| 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/err.h> |
| 38 | #include <linux/types.h> |
| 39 | #include <linux/mm.h> |
| 40 | #include <linux/slab.h> |
| 41 | #include <linux/scatterlist.h> |
| 42 | #include <linux/crypto.h> |
| 43 | #include <linux/highmem.h> |
| 44 | #include <linux/pagemap.h> |
| 45 | #include <linux/sunrpc/gss_krb5.h> |
| 46 | #include <linux/sunrpc/xdr.h> |
| 47 | |
| 48 | #ifdef RPC_DEBUG |
| 49 | # define RPCDBG_FACILITY RPCDBG_AUTH |
| 50 | #endif |
| 51 | |
| 52 | u32 |
| 53 | krb5_encrypt( |
| 54 | struct crypto_blkcipher *tfm, |
| 55 | void * iv, |
| 56 | void * in, |
| 57 | void * out, |
| 58 | int length) |
| 59 | { |
| 60 | u32 ret = -EINVAL; |
| 61 | struct scatterlist sg[1]; |
| 62 | u8 local_iv[16] = {0}; |
| 63 | struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv }; |
| 64 | |
| 65 | if (length % crypto_blkcipher_blocksize(tfm) != 0) |
| 66 | goto out; |
| 67 | |
| 68 | if (crypto_blkcipher_ivsize(tfm) > 16) { |
| 69 | dprintk("RPC: gss_k5encrypt: tfm iv size to large %d\n", |
| 70 | crypto_blkcipher_ivsize(tfm)); |
| 71 | goto out; |
| 72 | } |
| 73 | |
| 74 | if (iv) |
| 75 | memcpy(local_iv, iv, crypto_blkcipher_ivsize(tfm)); |
| 76 | |
| 77 | memcpy(out, in, length); |
| 78 | sg_set_buf(sg, out, length); |
| 79 | |
| 80 | ret = crypto_blkcipher_encrypt_iv(&desc, sg, sg, length); |
| 81 | out: |
| 82 | dprintk("RPC: krb5_encrypt returns %d\n", ret); |
| 83 | return ret; |
| 84 | } |
| 85 | |
| 86 | EXPORT_SYMBOL(krb5_encrypt); |
| 87 | |
| 88 | u32 |
| 89 | krb5_decrypt( |
| 90 | struct crypto_blkcipher *tfm, |
| 91 | void * iv, |
| 92 | void * in, |
| 93 | void * out, |
| 94 | int length) |
| 95 | { |
| 96 | u32 ret = -EINVAL; |
| 97 | struct scatterlist sg[1]; |
| 98 | u8 local_iv[16] = {0}; |
| 99 | struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv }; |
| 100 | |
| 101 | if (length % crypto_blkcipher_blocksize(tfm) != 0) |
| 102 | goto out; |
| 103 | |
| 104 | if (crypto_blkcipher_ivsize(tfm) > 16) { |
| 105 | dprintk("RPC: gss_k5decrypt: tfm iv size to large %d\n", |
| 106 | crypto_blkcipher_ivsize(tfm)); |
| 107 | goto out; |
| 108 | } |
| 109 | if (iv) |
| 110 | memcpy(local_iv,iv, crypto_blkcipher_ivsize(tfm)); |
| 111 | |
| 112 | memcpy(out, in, length); |
| 113 | sg_set_buf(sg, out, length); |
| 114 | |
| 115 | ret = crypto_blkcipher_decrypt_iv(&desc, sg, sg, length); |
| 116 | out: |
| 117 | dprintk("RPC: gss_k5decrypt returns %d\n",ret); |
| 118 | return ret; |
| 119 | } |
| 120 | |
| 121 | EXPORT_SYMBOL(krb5_decrypt); |
| 122 | |
| 123 | static int |
| 124 | checksummer(struct scatterlist *sg, void *data) |
| 125 | { |
| 126 | struct hash_desc *desc = data; |
| 127 | |
| 128 | return crypto_hash_update(desc, sg, sg->length); |
| 129 | } |
| 130 | |
| 131 | /* checksum the plaintext data and hdrlen bytes of the token header */ |
| 132 | s32 |
| 133 | make_checksum(char *cksumname, char *header, int hdrlen, struct xdr_buf *body, |
| 134 | int body_offset, struct xdr_netobj *cksum) |
