open-nomad/vendor/github.com/miekg/dns/dnssec_keygen.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

141 lines
3.1 KiB
Go

package dns
import (
"crypto"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/rsa"
"math/big"
"golang.org/x/crypto/ed25519"
)
// Generate generates a DNSKEY of the given bit size.
// The public part is put inside the DNSKEY record.
// The Algorithm in the key must be set as this will define
// what kind of DNSKEY will be generated.
// The ECDSA algorithms imply a fixed keysize, in that case
// bits should be set to the size of the algorithm.
func (k *DNSKEY) Generate(bits int) (crypto.PrivateKey, error) {
switch k.Algorithm {
case RSAMD5, DSA, DSANSEC3SHA1:
return nil, ErrAlg
case RSASHA1, RSASHA256, RSASHA1NSEC3SHA1:
if bits < 512 || bits > 4096 {
return nil, ErrKeySize
}
case RSASHA512:
if bits < 1024 || bits > 4096 {
return nil, ErrKeySize
}
case ECDSAP256SHA256:
if bits != 256 {
return nil, ErrKeySize
}
case ECDSAP384SHA384:
if bits != 384 {
return nil, ErrKeySize
}
case ED25519:
if bits != 256 {
return nil, ErrKeySize
}
}
switch k.Algorithm {
case RSASHA1, RSASHA256, RSASHA512, RSASHA1NSEC3SHA1:
priv, err := rsa.GenerateKey(rand.Reader, bits)
if err != nil {
return nil, err
}
k.setPublicKeyRSA(priv.PublicKey.E, priv.PublicKey.N)
return priv, nil
case ECDSAP256SHA256, ECDSAP384SHA384:
var c elliptic.Curve
switch k.Algorithm {
case ECDSAP256SHA256:
c = elliptic.P256()
case ECDSAP384SHA384:
c = elliptic.P384()
}
priv, err := ecdsa.GenerateKey(c, rand.Reader)
if err != nil {
return nil, err
}
k.setPublicKeyECDSA(priv.PublicKey.X, priv.PublicKey.Y)
return priv, nil
case ED25519:
pub, priv, err := ed25519.GenerateKey(rand.Reader)
if err != nil {
return nil, err
}
k.setPublicKeyED25519(pub)
return priv, nil
default:
return nil, ErrAlg
}
}
// Set the public key (the value E and N)
func (k *DNSKEY) setPublicKeyRSA(_E int, _N *big.Int) bool {
if _E == 0 || _N == nil {
return false
}
buf := exponentToBuf(_E)
buf = append(buf, _N.Bytes()...)
k.PublicKey = toBase64(buf)
return true
}
// Set the public key for Elliptic Curves
func (k *DNSKEY) setPublicKeyECDSA(_X, _Y *big.Int) bool {
if _X == nil || _Y == nil {
return false
}
var intlen int
switch k.Algorithm {
case ECDSAP256SHA256:
intlen = 32
case ECDSAP384SHA384:
intlen = 48
}
k.PublicKey = toBase64(curveToBuf(_X, _Y, intlen))
return true
}
// Set the public key for Ed25519
func (k *DNSKEY) setPublicKeyED25519(_K ed25519.PublicKey) bool {
if _K == nil {
return false
}
k.PublicKey = toBase64(_K)
return true
}
// Set the public key (the values E and N) for RSA
// RFC 3110: Section 2. RSA Public KEY Resource Records
func exponentToBuf(_E int) []byte {
var buf []byte
i := big.NewInt(int64(_E)).Bytes()
if len(i) < 256 {
buf = make([]byte, 1, 1+len(i))
buf[0] = uint8(len(i))
} else {
buf = make([]byte, 3, 3+len(i))
buf[0] = 0
buf[1] = uint8(len(i) >> 8)
buf[2] = uint8(len(i))
}
buf = append(buf, i...)
return buf
}
// Set the public key for X and Y for Curve. The two
// values are just concatenated.
func curveToBuf(_X, _Y *big.Int, intlen int) []byte {
buf := intToBytes(_X, intlen)
buf = append(buf, intToBytes(_Y, intlen)...)
return buf
}