/// <summary>
/// Упаковка открытого ключа ГОСТ 34.10-2012 512 и его параметров в Asn1c структуру.
/// </summary>
///
/// <param name="pub">Открытый ключ.</param>
///
/// <returns>Asn1c структура <c>SubjectPublicKeyInfo</c> открытого
/// ключа.</returns>
private static SubjectPublicKeyInfo PackPublicKeyInfo2012_512(
Gost3410CspObject pub)
{
SubjectPublicKeyInfo spki = new SubjectPublicKeyInfo();
Asn1BerEncodeBuffer buffer = new Asn1BerEncodeBuffer();
Asn1OctetString publicKey = new Asn1OctetString(pub._publicKey);
publicKey.Encode(buffer);
byte[] octetString = buffer.MsgCopy;
spki.subjectPublicKey = new Asn1BitString(
octetString.Length * 8, octetString);
GostR3410_2012_PublicKeyParameters par =
new GostR3410_2012_PublicKeyParameters();
par.publicKeyParamSet = fromString(pub._publicKeyParamSet);
par.digestParamSet = fromString(pub._digestParamSet);
par.encryptionParamSet = CreateGost28147_89_ParamSet(
pub._encryptionParamSet);
buffer.Reset();
par.Encode(buffer);
spki.algorithm = new AlgorithmIdentifier(
fromString(GostConstants.OID_CP_GOST_R3410_12_512),
new Asn1OpenType(buffer.MsgCopy));
return(spki);
}
/// <summary>
/// Кодирование Public ключа ГОСТ 34.10 в BLOB для импорта.
/// </summary>
///
/// <param name="cspObject">Открытый ключ с параметрами.</param>
/// <param name="alg">Тип алгоритма</param>
///
/// <returns>BLOB для импорта.</returns>
///
/// <exception cref="CryptographicException">При ошибках
/// кодирования структуры.</exception>
/// <argnull name="cspObject" />
///
/// <intdoc><para>Аналог в MS отсутствует, часть реализации
/// присутствует в ImportKey. У нас функция используется еще
/// и при разборе открытого клуча в обходе
/// CryptoPro.Sharpei.NetDetours.CPPublicKey.</para></intdoc>
///
/// <unmanagedperm action="LinkDemand" />
internal static byte[] EncodePublicBlob(Gost3410CspObject cspObject, CspAlgorithmType alg)
{
int keySize;
int algId;
switch (alg)
{
case CspAlgorithmType.PROV_GOST_2001_DH:
keySize = GostConstants.GOST_3410EL_SIZE;
algId = GostConstants.CALG_GR3410EL;
break;
case CspAlgorithmType.PROV_GOST_2012_256:
keySize = GostConstants.GOST3410_2012_256KEY_SIZE;
algId = GostConstants.CALG_GR3410_2012_256;
break;
case CspAlgorithmType.PROV_GOST_2012_512:
keySize = GostConstants.GOST3410_2012_512KEY_SIZE;
algId = GostConstants.CALG_GR3410_2012_512;
break;
default:
throw new CryptographicException(SR.Cryptography_CSP_WrongKeySpec);
}
if (cspObject == null)
{
throw new ArgumentNullException("cspObject");
}
byte[] encodedParameters = cspObject.EncodeParameters();
byte[] data = new byte[16 + encodedParameters.Length
+ cspObject._publicKey.Length];
data[0] = GostConstants.PUBLICKEYBLOB;
data[1] = GostConstants.CSP_CUR_BLOB_VERSION;
byte[] algid = BitConverter.GetBytes(algId);
Array.Copy(algid, 0, data, 4, 4);
byte[] magic = BitConverter.GetBytes(GostConstants.GR3410_1_MAGIC);
Array.Copy(magic, 0, data, 8, 4);
byte[] bitlen = BitConverter.GetBytes(keySize);
Array.Copy(bitlen, 0, data, 12, 4);
Array.Copy(encodedParameters, 0, data, 16,
encodedParameters.Length);
Array.Copy(cspObject._publicKey, 0, data,
16 + encodedParameters.Length,
cspObject._publicKey.Length);
return(data);
}
/// <summary>
/// Упаковка открытого ключа ГОСТ 34.10 и его параметров в Asn1c структуру.
/// </summary>
///
/// <param name="pub">Открытый ключ.</param>
/// <param name="alg"></param>
///
/// <returns>Asn1c структура <c>SubjectPublicKeyInfo</c> открытого
/// ключа.</returns>
///
private static SubjectPublicKeyInfo PackPublicKeyInfo(
Gost3410CspObject pub, CspAlgorithmType alg)
{
switch (alg)
{
case CspAlgorithmType.Gost2001:
return(PackPublicKeyInfo2001(pub));
case CspAlgorithmType.Gost2012_256:
return(PackPublicKeyInfo2012_256(pub));
case CspAlgorithmType.Gost2012_512:
return(PackPublicKeyInfo2012_512(pub));
default:
throw new CryptographicException(
"Cryptography_CSP_WrongKeySpec");
}
}
/// <summary>
/// Разбор декодированной ASN1c структуры ГОСТ 34.10-2012 <c>SubjectPublicKeyInfo</c>.
