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TOMOYO Linux Cross Reference
Linux/crypto/ansi_cprng.c

Version: ~ [ linux-6.11.5 ] ~ [ linux-6.10.14 ] ~ [ linux-6.9.12 ] ~ [ linux-6.8.12 ] ~ [ linux-6.7.12 ] ~ [ linux-6.6.58 ] ~ [ linux-6.5.13 ] ~ [ linux-6.4.16 ] ~ [ linux-6.3.13 ] ~ [ linux-6.2.16 ] ~ [ linux-6.1.114 ] ~ [ linux-6.0.19 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.169 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.228 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.284 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.322 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.336 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.337 ] ~ [ linux-4.4.302 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

Diff markup

Differences between /crypto/ansi_cprng.c (Version linux-6.11.5) and /crypto/ansi_cprng.c (Version linux-4.9.337)


  1 // SPDX-License-Identifier: GPL-2.0-or-later   << 
  2 /*                                                  1 /*
  3  * PRNG: Pseudo Random Number Generator             2  * PRNG: Pseudo Random Number Generator
  4  *       Based on NIST Recommended PRNG From A      3  *       Based on NIST Recommended PRNG From ANSI X9.31 Appendix A.2.4 using
  5  *       AES 128 cipher                             4  *       AES 128 cipher
  6  *                                                  5  *
  7  *  (C) Neil Horman <nhorman@tuxdriver.com>         6  *  (C) Neil Horman <nhorman@tuxdriver.com>
                                                   >>   7  *
                                                   >>   8  *  This program is free software; you can redistribute it and/or modify it
                                                   >>   9  *  under the terms of the GNU General Public License as published by the
                                                   >>  10  *  Free Software Foundation; either version 2 of the License, or (at your
                                                   >>  11  *  any later version.
                                                   >>  12  *
                                                   >>  13  *
  8  */                                                14  */
  9                                                    15 
 10 #include <crypto/internal/cipher.h>            << 
 11 #include <crypto/internal/rng.h>                   16 #include <crypto/internal/rng.h>
 12 #include <linux/err.h>                             17 #include <linux/err.h>
 13 #include <linux/init.h>                            18 #include <linux/init.h>
 14 #include <linux/module.h>                          19 #include <linux/module.h>
 15 #include <linux/moduleparam.h>                     20 #include <linux/moduleparam.h>
 16 #include <linux/string.h>                          21 #include <linux/string.h>
 17                                                    22 
 18 #define DEFAULT_PRNG_KEY "0123456789abcdef"        23 #define DEFAULT_PRNG_KEY "0123456789abcdef"
 19 #define DEFAULT_PRNG_KSZ 16                        24 #define DEFAULT_PRNG_KSZ 16
 20 #define DEFAULT_BLK_SZ 16                          25 #define DEFAULT_BLK_SZ 16
 21 #define DEFAULT_V_SEED "zaybxcwdveuftgsh"          26 #define DEFAULT_V_SEED "zaybxcwdveuftgsh"
 22                                                    27 
 23 /*                                                 28 /*
 24  * Flags for the prng_context flags field          29  * Flags for the prng_context flags field
 25  */                                                30  */
 26                                                    31 
 27 #define PRNG_FIXED_SIZE 0x1                        32 #define PRNG_FIXED_SIZE 0x1
 28 #define PRNG_NEED_RESET 0x2                        33 #define PRNG_NEED_RESET 0x2
 29                                                    34 
 30 /*                                                 35 /*
 31  * Note: DT is our counter value                   36  * Note: DT is our counter value
 32  *       I is our intermediate value               37  *       I is our intermediate value
 33  *       V is our seed vector                      38  *       V is our seed vector
 34  * See http://csrc.nist.gov/groups/STM/cavp/do     39  * See http://csrc.nist.gov/groups/STM/cavp/documents/rng/931rngext.pdf
 35  * for implementation details                      40  * for implementation details
 36  */                                                41  */
 37                                                    42 
 38                                                    43 
 39 struct prng_context {                              44 struct prng_context {
 40         spinlock_t prng_lock;                      45         spinlock_t prng_lock;
 41         unsigned char rand_data[DEFAULT_BLK_SZ     46         unsigned char rand_data[DEFAULT_BLK_SZ];
 42         unsigned char last_rand_data[DEFAULT_B     47         unsigned char last_rand_data[DEFAULT_BLK_SZ];
 43         unsigned char DT[DEFAULT_BLK_SZ];          48         unsigned char DT[DEFAULT_BLK_SZ];
