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RSA

Introduction

The W80x supports hardware modular exponentiation. The purpose of modular exponentiation is to efficiently calculate (A^E mod N), which means computing A raised to the power of E and then taking the result modulo N. The W80x SDK adapts the modular exponentiation in the MbedTLS library using hardware. Users can encrypt data using mbedtls_rsa_pkcs1_encrypt and decrypt data using mbedtls_rsa_pkcs1_decrypt.

Function List

1. Initialization —— Initialize the RSA driver.

2. Modular Exponentiation Calculation.

Initialize the RSA driver

Call wm_drv_rsa_init() , To obtain a device pointer pointing to the RSA module, which is necessary for invoking the wm_drv_rsa_expt_mod function. Example:

wm_device_t *dev;
dev = wm_drv_rsa_init("rsa");

The function parameter specifies the device name, which is defined in the device table.

Perform Modular Exponentiation

Call wm_drv_rsa_expt_mod() , Perform modular exponentiation, where X = A^E mod N. Here is an example of adapting modular exponentiation in the MbedTLS library:

wm_device_t* wm_drv_rsa_dev = wm_dt_get_device_by_name("rsa");

MBEDTLS_MPI_CHK(wm_drv_rsa_expt_mod(wm_drv_rsa_dev, &T, &T, &ctx->E, &ctx->N));

The first parameter is: a pointer to the device.

The second parameter is: a pointer to the result X.

The third parameter is: a pointer to the base A.

The fourth parameter is: a pointer to the exponent E.

The fifth parameter is: a pointer to the modulus N.

Application Demo

To use RSA, please refer to:ref:examples/peripheral/rsa<peripheral_example>

API Reference

For looking up RSA-related APIs, please refer to:

RSA API Reference