| 135 | { |
| 136 | struct hash_desc desc; /* XXX add to ctx? */ |
| 137 | struct scatterlist sg[1]; |
| 138 | int err; |
| 139 | |
| 140 | desc.tfm = crypto_alloc_hash(cksumname, 0, CRYPTO_ALG_ASYNC); |
| 141 | if (IS_ERR(desc.tfm)) |
| 142 | return GSS_S_FAILURE; |
| 143 | cksum->len = crypto_hash_digestsize(desc.tfm); |
| 144 | desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| 145 | |
| 146 | err = crypto_hash_init(&desc); |
| 147 | if (err) |
| 148 | goto out; |
| 149 | sg_set_buf(sg, header, hdrlen); |
| 150 | err = crypto_hash_update(&desc, sg, hdrlen); |
| 151 | if (err) |
| 152 | goto out; |
| 153 | err = xdr_process_buf(body, body_offset, body->len - body_offset, |
| 154 | checksummer, &desc); |
| 155 | if (err) |
| 156 | goto out; |
| 157 | err = crypto_hash_final(&desc, cksum->data); |
| 158 | |
| 159 | out: |
| 160 | crypto_free_hash(desc.tfm); |
| 161 | return err ? GSS_S_FAILURE : 0; |
| 162 | } |
| 163 | |
| 164 | EXPORT_SYMBOL(make_checksum); |
| 165 | |
| 166 | struct encryptor_desc { |
| 167 | u8 iv[8]; /* XXX hard-coded blocksize */ |
| 168 | struct blkcipher_desc desc; |
| 169 | int pos; |
| 170 | struct xdr_buf *outbuf; |
| 171 | struct page **pages; |
| 172 | struct scatterlist infrags[4]; |
| 173 | struct scatterlist outfrags[4]; |
| 174 | int fragno; |
| 175 | int fraglen; |
| 176 | }; |
| 177 | |
| 178 | static int |
| 179 | encryptor(struct scatterlist *sg, void *data) |
| 180 | { |
| 181 | struct encryptor_desc *desc = data; |
| 182 | struct xdr_buf *outbuf = desc->outbuf; |
| 183 | struct page *in_page; |
| 184 | int thislen = desc->fraglen + sg->length; |
| 185 | int fraglen, ret; |
| 186 | int page_pos; |
| 187 | |
| 188 | /* Worst case is 4 fragments: head, end of page 1, start |
| 189 | * of page 2, tail. Anything more is a bug. */ |
| 190 | BUG_ON(desc->fragno > 3); |
| 191 | desc->infrags[desc->fragno] = *sg; |
| 192 | desc->outfrags[desc->fragno] = *sg; |
| 193 | |
| 194 | page_pos = desc->pos - outbuf->head[0].iov_len; |
| 195 | if (page_pos >= 0 && page_pos < outbuf->page_len) { |
| 196 | /* pages are not in place: */ |
| 197 | int i = (page_pos + outbuf->page_base) >> PAGE_CACHE_SHIFT; |
| 198 | in_page = desc->pages[i]; |
| 199 | } else { |
| 200 | in_page = sg_page(sg); |
| 201 | } |
| 202 | sg_assign_page(&desc->infrags[desc->fragno], in_page); |
| 203 | desc->fragno++; |
| 204 | desc->fraglen += sg->length; |
| 205 | desc->pos += sg->length; |
| 206 | |
| 207 | fraglen = thislen & 7; /* XXX hardcoded blocksize */ |
| 208 | thislen -= fraglen; |
| 209 | |
| 210 | if (thislen == 0) |
| 211 | return 0; |
| 212 | |
| 213 | ret = crypto_blkcipher_encrypt_iv(&desc->desc, desc->outfrags, |
| 214 | desc->infrags, thislen); |
| 215 | if (ret) |
| 216 | return ret; |
| 217 | if (fraglen) { |
| 218 | sg_set_page(&desc->outfrags[0], sg_page(sg), fraglen, |
| 219 | sg->offset + sg->length - fraglen); |
| 220 | desc->infrags[0] = desc->outfrags[0]; |
| 221 | sg_assign_page(&desc->infrags[0], in_page); |
