1 /** 2 * AES GCM routines supporting the Power 7+ Nest Accelerators driver 3 * 4 * Copyright (C) 2012 International Business Machines Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; version 2 only. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 18 * 19 * Author: Kent Yoder <yoder1@us.ibm.com> 20 */ 21 22 #include <crypto/internal/aead.h> 23 #include <crypto/aes.h> 24 #include <crypto/algapi.h> 25 #include <crypto/scatterwalk.h> 26 #include <linux/module.h> 27 #include <linux/types.h> 28 #include <linux/crypto.h> 29 #include <asm/vio.h> 30 31 #include "nx_csbcpb.h" 32 #include "nx.h" 33 34 35 static int gcm_aes_nx_set_key(struct crypto_aead *tfm, 36 const u8 *in_key, 37 unsigned int key_len) 38 { 39 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base); 40 struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; 41 struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead; 42 43 nx_ctx_init(nx_ctx, HCOP_FC_AES); 44 45 switch (key_len) { 46 case AES_KEYSIZE_128: 47 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128); 48 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_128); 49 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128]; 50 break; 51 case AES_KEYSIZE_192: 52 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192); 53 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_192); 54 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192]; 55 break; 56 case AES_KEYSIZE_256: 57 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256); 58 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_256); 59 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256]; 60 break; 61 default: 62 return -EINVAL; 63 } 64 65 csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM; 66 memcpy(csbcpb->cpb.aes_gcm.key, in_key, key_len); 67 68 csbcpb_aead->cpb.hdr.mode = NX_MODE_AES_GCA; 69 memcpy(csbcpb_aead->cpb.aes_gca.key, in_key, key_len); 70 71 return 0; 72 } 73 74 static int gcm4106_aes_nx_set_key(struct crypto_aead *tfm, 75 const u8 *in_key, 76 unsigned int key_len) 77 { 78 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base); 79 char *nonce = nx_ctx->priv.gcm.nonce; 80 int rc; 81 82 if (key_len < 4) 83 return -EINVAL; 84 85 key_len -= 4; 86 87 rc = gcm_aes_nx_set_key(tfm, in_key, key_len); 88 if (rc) 89 goto out; 90 91 memcpy(nonce, in_key + key_len, 4); 92 out: 93 return rc; 94 } 95 96 static int gcm_aes_nx_setauthsize(struct crypto_aead *tfm, 97 unsigned int authsize) 98 { 99 if (authsize > crypto_aead_alg(tfm)->maxauthsize) 100 return -EINVAL; 101 102 crypto_aead_crt(tfm)->authsize = authsize; 103 104 return 0; 105 } 106 107 static int gcm4106_aes_nx_setauthsize(struct crypto_aead *tfm, 108 unsigned int authsize) 109 { 110 switch (authsize) { 111 case 8: 112 case 12: 113 case 16: 114 break; 115 default: 116 return -EINVAL; 117 } 118 119 crypto_aead_crt(tfm)->authsize = authsize; 120 121 return 0; 122 } 123 124 static int nx_gca(struct nx_crypto_ctx *nx_ctx, 125 struct aead_request *req, 126 u8 *out) 127 { 128 struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead; 129 int rc = -EINVAL; 130 struct scatter_walk walk; 131 struct nx_sg *nx_sg = nx_ctx->in_sg; 132 133 if (req->assoclen > nx_ctx->ap->databytelen) 134 goto out; 135 136 if (req->assoclen <= AES_BLOCK_SIZE) { 