/// </summary>
///
/// <param name="spki">ASN1c структура <c>SubjectPublicKeyInfo</c>.
/// </param>
///
/// <returns>Параметры открытого ключа.</returns>
/// <argnull name="spki" />
/// <exception cref="ArgumentException">Если вложенная структура
/// не приводится к <c>GostR3410_2001_PublicKeyParameters</c>
/// </exception>
private static Gost3410CspObject UnpackPublicKeyInfo2012(
SubjectPublicKeyInfo spki)
{
if (spki == null)
{
throw new ArgumentNullException("spki");
}
Asn1Choice choice = spki.algorithm.parameters as Asn1Choice;
if (choice == null)
{
throw new ArgumentException(
"spki.algorithm.parameters");
}
GostR3410_2012_PublicKeyParameters publicKeyParameters =
choice.GetElement() as GostR3410_2012_PublicKeyParameters;
if (publicKeyParameters == null)
{
throw new ArgumentException(
"spki.algorithm.parameters.element");
}
byte[] bitString = spki.subjectPublicKey.Value;
Asn1BerDecodeBuffer buffer = new Asn1BerDecodeBuffer(bitString);
Asn1OctetString publicKey = new Asn1OctetString();
publicKey.Decode(buffer);
Gost3410CspObject ret = new Gost3410CspObject();
ret._publicKeyParamSet = toString(
publicKeyParameters.publicKeyParamSet);
ret._digestParamSet = toString(
publicKeyParameters.digestParamSet);
ret._encryptionParamSet = toString(
publicKeyParameters.encryptionParamSet);
ret._publicKey = publicKey.Value;
ret._privateKey = null;
return(ret);
}
/// <summary>
/// Разбор BLOB открытого ключа ГОСТ 34.10.
/// </summary>
///
/// <param name="obj">Gost3410CspObject</param>
/// <param name="data">BLOB</param>
/// <param name="alg">Тип алгоритма</param>
///
/// <argnull name="obj" />
/// <exception cref="CryptographicException">Если
/// <paramref name="obj"/> не объект типа
/// <see cref="Gost3410CspObject"/></exception>
///
/// <intdoc><para>Аналог в MS отсутствует, часть реализации
/// присутствует в ImportKey. </para></intdoc>
///
/// <unmanagedperm action="LinkDemand" />
internal static void DecodePublicBlob(Object obj, byte[] data, CspAlgorithmType alg)
{
int keySize;
switch (alg)
{
case CspAlgorithmType.PROV_GOST_2001_DH:
keySize = GostConstants.GOST_3410EL_SIZE;
break;
case CspAlgorithmType.PROV_GOST_2012_256:
keySize = GostConstants.GOST3410_2012_256KEY_SIZE;
break;
case CspAlgorithmType.PROV_GOST_2012_512:
keySize = GostConstants.GOST3410_2012_512KEY_SIZE;
break;
default:
throw new CryptographicException(SR.Cryptography_CSP_WrongKeySpec);
}
if (obj == null)
{
throw new ArgumentNullException("obj");
}
Gost3410CspObject cspObject = obj as Gost3410CspObject;
if (cspObject == null)
{
throw new CryptographicException(GostConstants.NTE_BAD_ALGID);
}
if (data.Length < 16 + keySize / 8)
{
throw new CryptographicException(GostConstants.NTE_BAD_DATA);
}
// CRYPT_PUBKEYPARAM -> 8 { Magic, BitLen )
uint magic = BitConverter.ToUInt32(data, 8);
uint bitlen = BitConverter.ToUInt32(data, 12);
if (magic != GostConstants.GR3410_1_MAGIC)
{
throw new CryptographicException(GostConstants.NTE_BAD_DATA);
}
if (bitlen != keySize)
{
throw new CryptographicException(GostConstants.NTE_BAD_DATA);
}
byte[] tmp = new byte[data.Length - 16 - keySize / 8];
Array.Copy(data, 16, tmp, 0, data.Length - 16 - keySize / 8);
var publicKeyParameters = new GostKeyExchangeParameters();
var encodeKeyParameters = new byte[(data.Length - 16) - keySize / 8];
Array.Copy(data, 16, encodeKeyParameters, 0, (data.Length - 16) - keySize / 8);
publicKeyParameters.DecodeParameters(encodeKeyParameters);
var publicKey = new byte[keySize / 8];
Array.Copy(data, data.Length - keySize / 8, publicKey, 0, keySize / 8);
publicKeyParameters.PublicKey = publicKey;
cspObject._publicKey = publicKeyParameters.PublicKey;
cspObject._publicKeyParamSet = publicKeyParameters.PublicKeyParamSet;
cspObject._digestParamSet = publicKeyParameters.DigestParamSet;
}