| 222 | desc->fragno = 1; |
| 223 | desc->fraglen = fraglen; |
| 224 | } else { |
| 225 | desc->fragno = 0; |
| 226 | desc->fraglen = 0; |
| 227 | } |
| 228 | return 0; |
| 229 | } |
| 230 | |
| 231 | int |
| 232 | gss_encrypt_xdr_buf(struct crypto_blkcipher *tfm, struct xdr_buf *buf, |
| 233 | int offset, struct page **pages) |
| 234 | { |
| 235 | int ret; |
| 236 | struct encryptor_desc desc; |
| 237 | |
| 238 | BUG_ON((buf->len - offset) % crypto_blkcipher_blocksize(tfm) != 0); |
| 239 | |
| 240 | memset(desc.iv, 0, sizeof(desc.iv)); |
| 241 | desc.desc.tfm = tfm; |
| 242 | desc.desc.info = desc.iv; |
| 243 | desc.desc.flags = 0; |
| 244 | desc.pos = offset; |
| 245 | desc.outbuf = buf; |
| 246 | desc.pages = pages; |
| 247 | desc.fragno = 0; |
| 248 | desc.fraglen = 0; |
| 249 | |
| 250 | ret = xdr_process_buf(buf, offset, buf->len - offset, encryptor, &desc); |
| 251 | return ret; |
| 252 | } |
| 253 | |
| 254 | EXPORT_SYMBOL(gss_encrypt_xdr_buf); |
| 255 | |
| 256 | struct decryptor_desc { |
| 257 | u8 iv[8]; /* XXX hard-coded blocksize */ |
| 258 | struct blkcipher_desc desc; |
| 259 | struct scatterlist frags[4]; |
| 260 | int fragno; |
| 261 | int fraglen; |
| 262 | }; |
| 263 | |
| 264 | static int |
| 265 | decryptor(struct scatterlist *sg, void *data) |
| 266 | { |
| 267 | struct decryptor_desc *desc = data; |
| 268 | int thislen = desc->fraglen + sg->length; |
| 269 | int fraglen, ret; |
| 270 | |
| 271 | /* Worst case is 4 fragments: head, end of page 1, start |
| 272 | * of page 2, tail. Anything more is a bug. */ |
| 273 | BUG_ON(desc->fragno > 3); |
| 274 | desc->frags[desc->fragno] = *sg; |
| 275 | desc->fragno++; |
| 276 | desc->fraglen += sg->length; |
| 277 | |
| 278 | fraglen = thislen & 7; /* XXX hardcoded blocksize */ |
| 279 | thislen -= fraglen; |
| 280 | |
| 281 | if (thislen == 0) |
| 282 | return 0; |
| 283 | |
| 284 | ret = crypto_blkcipher_decrypt_iv(&desc->desc, desc->frags, |
| 285 | desc->frags, thislen); |
| 286 | if (ret) |
| 287 | return ret; |
| 288 | if (fraglen) { |
| 289 | sg_set_page(&desc->frags[0], sg_page(sg), fraglen, |
| 290 | sg->offset + sg->length - fraglen); |
| 291 | desc->fragno = 1; |
| 292 | desc->fraglen = fraglen; |
| 293 | } else { |
| 294 | desc->fragno = 0; |
| 295 | desc->fraglen = 0; |
| 296 | } |
| 297 | return 0; |
| 298 | } |
| 299 | |
| 300 | int |
| 301 | gss_decrypt_xdr_buf(struct crypto_blkcipher *tfm, struct xdr_buf *buf, |
| 302 | int offset) |
| 303 | { |
| 304 | struct decryptor_desc desc; |
| 305 | |
| 306 | /* XXXJBF: */ |
| 307 | BUG_ON((buf->len - offset) % crypto_blkcipher_blocksize(tfm) != 0); |
| 308 | |
| 309 | memset(desc.iv, 0, sizeof(desc.iv)); |
| 310 | desc.desc.tfm = tfm; |
| 311 | desc.desc.info = desc.iv; |
| 312 | desc.desc.flags = 0; |
| 313 | desc.fragno = 0; |
| 314 | desc.fraglen = 0; |
| 315 | return xdr_process_buf(buf, offset, buf->len - offset, decryptor, &desc); |
| 316 | } |
| 317 | |
| 318 | EXPORT_SYMBOL(gss_decrypt_xdr_buf); |