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 118