1 /* 2 * linux/net/sunrpc/gss_krb5_crypto.c 3 * 4 * Copyright (c) 2000 The Regents of the University of Michigan. 5 * All rights reserved. 6 * 7 * Andy Adamson <andros@umich.edu> 8 * Bruce Fields <bfields@umich.edu> 9 */ 10 11 /* 12 * Copyright (C) 1998 by the FundsXpress, INC. 13 * 14 * All rights reserved. 15 * 16 * Export of this software from the United States of America may require 17 * a specific license from the United States Government. It is the 18 * responsibility of any person or organization contemplating export to 19 * obtain such a license before exporting. 20 * 21 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and 22 * distribute this software and its documentation for any purpose and 23 * without fee is hereby granted, provided that the above copyright 24 * notice appear in all copies and that both that copyright notice and 25 * this permission notice appear in supporting documentation, and that 26 * the name of FundsXpress. not be used in advertising or publicity pertaining 27 * to distribution of the software without specific, written prior 28 * permission. FundsXpress makes no representations about the suitability of 29 * this software for any purpose. It is provided "as is" without express 30 * or implied warranty. 31 * 32 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 33 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 34 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 35 */ 36 37 #include <linux/types.h> 38 #include <linux/mm.h> 39 #include <linux/slab.h> 40 #include <linux/scatterlist.h> 41 #include <linux/crypto.h> 42 #include <linux/highmem.h> 43 #include <linux/pagemap.h> 44 #include <linux/sunrpc/gss_krb5.h> 45 46 #ifdef RPC_DEBUG 47 # define RPCDBG_FACILITY RPCDBG_AUTH 48 #endif 49 50 u32 51 krb5_encrypt( 52 struct crypto_tfm *tfm, 53 void * iv, 54 void * in, 55 void * out, 56 int length) 57 { 58 u32 ret = -EINVAL; 59 struct scatterlist sg[1]; 60 u8 local_iv[16] = {0}; 61 62 dprintk("RPC: krb5_encrypt: input data:\n"); 63 print_hexl((u32 *)in, length, 0); 64 65 if (length % crypto_tfm_alg_blocksize(tfm) != 0) 66 goto out; 67 68 if (crypto_tfm_alg_ivsize(tfm) > 16) { 69 dprintk("RPC: gss_k5encrypt: tfm iv size to large %d\n", 70 crypto_tfm_alg_ivsize(tfm)); 71 goto out; 72 } 73 74 if (iv) 75 memcpy(local_iv, iv, crypto_tfm_alg_ivsize(tfm)); 76 77 memcpy(out, in, length); 78 sg_set_buf(sg, out, length); 79 80 ret = crypto_cipher_encrypt_iv(tfm, sg, sg, length, local_iv); 81 82 dprintk("RPC: krb5_encrypt: output data:\n"); 83 print_hexl((u32 *)out, length, 0); 84 out: 85 dprintk("RPC: krb5_encrypt returns %d\n",ret); 86 return(ret); 87 } 88 89 EXPORT_SYMBOL(krb5_encrypt); 90 91 u32 92 krb5_decrypt( 93 struct crypto_tfm *tfm, 94 void * iv, 95 void * in, 96 void * out, 97 int length) 98 { 99 u32 ret = -EINVAL; 100 struct scatterlist sg[1]; 101 u8 local_iv[16] = {0}; 102 103 dprintk("RPC: krb5_decrypt: input data:\n"); 104 print_hexl((u32 *)in, length, 0); 105 106 if (length % crypto_tfm_alg_blocksize(tfm) != 0) 107 goto out; 108 109 if (crypto_tfm_alg_ivsize(tfm) > 16) { 110 dprintk("RPC: gss_k5decrypt: tfm iv size to large %d\n", 111 crypto_tfm_alg_ivsize(tfm)); 112 goto out; 113 } 114 if (iv) 115 memcpy(local_iv,iv, crypto_tfm_alg_ivsize(tfm)); 116 117 memcpy(out, in, length); 118 sg_set_buf(sg, out, length); 119 120 ret = crypto_cipher_decrypt_iv(tfm, sg, sg, length, local_iv); 121 122 dprintk("RPC: krb5_decrypt: output_data:\n"); 123 print_hexl((u32 *)out, length, 