1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * Public Key Encryption 4 * 5 * Copyright (c) 2015, Intel Corporation 6 * Authors: Tadeusz Struk <tadeusz.struk@intel.com> 7 */ 8 #ifndef _CRYPTO_AKCIPHER_H 9 #define _CRYPTO_AKCIPHER_H 10 11 #include <linux/atomic.h> 12 #include <linux/crypto.h> 13 14 /** 15 * struct akcipher_request - public key cipher request 16 * 17 * @base: Common attributes for async crypto requests 18 * @src: Source data 19 * @dst: Destination data 20 * @src_len: Size of the input buffer 21 * @dst_len: Size of @dst buffer 22 * It needs to be at least as big as the expected result 23 * depending on the operation. 24 * After operation it will be updated with the actual size of the 25 * result. 26 * In case of error where the dst sgl size was insufficient, 27 * it will be updated to the size required for the operation. 28 * @__ctx: Start of private context data 29 */ 30 struct akcipher_request { 31 struct crypto_async_request base; 32 struct scatterlist *src; 33 struct scatterlist *dst; 34 unsigned int src_len; 35 unsigned int dst_len; 36 void *__ctx[] CRYPTO_MINALIGN_ATTR; 37 }; 38 39 /** 40 * struct crypto_akcipher - user-instantiated objects which encapsulate 41 * algorithms and core processing logic 42 * 43 * @reqsize: Request context size required by algorithm implementation 44 * @base: Common crypto API algorithm data structure 45 */ 46 struct crypto_akcipher { 47 unsigned int reqsize; 48 49 struct crypto_tfm base; 50 }; 51 52 /** 53 * struct akcipher_alg - generic public key cipher algorithm 54 * 55 * @encrypt: Function performs an encrypt operation as defined by public key 56 * algorithm. In case of error, where the dst_len was insufficient, 57 * the req->dst_len will be updated to the size required for the 58 * operation 59 * @decrypt: Function performs a decrypt operation as defined by public key 60 * algorithm. In case of error, where the dst_len was insufficient, 61 * the req->dst_len will be updated to the size required for the 62 * operation 63 * @set_pub_key: Function invokes the algorithm specific set public key 64 * function, which knows how to decode and interpret 65 * the BER encoded public key and parameters 66 * @set_priv_key: Function invokes the algorithm specific set private key 67 * function, which knows how to decode and interpret 68 * the BER encoded private key and parameters 69 * @max_size: Function returns dest buffer size required for a given key. 70 * @init: Initialize the cryptographic transformation object. 71 * This function is used to initialize the cryptographic 72 * transformation object. This function is called only once at 73 * the instantiation time, right after the transformation context 74 * was allocated. In case the cryptographic hardware has some 75 * special requirements which need to be handled by software, this 76 * function shall check for the precise requirement of the 77 * transformation and put any software fallbacks in place. 78 * @exit: Deinitialize the cryptographic transformation object. This is a 79 * counterpart to @init, used to remove various changes set in 80 * @init. 81 * 82 * @base: Common crypto API algorithm data structure 83 */ 84 struct akcipher_alg { 85 int (*encrypt)(struct akcipher_request *req); 86 int (*decrypt)(struct akcipher_request *req); 87 int (*set_pub_key)(struct crypto_akcipher *tfm, const void *key, 88 unsigned int keylen); 89 int (*set_priv_key)(struct crypto_akcipher *tfm, const void *key, 90 unsigned int keylen); 91 unsigned int (*max_size)(struct crypto_akcipher *tfm); 92 int (*init)(struct crypto_akcipher *tfm); 93 void (*exit)(struct crypto_akcipher *tfm); 94 95 struct crypto_alg base; 96 }; 97 98 /** 99 * DOC: Generic Public Key Cipher API 100 * 101 * The Public Key Cipher API is used with the algorithms of type 102 * CRYPTO_ALG_TYPE_AKCIPHER (listed as type "akcipher" in /proc/crypto) 103 */ 104 105 /** 106 * crypto_alloc_akcipher() - allocate AKCIPHER tfm handle 107 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the 108 * public key algorithm e.g. "rsa" 109 * @type: specifies the type of the algorithm 110 * @mask: specifies the mask for the algorithm 111 * 112 * Allocate a handle for public key algorithm. The returned struct 113 * crypto_akcipher is the handle that is required for any subsequent 114 * API invocation for the public key operations. 