include/u-boot/rsa.h

   1 /*
   2  * Copyright (c) 2013, Google Inc.
   3  *
   4  * (C) Copyright 2008 Semihalf
   5  *
   6  * (C) Copyright 2000-2006
   7  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   8  *
   9  * SPDX-License-Identifier:     GPL-2.0+
  10  */
  11
  12 #ifndef _RSA_H
  13 #define _RSA_H
  14
  15 #include <errno.h>
  16 #include <image.h>
  17
  18 /**
  19  * struct rsa_public_key - holder for a public key
  20  *
  21  * An RSA public key consists of a modulus (typically called N), the inverse
  22  * and R^2, where R is 2^(# key bits).
  23  */
  24
  25 struct rsa_public_key {
  26         uint len;               /* len of modulus[] in number of uint32_t */
  27         uint32_t n0inv;         /* -1 / modulus[0] mod 2^32 */
  28         uint32_t *modulus;      /* modulus as little endian array */
  29         uint32_t *rr;           /* R^2 as little endian array */
  30         uint64_t exponent;      /* public exponent */
  31 };
  32
  33 struct image_sign_info;
  34
  35 #if IMAGE_ENABLE_SIGN
  36 /**
  37  * sign() - calculate and return signature for given input data
  38  *
  39  * @info:       Specifies key and FIT information
  40  * @data:       Pointer to the input data
  41  * @data_len:   Data length
  42  * @sigp:       Set to an allocated buffer holding the signature
  43  * @sig_len:    Set to length of the calculated hash
  44  *
  45  * This computes input data signature according to selected algorithm.
  46  * Resulting signature value is placed in an allocated buffer, the
  47  * pointer is returned as *sigp. The length of the calculated
  48  * signature is returned via the sig_len pointer argument. The caller
  49  * should free *sigp.
  50  *
  51  * @return: 0, on success, -ve on error
  52  */
  53 int rsa_sign(struct image_sign_info *info,
  54              const struct image_region region[],
  55              int region_count, uint8_t **sigp, uint *sig_len);
  56
  57 /**
  58  * add_verify_data() - Add verification information to FDT
  59  *
  60  * Add public key information to the FDT node, suitable for
  61  * verification at run-time. The information added depends on the
  62  * algorithm being used.
  63  *
  64  * @info:       Specifies key and FIT information
  65  * @keydest:    Destination FDT blob for public key data
  66  * @return: 0, on success, -ENOSPC if the keydest FDT blob ran out of space,
  67                 other -ve value on error
  68 */
  69 int rsa_add_verify_data(struct image_sign_info *info, void *keydest);
  70 #else
  71 static inline int rsa_sign(struct image_sign_info *info,
  72                 const struct image_region region[], int region_count,
  73                 uint8_t **sigp, uint *sig_len)
  74 {
  75         return -ENXIO;
  76 }
  77
  78 static inline int rsa_add_verify_data(struct image_sign_info *info,
  79                                       void *keydest)
  80 {
  81         return -ENXIO;
  82 }
  83 #endif
  84
  85 #if IMAGE_ENABLE_VERIFY
  86 /**
  87  * rsa_verify() - Verify a signature against some data
  88  *
  89  * Verify a RSA PKCS1.5 signature against an expected hash.
  90  *
  91  * @info:       Specifies key and FIT information
  92  * @data:       Pointer to the input data
  93  * @data_len:   Data length
  94  * @sig:        Signature
  95  * @sig_len:    Number of bytes in signature
  96  * @return 0 if verified, -ve on error
  97  */
  98 int rsa_verify(struct image_sign_info *info,
  99                const struct image_region region[], int region_count,
 100                uint8_t *sig, uint sig_len);
 101 #else
 102 static inline int rsa_verify(struct image_sign_info *info,
 103                 const struct image_region region[], int region_count,
 104                 uint8_t *sig, uint sig_len)
 105 {
 106         return -ENXIO;
 107 }
 108 #endif
 109
 110 #define RSA2048_BYTES   (2048 / 8)
 111 #define RSA4096_BYTES   (4096 / 8)
 112
 113 /* This is the minimum/maximum key size we support, in bits */
 114 #define RSA_MIN_KEY_BITS        2048
 115 #define RSA_MAX_KEY_BITS        4096
 116
 117 /* This is the maximum signature length that we support, in bits */
 118 #define RSA_MAX_SIG_BITS        4096
 119
 120 #endif