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 #if IMAGE_ENABLE_SIGN
  34 /**
  35  * sign() - calculate and return signature for given input data
  36  *
  37  * @info:       Specifies key and FIT information
  38  * @data:       Pointer to the input data
  39  * @data_len:   Data length
  40  * @sigp:       Set to an allocated buffer holding the signature
  41  * @sig_len:    Set to length of the calculated hash
  42  *
  43  * This computes input data signature according to selected algorithm.
  44  * Resulting signature value is placed in an allocated buffer, the
  45  * pointer is returned as *sigp. The length of the calculated
  46  * signature is returned via the sig_len pointer argument. The caller
  47  * should free *sigp.
  48  *
  49  * @return: 0, on success, -ve on error
  50  */
  51 int rsa_sign(struct image_sign_info *info,
  52              const struct image_region region[],
  53              int region_count, uint8_t **sigp, uint *sig_len);
  54
  55 /**
  56  * add_verify_data() - Add verification information to FDT
  57  *
  58  * Add public key information to the FDT node, suitable for
  59  * verification at run-time. The information added depends on the
  60  * algorithm being used.
  61  *
  62  * @info:       Specifies key and FIT information
  63  * @keydest:    Destination FDT blob for public key data
  64  * @return: 0, on success, -ENOSPC if the keydest FDT blob ran out of space,
  65                 other -ve value on error
  66 */
  67 int rsa_add_verify_data(struct image_sign_info *info, void *keydest);
  68 #else
  69 static inline int rsa_sign(struct image_sign_info *info,
  70                 const struct image_region region[], int region_count,
  71                 uint8_t **sigp, uint *sig_len)
  72 {
  73         return -ENXIO;
  74 }
  75
  76 static inline int rsa_add_verify_data(struct image_sign_info *info,
  77                                       void *keydest)
  78 {
  79         return -ENXIO;
  80 }
  81 #endif
  82
  83 #if IMAGE_ENABLE_VERIFY
  84 /**
  85  * rsa_verify() - Verify a signature against some data
  86  *
  87  * Verify a RSA PKCS1.5 signature against an expected hash.
  88  *
  89  * @info:       Specifies key and FIT information
  90  * @data:       Pointer to the input data
  91  * @data_len:   Data length
  92  * @sig:        Signature
  93  * @sig_len:    Number of bytes in signature
  94  * @return 0 if verified, -ve on error
  95  */
  96 int rsa_verify(struct image_sign_info *info,
  97                const struct image_region region[], int region_count,
  98                uint8_t *sig, uint sig_len);
  99 #else
 100 static inline int rsa_verify(struct image_sign_info *info,
 101                 const struct image_region region[], int region_count,
 102                 uint8_t *sig, uint sig_len)
 103 {
 104         return -ENXIO;
 105 }
 106 #endif
 107
 108 #define RSA2048_BYTES   (2048 / 8)
 109 #define RSA4096_BYTES   (4096 / 8)
 110
 111 /* This is the minimum/maximum key size we support, in bits */
 112 #define RSA_MIN_KEY_BITS        2048
 113 #define RSA_MAX_KEY_BITS        4096
 114
 115 /* This is the maximum signature length that we support, in bits */
 116 #define RSA_MAX_SIG_BITS        4096
 117
 118 #endif