 44         unsigned char I[DEFAULT_BLK_SZ];           49         unsigned char I[DEFAULT_BLK_SZ];
 45         unsigned char V[DEFAULT_BLK_SZ];           50         unsigned char V[DEFAULT_BLK_SZ];
 46         u32 rand_data_valid;                       51         u32 rand_data_valid;
 47         struct crypto_cipher *tfm;                 52         struct crypto_cipher *tfm;
 48         u32 flags;                                 53         u32 flags;
 49 };                                                 54 };
 50                                                    55 
 51 static int dbg;                                    56 static int dbg;
 52                                                    57 
 53 static void hexdump(char *note, unsigned char      58 static void hexdump(char *note, unsigned char *buf, unsigned int len)
 54 {                                                  59 {
 55         if (dbg) {                                 60         if (dbg) {
 56                 printk(KERN_CRIT "%s", note);      61                 printk(KERN_CRIT "%s", note);
 57                 print_hex_dump(KERN_CONT, "",      62                 print_hex_dump(KERN_CONT, "", DUMP_PREFIX_OFFSET,
 58                                 16, 1,             63                                 16, 1,
 59                                 buf, len, fals     64                                 buf, len, false);
 60         }                                          65         }
 61 }                                                  66 }
 62                                                    67 
 63 #define dbgprint(format, args...) do {\            68 #define dbgprint(format, args...) do {\
 64 if (dbg)\                                          69 if (dbg)\
 65         printk(format, ##args);\                   70         printk(format, ##args);\
 66 } while (0)                                        71 } while (0)
 67                                                    72 
 68 static void xor_vectors(unsigned char *in1, un     73 static void xor_vectors(unsigned char *in1, unsigned char *in2,
 69                         unsigned char *out, un     74                         unsigned char *out, unsigned int size)
 70 {                                                  75 {
 71         int i;                                     76         int i;
 72                                                    77 
 73         for (i = 0; i < size; i++)                 78         for (i = 0; i < size; i++)
 74                 out[i] = in1[i] ^ in2[i];          79                 out[i] = in1[i] ^ in2[i];
 75                                                    80 
 76 }                                                  81 }
 77 /*                                                 82 /*
 78  * Returns DEFAULT_BLK_SZ bytes of random data     83  * Returns DEFAULT_BLK_SZ bytes of random data per call
 79  * returns 0 if generation succeeded, <0 if so     84  * returns 0 if generation succeeded, <0 if something went wrong
 80  */                                                85  */
 81 static int _get_more_prng_bytes(struct prng_co     86 static int _get_more_prng_bytes(struct prng_context *ctx, int cont_test)
 82 {                                                  87 {
 83         int i;                                     88         int i;
 84         unsigned char tmp[DEFAULT_BLK_SZ];         89         unsigned char tmp[DEFAULT_BLK_SZ];
 85         unsigned char *output = NULL;              90         unsigned char *output = NULL;
 86                                                    91 
 87                                                    92 
 88         dbgprint(KERN_CRIT "Calling _get_more_     93         dbgprint(KERN_CRIT "Calling _get_more_prng_bytes for context %p\n",
 89                 ctx);                              94                 ctx);
 90                                                    95 
 91         hexdump("Input DT: ", ctx->DT, DEFAULT     96         hexdump("Input DT: ", ctx->DT, DEFAULT_BLK_SZ);
 92         hexdump("Input I: ", ctx->I, DEFAULT_B     97         hexdump("Input I: ", ctx->I, DEFAULT_BLK_SZ);
 93         hexdump("Input V: ", ctx->V, DEFAULT_B     98         hexdump("Input V: ", ctx->V, DEFAULT_BLK_SZ);
 94                                                    99 
 95         /*                                        100         /*
 96          * This algorithm is a 3 stage state m    101          * This algorithm is a 3 stage state machine
 97          */                                       102          */
 98         for (i = 0; i < 3; i++) {                 103         for (i = 0; i < 3; i++) {
 99                                                   104 
100                 switch (i) {                      105                 switch (i) {
101                 case 0:                           106                 case 0:
102                         /*                        107                         /*