0); 124 out: 125 dprintk("RPC: gss_k5decrypt returns %d\n",ret); 126 return(ret); 127 } 128 129 EXPORT_SYMBOL(krb5_decrypt); 130 131 static int 132 process_xdr_buf(struct xdr_buf *buf, int offset, int len, 133 int (*actor)(struct scatterlist *, void *), void *data) 134 { 135 int i, page_len, thislen, page_offset, ret = 0; 136 struct scatterlist sg[1]; 137 138 if (offset >= buf->head[0].iov_len) { 139 offset -= buf->head[0].iov_len; 140 } else { 141 thislen = buf->head[0].iov_len - offset; 142 if (thislen > len) 143 thislen = len; 144 sg_set_buf(sg, buf->head[0].iov_base + offset, thislen); 145 ret = actor(sg, data); 146 if (ret) 147 goto out; 148 offset = 0; 149 len -= thislen; 150 } 151 if (len == 0) 152 goto out; 153 154 if (offset >= buf->page_len) { 155 offset -= buf->page_len; 156 } else { 157 page_len = buf->page_len - offset; 158 if (page_len > len) 159 page_len = len; 160 len -= page_len; 161 page_offset = (offset + buf->page_base) & (PAGE_CACHE_SIZE - 1); 162 i = (offset + buf->page_base) >> PAGE_CACHE_SHIFT; 163 thislen = PAGE_CACHE_SIZE - page_offset; 164 do { 165 if (thislen > page_len) 166 thislen = page_len; 167 sg->page = buf->pages[i]; 168 sg->offset = page_offset; 169 sg->length = thislen; 170 ret = actor(sg, data); 171 if (ret) 172 goto out; 173 page_len -= thislen; 174 i++; 175 page_offset = 0; 176 thislen = PAGE_CACHE_SIZE; 177 } while (page_len != 0); 178 offset = 0; 179 } 180 if (len == 0) 181 goto out; 182 183 if (offset < buf->tail[0].iov_len) { 184 thislen = buf->tail[0].iov_len - offset; 185 if (thislen > len) 186 thislen = len; 187 sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen); 188 ret = actor(sg, data); 189 len -= thislen; 190 } 191 if (len != 0) 192 ret = -EINVAL; 193 out: 194 return ret; 195 } 196 197 static int 198 checksummer(struct scatterlist *sg, void *data) 199 { 200 struct crypto_tfm *tfm = (struct crypto_tfm *)data; 201 202 crypto_digest_update(tfm, sg, 1); 203 204 return 0; 205 } 206 207 /* checksum the plaintext data and hdrlen bytes of the token header */ 208 s32 209 make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body, 210 int body_offset, struct xdr_netobj *cksum) 211 { 212 char *cksumname; 213 struct crypto_tfm *tfm = NULL; /* XXX add to ctx? */ 214 struct scatterlist sg[1]; 215 216 switch (cksumtype) { 217 case CKSUMTYPE_RSA_MD5: 218 cksumname = "md5"; 219 break; 220 default: 221 dprintk("RPC: krb5_make_checksum:" 222 " unsupported checksum %d", cksumtype); 223 return GSS_S_FAILURE; 224 } 225 if (!(tfm = crypto_alloc_tfm(cksumname, CRYPTO_TFM_REQ_MAY_SLEEP))) 226 return GSS_S_FAILURE; 227 cksum->len = crypto_tfm_alg_digestsize(tfm); 228 229 crypto_digest_init(tfm); 230 sg_set_buf(sg, header, hdrlen); 231 crypto_digest_update(tfm, sg, 1); 232 process_xdr_buf(body, body_offset, body->len - body_offset, 233 checksummer, tfm); 234 crypto_digest_final(tfm, cksum->data); 235 crypto_free_tfm(tfm); 236 return 0; 237 } 238 239 EXPORT_SYMBOL(make_checksum); 240 241 struct encryptor_desc { 242 u8 iv[8]; /* XXX hard-coded blocksize */ 243 struct crypto_tfm *tfm; 244 int pos; 245 struct xdr_buf *outbuf; 246 struct page **pages; 247 struct scatterlist infrags[4]; 248 struct scatterlist outfrags[4]; 249 int fragno; 250 int fraglen; 251 }; 252 253 static int 254 encryptor(struct scatterlist *sg, void *data) 255 { 256 struct encryptor_desc *desc = data; 257 struct xdr_buf *outbuf = desc->outbuf; 258 struct page *in_page; 259 int thislen = desc->fraglen + sg->length; 260 