dns/dnssec_privkey.go

86 lines
2.7 KiB
Go

package dns
import (
"crypto"
"crypto/dsa"
"crypto/ecdsa"
"crypto/rsa"
"math/big"
"strconv"
)
const format = "Private-key-format: v1.3\n"
// 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 (the algorithm), so its a method of the DNSKEY
// It supports rsa.PrivateKey, ecdsa.PrivateKey and dsa.PrivateKey
func (r *DNSKEY) PrivateKeyString(p crypto.PrivateKey) string {
algorithm := strconv.Itoa(int(r.Algorithm))
algorithm += " (" + AlgorithmToString[r.Algorithm] + ")"
switch p := p.(type) {
case *rsa.PrivateKey:
modulus := toBase64(p.PublicKey.N.Bytes())
e := big.NewInt(int64(p.PublicKey.E))
publicExponent := toBase64(e.Bytes())
privateExponent := toBase64(p.D.Bytes())
prime1 := toBase64(p.Primes[0].Bytes())
prime2 := toBase64(p.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)
p1 := big.NewInt(0).Sub(p.Primes[0], one)
q1 := big.NewInt(0).Sub(p.Primes[1], one)
exp1 := big.NewInt(0).Mod(p.D, p1)
exp2 := big.NewInt(0).Mod(p.D, q1)
coeff := big.NewInt(0).ModInverse(p.Primes[1], p.Primes[0])
exponent1 := toBase64(exp1.Bytes())
exponent2 := toBase64(exp2.Bytes())
coefficient := toBase64(coeff.Bytes())
return format +
"Algorithm: " + algorithm + "\n" +
"Modulus: " + 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:
var intlen int
switch r.Algorithm {
case ECDSAP256SHA256:
intlen = 32
case ECDSAP384SHA384:
intlen = 48
}
private := toBase64(intToBytes(p.D, intlen))
return format +
"Algorithm: " + algorithm + "\n" +
"PrivateKey: " + private + "\n"
case *dsa.PrivateKey:
T := divRoundUp(divRoundUp(p.PublicKey.Parameters.G.BitLen(), 8)-64, 8)
prime := toBase64(intToBytes(p.PublicKey.Parameters.P, 64+T*8))
subprime := toBase64(intToBytes(p.PublicKey.Parameters.Q, 20))
base := toBase64(intToBytes(p.PublicKey.Parameters.G, 64+T*8))
priv := toBase64(intToBytes(p.X, 20))
pub := toBase64(intToBytes(p.PublicKey.Y, 64+T*8))
return 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"
default:
return ""
}
}