. func (pu *EcdsaPublicKey) MarshalPem() (marshalledPemBlock, error) { asn1, err := x509.MarshalPKIXPublicKey(pu.public_key) if err != nil { return nil, err } @@ -93,7 +98,9 @@ func (pu *EcdsaPublicKey) MarshalPem() (marshalledPemBlock, error) { return pem.EncodeToMemory(&pem_block), nil } -// verify a message using the ecdsa public key +// This function verifies a message using the public key, signature and hash +// function. +// The hash function must be the same as was used to create the signature. func (pu *EcdsaPublicKey) Verify(message []byte, signature_raw []byte, hash crypto.Hash) (bool, error) { var sig signatureEcdsa _, err := asn1.Unmarshal(signature_raw, &sig) |