include/u-boot/rsa-mod-exp.h

   1 /*
   2  * Copyright 2014 Freescale Semiconductor, Inc.
   3  *
   4  * SPDX-License-Identifier:    GPL-2.0+
   5 */
   6
   7 #ifndef _RSA_MOD_EXP_H
   8 #define _RSA_MOD_EXP_H
   9
  10 #include <errno.h>
  11 #include <image.h>
  12
  13 /**
  14  * struct key_prop - holder for a public key properties
  15  *
  16  * The struct has pointers to modulus (Typically called N),
  17  * The inverse, R^2, exponent. These can be typecasted and
  18  * used as byte arrays or converted to the required format
  19  * as per requirement of RSA implementation.
  20  */
  21 struct key_prop {
  22         const void *rr;         /* R^2 can be treated as byte array */
  23         const void *modulus;    /* modulus as byte array */
  24         const void *public_exponent; /* public exponent as byte array */
  25         uint32_t n0inv;         /* -1 / modulus[0] mod 2^32 */
  26         int num_bits;           /* Key length in bits */
  27         uint32_t exp_len;       /* Exponent length in number of uint8_t */
  28 };
  29
  30 /**
  31  * rsa_mod_exp_sw() - Perform RSA Modular Exponentiation in sw
  32  *
  33  * Operation: out[] = sig ^ exponent % modulus
  34  *
  35  * @sig:        RSA PKCS1.5 signature
  36  * @sig_len:    Length of signature in number of bytes
  37  * @node:       Node with RSA key elements like modulus, exponent, R^2, n0inv
  38  * @out:        Result in form of byte array of len equal to sig_len
  39  */
  40 int rsa_mod_exp_sw(const uint8_t *sig, uint32_t sig_len,
  41                 struct key_prop *node, uint8_t *out);
  42
  43 int rsa_mod_exp(struct udevice *dev, const uint8_t *sig, uint32_t sig_len,
  44                 struct key_prop *node, uint8_t *out);
  45
  46 /**
  47  * struct struct mod_exp_ops - Driver model for RSA Modular Exponentiation
  48  *                              operations
  49  *
  50  * The uclass interface is implemented by all crypto devices which use
  51  * driver model.
  52  */
  53 struct mod_exp_ops {
  54         /**
  55          * Perform Modular Exponentiation
  56          *
  57          * Operation: out[] = sig ^ exponent % modulus
  58          *
  59          * @dev:        RSA Device
  60          * @sig:        RSA PKCS1.5 signature
  61          * @sig_len:    Length of signature in number of bytes
  62          * @node:       Node with RSA key elements like modulus, exponent,
  63          *              R^2, n0inv
  64          * @out:        Result in form of byte array of len equal to sig_len
  65          *
  66          * This function computes exponentiation over the signature.
  67          * Returns: 0 if exponentiation is successful, or a negative value
  68          * if it wasn't.
  69          */
  70         int (*mod_exp)(struct udevice *dev, const uint8_t *sig,
  71                            uint32_t sig_len, struct key_prop *node,
  72                            uint8_t *outp);
  73 };
  74
  75 #endif