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1 /* |
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2 * Copyright (c) 2004 Nokia Corporation and/or its subsidiary(-ies). |
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3 * All rights reserved. |
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4 * This component and the accompanying materials are made available |
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5 * under the terms of "Eclipse Public License v1.0" |
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6 * which accompanies this distribution, and is available |
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7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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8 * |
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9 * Initial Contributors: |
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10 * Nokia Corporation - initial contribution. |
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11 * |
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12 * Contributors: |
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13 * |
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14 * Description: Contains a cryptographic handler for SRTP/SRTCP streams. |
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15 * |
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16 */ |
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17 |
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18 |
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19 |
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20 |
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21 #ifndef __SRTP_CRYPTOHANDLER_H__ |
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22 #define __SRTP_CRYPTOHANDLER_H__ |
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23 |
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24 // INCLUDES |
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25 #include <e32base.h> |
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26 #include "srtpdef.h" |
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27 #include "msrtpcryptohandlercontext.h" |
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28 #include "srtpcryptocontext.h" |
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29 #include "srtpcryptoparams.h" |
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30 |
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31 // FORWARD DECLARATIONS |
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32 class CSRTPMasterKey; |
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33 class CSRTPMasterSalt; |
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34 class CSRTPCryptoContext; |
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35 class CSRTPStream; |
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36 class MSRTPCipher; |
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37 class MSRTPKeyDerivation; |
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38 class MSRTPAuthentication; |
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39 class CSRTPPacket; |
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40 |
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41 /** |
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42 * Contains RTP/RTCP common handling of cryptographic context. |
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43 */ |
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44 class CSRTPCryptoHandler : public CBase, public MSRTPCryptoHandlerContext |
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45 { |
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46 |
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47 public: // from MSRTPCryptoHandlerContext |
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48 |
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49 /* |
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50 * virtual function for initializing |
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51 * plain packet class (CSRTPPacketRTP or CSRTPPacketRTCP) |
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52 * @param aPacket RTP/RTCP packet. |
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53 * @leave KErrNone if success, system-wide error code otherwise |
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54 * @return void |
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55 */ |
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56 virtual void InitializePlainPacketL(const TDesC8& aPacket)=0; |
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57 |
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58 /* |
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59 * virtual function for initializing |
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60 * encrypted packet class (CSRTPPacketSRTP or CSRTPPacketSRTCP) |
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61 * @param aPacket SRTP/SRTCP packet. |
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62 * @leave KErrNone if success, system-wide error code otherwise |
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63 * @return void |
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64 */ |
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65 virtual void InitializeEncryptedPacketL(const TDesC8& aPacket)=0; |
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66 /* |
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67 * Virtual function for deriving session |
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68 * encryption, salting and authentication keys |
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69 * for RTP or RTCP |
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70 * @leave KErrNone if success, system-wide error code otherwise |
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71 * @return void |
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72 */ |
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73 virtual void DeriveSessionKeysL()=0; |
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74 |
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75 /* |
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76 * virtual function for checking that crypto context MKI and |
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77 * packet MKI match. |
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78 * @leave KErrNone if success, system-wide error code otherwise |
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79 * @return void |
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80 */ |
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81 virtual void CheckMasterKeyIdentifierL()=0; |
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82 |
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83 /* |
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84 * virtual function for performing the authentication step |
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85 * @leave KErrNone if success, system-wide error code otherwise |
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86 * @return void |
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87 */ |
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88 virtual void AuthenticateL()=0; |
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89 |
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90 /* |
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91 * virtual function for performing the replay protection step |
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92 * @leave KErrNone if success, system-wide error code otherwise |
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93 * @return void |
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94 */ |
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95 virtual void ReplayProtectionL()=0; |
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96 |
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97 /* |
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98 * virtual function for encrypting plain packet |
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99 * @leave KErrNone if success, system-wide error code otherwise |
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100 * @return encrypted packet |
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101 */ |
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102 virtual HBufC8* EncryptL()=0; |
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103 |
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104 /* |
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105 * virtual function for decrypting ciphered packet |
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106 * @leave KErrNone if success, system-wide error code otherwise |
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107 * @return plain packet |
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108 */ |
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109 virtual HBufC8* DecryptL()=0; |
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110 |
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111 /* |
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112 * function for querying whether master key or salt has been updated |
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113 * @return master keys update status |
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114 */ |
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115 virtual TBool MasterKeysUpdated()=0; |
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116 |
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117 public: // from CSRTPCryptoContext |
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118 /** |
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119 * Callback from CSRTPCryptoContext when a master key is changed. |
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120 */ |
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121 void SRTPMasterKeyChanged(); |
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122 /** |
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123 * Callback from CSRTPCryptoContext when a master salt is changed. |
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124 */ |
