1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  *  Copyright IBM Corp. 2001, 2006
4  *  Author(s): Robert Burroughs
5  *	       Eric Rossman (edrossma@us.ibm.com)
6  *
7  *  Hotplug & misc device support: Jochen Roehrig (roehrig@de.ibm.com)
8  *  Major cleanup & driver split: Martin Schwidefsky <schwidefsky@de.ibm.com>
9  */
10 
11 #ifndef _ZCRYPT_CCA_KEY_H_
12 #define _ZCRYPT_CCA_KEY_H_
13 
14 struct t6_keyblock_hdr {
15 	unsigned short blen;
16 	unsigned short ulen;
17 	unsigned short flags;
18 };
19 
20 /**
21  * mapping for the cca private ME key token.
22  * Three parts of interest here: the header, the private section and
23  * the public section.
24  *
25  * mapping for the cca key token header
26  */
27 struct cca_token_hdr {
28 	unsigned char  token_identifier;
29 	unsigned char  version;
30 	unsigned short token_length;
31 	unsigned char  reserved[4];
32 } __packed;
33 
34 #define CCA_TKN_HDR_ID_EXT 0x1E
35 
36 #define CCA_PVT_USAGE_ALL 0x80
37 
38 /**
39  * mapping for the cca public section
40  * In a private key, the modulus doesn't appear in the public
41  * section. So, an arbitrary public exponent of 0x010001 will be
42  * used, for a section length of 0x0F always.
43  */
44 struct cca_public_sec {
45 	unsigned char  section_identifier;
46 	unsigned char  version;
47 	unsigned short section_length;
48 	unsigned char  reserved[2];
49 	unsigned short exponent_len;
50 	unsigned short modulus_bit_len;
51 	unsigned short modulus_byte_len;    /* In a private key, this is 0 */
52 } __packed;
53 
54 /**
55  * mapping for the cca private CRT key 'token'
56  * The first three parts (the only parts considered in this release)
57  * are: the header, the private section and the public section.
58  * The header and public section are the same as for the
59  * struct cca_private_ext_ME
60  *
61  * Following the structure are the quantities p, q, dp, dq, u, pad,
62  * and modulus, in that order, where pad_len is the modulo 8
63  * complement of the residue modulo 8 of the sum of
64  * (p_len + q_len + dp_len + dq_len + u_len).
65  */
66 struct cca_pvt_ext_crt_sec {
67 	unsigned char  section_identifier;
68 	unsigned char  version;
69 	unsigned short section_length;
70 	unsigned char  private_key_hash[20];
71 	unsigned char  reserved1[4];
72 	unsigned char  key_format;
73 	unsigned char  reserved2;
74 	unsigned char  key_name_hash[20];
75 	unsigned char  key_use_flags[4];
76 	unsigned short p_len;
77 	unsigned short q_len;
78 	unsigned short dp_len;
79 	unsigned short dq_len;
80 	unsigned short u_len;
81 	unsigned short mod_len;
82 	unsigned char  reserved3[4];
83 	unsigned short pad_len;
84 	unsigned char  reserved4[52];
85 	unsigned char  confounder[8];
86 } __packed;
87 
88 #define CCA_PVT_EXT_CRT_SEC_ID_PVT 0x08
89 #define CCA_PVT_EXT_CRT_SEC_FMT_CL 0x40
90 
91 /**
92  * Set up private key fields of a type6 MEX message. The _pad variant
93  * strips leading zeroes from the b_key.
94  * Note that all numerics in the key token are big-endian,
95  * while the entries in the key block header are little-endian.
96  *
97  * @mex: pointer to user input data
98  * @p: pointer to memory area for the key
99  *
100  * Returns the size of the key area or negative errno value.
101  */
102 static inline int zcrypt_type6_mex_key_en(struct ica_rsa_modexpo *mex, void *p)
103 {
104 	static struct cca_token_hdr static_pub_hdr = {
105 		.token_identifier	=  0x1E,
106 	};
107 	static struct cca_public_sec static_pub_sec = {
108 		.section_identifier	=  0x04,
109 	};
110 	struct {
111 		struct t6_keyblock_hdr t6_hdr;
112 		struct cca_token_hdr pubhdr;
113 		struct cca_public_sec pubsec;
114 		char exponent[0];
115 	} __packed *key = p;
116 	unsigned char *temp;
117 	int i;
118 
119 	/*
120 	 * The inputdatalength was a selection criteria in the dispatching
121 	 * function zcrypt_rsa_modexpo(). However, do a plausibility check
122 	 * here to make sure the following copy_from_user() can't be utilized
123 	 * to compromise the system.
