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1 /* |
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2 * Copyright (c) 2003-2009 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 the License "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: |
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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 #include <e32base.h> |
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20 #include <padding.h> |
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21 #include <securityerr.h> |
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22 #include <cryptopanic.h> |
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23 |
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24 /* CPaddingPKCS7 */ |
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25 EXPORT_C CPaddingPKCS7* CPaddingPKCS7::NewL(TInt aBlockBytes) |
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26 { |
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27 __ASSERT_ALWAYS(aBlockBytes > 0, User::Leave(KErrArgument)); |
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28 return new(ELeave)CPaddingPKCS7(aBlockBytes); |
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29 } |
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30 |
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31 EXPORT_C CPaddingPKCS7* CPaddingPKCS7::NewLC(TInt aBlockBytes) |
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32 { |
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33 CPaddingPKCS7* self = CPaddingPKCS7::NewL(aBlockBytes); |
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34 CleanupStack::PushL(self); |
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35 return self; |
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36 } |
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37 |
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38 EXPORT_C CPaddingPKCS7::CPaddingPKCS7(TInt aBlockBytes):CPadding(aBlockBytes) |
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39 { |
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40 } |
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41 |
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42 void CPaddingPKCS7::DoPadL(const TDesC8& aInput,TDes8& aOutput) |
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43 { |
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44 TInt paddingBytes = BlockSize()-(aInput.Length()%BlockSize()); |
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45 aOutput.Append(aInput); |
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46 aOutput.SetLength(aOutput.Length()+paddingBytes); |
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47 for (TInt i=1;i<=paddingBytes;i++) |
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48 { |
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49 aOutput[aOutput.Length()-i]=(TUint8)(paddingBytes); |
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50 } |
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51 } |
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52 |
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53 void CPaddingPKCS7::UnPadL(const TDesC8& aInput,TDes8& aOutput) |
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54 { |
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55 TUint inputLen = aInput.Length(); |
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56 TUint paddingLen = (TUint)(aInput[inputLen - 1]); |
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57 |
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58 if (paddingLen > inputLen) |
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59 { |
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60 User::Leave(KErrInvalidPadding); |
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61 } |
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62 |
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63 TInt outlen = aInput.Length() - paddingLen; |
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64 |
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65 __ASSERT_DEBUG(aOutput.MaxLength() >= outlen, User::Panic(KCryptoPanic, ECryptoPanicOutputDescriptorOverflow)); |
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66 |
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67 aOutput.Append(aInput.Left(outlen)); |
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68 for (TInt i=outlen;i<inputLen;i++) |
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69 { |
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70 //All padding bytes must equal the length of padding expected |
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71 if (aInput[i]!=paddingLen) |
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72 { |
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73 User::Leave(KErrInvalidPadding); |
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74 } |
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75 } |
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76 } |
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77 |
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78 TInt CPaddingPKCS7::MinPaddingLength(void) const |
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79 { |
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80 //if aInputBytes is 1 less than the blocksize then we get 1 byte of padding |
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81 return 1; |
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82 } |
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83 |
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84 TInt CPaddingPKCS7::MaxPaddedLength(TInt aInputBytes) const |
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85 { |
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86 TUint padBytes = BlockSize() - (aInputBytes % BlockSize()); |
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87 return padBytes + aInputBytes; |
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88 } |
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89 |