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/*
* Copyright (c) 2013, Google Inc.
*
* (C) Copyright 2008 Semihalf
*
* (C) Copyright 2000-2006
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef _RSA_H
#define _RSA_H
#include <errno.h>
#include <image.h>
/**
* struct rsa_public_key - holder for a public key
*
* An RSA public key consists of a modulus (typically called N), the inverse
* and R^2, where R is 2^(# key bits).
*/
struct rsa_public_key {
uint len; /* len of modulus[] in number of uint32_t */
uint32_t n0inv; /* -1 / modulus[0] mod 2^32 */
uint32_t *modulus; /* modulus as little endian array */
uint32_t *rr; /* R^2 as little endian array */
};
#if IMAGE_ENABLE_SIGN
/**
* sign() - calculate and return signature for given input data
*
* @info: Specifies key and FIT information
* @data: Pointer to the input data
* @data_len: Data length
* @sigp: Set to an allocated buffer holding the signature
* @sig_len: Set to length of the calculated hash
*
* This computes input data signature according to selected algorithm.
* Resulting signature value is placed in an allocated buffer, the
* pointer is returned as *sigp. The length of the calculated
* signature is returned via the sig_len pointer argument. The caller
* should free *sigp.
*
* @return: 0, on success, -ve on error
*/
int rsa_sign(struct image_sign_info *info,
const struct image_region region[],
int region_count, uint8_t **sigp, uint *sig_len);
/**
* add_verify_data() - Add verification information to FDT
*
* Add public key information to the FDT node, suitable for
* verification at run-time. The information added depends on the
* algorithm being used.
*
* @info: Specifies key and FIT information
* @keydest: Destination FDT blob for public key data
* @return: 0, on success, -ENOSPC if the keydest FDT blob ran out of space,
other -ve value on error
*/
int rsa_add_verify_data(struct image_sign_info *info, void *keydest);
#else
static inline int rsa_sign(struct image_sign_info *info,
const struct image_region region[], int region_count,
uint8_t **sigp, uint *sig_len)
{
return -ENXIO;
}
static inline int rsa_add_verify_data(struct image_sign_info *info,
void *keydest)
{
return -ENXIO;
}
#endif
#if IMAGE_ENABLE_VERIFY
/**
* rsa_verify() - Verify a signature against some data
*
* Verify a RSA PKCS1.5 signature against an expected hash.
*
* @info: Specifies key and FIT information
* @data: Pointer to the input data
* @data_len: Data length
* @sig: Signature
* @sig_len: Number of bytes in signature
* @return 0 if verified, -ve on error
*/
int rsa_verify(struct image_sign_info *info,
const struct image_region region[], int region_count,
uint8_t *sig, uint sig_len);
#else
static inline int rsa_verify(struct image_sign_info *info,
const struct image_region region[], int region_count,
uint8_t *sig, uint sig_len)
{
return -ENXIO;
}
#endif
#define RSA2048_BYTES (2048 / 8)
#define RSA4096_BYTES (4096 / 8)
/* This is the minimum/maximum key size we support, in bits */
#define RSA_MIN_KEY_BITS 2048
#define RSA_MAX_KEY_BITS 4096
/* This is the maximum signature length that we support, in bits */
#define RSA_MAX_SIG_BITS 4096
#endif