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 request 16 * 17 * @base: Common attributes for async crypto requests 18 * @src: Source data 19 * For verify op this is signature + digest, in that case 20 * total size of @src is @src_len + @dst_len. 21 * @dst: Destination data (Should be NULL for verify op) 22 * @src_len: Size of the input buffer 23 * For verify op it's size of signature part of @src, this part 24 * is supposed to be operated by cipher. 25 * @dst_len: Size of @dst buffer (for all ops except verify). 26 * It needs to be at least as big as the expected result 27 * depending on the operation. 28 * After operation it will be updated with the actual size of the 29 * result. 30 * In case of error where the dst sgl size was insufficient, 31 * it will be updated to the size required for the operation. 32 * For verify op this is size of digest part in @src. 33 * @__ctx: Start of private context data 34 */ 35 struct akcipher_request { 36 struct crypto_async_request base; 37 struct scatterlist *src; 38 struct scatterlist *dst; 39 unsigned int src_len; 40 unsigned int dst_len; 41 void *__ctx[] CRYPTO_MINALIGN_ATTR; 42 }; 43 44 /** 45 * struct crypto_akcipher - user-instantiated objects which encapsulate 46 * algorithms and core processing logic 47 * 48 * @reqsize: Request context size required by algorithm implementation 49 * @base: Common crypto API algorithm data structure 50 */ 51 struct crypto_akcipher { 52 unsigned int reqsize; 53 54 struct crypto_tfm base; 55 }; 56 57 /** 58 * struct akcipher_alg - generic public key algorithm 59 * 60 * @sign: Function performs a sign operation as defined by public key 61 * algorithm. In case of error, where the dst_len was insufficient, 62 * the req->dst_len will be updated to the size required for the 63 * operation 64 * @verify: Function performs a complete verify operation as defined by 65 * public key algorithm, returning verification status. Requires 66 * digest value as input parameter. 67 * @encrypt: Function performs an encrypt operation as defined by public key 68 * algorithm. In case of error, where the dst_len was insufficient, 69 * the req->dst_len will be updated to the size required for the 70 * operation 71 * @decrypt: Function performs a decrypt operation as defined by public key 72 * algorithm. In case of error, where the dst_len was insufficient, 73 * the req->dst_len will be updated to the size required for the 74 * operation 75 * @set_pub_key: Function invokes the algorithm specific set public key 76 * function, which knows how to decode and interpret 77 * the BER encoded public key and parameters 78 * @set_priv_key: Function invokes the algorithm specific set private key 79 * function, which knows how to decode and interpret 80 * the BER encoded private key and parameters 81 * @max_size: Function returns dest buffer size required for a given key. 82 * @init: Initialize the cryptographic transformation object. 83 * This function is used to initialize the cryptographic 84 * transformation object. This function is called only once at 85 * the instantiation time, right after the transformation context 86 * was allocated. In case the cryptographic hardware has some 87 * special requirements which need to be handled by software, this 88 * function shall check for the precise requirement of the 89 * transformation and put any software fallbacks in place. 90 * @exit: Deinitialize the cryptographic transformation object. This is a 91 * counterpart to @init, used to remove various changes set in 92 * @init. 93 * 94 * @base: Common crypto API algorithm data structure 95 */ 96 struct akcipher_alg { 97 int (*sign)(struct akcipher_request *req); 98 int (*verify)(struct akcipher_request *req); 99 int (*encrypt)(struct akcipher_request *req); 100 int (*decrypt)(struct akcipher_request *req); 101 int (*set_pub_key)(struct crypto_akcipher *tfm, const void *key, 102 unsigned int keylen); 103 int (*set_priv_key)(struct crypto_akcipher *tfm, const void *key, 104 unsigned int keylen); 105 unsigned int (*max_size)(struct crypto_akcipher *tfm); 106 int (*init)(struct crypto_akcipher *tfm); 107 void (*exit)(struct crypto_akcipher *tfm); 108 109 struct crypto_alg base; 110 }; 111 112 /** 113 * DOC: Generic Public Key API 114 * 115 * The Public Key API is used with the algorithms of type 116 * CRYPTO_ALG_TYPE_AKCIPHER (listed as type "akcipher" in /proc/crypto) 117 */ 118 119 /** 120 * crypto_alloc_akcipher() - allocate AKCIPHER tfm handle 121 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the 122 * public key algorithm e.g. "rsa" 123 * @type: specifies the type of the algorithm 124 * @mask: specifies the mask for the algorithm 125 * 126 * Allocate a handle for public key algorithm. The returned struct 127 * crypto_akcipher is the handle that is required for any subsequent 128 * API invocation for the public key operations. 