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Add initial x509 code.

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R=rsc
APPROVED=rsc
DELTA=659  (659 added, 0 deleted, 0 changed)
OCL=35932
CL=35975
This commit is contained in:
Adam Langley 2009-10-21 17:53:50 -07:00
parent d7ad3c4e86
commit fd74a835bc
9 changed files with 659 additions and 0 deletions
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37
src/pkg/crypto/rsa/rsa.go
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@ -97,6 +97,43 @@ type PrivateKey struct {
P, Q *big.Int; // prime factors of N
}
// Validate performs basic sanity checks on the key.
// It returns nil if the key is valid, or else an os.Error describing a problem.
func (priv PrivateKey) Validate() os.Error {
// Check that p and q are prime.
if !priv.P.ProbablyPrime(20) {
return os.ErrorString("P is composite");
}
if !priv.Q.ProbablyPrime(20) {
return os.ErrorString("Q is composite");
}
// Check that p*q == n.
modulus := new(big.Int).Mul(priv.P, priv.Q);
if big.CmpInt(modulus, priv.N) != 0 {
return os.ErrorString("invalid modulus");
}
// Check that e and totient(p, q) are coprime.
pminus1 := new(big.Int).Sub(priv.P, bigOne);
qminus1 := new(big.Int).Sub(priv.Q, bigOne);
totient := new(big.Int).Mul(pminus1, qminus1);
e := big.NewInt(int64(priv.E));
gcd := new(big.Int);
x := new(big.Int);
y := new(big.Int);
big.GcdInt(gcd, x, y, totient, e);
if big.CmpInt(gcd, bigOne) != 0 {
return os.ErrorString("invalid public exponent E");
}
// Check that de ≡ 1 (mod totient(p, q))
de := new(big.Int).Mul(priv.D, e);
de.Mod(de, totient);
if big.CmpInt(de, bigOne) != 0 {
return os.ErrorString("invalid private exponent D");
}
return nil;
}
// GenerateKeyPair generates an RSA keypair of the given bit size.
func GenerateKey(rand io.Reader, bits int) (priv *PrivateKey, err os.Error) {
priv = new(PrivateKey);