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 119