/*
* Create an instance over the provided ASN.1 element. If
* 'checkTag' is true, then the outer tag will be checked to
* match the universal tag for SEQUENCE. Set 'checkTag' to
* false if the tag was already checked, or if it has been
* overwritten with an implicit tag.
*/
internal AlgorithmIdentifier(AsnElt ai, bool checkTag)
{
if (checkTag)
{
ai.CheckTag(AsnElt.SEQUENCE);
}
ai.CheckNumSubMin(1);
ai.CheckNumSubMax(2);
AsnElt ao = ai.GetSub(0);
ao.CheckTag(AsnElt.OBJECT_IDENTIFIER);
oid = ao.GetOID();
if (ai.Sub.Length >= 2)
{
parameters = ai.GetSub(1);
}
else
{
parameters = null;
}
}
static RSAPrivateKey DecodePrivateKeyRSA(AsnElt ak)
{
ak.CheckNumSubMin(9);
ak.GetSub(0).CheckTag(AsnElt.INTEGER);
long kt = ak.GetSub(0).GetInteger();
if (kt != 0)
{
throw new AsnException(
"Unsupported RSA key type: " + kt);
}
ak.CheckNumSub(9);
return(new RSAPrivateKey(
GetPositiveInteger(ak.GetSub(1)),
GetPositiveInteger(ak.GetSub(2)),
GetPositiveInteger(ak.GetSub(3)),
GetPositiveInteger(ak.GetSub(4)),
GetPositiveInteger(ak.GetSub(5)),
GetPositiveInteger(ak.GetSub(6)),
GetPositiveInteger(ak.GetSub(7)),
GetPositiveInteger(ak.GetSub(8))));
}
/*
* Create an instance by decoding the provided object.
* This constructor assumes ASN.1 DER encoding (not Base64,
* not PEM).
*
* On decoding error, an AsnException is thrown.
*/
public X509Cert(byte[] cert)
{
/*
* Compute thumbprint.
*/
thumbprint = M.DoSHA1(cert).ToUpperInvariant();
/*
* Outer layer decoding and extraction of the signature
* hash algorithm.
*/
AsnElt ac = AsnElt.Decode(cert);
ac.CheckTag(AsnElt.SEQUENCE);
ac.CheckNumSub(3);
hashAlgorithm = GetSignHashName(
new AlgorithmIdentifier(ac.GetSub(1)));
/*
* TBS exploration. First field is optional; if present,
* it contains the certificate version.
*/
AsnElt atbs = ac.GetSub(0);
atbs.CheckNumSubMin(6);
atbs.CheckNumSubMax(10);
int off = 0;
if (atbs.GetSub(0).TagValue == 0)
{
off++;
}
/*
* Serial numer: nominally an INTEGER, we extract the
* raw bytes, because some CA wrongly use unsigned
* encoding.
*/
AsnElt aserial = atbs.GetSub(off);
aserial.CheckTag(AsnElt.INTEGER);
byte[] sv = aserial.CopyValue();
int svk = 0;
while (svk < sv.Length && sv[svk] == 0)
{
svk++;
}
if (svk == sv.Length)
{
serialHex = "00";
}
else
{
StringBuilder sb = new StringBuilder();
while (svk < sv.Length)
{
sb.AppendFormat("{0:X2}", sv[svk++]);
}
serialHex = sb.ToString();
}
/*
* Issuer and subject DN.
*/
issuerDN = new X500Name(atbs.GetSub(off + 2));
subjectDN = new X500Name(atbs.GetSub(off + 4));
/*
* Validity dates.
*/
AsnElt adates = atbs.GetSub(off + 3);
adates.CheckTag(AsnElt.SEQUENCE);
adates.CheckNumSub(2);
validFrom = adates.GetSub(0).GetTime();
validTo = adates.GetSub(1).GetTime();
/*
* Public key.
*/
AsnElt aspki = atbs.GetSub(off + 5);
aspki.CheckTag(AsnElt.SEQUENCE);
aspki.CheckNumSub(2);
AlgorithmIdentifier kt =
new AlgorithmIdentifier(aspki.GetSub(0));
AsnElt aktp = kt.Parameters;
AsnElt apkv = aspki.GetSub(1);
apkv.CheckTag(AsnElt.BIT_STRING);
byte[] kv = apkv.GetBitString();
curveOID = null;
keyType = "UNKNOWN";
keySize = 0;
switch (kt.OID)
{
/*
* RSA public keys should use the 'rsaEncryption' OID,
* but some are tagged with the OAEP or the PSS OID,
* to somehow specify that the RSA key should be used
* only with OAEP or PSS.
*/
case "1.2.840.113549.1.1.1":
case "1.2.840.113549.1.1.7":
case "1.2.840.113549.1.1.10":
keyType = "RSA";
keySize = GetRSAPublicKeySize(kv);
break;
/*
* All DSA public keys should use that OID.
