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 121