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125 void SRTPMasterSaltChanged(); |
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126 |
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127 |
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128 |
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129 public: |
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130 /** |
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131 * Get roll-over counter value. |
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132 * @return current ROC value. |
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133 */ |
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134 TUint32 ROC( ) const; |
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135 /* |
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136 * Get corresponding CSRTPCryptoContext |
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137 * (either session or stream specific) |
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138 * @return CSRTPCryptoContext |
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139 */ |
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140 CSRTPCryptoContext& Context(); |
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141 |
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142 const TSrtpCryptoParams& CryptoParams(); |
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143 |
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144 virtual ~CSRTPCryptoHandler( ); |
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145 |
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146 protected: // methods |
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147 |
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148 CSRTPCryptoHandler( CSRTPStream& aStream); |
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149 |
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150 void ConstructL( ); |
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151 |
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152 |
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153 /* |
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154 * Deletes session keys (encryption, |
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155 * salting and authentication) and sets them NULL |
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156 * @return void |
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157 */ |
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158 void DeleteSessionKeys(); |
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159 |
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160 /** |
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161 * Set roll-over counter value. |
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162 * @param aROC The new ROC value. |
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163 * @return void |
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164 */ |
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165 void SetROC( TUint32 aROC ); |
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166 |
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167 /** |
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168 * Get 32 bit SSRC value |
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169 * @return SSRC |
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170 */ |
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171 TUint SSRC() const; |
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172 |
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173 /* |
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174 * Count X value, |
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175 * which used in session key derivation |
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176 * Common to RTP and RTCP. |
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177 * The length of X is the same as master key length |
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178 * (padding will be performed later) |
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179 * @param a_R, r, index DIV key_derivation_rate |
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180 * @param aLabel, label 8 bit RTP/RTCP label |
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181 * @param aIndexLength, |
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182 * @param &aRes resulting n bit x value |
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183 * @return void |
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184 */ |
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185 void Count_X(TUint64 a_R, |
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186 TInt8 aLabel, |
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187 const TUint64 aIndexLength, |
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188 TDes8 &aRes); |
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189 |
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190 |
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191 |
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192 /* |
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193 * Check Packet Index with Replay window |
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194 * Common for RTP and RTCP. |
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195 * @param aDelta the difference between the stored packet Index and |
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196 * current Packet Index |
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197 * @return KErrNone if checks Ok, if not, return KErrArgument |
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198 */ |
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199 TInt ReplayCheck(TInt aDelta) ; |
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200 |
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201 /* |
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202 * Set Encryptor and Auth |
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203 * Common for RTP and RTCP. |
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204 * @param aEngAlg Encrption Alg using for cryptor handler |
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205 * @param aAuthAlg Authentication Algorithem using for crypto handler |
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206 * @return void |
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207 */ |
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208 void SetEncAndAuthL (TSRTPEncAlg aEngAlg, |
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209 TSRTPAuthAlg aAuthAlg); |
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210 |
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211 public: |
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212 /** |
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213 * iHandlerOffset, List offset. |
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214 * Owned by CCryptoContext object. |
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215 */ |
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216 static const TInt iHandlerOffset; |
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217 |
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218 /** |
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219 * iHandlerLink, Link to list. |
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220 * Owned by CSRTPCryptoHandler object. |
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221 */ |
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222 TSglQueLink iHandlerLink; |
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223 |
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224 protected: // data |
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225 |
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226 CSRTPStream& iStream; // stream |
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227 |
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228 CSRTPPacket* iCurrentPacket; // packet class |
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229 // algorithms: |
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230 MSRTPKeyDerivation* iKeyDeriver; // key divider algorithm |
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231 MSRTPAuthentication* iAuthenticator; // authentication algorithm |
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232 MSRTPCipher* iCipher; // encryption/decryption alg. |
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233 TBool iMasterDataUpdated; // is master key or salt updated |
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234 |
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235 // session keys: |
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236 HBufC8* iSessionEncrKey; // session encryption/decryption key (k_e) |
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237 HBufC8* iSessionAuthKey; // session authentication key (k_a) |
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238 HBufC8* iSessionSaltKey; // session salting key (k_s) |
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239 TBool iReKey; // is master key or salt updated |
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240 TUint64 iBitmap; //Replay List |
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241 TUint64 iNumPackets; //Number of packets has been recived / sending |
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242 |
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243 private: |
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244 #ifdef EUNIT_TESTING |
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245 friend class UT_CSRTPCryptoHandler; |
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246 friend class UT_CSRTPCryptoHandlerSRTP; |
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247 friend class UT_CSRTPStreamIn; |
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248 friend class UT_CSRTPStreamOut; |
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249 #endif |
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250 |
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251 }; |
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252 #endif // __SRTP_CRYPTOHANDLER_H__ |