137 scatterwalk_start(&walk, req->assoc); 138 scatterwalk_copychunks(out, &walk, req->assoclen, 139 SCATTERWALK_FROM_SG); 140 scatterwalk_done(&walk, SCATTERWALK_FROM_SG, 0); 141 142 rc = 0; 143 goto out; 144 } 145 146 nx_sg = nx_walk_and_build(nx_sg, nx_ctx->ap->sglen, req->assoc, 0, 147 req->assoclen); 148 nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_sg) * sizeof(struct nx_sg); 149 150 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op_aead, 151 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 152 if (rc) 153 goto out; 154 155 atomic_inc(&(nx_ctx->stats->aes_ops)); 156 atomic64_add(req->assoclen, &(nx_ctx->stats->aes_bytes)); 157 158 memcpy(out, csbcpb_aead->cpb.aes_gca.out_pat, AES_BLOCK_SIZE); 159 out: 160 return rc; 161 } 162 163 static int gcm_aes_nx_crypt(struct aead_request *req, int enc) 164 { 165 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 166 struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; 167 struct blkcipher_desc desc; 168 unsigned int nbytes = req->cryptlen; 169 int rc = -EINVAL; 170 171 if (nbytes > nx_ctx->ap->databytelen) 172 goto out; 173 174 desc.info = nx_ctx->priv.gcm.iv; 175 /* initialize the counter */ 176 *(u32 *)(desc.info + NX_GCM_CTR_OFFSET) = 1; 177 178 /* For scenarios where the input message is zero length, AES CTR mode 179 * may be used. Set the source data to be a single block (16B) of all 180 * zeros, and set the input IV value to be the same as the GMAC IV 181 * value. - nx_wb 4.8.1.3 */ 182 if (nbytes == 0) { 183 char src[AES_BLOCK_SIZE] = {}; 184 struct scatterlist sg; 185 186 desc.tfm = crypto_alloc_blkcipher("ctr(aes)", 0, 0); 187 if (IS_ERR(desc.tfm)) { 188 rc = -ENOMEM; 189 goto out; 190 } 191 192 crypto_blkcipher_setkey(desc.tfm, csbcpb->cpb.aes_gcm.key, 193 NX_CPB_KEY_SIZE(csbcpb) == NX_KS_AES_128 ? 16 : 194 NX_CPB_KEY_SIZE(csbcpb) == NX_KS_AES_192 ? 24 : 32); 195 196 sg_init_one(&sg, src, AES_BLOCK_SIZE); 197 if (enc) 198 crypto_blkcipher_encrypt_iv(&desc, req->dst, &sg, 199 AES_BLOCK_SIZE); 200 else 201 crypto_blkcipher_decrypt_iv(&desc, req->dst, &sg, 202 AES_BLOCK_SIZE); 203 crypto_free_blkcipher(desc.tfm); 204 205 rc = 0; 206 goto out; 207 } 208 209 desc.tfm = (struct crypto_blkcipher *)req->base.tfm; 210 211 csbcpb->cpb.aes_gcm.bit_length_aad = req->assoclen * 8; 212 213 if (req->assoclen) { 214 rc = nx_gca(nx_ctx, req, csbcpb->cpb.aes_gcm.in_pat_or_aad); 215 if (rc) 216 goto out; 217 } 218 219 if (enc) 220 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT; 221 else 222 nbytes -= crypto_aead_authsize(crypto_aead_reqtfm(req)); 223 224 csbcpb->cpb.aes_gcm.bit_length_data = nbytes * 8; 225 226 rc = nx_build_sg_lists(nx_ctx, &desc, req->dst, req->src, nbytes, 227 csbcpb->cpb.aes_gcm.iv_or_cnt); 228 if (rc) 229 goto out; 230 231 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 232 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 233 if (rc) 234 goto out; 235 236 atomic_inc(&(nx_ctx->stats->aes_ops)); 237 atomic64_add(csbcpb->csb.processed_byte_count, 238 &(nx_ctx->stats->aes_bytes)); 239 240 if (enc) { 241 /* copy out the auth tag */ 242 scatterwalk_map_and_copy(csbcpb->cpb.aes_gcm.out_pat_or_mac, 243 req->dst, nbytes, 244 crypto_aead_authsize(crypto_aead_reqtfm(req)), 245 SCATTERWALK_TO_SG); 246 } else if (req->assoclen) { 247 u8 *itag = nx_ctx->priv.gcm.iauth_tag; 248 u8 *otag = csbcpb->cpb.aes_gcm.out_pat_or_mac; 249 250 scatterwalk_map_and_copy(itag, req->dst, nbytes, 251 crypto_aead_authsize(crypto_aead_reqtfm(req)), 252 SCATTERWALK_FROM_SG); 253 rc = memcmp(itag, otag, 254 crypto_aead_authsize(crypto_aead_reqtfm(req))) ? 