115 * 116 * Return: allocated handle in case of success; IS_ERR() is true in case 117 * of an error, PTR_ERR() returns the error code. 118 */ 119 struct crypto_akcipher *crypto_alloc_akcipher(const char *alg_name, u32 type, 120 u32 mask); 121 122 static inline struct crypto_tfm *crypto_akcipher_tfm( 123 struct crypto_akcipher *tfm) 124 { 125 return &tfm->base; 126 } 127 128 static inline struct akcipher_alg *__crypto_akcipher_alg(struct crypto_alg *alg) 129 { 130 return container_of(alg, struct akcipher_alg, base); 131 } 132 133 static inline struct crypto_akcipher *__crypto_akcipher_tfm( 134 struct crypto_tfm *tfm) 135 { 136 return container_of(tfm, struct crypto_akcipher, base); 137 } 138 139 static inline struct akcipher_alg *crypto_akcipher_alg( 140 struct crypto_akcipher *tfm) 141 { 142 return __crypto_akcipher_alg(crypto_akcipher_tfm(tfm)->__crt_alg); 143 } 144 145 static inline unsigned int crypto_akcipher_reqsize(struct crypto_akcipher *tfm) 146 { 147 return tfm->reqsize; 148 } 149 150 static inline void akcipher_request_set_tfm(struct akcipher_request *req, 151 struct crypto_akcipher *tfm) 152 { 153 req->base.tfm = crypto_akcipher_tfm(tfm); 154 } 155 156 static inline struct crypto_akcipher *crypto_akcipher_reqtfm( 157 struct akcipher_request *req) 158 { 159 return __crypto_akcipher_tfm(req->base.tfm); 160 } 161 162 /** 163 * crypto_free_akcipher() - free AKCIPHER tfm handle 164 * 165 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher() 166 * 167 * If @tfm is a NULL or error pointer, this function does nothing. 168 */ 169 static inline void crypto_free_akcipher(struct crypto_akcipher *tfm) 170 { 171 crypto_destroy_tfm(tfm, crypto_akcipher_tfm(tfm)); 172 } 173 174 /** 175 * akcipher_request_alloc() - allocates public key request 176 * 177 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher() 178 * @gfp: allocation flags 179 * 180 * Return: allocated handle in case of success or NULL in case of an error. 181 */ 182 static inline struct akcipher_request *akcipher_request_alloc( 183 struct crypto_akcipher *tfm, gfp_t gfp) 184 { 185 struct akcipher_request *req; 186 187 req = kmalloc(sizeof(*req) + crypto_akcipher_reqsize(tfm), gfp); 188 if (likely(req)) 189 akcipher_request_set_tfm(req, tfm); 190 191 return req; 192 } 193 194 /** 195 * akcipher_request_free() - zeroize and free public key request 196 * 197 * @req: request to free 198 */ 199 static inline void akcipher_request_free(struct akcipher_request *req) 200 { 201 kfree_sensitive(req); 202 } 203 204 /** 205 * akcipher_request_set_callback() - Sets an asynchronous callback. 206 * 207 * Callback will be called when an asynchronous operation on a given 208 * request is finished. 209 * 210 * @req: request that the callback will be set for 211 * @flgs: specify for instance if the operation may backlog 212 * @cmpl: callback which will be called 213 * @data: private data used by the caller 214 */ 215 static inline void akcipher_request_set_callback(struct akcipher_request *req, 216 u32 flgs, 217 crypto_completion_t cmpl, 218 void *data) 219 { 220 req->base.complete = cmpl; 221 req->base.data = data; 222 req->base.flags = flgs; 223 } 224 225 /** 226 * akcipher_request_set_crypt() - Sets request parameters 227 * 228 * Sets parameters required by crypto operation 229 * 230 * @req: public key request 231 * @src: ptr to input scatter list 232 * @dst: ptr to output scatter list 233 * @src_len: size of the src input scatter list to be processed 234 * @dst_len: size of the dst output scatter list 235 */ 236 static inline void akcipher_request_set_crypt(struct akcipher_request *req, 237 struct scatterlist *src, 238 struct scatterlist *dst, 239 unsigned int src_len, 240 unsigned int dst_len) 241 { 242 req->src = src; 243 req->dst = dst; 244 req->src_len = src_len; 245 req->dst_len = dst_len; 246 } 247 248 /** 249 * crypto_akcipher_maxsize() - Get len for output buffer 250 * 251 * Function returns the dest buffer size required for a given key. 252 * Function assumes that the key is already set in the transformation. If this 253 * function is called without a setkey or with a failed setkey, you will end up 254 * in a NULL dereference. 