1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Copyright (c) 2013, Google Inc.
4  *
5  * (C) Copyright 2008 Semihalf
6  *
7  * (C) Copyright 2000-2006
8  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
9  */
10 
11 #ifndef _RSA_H
12 #define _RSA_H
13 
14 #include <errno.h>
15 #include <image.h>
16 
17 /**
18  * struct rsa_public_key - holder for a public key
19  *
20  * An RSA public key consists of a modulus (typically called N), the inverse
21  * and R^2, where R is 2^(# key bits).
22  */
23 
24 struct rsa_public_key {
25 	uint len;		/* len of modulus[] in number of uint32_t */
26 	uint32_t n0inv;		/* -1 / modulus[0] mod 2^32 */
27 	uint32_t *modulus;	/* modulus as little endian array */
28 	uint32_t *rr;		/* R^2 as little endian array */
29 	uint64_t exponent;	/* public exponent */
30 };
31 
32 struct image_sign_info;
33 
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 
69 /**
70  * rsa_verify_hash() - Verify a signature against a hash
71  *
72  * Verify a RSA PKCS1.5 signature against an expected hash.
73  *
74  * @info:	Specifies key and FIT information
75  * @hash:	Hash according to algorithm specified in @info
76  * @sig:	Signature
77  * @sig_len:	Number of bytes in signature
78  * @return 0 if verified, -ve on error
79  */
80 int rsa_verify_hash(struct image_sign_info *info,
81 		    const uint8_t *hash, uint8_t *sig, uint sig_len);
82 
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 
99 int rsa_verify_with_pkey(struct image_sign_info *info,
100 			 const void *hash, uint8_t *sig, uint sig_len);
101 
102 int padding_pkcs_15_verify(struct image_sign_info *info,
103 			   uint8_t *msg, int msg_len,
104 			   const uint8_t *hash, int hash_len);
105 
106 int padding_pss_verify(struct image_sign_info *info,
107 		       uint8_t *msg, int msg_len,
108 		       const uint8_t *hash, int hash_len);
109 
110 #define RSA_DEFAULT_PADDING_NAME		"pkcs-1.5"
111 
112 #define RSA2048_BYTES	(2048 / 8)
113 #define RSA4096_BYTES	(4096 / 8)
114 
115 /* This is the minimum/maximum key size we support, in bits */
116 #define RSA_MIN_KEY_BITS	2048
117 #define RSA_MAX_KEY_BITS	4096
118 
119 /* This is the maximum signature length that we support, in bits */
120 #define RSA_MAX_SIG_BITS	4096
121 
122 #endif
123