124 	 */
125 	if (WARN_ON_ONCE(mex->inputdatalength > 512))
126 		return -EINVAL;
127 
128 	memset(key, 0, sizeof(*key));
129 
130 	key->pubhdr = static_pub_hdr;
131 	key->pubsec = static_pub_sec;
132 
133 	/* key parameter block */
134 	temp = key->exponent;
135 	if (copy_from_user(temp, mex->b_key, mex->inputdatalength))
136 		return -EFAULT;
137 	/* Strip leading zeroes from b_key. */
138 	for (i = 0; i < mex->inputdatalength; i++)
139 		if (temp[i])
140 			break;
141 	if (i >= mex->inputdatalength)
142 		return -EINVAL;
143 	memmove(temp, temp + i, mex->inputdatalength - i);
144 	temp += mex->inputdatalength - i;
145 	/* modulus */
146 	if (copy_from_user(temp, mex->n_modulus, mex->inputdatalength))
147 		return -EFAULT;
148 
149 	key->pubsec.modulus_bit_len = 8 * mex->inputdatalength;
150 	key->pubsec.modulus_byte_len = mex->inputdatalength;
151 	key->pubsec.exponent_len = mex->inputdatalength - i;
152 	key->pubsec.section_length = sizeof(key->pubsec) +
153 					2 * mex->inputdatalength - i;
154 	key->pubhdr.token_length =
155 		key->pubsec.section_length + sizeof(key->pubhdr);
156 	key->t6_hdr.ulen = key->pubhdr.token_length + 4;
157 	key->t6_hdr.blen = key->pubhdr.token_length + 6;
158 	return sizeof(*key) + 2 * mex->inputdatalength - i;
159 }
160 
161 /**
162  * Set up private key fields of a type6 CRT message.
163  * Note that all numerics in the key token are big-endian,
164  * while the entries in the key block header are little-endian.
165  *
166  * @mex: pointer to user input data
167  * @p: pointer to memory area for the key
168  *
169  * Returns the size of the key area or -EFAULT
170  */
171 static inline int zcrypt_type6_crt_key(struct ica_rsa_modexpo_crt *crt, void *p)
172 {
173 	static struct cca_public_sec static_cca_pub_sec = {
174 		.section_identifier = 4,
175 		.section_length = 0x000f,
176 		.exponent_len = 0x0003,
177 	};
178 	static char pk_exponent[3] = { 0x01, 0x00, 0x01 };
179 	struct {
180 		struct t6_keyblock_hdr t6_hdr;
181 		struct cca_token_hdr token;
182 		struct cca_pvt_ext_crt_sec pvt;
183 		char key_parts[0];
184 	} __packed *key = p;
185 	struct cca_public_sec *pub;
186 	int short_len, long_len, pad_len, key_len, size;
187 
188 	/*
189 	 * The inputdatalength was a selection criteria in the dispatching
190 	 * function zcrypt_rsa_crt(). However, do a plausibility check
191 	 * here to make sure the following copy_from_user() can't be utilized
192 	 * to compromise the system.
193 	 */
194 	if (WARN_ON_ONCE(crt->inputdatalength > 512))
195 		return -EINVAL;
196 
197 	memset(key, 0, sizeof(*key));
198 
199 	short_len = (crt->inputdatalength + 1) / 2;
200 	long_len = short_len + 8;
201 	pad_len = -(3 * long_len + 2 * short_len) & 7;
202 	key_len = 3 * long_len + 2 * short_len + pad_len + crt->inputdatalength;
203 	size = sizeof(*key) + key_len + sizeof(*pub) + 3;
204 
205 	/* parameter block.key block */
206 	key->t6_hdr.blen = size;
207 	key->t6_hdr.ulen = size - 2;
208 
209 	/* key token header */
210 	key->token.token_identifier = CCA_TKN_HDR_ID_EXT;
211 	key->token.token_length = size - 6;
212 
213 	/* private section */
214 	key->pvt.section_identifier = CCA_PVT_EXT_CRT_SEC_ID_PVT;
215 	key->pvt.section_length = sizeof(key->pvt) + key_len;
216 	key->pvt.key_format = CCA_PVT_EXT_CRT_SEC_FMT_CL;
217 	key->pvt.key_use_flags[0] = CCA_PVT_USAGE_ALL;
218 	key->pvt.p_len = key->pvt.dp_len = key->pvt.u_len = long_len;
219 	key->pvt.q_len = key->pvt.dq_len = short_len;
220 	key->pvt.mod_len = crt->inputdatalength;
221 	key->pvt.pad_len = pad_len;
222 
223 	/* key parts */
224 	if (copy_from_user(key->key_parts, crt->np_prime, long_len) ||
225 	    copy_from_user(key->key_parts + long_len,
226 			   crt->nq_prime, short_len) ||
227 	    copy_from_user(key->key_parts + long_len + short_len,
228 			   crt->bp_key, long_len) ||
229 	    copy_from_user(key->key_parts + 2 * long_len + short_len,
230 			   crt->bq_key, short_len) ||
231 	    copy_from_user(key->key_parts + 2 * long_len + 2 * short_len,
232 			   crt->u_mult_inv, long_len))
233 		return -EFAULT;
234 	memset(key->key_parts + 3 * long_len + 2 * short_len + pad_len,
235 	       0xff, crt->inputdatalength);
236 	pub = (struct cca_public_sec *)(key->key_parts + key_len);
237 	*pub = static_cca_pub_sec;
238 	pub->modulus_bit_len = 8 * crt->inputdatalength;
239 	/*
240 	 * In a private key, the modulus doesn't appear in the public
241 	 * section. So, an arbitrary public exponent of 0x010001 will be
242 	 * used.
243 	 */
244 	memcpy((char *)(pub + 1), pk_exponent, 3);
245 	return size;
246 }
247 
248 #endif /* _ZCRYPT_CCA_KEY_H_ */
249