103                          * Start by encrypting    108                          * Start by encrypting the counter value
104                          * This gives us an in    109                          * This gives us an intermediate value I
105                          */                       110                          */
106                         memcpy(tmp, ctx->DT, D    111                         memcpy(tmp, ctx->DT, DEFAULT_BLK_SZ);
107                         output = ctx->I;          112                         output = ctx->I;
108                         hexdump("tmp stage 0:     113                         hexdump("tmp stage 0: ", tmp, DEFAULT_BLK_SZ);
109                         break;                    114                         break;
110                 case 1:                           115                 case 1:
111                                                   116 
112                         /*                        117                         /*
113                          * Next xor I with our    118                          * Next xor I with our secret vector V
114                          * encrypt that result    119                          * encrypt that result to obtain our
115                          * pseudo random data     120                          * pseudo random data which we output
116                          */                       121                          */
117                         xor_vectors(ctx->I, ct    122                         xor_vectors(ctx->I, ctx->V, tmp, DEFAULT_BLK_SZ);
118                         hexdump("tmp stage 1:     123                         hexdump("tmp stage 1: ", tmp, DEFAULT_BLK_SZ);
119                         output = ctx->rand_dat    124                         output = ctx->rand_data;
120                         break;                    125                         break;
121                 case 2:                           126                 case 2:
122                         /*                        127                         /*
123                          * First check that we    128                          * First check that we didn't produce the same
124                          * random data that we    129                          * random data that we did last time around through this
125                          */                       130                          */
126                         if (!memcmp(ctx->rand_    131                         if (!memcmp(ctx->rand_data, ctx->last_rand_data,
127                                         DEFAUL    132                                         DEFAULT_BLK_SZ)) {
128                                 if (cont_test)    133                                 if (cont_test) {
129                                         panic(    134                                         panic("cprng %p Failed repetition check!\n",
130                                                   135                                                 ctx);
131                                 }                 136                                 }
132                                                   137 
133                                 printk(KERN_ER    138                                 printk(KERN_ERR
134                                         "ctx %    139                                         "ctx %p Failed repetition check!\n",
135                                         ctx);     140                                         ctx);
136                                                   141 
137                                 ctx->flags |=     142                                 ctx->flags |= PRNG_NEED_RESET;
138                                 return -EINVAL    143                                 return -EINVAL;
139                         }                         144                         }
140                         memcpy(ctx->last_rand_    145                         memcpy(ctx->last_rand_data, ctx->rand_data,
141                                 DEFAULT_BLK_SZ    146                                 DEFAULT_BLK_SZ);
142                                                   147 
143                         /*                        148                         /*
144                          * Lastly xor the rand    149                          * Lastly xor the random data with I
145                          * and encrypt that to    150                          * and encrypt that to obtain a new secret vector V
146                          */                       151                          */
147                         xor_vectors(ctx->rand_    152                         xor_vectors(ctx->rand_data, ctx->I, tmp,
148                                 DEFAULT_BLK_SZ    153                                 DEFAULT_BLK_SZ);
149                         output = ctx->V;          154                         output = ctx->V;
150                         hexdump("tmp stage 2:     155                         hexdump("tmp stage 2: ", tmp, DEFAULT_BLK_SZ);
