1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/security/cryptoservices/certificateandkeymgmt/asn1/bitstrenc.cpp Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,160 @@
1.4 +/*
1.5 +* Copyright (c) 2002-2009 Nokia Corporation and/or its subsidiary(-ies).
1.6 +* All rights reserved.
1.7 +* This component and the accompanying materials are made available
1.8 +* under the terms of the License "Eclipse Public License v1.0"
1.9 +* which accompanies this distribution, and is available
1.10 +* at the URL "http://www.eclipse.org/legal/epl-v10.html".
1.11 +*
1.12 +* Initial Contributors:
1.13 +* Nokia Corporation - initial contribution.
1.14 +*
1.15 +* Contributors:
1.16 +*
1.17 +* Description:
1.18 +* This file contains the implementation for class encoding bit strings in ASN1 DER.
1.19 +*
1.20 +*/
1.21 +
1.22 +
1.23 +/**
1.24 + @file
1.25 +*/
1.26 +
1.27 +#include <asn1enc.h>
1.28 +
1.29 +EXPORT_C CASN1EncBitString* CASN1EncBitString::NewLC(const TDesC8& aBitStr)
1.30 + {
1.31 + CASN1EncBitString* self = new (ELeave) CASN1EncBitString();
1.32 + CleanupStack::PushL(self);
1.33 + self->ConstructL(aBitStr);
1.34 + return self;
1.35 + }
1.36 +
1.37 +EXPORT_C CASN1EncBitString* CASN1EncBitString::NewL(const TDesC8& aBitStr)
1.38 + {
1.39 + CASN1EncBitString* self = NewLC(aBitStr);
1.40 + CleanupStack::Pop(self);
1.41 + return self;
1.42 + }
1.43 +
1.44 +EXPORT_C CASN1EncBitString* CASN1EncBitString::NewLC(const TDesC8& aBitStr,
1.45 + TUint aLengthBits)
1.46 + {
1.47 + CASN1EncBitString* self = new (ELeave) CASN1EncBitString();
1.48 + CleanupStack::PushL(self);
1.49 + self->ConstructL(aBitStr, aLengthBits);
1.50 + return self;
1.51 + }
1.52 +
1.53 +EXPORT_C CASN1EncBitString* CASN1EncBitString::NewL(const TDesC8& aBitStr,
1.54 + TUint aLengthBits)
1.55 + {
1.56 + CASN1EncBitString* self = NewLC(aBitStr, aLengthBits);
1.57 + CleanupStack::Pop(self);
1.58 + return self;
1.59 + }
1.60 +
1.61 +EXPORT_C CASN1EncBitString* CASN1EncBitString::NewL(const CASN1EncBase& aEncObj)
1.62 + {
1.63 + CASN1EncBitString* self = NewLC(aEncObj);
1.64 + CleanupStack::Pop(self);
1.65 + return self;
1.66 + }
1.67 +
1.68 +EXPORT_C CASN1EncBitString* CASN1EncBitString::NewLC(const CASN1EncBase& aEncObj)
1.69 + {
1.70 + CASN1EncBitString* self = new (ELeave) CASN1EncBitString();
1.71 + CleanupStack::PushL(self);
1.72 + self->ConstructL(aEncObj);
1.73 + return self;
1.74 + }
1.75 +
1.76 +EXPORT_C CASN1EncBitString::~CASN1EncBitString()
1.77 + {
1.78 + delete iContents;
1.79 + }
1.80 +
1.81 +CASN1EncBitString::CASN1EncBitString()
1.82 +: CASN1EncPrimitive(EASN1BitString),
1.83 + iPadding(0)
1.84 + {
1.85 + }
1.86 +
1.87 +void CASN1EncBitString::ConstructL(const TDesC8& aBitStr)
1.88 + {
1.89 + iContents = aBitStr.AllocL();
1.90 + CASN1EncPrimitive::ConstructL();
1.91 + }
1.92 +
1.93 +void CASN1EncBitString::ConstructL(const TDesC8& aBitStr, TUint aLengthBits)
1.94 + {
1.95 + iContents = aBitStr.AllocL();
1.96 + CASN1EncPrimitive::ConstructL();
1.97 + TUint totalBits = aBitStr.Length() * 8;
1.98 + __ASSERT_ALWAYS(aLengthBits <= totalBits, User::Leave(KErrArgument));
1.99 + iPadding = (TUint8)(totalBits - aLengthBits);
1.100 + if(iPadding > 7)
1.101 + User::Leave(KErrArgument);
1.102 + }
1.103 +
1.104 +/**
1.105 + * @internalTechnology
1.106 + * Constructs bit string from ASN.1 encoding object.
1.107 + * @param aEncObj ASN.1 encoding object to wrap in bit string.
1.108 + * @note First produces raw DER encoding from the object, then creates
1.109 + * a bit string using other construct function.
1.110 + */
1.111 +void CASN1EncBitString::ConstructL(const CASN1EncBase& aEncObj)
1.112 + {
1.113 + // produce raw DER encoding from the created ASN.1 encoding
1.114 + TUint len = aEncObj.LengthDER();
1.115 + HBufC8* intDer = HBufC8::NewMaxLC(len);
1.116 + TPtr8 ptrDer = intDer->Des();
1.117 + TUint pos = 0;
1.118 + aEncObj.WriteDERL(ptrDer, pos);
1.119 + // wrap the produced DER encoding into a bit string
1.120 + ConstructL(*intDer);
1.121 + // cleanup
1.122 + CleanupStack::PopAndDestroy(intDer);
1.123 + }
1.124 +
1.125 +/**
1.126 + * @internalTechnology
1.127 + * Calculates length of DER-encoded bit string contents. For non empty
1.128 + * bit strings this differs from octet string in the extra leading byte
1.129 + * containing the number of unused bits in the last octet.
1.130 + */
1.131 +void CASN1EncBitString::CalculateContentsLengthDER()
1.132 + {
1.133 + iContentsLengthDER = iContents->Length();
1.134 + if (iContentsLengthDER > 0)
1.135 + {
1.136 + iContentsLengthDER++;
1.137 + }
1.138 + }
1.139 +
1.140 +/**
1.141 + * @internalTechnology
1.142 + * Writes DER-encoded bit string contents to aBuf. Prepends
1.143 + * the actual bit string octets with extra octet containing
1.144 + * number of unused bits in the last octet. Before writing,
1.145 + * converts contents of the bit string to big-endian form.
1.146 + * @param aBuf Buffer to write to; must be long enough;
1.147 + * see #CalculateContentsLengthDER method.
1.148 + */
1.149 +void CASN1EncBitString::WriteContentsDERL(TDes8& aBuf) const
1.150 + {
1.151 + if (iContents->Length() > 0)
1.152 + {
1.153 + aBuf[0] = iPadding;
1.154 + TUint len = iContents->Length();
1.155 + // We do not need to swap bits, as it is already done.
1.156 + aBuf.Replace(1, len, *iContents);
1.157 + }
1.158 + else
1.159 + {
1.160 + // no padding octet for the empty bit string
1.161 + aBuf.SetLength(0);
1.162 + }
1.163 + }