129 * 130 * Return: allocated handle in case of success; IS_ERR() is true in case 131 * of an error, PTR_ERR() returns the error code. 132 */ 133 struct crypto_akcipher *crypto_alloc_akcipher(const char *alg_name, u32 type, 134 u32 mask); 135 136 static inline struct crypto_tfm *crypto_akcipher_tfm( 137 struct crypto_akcipher *tfm) 138 { 139 return &tfm->base; 140 } 141 142 static inline struct akcipher_alg *__crypto_akcipher_alg(struct crypto_alg *alg) 143 { 144 return container_of(alg, struct akcipher_alg, base); 145 } 146 147 static inline struct crypto_akcipher *__crypto_akcipher_tfm( 148 struct crypto_tfm *tfm) 149 { 150 return container_of(tfm, struct crypto_akcipher, base); 151 } 152 153 static inline struct akcipher_alg *crypto_akcipher_alg( 154 struct crypto_akcipher *tfm) 155 { 156 return __crypto_akcipher_alg(crypto_akcipher_tfm(tfm)->__crt_alg); 157 } 158 159 static inline unsigned int crypto_akcipher_reqsize(struct crypto_akcipher *tfm) 160 { 161 return tfm->reqsize; 162 } 163 164 static inline void akcipher_request_set_tfm(struct akcipher_request *req, 165 struct crypto_akcipher *tfm) 166 { 167 req->base.tfm = crypto_akcipher_tfm(tfm); 168 } 169 170 static inline struct crypto_akcipher *crypto_akcipher_reqtfm( 171 struct akcipher_request *req) 172 { 173 return __crypto_akcipher_tfm(req->base.tfm); 174 } 175 176 /** 177 * crypto_free_akcipher() - free AKCIPHER tfm handle 178 * 179 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher() 180 * 181 * If @tfm is a NULL or error pointer, this function does nothing. 182 */ 183 static inline void crypto_free_akcipher(struct crypto_akcipher *tfm) 184 { 185 crypto_destroy_tfm(tfm, crypto_akcipher_tfm(tfm)); 186 } 187 188 /** 189 * akcipher_request_alloc() - allocates public key request 190 * 191 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher() 192 * @gfp: allocation flags 193 * 194 * Return: allocated handle in case of success or NULL in case of an error. 195 */ 196 static inline struct akcipher_request *akcipher_request_alloc( 197 struct crypto_akcipher *tfm, gfp_t gfp) 198 { 199 struct akcipher_request *req; 200 201 req = kmalloc(sizeof(*req) + crypto_akcipher_reqsize(tfm), gfp); 202 if (likely(req)) 203 akcipher_request_set_tfm(req, tfm); 204 205 return req; 206 } 207 208 /** 209 * akcipher_request_free() - zeroize and free public key request 210 * 211 * @req: request to free 212 */ 213 static inline void akcipher_request_free(struct akcipher_request *req) 214 { 215 kfree_sensitive(req); 216 } 217 218 /** 219 * akcipher_request_set_callback() - Sets an asynchronous callback. 220 * 221 * Callback will be called when an asynchronous operation on a given 222 * request is finished. 223 * 224 * @req: request that the callback will be set for 225 * @flgs: specify for instance if the operation may backlog 226 * @cmpl: callback which will be called 227 * @data: private data used by the caller 228 */ 229 static inline void akcipher_request_set_callback(struct akcipher_request *req, 230 u32 flgs, 231 crypto_completion_t cmpl, 232 void *data) 233 { 234 req->base.complete = cmpl; 235 req->base.data = data; 236 req->base.flags = flgs; 237 } 238 239 /** 240 * akcipher_request_set_crypt() - Sets request parameters 241 * 242 * Sets parameters required by crypto operation 243 * 244 * @req: public key request 245 * @src: ptr to input scatter list 246 * @dst: ptr to output scatter list or NULL for verify op 247 * @src_len: size of the src input scatter list to be processed 248 * @dst_len: size of the dst output scatter list or size of signature 249 * portion in @src for verify op 250 */ 251 static inline void akcipher_request_set_crypt(struct akcipher_request *req, 252 struct scatterlist *src, 253 struct scatterlist *dst, 254 unsigned int src_len, 255 unsigned int dst_len) 256 { 257 req->src = src; 258 req->dst = dst; 259 req->src_len = src_len; 260 req->dst_len = dst_len; 261 } 262 263 /** 264 * crypto_akcipher_maxsize() - Get len for output buffer 265 * 266 * Function returns the dest buffer size required for a given key. 267 * Function assumes that the key is already set in the transformation. If this 268 * function is called without a setkey or with a failed setkey, you will end up 269 * in a NULL dereference. 