151                         break;                    156                         break;
152                 }                                 157                 }
153                                                   158 
154                                                   159 
155                 /* do the encryption */           160                 /* do the encryption */
156                 crypto_cipher_encrypt_one(ctx-    161                 crypto_cipher_encrypt_one(ctx->tfm, output, tmp);
157                                                   162 
158         }                                         163         }
159                                                   164 
160         /*                                        165         /*
161          * Now update our DT value                166          * Now update our DT value
162          */                                       167          */
163         for (i = DEFAULT_BLK_SZ - 1; i >= 0; i    168         for (i = DEFAULT_BLK_SZ - 1; i >= 0; i--) {
164                 ctx->DT[i] += 1;                  169                 ctx->DT[i] += 1;
165                 if (ctx->DT[i] != 0)              170                 if (ctx->DT[i] != 0)
166                         break;                    171                         break;
167         }                                         172         }
168                                                   173 
169         dbgprint("Returning new block for cont    174         dbgprint("Returning new block for context %p\n", ctx);
170         ctx->rand_data_valid = 0;                 175         ctx->rand_data_valid = 0;
171                                                   176 
172         hexdump("Output DT: ", ctx->DT, DEFAUL    177         hexdump("Output DT: ", ctx->DT, DEFAULT_BLK_SZ);
173         hexdump("Output I: ", ctx->I, DEFAULT_    178         hexdump("Output I: ", ctx->I, DEFAULT_BLK_SZ);
174         hexdump("Output V: ", ctx->V, DEFAULT_    179         hexdump("Output V: ", ctx->V, DEFAULT_BLK_SZ);
175         hexdump("New Random Data: ", ctx->rand    180         hexdump("New Random Data: ", ctx->rand_data, DEFAULT_BLK_SZ);
176                                                   181 
177         return 0;                                 182         return 0;
178 }                                                 183 }
179                                                   184 
180 /* Our exported functions */                      185 /* Our exported functions */
181 static int get_prng_bytes(char *buf, size_t nb    186 static int get_prng_bytes(char *buf, size_t nbytes, struct prng_context *ctx,
182                                 int do_cont_te    187                                 int do_cont_test)
183 {                                                 188 {
184         unsigned char *ptr = buf;                 189         unsigned char *ptr = buf;
185         unsigned int byte_count = (unsigned in    190         unsigned int byte_count = (unsigned int)nbytes;
186         int err;                                  191         int err;
187                                                   192 
188                                                   193 
189         spin_lock_bh(&ctx->prng_lock);            194         spin_lock_bh(&ctx->prng_lock);
190                                                   195 
191         err = -EINVAL;                            196         err = -EINVAL;
192         if (ctx->flags & PRNG_NEED_RESET)         197         if (ctx->flags & PRNG_NEED_RESET)
193                 goto done;                        198                 goto done;
194                                                   199 
195         /*                                        200         /*
196          * If the FIXED_SIZE flag is on, only     201          * If the FIXED_SIZE flag is on, only return whole blocks of
197          * pseudo random data                     202          * pseudo random data
198          */                                       203          */
199         err = -EINVAL;                            204         err = -EINVAL;
200         if (ctx->flags & PRNG_FIXED_SIZE) {       205         if (ctx->flags & PRNG_FIXED_SIZE) {
201                 if (nbytes < DEFAULT_BLK_SZ)      206                 if (nbytes < DEFAULT_BLK_SZ)
202                         goto done;                207                         goto done;
203                 byte_count = DEFAULT_BLK_SZ;      208                 byte_count = DEFAULT_BLK_SZ;
204         }                                         209         }
205                                                   210 
206         /*                                        211         /*
207          * Return 0 in case of success as mand    212          * Return 0 in case of success as mandated by the kernel
208          * crypto API interface definition.       213          * crypto API interface definition.
