public static SDPSecurityDescription CreateNew(uint tag = 1, CryptoSuites cryptoSuite = CryptoSuites.AES_CM_128_HMAC_SHA1_80)
{
SDPSecurityDescription secdesc = new SDPSecurityDescription(tag, cryptoSuite);
secdesc.KeyParams.Add(KeyParameter.CreateNew(cryptoSuite));
return(secdesc);
}
public static bool TryParse(string keyParamString, out KeyParameter keyParam,
CryptoSuites cryptoSuite = CryptoSuites.AES_CM_128_HMAC_SHA1_80)
{
keyParam = null;
if (!string.IsNullOrWhiteSpace(keyParamString))
{
string p = keyParamString.Trim();
try
{
if (p.StartsWith(KEY_METHOD))
{
string sKeyMethod = KEY_METHOD;
int poscln = p.IndexOf(COLON);
if (poscln == sKeyMethod.Length)
{
string sKeyInfo = p.Substring(poscln + 1);
if (!sKeyInfo.Contains(";"))
{
checkValidKeyInfoCharacters(keyParamString, sKeyInfo);
string sMkiVal, sMkiLen, sLifeTime, sBase64KeySalt;
parseKeyInfo(keyParamString, sKeyInfo, out sMkiVal, out sMkiLen, out sLifeTime,
out sBase64KeySalt);
if (!string.IsNullOrWhiteSpace(sBase64KeySalt))
{
byte[] bKey, bSalt;
parseKeySaltBase64(cryptoSuite, sBase64KeySalt, out bKey, out bSalt);
keyParam = new KeyParameter(bKey, bSalt);
if (!string.IsNullOrWhiteSpace(sMkiVal) && !string.IsNullOrWhiteSpace(sMkiLen))
{
keyParam.MkiValue = uint.Parse(sMkiVal);
keyParam.MkiLength = uint.Parse(sMkiLen);
}
if (!string.IsNullOrWhiteSpace(sLifeTime))
{
if (sLifeTime.Contains('^'))
{
keyParam.LifeTimeString = sLifeTime;
}
else
{
keyParam.LifeTime = uint.Parse(sLifeTime);
}
}
}
}
}
}
}
catch
{
//catch all errors and throw own FormatException
}
}
return(false);
}
public SDPSecurityDescription(uint tag, CryptoSuites cryptoSuite)
{
this.Tag = tag;
this.CryptoSuite = cryptoSuite;
this.KeyParams = new List <KeyParameter>();
}
public static SessionParameter Parse(string sessionParam,
CryptoSuites cryptoSuite = CryptoSuites.AES_CM_128_HMAC_SHA1_80)
{
if (string.IsNullOrWhiteSpace(sessionParam))
{
return(null);
}
string p = sessionParam.Trim();
try
{
SessionParameter.SrtpSessionParams paramType = SrtpSessionParams.unknown;
if (p.StartsWith(KDR_PREFIX))
{
string sKdr = p.Substring(KDR_PREFIX.Length);
uint kdr = 0;
if (uint.TryParse(sKdr, out kdr))
{
return(new SessionParameter(SrtpSessionParams.kdr)
{
Kdr = kdr
});
}
}
else if (p.StartsWith(WSH_PREFIX))
{
string sWsh = p.Substring(WSH_PREFIX.Length);
uint wsh = 0;
if (uint.TryParse(sWsh, out wsh))
{
return(new SessionParameter(SrtpSessionParams.wsh)
{
Wsh = wsh
});
}
}
else if (p.StartsWith(FEC_KEY_PREFIX))
{
string sFecKey = p.Substring(FEC_KEY_PREFIX.Length);
KeyParameter fecKey = KeyParameter.Parse(sFecKey, cryptoSuite);
return(new SessionParameter(SrtpSessionParams.fec_key)
{
FecKey = fecKey
});
}
else if (p.StartsWith(FEC_ORDER_PREFIX))
{
string sFecOrder = p.Substring(FEC_ORDER_PREFIX.Length);
SessionParameter.FecTypes fecOrder =
(from e in Enum.GetNames(typeof(FecTypes))
where e.CompareTo(sFecOrder) == 0
select(FecTypes) Enum.Parse(typeof(FecTypes), e)).FirstOrDefault();
if (fecOrder == FecTypes.unknown)
{
throw new FormatException(
$"sessionParam '{sessionParam}' is not recognized as a valid SRTP_SESSION_PARAM ");
}
return(new SessionParameter(SrtpSessionParams.fec_order)
{
FecOrder = fecOrder
});
}
else
{
paramType = (from e in Enum.GetNames(typeof(SrtpSessionParams))
where e.CompareTo(p) == 0
select(SrtpSessionParams) Enum.Parse(typeof(SrtpSessionParams), e)).FirstOrDefault();
if (paramType == SrtpSessionParams.unknown)
{
throw new FormatException(
$"sessionParam '{sessionParam}' is not recognized as a valid SRTP_SESSION_PARAM ");
}
switch (paramType)
{
case SrtpSessionParams.UNAUTHENTICATED_SRTP:
case SrtpSessionParams.UNENCRYPTED_SRTCP:
case SrtpSessionParams.UNENCRYPTED_SRTP:
return(new SessionParameter(paramType));
}
}
}
catch
{