*/
case "1.2.840.10040.4.1":
keyType = "DSA";
keySize = GetDSAPublicKeySize(aktp);
break;
/*
* Elliptic curve keys.
* We only support "normal" elliptic curve keys, not
* restricted keys.
* We only supported named curves (RFC 5480 forbids
* explicit curve parameters).
*/
case "1.2.840.10045.2.1":
if (aktp == null)
{
break;
}
if (aktp.TagClass != AsnElt.UNIVERSAL ||
aktp.TagValue != AsnElt.OBJECT_IDENTIFIER)
{
break;
}
keyType = "EC";
curveOID = aktp.GetOID();
keySize = GetCurveSize(curveOID);
break;
/* TODO: GOST R 34.10-94 and GOST R 34.10-2001 */
}
/*
* If there are extensions, process them.
* extract the dNSNames.
*/
serverNames = null;
extensions = new SortedDictionary <string, Extension>(
StringComparer.Ordinal);
for (int i = off + 6; i < atbs.Sub.Length; i++)
{
AsnElt aexts = atbs.GetSub(i);
if (aexts.TagClass != AsnElt.CONTEXT ||
aexts.TagValue != 3)
{
continue;
}
aexts.CheckNumSub(1);
aexts = aexts.GetSub(0);
aexts.CheckTag(AsnElt.SEQUENCE);
foreach (AsnElt aext in aexts.Sub)
{
aext.CheckTag(AsnElt.SEQUENCE);
aext.CheckNumSubMin(2);
aext.CheckNumSubMax(3);
AsnElt aoid = aext.GetSub(0);
aoid.CheckTag(AsnElt.OBJECT_IDENTIFIER);
string oid = aoid.GetOID();
AsnElt av;
bool critical = false;
if (aext.Sub.Length == 2)
{
av = aext.GetSub(1);
}
else
{
AsnElt acrit = aext.GetSub(1);
acrit.CheckTag(AsnElt.BOOLEAN);
critical = acrit.GetBoolean();
av = aext.GetSub(2);
}
av.CheckTag(AsnElt.OCTET_STRING);
Extension ext = new Extension(
oid, critical, av.CopyValue());
if (extensions.ContainsKey(oid))
{
throw new AsnException(
"duplicate extension " + oid);
}
extensions[oid] = ext;
ProcessExtension(ext);
}
}
/*
* If there was no SAN, or no dNSName in the SAN, then
* get the Common Name from the subjectDN.
*/
string cn = null;
foreach (DNPart dnp in subjectDN.Parts)
{
if (dnp.FriendlyType == DNPart.COMMON_NAME)
{
if (cn != null)
{
throw new AsnException(
"multiple CN in subject DN");
}
cn = dnp.Value;
}
}
if (serverNames == null)
{
if (cn == null)
{
serverNames = new string[0];
}
else
{
serverNames = new string[] { cn };
}
}
}
static ECPrivateKey DecodePrivateKeyEC(AsnElt ak, ECCurve curve)
{
ak.CheckNumSubMin(2);
ak.GetSub(0).CheckTag(AsnElt.INTEGER);
ak.GetSub(1).CheckTag(AsnElt.OCTET_STRING);
long kt = ak.GetSub(0).GetInteger();
if (kt != 1)
{
throw new AsnException(
"Unsupported EC key type: " + kt);
}
byte[] x = ak.GetSub(1).CopyValue();
byte[] pub = null;
int n = ak.Sub.Length;
int p = 2;
if (p < n)
{
AsnElt acc = ak.GetSub(p);
if (acc.TagClass == AsnElt.CONTEXT &&
acc.TagValue == 0)
{
acc.CheckNumSub(1);
acc = acc.GetSub(0);
ECCurve curve2 = DecodeCurve(acc);
/*
* Here, we support only named curves.
*/
/* obsolete
*/
if (curve == null)
{
curve = curve2;
}
else if (!curve.Equals(curve2))
{
throw new AsnException(string.Format(
"Inconsistent curve"
+ " specification ({0} / {1})",
curve.Name, curve2.Name));
}
p++;
}
}
if (p < n)
{
AsnElt acc = ak.GetSub(p);
if (acc.TagClass == AsnElt.CONTEXT &&
acc.TagValue == 1)
{
acc.CheckNumSub(1);
acc = acc.GetSub(0);
acc.CheckTag(AsnElt.BIT_STRING);
pub = acc.GetBitString();
}
}
if (curve == null)
{
throw new AsnException("No curve specified for EC key");
}
ECPrivateKey esk = new ECPrivateKey(curve, x);
if (pub != null)
{
ECPublicKey epk = new ECPublicKey(curve, pub);
if (!epk.Equals(esk.PublicKey))
{
throw new CryptoException(
"EC key pair public/private mismatch");
}
}
return(esk);
}