209          */                                       214          */
210         err = 0;                                  215         err = 0;
211                                                   216 
212         dbgprint(KERN_CRIT "getting %d random     217         dbgprint(KERN_CRIT "getting %d random bytes for context %p\n",
213                 byte_count, ctx);                 218                 byte_count, ctx);
214                                                   219 
215                                                   220 
216 remainder:                                        221 remainder:
217         if (ctx->rand_data_valid == DEFAULT_BL    222         if (ctx->rand_data_valid == DEFAULT_BLK_SZ) {
218                 if (_get_more_prng_bytes(ctx,     223                 if (_get_more_prng_bytes(ctx, do_cont_test) < 0) {
219                         memset(buf, 0, nbytes)    224                         memset(buf, 0, nbytes);
220                         err = -EINVAL;            225                         err = -EINVAL;
221                         goto done;                226                         goto done;
222                 }                                 227                 }
223         }                                         228         }
224                                                   229 
225         /*                                        230         /*
226          * Copy any data less than an entire b    231          * Copy any data less than an entire block
227          */                                       232          */
228         if (byte_count < DEFAULT_BLK_SZ) {        233         if (byte_count < DEFAULT_BLK_SZ) {
229 empty_rbuf:                                       234 empty_rbuf:
230                 while (ctx->rand_data_valid <     235                 while (ctx->rand_data_valid < DEFAULT_BLK_SZ) {
231                         *ptr = ctx->rand_data[    236                         *ptr = ctx->rand_data[ctx->rand_data_valid];
232                         ptr++;                    237                         ptr++;
233                         byte_count--;             238                         byte_count--;
234                         ctx->rand_data_valid++    239                         ctx->rand_data_valid++;
235                         if (byte_count == 0)      240                         if (byte_count == 0)
236                                 goto done;        241                                 goto done;
237                 }                                 242                 }
238         }                                         243         }
239                                                   244 
240         /*                                        245         /*
241          * Now copy whole blocks                  246          * Now copy whole blocks
242          */                                       247          */
243         for (; byte_count >= DEFAULT_BLK_SZ; b    248         for (; byte_count >= DEFAULT_BLK_SZ; byte_count -= DEFAULT_BLK_SZ) {
244                 if (ctx->rand_data_valid == DE    249                 if (ctx->rand_data_valid == DEFAULT_BLK_SZ) {
245                         if (_get_more_prng_byt    250                         if (_get_more_prng_bytes(ctx, do_cont_test) < 0) {
246                                 memset(buf, 0,    251                                 memset(buf, 0, nbytes);
247                                 err = -EINVAL;    252                                 err = -EINVAL;
248                                 goto done;        253                                 goto done;
249                         }                         254                         }
250                 }                                 255                 }
251                 if (ctx->rand_data_valid > 0)     256                 if (ctx->rand_data_valid > 0)
252                         goto empty_rbuf;          257                         goto empty_rbuf;
253                 memcpy(ptr, ctx->rand_data, DE    258                 memcpy(ptr, ctx->rand_data, DEFAULT_BLK_SZ);
254                 ctx->rand_data_valid += DEFAUL    259                 ctx->rand_data_valid += DEFAULT_BLK_SZ;
255                 ptr += DEFAULT_BLK_SZ;            260                 ptr += DEFAULT_BLK_SZ;
256         }                                         261         }
257                                                   262 
258         /*                                        263         /*
259          * Now go back and get any remaining p    264          * Now go back and get any remaining partial block
260          */                                       265          */
261         if (byte_count)                           266         if (byte_count)
262                 goto remainder;                   267                 goto remainder;
263                                                   268 
264 done:                                             269 done:
265         spin_unlock_bh(&ctx->prng_lock);          270         spin_unlock_bh(&ctx->prng_lock);
266         dbgprint(KERN_CRIT "returning %d from     271         dbgprint(KERN_CRIT "returning %d from get_prng_bytes in context %p\n",
267                 err, ctx);                        272                 err, ctx);
268         return err;                               273         return err;
269 }                                                 274 }
270                                                   275 
271 static void free_prng_context(struct prng_cont    276 static void free_prng_context(struct prng_context *ctx)
