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GFpECSignSM2

Computes a digital signature over a message digest using the SM2 scheme.

Syntax

IppStatus ippsGFpECSignSM2(const IppsBigNumState* pMsgDigest, const IppsBigNumState* pRegPrivate, const IppsBigNumState* pEphPrivate, IppsBigNumState* pSignR, IppsBigNumState* pSignS, IppsGFpECState* pEC, Ipp8u* pScratchBuffer);

Include Files

ippcp.h

Parameters

pMsgDigest

Pointer to the message digest msg to be digitally signed, that is, to be encrypted with a private key.

pRegPrivate

Pointer to the regular private key of the signer.

pEphPrivate

Pointer to the ephemeral private key of the signer.

pSignR

Pointer to the integer r of the digital signature.

pSignS

Pointer to the integer s of the digital signature.

pEC

Pointer to the context of the elliptic curve.

pScratchBuffer

Pointer to the scratch buffer.

Description

The function computes two big numbers r and s that form the digital signature over a message digest msg.

The digital signature is computed using the SM2 scheme [SM2].

The regular private key regPrivKey and the ephemeral private key ephPrivKey can be generated by the functions GFpECPrivateKey and GFpECPublicKey with only the requirement that the key regPrivKey be different from the key ephPrivKey.

The elliptic curve domain parameters must be hitherto defined by the functions: GFpECInitStd, GFpECInit, GFpECSet, or GFpECSetSubgroup.

Return Values

ippStsNoErr

Indicates no error. Any other value indicates an error or warning.

ippStsNullPtrErr

Indicates an error condition if any of the specified pointers is NULL.

ippStsContextMatchErr

Indicates an error condition if any of the contexts pointed to by pMsgDigest, pRegPrivate, pEphPrivate, pSignR, pSignS, or pEC does not match the operation.

ippStsMessageErr

Indicates an error condition if the value of msg pointed to by pMsgDigest is negative.

ippStsRangeErr

Indicates an error condition if any of the parameters pointed to by pSignR or pSignS has a memory size that is smaller than the order n of the elliptic curve base point G.

ippStsIvalidPrivateKey

Indicates an error condition in the following cases:

  • Any of the parameters pointed to by pRegPrivate or pEphPrivate has a memory size that is smaller than the order n of the elliptic curve base point G.

  • Value of any of the private keys is greater than or equal to the order n of the elliptic curve base point G.

ippStsNotSupportedModeErr

Indicates an error condition if the finite field GFp under the elliptic curve is not prime.

ippStsEphemeralKeyErr

Indicates an error condition if values of the ephemeral keys ephPrivKey and ephPubKey are not valid: the digital signature calculation returns r=0 or s=0 as a result.

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