RSAValidate

Validates key components of the RSA cryptographic system.

Syntax

IppStatus ippsRSAValidate(const IppsBigNumState* pE, int nTrials, Ipp32u* pResult, IppsRSAState* pCtx, IppBitSuppler rndFunc, void* pRndParam);

Parameters

pE	Pointer to the IppsBigNumState context of the RSA public exponent (`e`).
nTrails	Parameter that determines the probability of primality for each `P` and `Q` factors of RSA modulo `N`.
pResult	Pointer to the result of validation.
pCtx	Pointer to the IppsRSAState context.
rndFunc	Pseudorandom number generator.
pRndParam	Pointer to the context of the pseudorandom number generator.

Description

This function is declared in the ippcp.h file. The function validates key components of the RSA cryptographic system and stores the result (IS_VALID_KEY, IS_INVALID_KEY, or IS_INCOMPLETED_KEY) of the validation procedure in *pResult.

The meanings of the values of *pResult are as follows:

IS_VALID_KEY

The RSA key is valid.

The private key is valid if it meets all the following conditions:

p and p are prime.
e*dP = 1 (mod p -1) and e*dQ = 1 (mod q -1)
q*qInv = 1 (mod p)

IS_INVALID_KEY

The RSA key is not valid.

The key is invalid if any of the above conditions is not met.

IS_INCOMPLETED_KEY

Some of the necessary key components of the quintuple (p, q, dP, dQ, or qInv) are not available.

Prepare the contexts for a call to RSAValidate as follows:

Initialize the pCtx* context for a private-key RSA system.

To do this, supply flag==IppRSAprivate to the RSAInit function.
Set up the private key in the form of a quintuple (p, q, dP, dQ, qInv).

There are two ways to do this:
- Set each component explicity through a sequence of calls to RSASetKey with IppRSAkeyP, IppRSAkeyQ, IppRSAkeyDp, IppRSAkeyDq, and IppRSAkeyQinv key tags.
- Use a sequence of calls to RSASetKey with IppRSAkeyP, IppRSAkeyQ, and IppRSAkeyD key tags. This suffices because in this case all the other key components are computed implicitly.

Note

Because the RSAGenerate and RSAValidate functions use similar algorithms, RSAValidate is unnecessary if the RSA system is generated by RSAGenerate. Call RSAValidate when RSA keys are got from outside and you are not sure whether they are valid.

Return Values