272 {                                                 277 {
273         crypto_free_cipher(ctx->tfm);             278         crypto_free_cipher(ctx->tfm);
274 }                                                 279 }
275                                                   280 
276 static int reset_prng_context(struct prng_cont    281 static int reset_prng_context(struct prng_context *ctx,
277                               const unsigned c    282                               const unsigned char *key, size_t klen,
278                               const unsigned c    283                               const unsigned char *V, const unsigned char *DT)
279 {                                                 284 {
280         int ret;                                  285         int ret;
281         const unsigned char *prng_key;            286         const unsigned char *prng_key;
282                                                   287 
283         spin_lock_bh(&ctx->prng_lock);            288         spin_lock_bh(&ctx->prng_lock);
284         ctx->flags |= PRNG_NEED_RESET;            289         ctx->flags |= PRNG_NEED_RESET;
285                                                   290 
286         prng_key = (key != NULL) ? key : (unsi    291         prng_key = (key != NULL) ? key : (unsigned char *)DEFAULT_PRNG_KEY;
287                                                   292 
288         if (!key)                                 293         if (!key)
289                 klen = DEFAULT_PRNG_KSZ;          294                 klen = DEFAULT_PRNG_KSZ;
290                                                   295 
291         if (V)                                    296         if (V)
292                 memcpy(ctx->V, V, DEFAULT_BLK_    297                 memcpy(ctx->V, V, DEFAULT_BLK_SZ);
293         else                                      298         else
294                 memcpy(ctx->V, DEFAULT_V_SEED,    299                 memcpy(ctx->V, DEFAULT_V_SEED, DEFAULT_BLK_SZ);
295                                                   300 
296         if (DT)                                   301         if (DT)
297                 memcpy(ctx->DT, DT, DEFAULT_BL    302                 memcpy(ctx->DT, DT, DEFAULT_BLK_SZ);
298         else                                      303         else
299                 memset(ctx->DT, 0, DEFAULT_BLK    304                 memset(ctx->DT, 0, DEFAULT_BLK_SZ);
300                                                   305 
301         memset(ctx->rand_data, 0, DEFAULT_BLK_    306         memset(ctx->rand_data, 0, DEFAULT_BLK_SZ);
302         memset(ctx->last_rand_data, 0, DEFAULT    307         memset(ctx->last_rand_data, 0, DEFAULT_BLK_SZ);
303                                                   308 
304         ctx->rand_data_valid = DEFAULT_BLK_SZ;    309         ctx->rand_data_valid = DEFAULT_BLK_SZ;
305                                                   310 
306         ret = crypto_cipher_setkey(ctx->tfm, p    311         ret = crypto_cipher_setkey(ctx->tfm, prng_key, klen);
307         if (ret) {                                312         if (ret) {
308                 dbgprint(KERN_CRIT "PRNG: setk    313                 dbgprint(KERN_CRIT "PRNG: setkey() failed flags=%x\n",
309                         crypto_cipher_get_flag    314                         crypto_cipher_get_flags(ctx->tfm));
310                 goto out;                         315                 goto out;
311         }                                         316         }
312                                                   317 
313         ret = 0;                                  318         ret = 0;
314         ctx->flags &= ~PRNG_NEED_RESET;           319         ctx->flags &= ~PRNG_NEED_RESET;
315 out:                                              320 out:
316         spin_unlock_bh(&ctx->prng_lock);          321         spin_unlock_bh(&ctx->prng_lock);
317         return ret;                               322         return ret;
318 }                                                 323 }
319                                                   324 
320 static int cprng_init(struct crypto_tfm *tfm)     325 static int cprng_init(struct crypto_tfm *tfm)
321 {                                                 326 {
322         struct prng_context *ctx = crypto_tfm_    327         struct prng_context *ctx = crypto_tfm_ctx(tfm);
323                                                   328 
324         spin_lock_init(&ctx->prng_lock);          329         spin_lock_init(&ctx->prng_lock);
325         ctx->tfm = crypto_alloc_cipher("aes",     330         ctx->tfm = crypto_alloc_cipher("aes", 0, 0);
326         if (IS_ERR(ctx->tfm)) {                   331         if (IS_ERR(ctx->tfm)) {
327                 dbgprint(KERN_CRIT "Failed to     332                 dbgprint(KERN_CRIT "Failed to alloc tfm for context %p\n",
328                                 ctx);             333                                 ctx);
329                 return PTR_ERR(ctx->tfm);         334                 return PTR_ERR(ctx->tfm);
330         }                                         335         }
331                                                   336 
332         if (reset_prng_context(ctx, NULL, DEFA    337         if (reset_prng_context(ctx, NULL, DEFAULT_PRNG_KSZ, NULL, NULL) < 0)
333                 return -EINVAL;                   338                 return -EINVAL;
334                                                   339 
335         /*                                        340         /*