255 * 256 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher() 257 */ 258 static inline unsigned int crypto_akcipher_maxsize(struct crypto_akcipher *tfm) 259 { 260 struct akcipher_alg *alg = crypto_akcipher_alg(tfm); 261 262 return alg->max_size(tfm); 263 } 264 265 /** 266 * crypto_akcipher_encrypt() - Invoke public key encrypt operation 267 * 268 * Function invokes the specific public key encrypt operation for a given 269 * public key algorithm 270 * 271 * @req: asymmetric key request 272 * 273 * Return: zero on success; error code in case of error 274 */ 275 static inline int crypto_akcipher_encrypt(struct akcipher_request *req) 276 { 277 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 278 279 return crypto_akcipher_alg(tfm)->encrypt(req); 280 } 281 282 /** 283 * crypto_akcipher_decrypt() - Invoke public key decrypt operation 284 * 285 * Function invokes the specific public key decrypt operation for a given 286 * public key algorithm 287 * 288 * @req: asymmetric key request 289 * 290 * Return: zero on success; error code in case of error 291 */ 292 static inline int crypto_akcipher_decrypt(struct akcipher_request *req) 293 { 294 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 295 296 return crypto_akcipher_alg(tfm)->decrypt(req); 297 } 298 299 /** 300 * crypto_akcipher_sync_encrypt() - Invoke public key encrypt operation 301 * 302 * Function invokes the specific public key encrypt operation for a given 303 * public key algorithm 304 * 305 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher() 306 * @src: source buffer 307 * @slen: source length 308 * @dst: destination obuffer 309 * @dlen: destination length 310 * 311 * Return: zero on success; error code in case of error 312 */ 313 int crypto_akcipher_sync_encrypt(struct crypto_akcipher *tfm, 314 const void *src, unsigned int slen, 315 void *dst, unsigned int dlen); 316 317 /** 318 * crypto_akcipher_sync_decrypt() - Invoke public key decrypt operation 319 * 320 * Function invokes the specific public key decrypt operation for a given 321 * public key algorithm 322 * 323 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher() 324 * @src: source buffer 325 * @slen: source length 326 * @dst: destination obuffer 327 * @dlen: destination length 328 * 329 * Return: Output length on success; error code in case of error 330 */ 331 int crypto_akcipher_sync_decrypt(struct crypto_akcipher *tfm, 332 const void *src, unsigned int slen, 333 void *dst, unsigned int dlen); 334 335 /** 336 * crypto_akcipher_set_pub_key() - Invoke set public key operation 337 * 338 * Function invokes the algorithm specific set key function, which knows 339 * how to decode and interpret the encoded key and parameters 340 * 341 * @tfm: tfm handle 342 * @key: BER encoded public key, algo OID, paramlen, BER encoded 343 * parameters 344 * @keylen: length of the key (not including other data) 345 * 346 * Return: zero on success; error code in case of error 347 */ 348 static inline int crypto_akcipher_set_pub_key(struct crypto_akcipher *tfm, 349 const void *key, 350 unsigned int keylen) 351 { 352 struct akcipher_alg *alg = crypto_akcipher_alg(tfm); 353 354 return alg->set_pub_key(tfm, key, keylen); 355 } 356 357 /** 358 * crypto_akcipher_set_priv_key() - Invoke set private key operation 359 * 360 * Function invokes the algorithm specific set key function, which knows 361 * how to decode and interpret the encoded key and parameters 362 * 363 * @tfm: tfm handle 364 * @key: BER encoded private key, algo OID, paramlen, BER encoded 365 * parameters 366 * @keylen: length of the key (not including other data) 367 * 368 * Return: zero on success; error code in case of error 369 */ 370 static inline int crypto_akcipher_set_priv_key(struct crypto_akcipher *tfm, 371 const void *key, 372 unsigned int keylen) 373 { 374 struct akcipher_alg *alg = crypto_akcipher_alg(tfm); 375 376 return alg->set_priv_key(tfm, key, keylen); 377 } 378 #endif 379