Cryptography for Intel(R) Integrated Performance Primitives Developer Reference

ID 768738
Date 12/16/2022
Document Table of Contents


Performs the private key RSA decryption operation.


mbx_status mbx_rsa_private_mb8(const int8u* const from_pa[8], int8u* const to_pa[8], const int64u* const d_pa[8], const int64u* const n_pa[8], int rsaBitlen, const mbx_RSA_Method* m, int8u* pBuffer);

mbx_status mbx_rsa_private_ssl_mb8(const int8u* const from_pa[8], int8u* const to_pa[8], const BIGNUM* const d_pa[8], const BIGNUM* const n_pa[8], int rsaBitlen);

Include Files




Array of pointers to the ciphertext data vectors.


Array of pointers to the recovered data vectors.


Array of pointers to the RSAs private exponent vectors.


Array of pointers to the RSAs modulus vectors.


Size of RSAs moduli in bits.


Pointer to the pre-defined data structure specified by the RSA encryption operation.


Pointer to the work buffer.

The mbx_rsa_private() function performs independent RSA private key operations using RSA private key in form of a pair - private exponent (d) and modulus (n). The exponents are passed through d_pa and moduli are passed though n_pa parameters. The size of RSAs moduli and private exponents must be the same and equal to rsaBitlen bits. The function decrypts ciphertexts specified by the from_pa parameter in parallel, and stores recovered ciphertexts in the memory locations specified by the to_pa parameter. Memory buffers of the plain- and ciphertext must be ceil(rsaBitlen/8) bytes length.

At the moment, RSA-10024, RSA-2048, RSA-3072 and RSA-4096 are supported only. If m is NULL, the function uses mbx_RSA_private_Method(rsaBitsize). If m is not NULL, it must be assigned to either mbx_RSA1K_ private_Method(), mbx_RSA2K_ private_Method(), mbx_RSA3K_ private_Method() or mbx_RSA4K_ private_Method() and match to rsaBitlen value.

If pBuffer is NULL, then the function allocated a work buffer of suitable size dynamically. An allocated buffer will be released before the function return. If the work buffer is allocated in the application, it affects performance positively. The mbx_RSA_Method_BufSize() function returns the size of the work buffer required for the operation.

The function itself does not support any kind of padding. The application is responsible for the padding if it is required.


The mbx_rsa_private_ssl() function is the "twin" of mbx_rsa_private() one. It acts the same. The basic difference in comparison with mbx_rsa_private() is the representation of RSA key stuff. mbx_rsa_private_ssl uses BIGNUM datatype instead of vector.

Return Values

The mbx_rsa_private() function returns the status that indicates whether the operation completed successfully or not. The status value of 0 indicates that all operations completed successfully. The error condition can be analyzed by the MBX_GET_STS() call.

See Also

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