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 };
  31
  32 #if IMAGE_ENABLE_SIGN
  33 /**
  34  * sign() - calculate and return signature for given input data
  35  *
  36  * @info:       Specifies key and FIT information
  37  * @data:       Pointer to the input data
  38  * @data_len:   Data length
  39  * @sigp:       Set to an allocated buffer holding the signature
  40  * @sig_len:    Set to length of the calculated hash
  41  *
  42  * This computes input data signature according to selected algorithm.
  43  * Resulting signature value is placed in an allocated buffer, the
  44  * pointer is returned as *sigp. The length of the calculated
  45  * signature is returned via the sig_len pointer argument. The caller
  46  * should free *sigp.
  47  *
  48  * @return: 0, on success, -ve on error
  49  */
  50 int rsa_sign(struct image_sign_info *info,
  51              const struct image_region region[],
  52              int region_count, uint8_t **sigp, uint *sig_len);
  53
  54 /**
  55  * add_verify_data() - Add verification information to FDT
  56  *
  57  * Add public key information to the FDT node, suitable for
  58  * verification at run-time. The information added depends on the
  59  * algorithm being used.
  60  *
  61  * @info:       Specifies key and FIT information
  62  * @keydest:    Destination FDT blob for public key data
  63  * @return: 0, on success, -ENOSPC if the keydest FDT blob ran out of space,
  64                 other -ve value on error
  65 */
  66 int rsa_add_verify_data(struct image_sign_info *info, void *keydest);
  67 #else
  68 static inline int rsa_sign(struct image_sign_info *info,
  69                 const struct image_region region[], int region_count,
  70                 uint8_t **sigp, uint *sig_len)
  71 {
  72         return -ENXIO;
  73 }
  74
  75 static inline int rsa_add_verify_data(struct image_sign_info *info,
  76                                       void *keydest)
  77 {
  78         return -ENXIO;
  79 }
  80 #endif
  81
  82 #if IMAGE_ENABLE_VERIFY
  83 /**
  84  * rsa_verify() - Verify a signature against some data
  85  *
  86  * Verify a RSA PKCS1.5 signature against an expected hash.
  87  *
  88  * @info:       Specifies key and FIT information
  89  * @data:       Pointer to the input data
  90  * @data_len:   Data length
  91  * @sig:        Signature
  92  * @sig_len:    Number of bytes in signature
  93  * @return 0 if verified, -ve on error
  94  */
  95 int rsa_verify(struct image_sign_info *info,
  96                const struct image_region region[], int region_count,
  97                uint8_t *sig, uint sig_len);
  98 #else
  99 static inline int rsa_verify(struct image_sign_info *info,
 100                 const struct image_region region[], int region_count,
 101                 uint8_t *sig, uint sig_len)
 102 {
 103         return -ENXIO;
 104 }
 105 #endif
 106
 107 #define RSA2048_BYTES   (2048 / 8)
 108 #define RSA4096_BYTES   (4096 / 8)
 109
 110 /* This is the minimum/maximum key size we support, in bits */
 111 #define RSA_MIN_KEY_BITS        2048
 112 #define RSA_MAX_KEY_BITS        4096
 113
 114 /* This is the maximum signature length that we support, in bits */
 115 #define RSA_MAX_SIG_BITS        4096
 116
 117 #endif