//catch all errors and throw own FormatException
}
throw new FormatException(
$"sessionParam '{sessionParam}' is not recognized as a valid SRTP_SESSION_PARAM ");
}
public static KeyParameter CreateNew(CryptoSuites cryptoSuite, string key = null, string salt = null)
{
switch (cryptoSuite)
{
case CryptoSuites.AES_CM_128_HMAC_SHA1_32:
case CryptoSuites.AES_CM_128_HMAC_SHA1_80:
case CryptoSuites.F8_128_HMAC_SHA1_80:
if (string.IsNullOrWhiteSpace(key))
{
key = Sys.Crypto.GetRandomString(128 / 8);
}
if (string.IsNullOrWhiteSpace(salt))
{
salt = Sys.Crypto.GetRandomString(112 / 8);
}
return(new KeyParameter(key, salt));
case CryptoSuites.AES_192_CM_HMAC_SHA1_80:
case CryptoSuites.AES_192_CM_HMAC_SHA1_32:
case CryptoSuites.AES_CM_192_HMAC_SHA1_80:
case CryptoSuites.AES_CM_192_HMAC_SHA1_32:
if (string.IsNullOrWhiteSpace(key))
{
key = Sys.Crypto.GetRandomString(192 / 8);
}
if (string.IsNullOrWhiteSpace(salt))
{
salt = Sys.Crypto.GetRandomString(112 / 8);
}
return(new KeyParameter(key, salt));
case CryptoSuites.AEAD_AES_128_GCM:
if (string.IsNullOrWhiteSpace(key))
{
key = Sys.Crypto.GetRandomString(128 / 8);
}
if (string.IsNullOrWhiteSpace(salt))
{
salt = Sys.Crypto.GetRandomString(96 / 8);
}
return(new KeyParameter(key, salt));
case CryptoSuites.AEAD_AES_256_GCM:
if (string.IsNullOrWhiteSpace(key))
{
key = Sys.Crypto.GetRandomString(256 / 8);
}
if (string.IsNullOrWhiteSpace(salt))
{
salt = Sys.Crypto.GetRandomString(96 / 8);
}
return(new KeyParameter(key, salt));
case CryptoSuites.AES_256_CM_HMAC_SHA1_80:
case CryptoSuites.AES_256_CM_HMAC_SHA1_32:
case CryptoSuites.AES_CM_256_HMAC_SHA1_80:
case CryptoSuites.AES_CM_256_HMAC_SHA1_32:
if (string.IsNullOrWhiteSpace(key))
{
key = Sys.Crypto.GetRandomString(256 / 8);
}
if (string.IsNullOrWhiteSpace(salt))
{
salt = Sys.Crypto.GetRandomString(112 / 8);
}
return(new KeyParameter(key, salt));
}
return(null);
}
private static void parseKeySaltBase64(CryptoSuites cryptoSuite, string base64KeySalt, out byte[] key,
out byte[] salt)
{
byte[] keysalt = Convert.FromBase64String(base64KeySalt);
key = null;
switch (cryptoSuite)
{
case CryptoSuites.AES_CM_128_HMAC_SHA1_32:
case CryptoSuites.AES_CM_128_HMAC_SHA1_80:
case CryptoSuites.F8_128_HMAC_SHA1_80:
case CryptoSuites.AEAD_AES_128_GCM:
key = new byte[128 / 8];
Array.Copy(keysalt, 0, key, 0, 128 / 8);
break;
case CryptoSuites.AES_192_CM_HMAC_SHA1_80:
case CryptoSuites.AES_192_CM_HMAC_SHA1_32:
case CryptoSuites.AES_CM_192_HMAC_SHA1_80:
case CryptoSuites.AES_CM_192_HMAC_SHA1_32:
key = new byte[192 / 8];
Array.Copy(keysalt, 0, key, 0, 192 / 8);
break;
case CryptoSuites.AEAD_AES_256_GCM:
case CryptoSuites.AES_256_CM_HMAC_SHA1_80:
case CryptoSuites.AES_256_CM_HMAC_SHA1_32:
case CryptoSuites.AES_CM_256_HMAC_SHA1_80:
case CryptoSuites.AES_CM_256_HMAC_SHA1_32:
key = new byte[256 / 8];
Array.Copy(keysalt, 0, key, 0, 256 / 8);
break;
}
salt = null;
switch (cryptoSuite)
{
case CryptoSuites.AES_CM_128_HMAC_SHA1_32:
case CryptoSuites.AES_CM_128_HMAC_SHA1_80:
case CryptoSuites.F8_128_HMAC_SHA1_80:
salt = new byte[112 / 8];
Array.Copy(keysalt, 128 / 8, salt, 0, 112 / 8);
break;
case CryptoSuites.AES_192_CM_HMAC_SHA1_80:
case CryptoSuites.AES_192_CM_HMAC_SHA1_32:
case CryptoSuites.AES_CM_192_HMAC_SHA1_80:
case CryptoSuites.AES_CM_192_HMAC_SHA1_32:
salt = new byte[112 / 8];
Array.Copy(keysalt, 192 / 8, salt, 0, 112 / 8);
break;
case CryptoSuites.AES_256_CM_HMAC_SHA1_80:
case CryptoSuites.AES_256_CM_HMAC_SHA1_32:
case CryptoSuites.AES_CM_256_HMAC_SHA1_80:
case CryptoSuites.AES_CM_256_HMAC_SHA1_32:
salt = new byte[256 / 8];
Array.Copy(keysalt, 256 / 8, salt, 0, 112 / 8);
break;
case CryptoSuites.AEAD_AES_256_GCM:
case CryptoSuites.AEAD_AES_128_GCM:
salt = new byte[96 / 8];
Array.Copy(keysalt, 128 / 8, salt, 0, 96 / 8);
break;
}
}