int fraglen, ret; 261 int page_pos; 262 263 /* Worst case is 4 fragments: head, end of page 1, start 264 * of page 2, tail. Anything more is a bug. */ 265 BUG_ON(desc->fragno > 3); 266 desc->infrags[desc->fragno] = *sg; 267 desc->outfrags[desc->fragno] = *sg; 268 269 page_pos = desc->pos - outbuf->head[0].iov_len; 270 if (page_pos >= 0 && page_pos < outbuf->page_len) { 271 /* pages are not in place: */ 272 int i = (page_pos + outbuf->page_base) >> PAGE_CACHE_SHIFT; 273 in_page = desc->pages[i]; 274 } else { 275 in_page = sg->page; 276 } 277 desc->infrags[desc->fragno].page = in_page; 278 desc->fragno++; 279 desc->fraglen += sg->length; 280 desc->pos += sg->length; 281 282 fraglen = thislen & 7; /* XXX hardcoded blocksize */ 283 thislen -= fraglen; 284 285 if (thislen == 0) 286 return 0; 287 288 ret = crypto_cipher_encrypt_iv(desc->tfm, desc->outfrags, desc->infrags, 289 thislen, desc->iv); 290 if (ret) 291 return ret; 292 if (fraglen) { 293 desc->outfrags[0].page = sg->page; 294 desc->outfrags[0].offset = sg->offset + sg->length - fraglen; 295 desc->outfrags[0].length = fraglen; 296 desc->infrags[0] = desc->outfrags[0]; 297 desc->infrags[0].page = in_page; 298 desc->fragno = 1; 299 desc->fraglen = fraglen; 300 } else { 301 desc->fragno = 0; 302 desc->fraglen = 0; 303 } 304 return 0; 305 } 306 307 int 308 gss_encrypt_xdr_buf(struct crypto_tfm *tfm, struct xdr_buf *buf, int offset, 309 struct page **pages) 310 { 311 int ret; 312 struct encryptor_desc desc; 313 314 BUG_ON((buf->len - offset) % crypto_tfm_alg_blocksize(tfm) != 0); 315 316 memset(desc.iv, 0, sizeof(desc.iv)); 317 desc.tfm = tfm; 318 desc.pos = offset; 319 desc.outbuf = buf; 320 desc.pages = pages; 321 desc.fragno = 0; 322 desc.fraglen = 0; 323 324 ret = process_xdr_buf(buf, offset, buf->len - offset, encryptor, &desc); 325 return ret; 326 } 327 328 EXPORT_SYMBOL(gss_encrypt_xdr_buf); 329 330 struct decryptor_desc { 331 u8 iv[8]; /* XXX hard-coded blocksize */ 332 struct crypto_tfm *tfm; 333 struct scatterlist frags[4]; 334 int fragno; 335 int fraglen; 336 }; 337 338 static int 339 decryptor(struct scatterlist *sg, void *data) 340 { 341 struct decryptor_desc *desc = data; 342 int thislen = desc->fraglen + sg->length; 343 int fraglen, ret; 344 345 /* Worst case is 4 fragments: head, end of page 1, start 346 * of page 2, tail. Anything more is a bug. */ 347 BUG_ON(desc->fragno > 3); 348 desc->frags[desc->fragno] = *sg; 349 desc->fragno++; 350 desc->fraglen += sg->length; 351 352 fraglen = thislen & 7; /* XXX hardcoded blocksize */ 353 thislen -= fraglen; 354 355 if (thislen == 0) 356 return 0; 357 358 ret = crypto_cipher_decrypt_iv(desc->tfm, desc->frags, desc->frags, 359 thislen, desc->iv); 360 if (ret) 361 return ret; 362 if (fraglen) { 363 desc->frags[0].page = sg->page; 364 desc->frags[0].offset = sg->offset + sg->length - fraglen; 365 desc->frags[0].length = fraglen; 366 desc->fragno = 1; 367 desc->fraglen = fraglen; 368 } else { 369 desc->fragno = 0; 370 desc->fraglen = 0; 371 } 372 return 0; 373 } 374 375 int 376 gss_decrypt_xdr_buf(struct crypto_tfm *tfm, struct xdr_buf *buf, int offset) 377 { 378 struct decryptor_desc desc; 379 380 /* XXXJBF: */ 381 BUG_ON((buf->len - offset) % crypto_tfm_alg_blocksize(tfm) != 0); 382 383 memset(desc.iv, 0, sizeof(desc.iv)); 384 desc.tfm = tfm; 385 desc.fragno = 0; 386 desc.fraglen = 0; 387 return process_xdr_buf(buf, offset, buf->len - offset, decryptor, &desc); 388 } 389 390 EXPORT_SYMBOL(gss_decrypt_xdr_buf); 391