void md5 (const void* buf, size_t len, unsigned char result_hash_value [16])
{
MD5_CTX context;
Md5Init (&context);
while (len)
{
unsigned int update_size = (unsigned int)stl::min (len, (size_t)(unsigned int)-1);
Md5Update (&context, (unsigned char*)buf, update_size);
buf = (const char*)buf + update_size;
len -= update_size;
}
Md5Final (result_hash_value, &context);
}
/**
Initator caculates its own expected hash value.
@param[in] ChapIdentifier iSCSI CHAP identifier sent by authenticator.
@param[in] ChapSecret iSCSI CHAP secret of the authenticator.
@param[in] SecretLength The length of iSCSI CHAP secret.
@param[in] ChapChallenge The challenge message sent by authenticator.
@param[in] ChallengeLength The length of iSCSI CHAP challenge message.
@param[out] ChapResponse The calculation of the expected hash value.
@retval EFI_SUCCESS The expected hash value was caculatedly successfully.
@retval EFI_PROTOCOL_ERROR The length of the secret should be at least the
length of the hash value for the hashing algorithm chosen.
@retval EFI_PROTOCOL_ERROR MD5 hash operation fail.
@retval EFI_OUT_OF_RESOURCES Fail to allocate resource to complete MD5.
**/
EFI_STATUS
IScsiCHAPCalculateResponse (
IN UINT32 ChapIdentifier,
IN CHAR8 *ChapSecret,
IN UINT32 SecretLength,
IN UINT8 *ChapChallenge,
IN UINT32 ChallengeLength,
OUT UINT8 *ChapResponse
)
{
UINTN Md5ContextSize;
VOID *Md5Ctx;
CHAR8 IdByte[1];
EFI_STATUS Status;
if (SecretLength < ISCSI_CHAP_SECRET_MIN_LEN) {
return EFI_PROTOCOL_ERROR;
}
Md5ContextSize = Md5GetContextSize ();
Md5Ctx = AllocatePool (Md5ContextSize);
if (Md5Ctx == NULL) {
return EFI_OUT_OF_RESOURCES;
}
Status = EFI_PROTOCOL_ERROR;
if (!Md5Init (Md5Ctx)) {
goto Exit;
}
//
// Hash Identifier - Only calculate 1 byte data (RFC1994)
//
IdByte[0] = (CHAR8) ChapIdentifier;
if (!Md5Update (Md5Ctx, IdByte, 1)) {
goto Exit;
}
//
// Hash Secret
//
if (!Md5Update (Md5Ctx, ChapSecret, SecretLength)) {
goto Exit;
}
//
// Hash Challenge received from Target
//
if (!Md5Update (Md5Ctx, ChapChallenge, ChallengeLength)) {
goto Exit;
}
if (Md5Final (Md5Ctx, ChapResponse)) {
Status = EFI_SUCCESS;
}
Exit:
FreePool (Md5Ctx);
return Status;
}
