150 lines
4.6 KiB
Go
150 lines
4.6 KiB
Go
package dns
|
|
|
|
import (
|
|
"crypto/dsa"
|
|
"crypto/ecdsa"
|
|
"crypto/elliptic"
|
|
"crypto/rand"
|
|
"crypto/rsa"
|
|
"math/big"
|
|
"strconv"
|
|
)
|
|
|
|
const _FORMAT = "Private-key-format: v1.3\n"
|
|
|
|
// Empty interface that is used as a wrapper around all possible
|
|
// private key implementations from the crypto package.
|
|
type PrivateKey interface{}
|
|
|
|
// 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 (r *RR_DNSKEY) Generate(bits int) (PrivateKey, error) {
|
|
switch r.Algorithm {
|
|
case DSA, DSANSEC3SHA1:
|
|
if bits != 1024 {
|
|
return nil, ErrKeySize
|
|
}
|
|
case RSAMD5, 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
|
|
}
|
|
}
|
|
|
|
switch r.Algorithm {
|
|
case DSA, DSANSEC3SHA1:
|
|
params := new(dsa.Parameters)
|
|
if err := dsa.GenerateParameters(params, rand.Reader, dsa.L1024N160); err != nil {
|
|
return nil, err
|
|
}
|
|
priv := new(dsa.PrivateKey)
|
|
priv.PublicKey.Parameters = *params
|
|
err := dsa.GenerateKey(priv, rand.Reader)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
r.setPublicKeyDSA(params.Q, params.P, params.G, priv.PublicKey.Y)
|
|
return priv, nil
|
|
case RSAMD5, RSASHA1, RSASHA256, RSASHA512, RSASHA1NSEC3SHA1:
|
|
priv, err := rsa.GenerateKey(rand.Reader, bits)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
r.setPublicKeyRSA(priv.PublicKey.E, priv.PublicKey.N)
|
|
return priv, nil
|
|
case ECDSAP256SHA256, ECDSAP384SHA384:
|
|
var c elliptic.Curve
|
|
switch r.Algorithm {
|
|
case ECDSAP256SHA256:
|
|
c = elliptic.P256()
|
|
case ECDSAP384SHA384:
|
|
c = elliptic.P384()
|
|
}
|
|
priv, err := ecdsa.GenerateKey(c, rand.Reader)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
r.setPublicKeyCurve(priv.PublicKey.X, priv.PublicKey.Y)
|
|
return priv, nil
|
|
default:
|
|
return nil, ErrAlg
|
|
}
|
|
return nil, nil // Dummy return
|
|
}
|
|
|
|
// PrivateKeyString converts a PrivateKey to a string. This
|
|
// string has the same format as the private-key-file of BIND9 (Private-key-format: v1.3).
|
|
// It needs some info from the key (hashing, keytag), so its a method of the RR_DNSKEY.
|
|
func (r *RR_DNSKEY) PrivateKeyString(p PrivateKey) (s string) {
|
|
switch t := p.(type) {
|
|
case *rsa.PrivateKey:
|
|
algorithm := strconv.Itoa(int(r.Algorithm)) + " (" + Alg_str[r.Algorithm] + ")"
|
|
modulus := unpackBase64(t.PublicKey.N.Bytes())
|
|
e := big.NewInt(int64(t.PublicKey.E))
|
|
publicExponent := unpackBase64(e.Bytes())
|
|
privateExponent := unpackBase64(t.D.Bytes())
|
|
prime1 := unpackBase64(t.Primes[0].Bytes())
|
|
prime2 := unpackBase64(t.Primes[1].Bytes())
|
|
// Calculate Exponent1/2 and Coefficient as per: http://en.wikipedia.org/wiki/RSA#Using_the_Chinese_remainder_algorithm
|
|
// and from: http://code.google.com/p/go/issues/detail?id=987
|
|
one := big.NewInt(1)
|
|
minusone := big.NewInt(-1)
|
|
p_1 := big.NewInt(0).Sub(t.Primes[0], one)
|
|
q_1 := big.NewInt(0).Sub(t.Primes[1], one)
|
|
exp1 := big.NewInt(0).Mod(t.D, p_1)
|
|
exp2 := big.NewInt(0).Mod(t.D, q_1)
|
|
coeff := big.NewInt(0).Exp(t.Primes[1], minusone, t.Primes[0])
|
|
|
|
exponent1 := unpackBase64(exp1.Bytes())
|
|
exponent2 := unpackBase64(exp2.Bytes())
|
|
coefficient := unpackBase64(coeff.Bytes())
|
|
|
|
s = _FORMAT +
|
|
"Algorithm: " + algorithm + "\n" +
|
|
"Modules: " + modulus + "\n" +
|
|
"PublicExponent: " + publicExponent + "\n" +
|
|
"PrivateExponent: " + privateExponent + "\n" +
|
|
"Prime1: " + prime1 + "\n" +
|
|
"Prime2: " + prime2 + "\n" +
|
|
"Exponent1: " + exponent1 + "\n" +
|
|
"Exponent2: " + exponent2 + "\n" +
|
|
"Coefficient: " + coefficient + "\n"
|
|
case *ecdsa.PrivateKey:
|
|
algorithm := strconv.Itoa(int(r.Algorithm)) + " (" + Alg_str[r.Algorithm] + ")"
|
|
private := unpackBase64(t.D.Bytes())
|
|
s = _FORMAT +
|
|
"Algorithm: " + algorithm + "\n" +
|
|
"PrivateKey: " + private + "\n"
|
|
case *dsa.PrivateKey:
|
|
algorithm := strconv.Itoa(int(r.Algorithm)) + " (" + Alg_str[r.Algorithm] + ")"
|
|
prime := unpackBase64(t.PublicKey.Parameters.P.Bytes())
|
|
subprime := unpackBase64(t.PublicKey.Parameters.Q.Bytes())
|
|
base := unpackBase64(t.PublicKey.Parameters.G.Bytes())
|
|
priv := unpackBase64(t.X.Bytes())
|
|
pub := unpackBase64(t.PublicKey.Y.Bytes())
|
|
s = _FORMAT +
|
|
"Algorithm: " + algorithm + "\n" +
|
|
"Prime(p): " + prime + "\n" +
|
|
"Subprime(q): " + subprime + "\n" +
|
|
"Base(g): " + base + "\n" +
|
|
"Private_value(x): " + priv + "\n" +
|
|
"Public_value(y): " + pub + "\n"
|
|
}
|
|
return
|
|
}
|