270 * 271 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher() 272 */ 273 static inline unsigned int crypto_akcipher_maxsize(struct crypto_akcipher *tfm) 274 { 275 struct akcipher_alg *alg = crypto_akcipher_alg(tfm); 276 277 return alg->max_size(tfm); 278 } 279 280 /** 281 * crypto_akcipher_encrypt() - Invoke public key encrypt operation 282 * 283 * Function invokes the specific public key encrypt operation for a given 284 * public key algorithm 285 * 286 * @req: asymmetric key request 287 * 288 * Return: zero on success; error code in case of error 289 */ 290 static inline int crypto_akcipher_encrypt(struct akcipher_request *req) 291 { 292 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 293 294 return crypto_akcipher_alg(tfm)->encrypt(req); 295 } 296 297 /** 298 * crypto_akcipher_decrypt() - Invoke public key decrypt operation 299 * 300 * Function invokes the specific public key decrypt operation for a given 301 * public key algorithm 302 * 303 * @req: asymmetric key request 304 * 305 * Return: zero on success; error code in case of error 306 */ 307 static inline int crypto_akcipher_decrypt(struct akcipher_request *req) 308 { 309 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 310 311 return crypto_akcipher_alg(tfm)->decrypt(req); 312 } 313 314 /** 315 * crypto_akcipher_sync_encrypt() - Invoke public key encrypt operation 316 * 317 * Function invokes the specific public key encrypt operation for a given 318 * public key algorithm 319 * 320 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher() 321 * @src: source buffer 322 * @slen: source length 323 * @dst: destination obuffer 324 * @dlen: destination length 325 * 326 * Return: zero on success; error code in case of error 327 */ 328 int crypto_akcipher_sync_encrypt(struct crypto_akcipher *tfm, 329 const void *src, unsigned int slen, 330 void *dst, unsigned int dlen); 331 332 /** 333 * crypto_akcipher_sync_decrypt() - Invoke public key decrypt operation 334 * 335 * Function invokes the specific public key decrypt operation for a given 336 * public key algorithm 337 * 338 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher() 339 * @src: source buffer 340 * @slen: source length 341 * @dst: destination obuffer 342 * @dlen: destination length 343 * 344 * Return: Output length on success; error code in case of error 345 */ 346 int crypto_akcipher_sync_decrypt(struct crypto_akcipher *tfm, 347 const void *src, unsigned int slen, 348 void *dst, unsigned int dlen); 349 350 /** 351 * crypto_akcipher_sign() - Invoke public key sign operation 352 * 353 * Function invokes the specific public key sign operation for a given 354 * public key algorithm 355 * 356 * @req: asymmetric key request 357 * 358 * Return: zero on success; error code in case of error 359 */ 360 static inline int crypto_akcipher_sign(struct akcipher_request *req) 361 { 362 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 363 364 return crypto_akcipher_alg(tfm)->sign(req); 365 } 366 367 /** 368 * crypto_akcipher_verify() - Invoke public key signature verification 369 * 370 * Function invokes the specific public key signature verification operation 371 * for a given public key algorithm. 372 * 373 * @req: asymmetric key request 374 * 375 * Note: req->dst should be NULL, req->src should point to SG of size 376 * (req->src_size + req->dst_size), containing signature (of req->src_size 377 * length) with appended digest (of req->dst_size length). 378 * 379 * Return: zero on verification success; error code in case of error. 380 */ 381 static inline int crypto_akcipher_verify(struct akcipher_request *req) 382 { 383 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 384 385 return crypto_akcipher_alg(tfm)->verify(req); 386 } 387 388 /** 389 * crypto_akcipher_set_pub_key() - Invoke set public key operation 390 * 391 * Function invokes the algorithm specific set key function, which knows 392 * how to decode and interpret the encoded key and parameters 393 * 394 * @tfm: tfm handle 395 * @key: BER encoded public key, algo OID, paramlen, BER encoded 396 * parameters 397 * @keylen: length of the key (not including other data) 398 * 399 * Return: zero on success; error code in case of error 400 */ 401 static inline int crypto_akcipher_set_pub_key(struct crypto_akcipher *tfm, 402 const void *key, 403 unsigned int keylen) 404 { 405 struct akcipher_alg *alg = crypto_akcipher_alg(tfm); 406 407 return alg->set_pub_key(tfm, key, keylen); 408 } 409 410 /** 411 * crypto_akcipher_set_priv_key() - Invoke set private key operation 412 * 413 * Function invokes the algorithm specific set key function, which knows 414 * how to decode and interpret the encoded key and parameters 415 * 416 * @tfm: tfm handle 417 * @key: BER encoded private key, algo OID, paramlen, BER encoded 418 * parameters 419 * @keylen: length of the key (not including other data) 420 * 421 * Return: zero on success; error code in case of error 422 */ 423 static inline int crypto_akcipher_set_priv_key(struct crypto_akcipher *tfm, 424 const void *key, 425 unsigned int keylen) 426 { 427 struct akcipher_alg *alg = crypto_akcipher_alg(tfm); 428 429 return alg->set_priv_key(tfm, key, keylen); 430 } 431 #endif 432