CArrayFixFlat<struct sadb_alg> *CIpsecCryptoManager::SupportedAlgorithms
(TInt &aNumAuth, TInt &aNumEncrypt)
/**
* Ask the supported algorithms of a library.
*
* This function has a very specialized use: return supported
* algorithms, when a PFKEY reply to the REGISTER message is generated
* (CProtocolKey::ExecRegister). The format of the return value is tailored
* for that purpose.
*
* Return a dynamically alloated (heap) array of 'sadb_alg'
* descriptions. The first aNumAuth descriptors are authentication
* algorithms, and the tail aNumEncrypt are encryption
* algorithms.
*
* @retval aNumAuth Count of authentication algorithms
* @retval aNumEncrypt Count of cipher algorithms
* return Algorithm descriptions
*
* The return is guaranteed to be non-NULL, if aNumAuth + aNumEncrypt > 0.
*/
{
CArrayFixFlat<struct sadb_alg> *algs;
TInt n;
aNumAuth = 0;
aNumEncrypt = 0;
if (iAlgorithmList == NULL ||
iLibraryList == NULL ||
(n = iAlgorithmList->Count()) == 0)
return NULL; // No algorithms supported!
//
// Allocate all the space that is needed
//
// Sets 'aNumEncrypt' in case the heap allocations
// fail (a NULL return with non-zero count is used
// to indicate Memory Allocation error).
aNumEncrypt = n;
algs = new CArrayFixFlat<struct sadb_alg>(n);
if (!algs)
return NULL;
TRAPD(left, algs->ResizeL(n));
if (left)
{
delete algs;
return NULL;
}
aNumEncrypt = 0;
//
// -- All requred heap space has now been allocated --
// (The space is contigous in memory)
struct sadb_alg *auth = algs->Back(0);
struct sadb_alg *encrypt = algs->End(0);
for (TInt i = 0; i < n; ++i)
{
struct sadb_alg *alg;
TAlgorithmMap &p = iAlgorithmList->At(i);
if (p.iAlgorithm.Length() == 0 && p.iClass == EAlgorithmClass_Cipher )
{
// The NULL encryption is indicated by empty string in the
// algorithm name. NULL encryption is supported, if the
// mapping has such entry configured...
alg = encrypt - ++aNumEncrypt;
alg->sadb_alg_id = (TUint8)p.iId;
alg->sadb_alg_ivlen = 0;
alg->sadb_alg_minbits = 0;
alg->sadb_alg_maxbits = 0;
alg->sadb_alg_reserved = 0;
continue;
}
TLibraryPtr *lib;
TInt j = iLibraryList->Lookup(p, &lib);
if (lib != NULL)
{
// A matching library instance and algorithm
// located, fill in the algorithm description.
if (p.iClass == EAlgorithmClass_Digest)
{
alg = auth + aNumAuth++;
alg->sadb_alg_ivlen = 0;
}
else if (p.iClass == EAlgorithmClass_Cipher)
{
alg = encrypt - ++aNumEncrypt;
alg->sadb_alg_ivlen = (TUint8)lib->iAlgs[j].iVector;
}
#ifdef SYMBIAN_IPSEC_VOIP_SUPPORT
else if (p.iClass == EAlgorithmClass_Mac )
{
alg = auth + aNumAuth++;
alg->sadb_alg_ivlen = 0;
}
#endif //SYMBIAN_IPSEC_VOIP_SUPPORT
else
continue; // Some unknown algorithm class, that
// cannot be used by this implementation.
alg->sadb_alg_id = (TUint8)p.iId;
alg->sadb_alg_minbits = (TUint16)lib->iAlgs[j].iMinBits;
alg->sadb_alg_maxbits = (TUint16)lib->iAlgs[j].iMaxBits;
alg->sadb_alg_reserved = 0;
}
}
return algs;
}