255 -EBADMSG : 0; 256 } 257 out: 258 return rc; 259 } 260 261 static int gcm_aes_nx_encrypt(struct aead_request *req) 262 { 263 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 264 char *iv = nx_ctx->priv.gcm.iv; 265 266 memcpy(iv, req->iv, 12); 267 268 return gcm_aes_nx_crypt(req, 1); 269 } 270 271 static int gcm_aes_nx_decrypt(struct aead_request *req) 272 { 273 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 274 char *iv = nx_ctx->priv.gcm.iv; 275 276 memcpy(iv, req->iv, 12); 277 278 return gcm_aes_nx_crypt(req, 0); 279 } 280 281 static int gcm4106_aes_nx_encrypt(struct aead_request *req) 282 { 283 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 284 char *iv = nx_ctx->priv.gcm.iv; 285 char *nonce = nx_ctx->priv.gcm.nonce; 286 287 memcpy(iv, nonce, NX_GCM4106_NONCE_LEN); 288 memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8); 289 290 return gcm_aes_nx_crypt(req, 1); 291 } 292 293 static int gcm4106_aes_nx_decrypt(struct aead_request *req) 294 { 295 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 296 char *iv = nx_ctx->priv.gcm.iv; 297 char *nonce = nx_ctx->priv.gcm.nonce; 298 299 memcpy(iv, nonce, NX_GCM4106_NONCE_LEN); 300 memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8); 301 302 return gcm_aes_nx_crypt(req, 0); 303 } 304 305 /* tell the block cipher walk routines that this is a stream cipher by 306 * setting cra_blocksize to 1. Even using blkcipher_walk_virt_block 307 * during encrypt/decrypt doesn't solve this problem, because it calls 308 * blkcipher_walk_done under the covers, which doesn't use walk->blocksize, 309 * but instead uses this tfm->blocksize. */ 310 struct crypto_alg nx_gcm_aes_alg = { 311 .cra_name = "gcm(aes)", 312 .cra_driver_name = "gcm-aes-nx", 313 .cra_priority = 300, 314 .cra_flags = CRYPTO_ALG_TYPE_AEAD, 315 .cra_blocksize = 1, 316 .cra_ctxsize = sizeof(struct nx_crypto_ctx), 317 .cra_type = &crypto_aead_type, 318 .cra_module = THIS_MODULE, 319 .cra_init = nx_crypto_ctx_aes_gcm_init, 320 .cra_exit = nx_crypto_ctx_exit, 321 .cra_aead = { 322 .ivsize = AES_BLOCK_SIZE, 323 .maxauthsize = AES_BLOCK_SIZE, 324 .setkey = gcm_aes_nx_set_key, 325 .setauthsize = gcm_aes_nx_setauthsize, 326 .encrypt = gcm_aes_nx_encrypt, 327 .decrypt = gcm_aes_nx_decrypt, 328 } 329 }; 330 331 struct crypto_alg nx_gcm4106_aes_alg = { 332 .cra_name = "rfc4106(gcm(aes))", 333 .cra_driver_name = "rfc4106-gcm-aes-nx", 334 .cra_priority = 300, 335 .cra_flags = CRYPTO_ALG_TYPE_AEAD, 336 .cra_blocksize = 1, 337 .cra_ctxsize = sizeof(struct nx_crypto_ctx), 338 .cra_type = &crypto_nivaead_type, 339 .cra_module = THIS_MODULE, 340 .cra_init = nx_crypto_ctx_aes_gcm_init, 341 .cra_exit = nx_crypto_ctx_exit, 342 .cra_aead = { 343 .ivsize = 8, 344 .maxauthsize = AES_BLOCK_SIZE, 345 .geniv = "seqiv", 346 .setkey = gcm4106_aes_nx_set_key, 347 .setauthsize = gcm4106_aes_nx_setauthsize, 348 .encrypt = gcm4106_aes_nx_encrypt, 349 .decrypt = gcm4106_aes_nx_decrypt, 350 } 351 }; 352