336          * after allocation, we should always     341          * after allocation, we should always force the user to reset
337          * so they don't inadvertently use the    342          * so they don't inadvertently use the insecure default values
338          * without specifying them intentially    343          * without specifying them intentially
339          */                                       344          */
340         ctx->flags |= PRNG_NEED_RESET;            345         ctx->flags |= PRNG_NEED_RESET;
341         return 0;                                 346         return 0;
342 }                                                 347 }
343                                                   348 
344 static void cprng_exit(struct crypto_tfm *tfm)    349 static void cprng_exit(struct crypto_tfm *tfm)
345 {                                                 350 {
346         free_prng_context(crypto_tfm_ctx(tfm))    351         free_prng_context(crypto_tfm_ctx(tfm));
347 }                                                 352 }
348                                                   353 
349 static int cprng_get_random(struct crypto_rng     354 static int cprng_get_random(struct crypto_rng *tfm,
350                             const u8 *src, uns    355                             const u8 *src, unsigned int slen,
351                             u8 *rdata, unsigne    356                             u8 *rdata, unsigned int dlen)
352 {                                                 357 {
353         struct prng_context *prng = crypto_rng    358         struct prng_context *prng = crypto_rng_ctx(tfm);
354                                                   359 
355         return get_prng_bytes(rdata, dlen, prn    360         return get_prng_bytes(rdata, dlen, prng, 0);
356 }                                                 361 }
357                                                   362 
358 /*                                                363 /*
359  *  This is the cprng_registered reset method     364  *  This is the cprng_registered reset method the seed value is
360  *  interpreted as the tuple { V KEY DT}          365  *  interpreted as the tuple { V KEY DT}
361  *  V and KEY are required during reset, and D    366  *  V and KEY are required during reset, and DT is optional, detected
362  *  as being present by testing the length of     367  *  as being present by testing the length of the seed
363  */                                               368  */
364 static int cprng_reset(struct crypto_rng *tfm,    369 static int cprng_reset(struct crypto_rng *tfm,
365                        const u8 *seed, unsigne    370                        const u8 *seed, unsigned int slen)
366 {                                                 371 {
367         struct prng_context *prng = crypto_rng    372         struct prng_context *prng = crypto_rng_ctx(tfm);
368         const u8 *key = seed + DEFAULT_BLK_SZ;    373         const u8 *key = seed + DEFAULT_BLK_SZ;
369         const u8 *dt = NULL;                      374         const u8 *dt = NULL;
370                                                   375 
371         if (slen < DEFAULT_PRNG_KSZ + DEFAULT_    376         if (slen < DEFAULT_PRNG_KSZ + DEFAULT_BLK_SZ)
372                 return -EINVAL;                   377                 return -EINVAL;
373                                                   378 
374         if (slen >= (2 * DEFAULT_BLK_SZ + DEFA    379         if (slen >= (2 * DEFAULT_BLK_SZ + DEFAULT_PRNG_KSZ))
375                 dt = key + DEFAULT_PRNG_KSZ;      380                 dt = key + DEFAULT_PRNG_KSZ;
376                                                   381 
377         reset_prng_context(prng, key, DEFAULT_    382         reset_prng_context(prng, key, DEFAULT_PRNG_KSZ, seed, dt);
378                                                   383 
379         if (prng->flags & PRNG_NEED_RESET)        384         if (prng->flags & PRNG_NEED_RESET)
380                 return -EINVAL;                   385                 return -EINVAL;
381         return 0;                                 386         return 0;
382 }                                                 387 }
383                                                   388 
384 #ifdef CONFIG_CRYPTO_FIPS                         389 #ifdef CONFIG_CRYPTO_FIPS
385 static int fips_cprng_get_random(struct crypto    390 static int fips_cprng_get_random(struct crypto_rng *tfm,
386                                  const u8 *src    391                                  const u8 *src, unsigned int slen,
387                                  u8 *rdata, un    392                                  u8 *rdata, unsigned int dlen)
388 {                                                 393 {
389         struct prng_context *prng = crypto_rng    394         struct prng_context *prng = crypto_rng_ctx(tfm);
390                                                   395 
391         return get_prng_bytes(rdata, dlen, prn    396         return get_prng_bytes(rdata, dlen, prng, 1);
392 }                                                 397 }
393                                                   398 
394 static int fips_cprng_reset(struct crypto_rng     399 static int fips_cprng_reset(struct crypto_rng *tfm,
395                             const u8 *seed, un    400                             const u8 *seed, unsigned int slen)
396 {                                                 401 {
397         u8 rdata[DEFAULT_BLK_SZ];                 402         u8 rdata[DEFAULT_BLK_SZ];
398         const u8 *key = seed + DEFAULT_BLK_SZ;    403         const u8 *key = seed + DEFAULT_BLK_SZ;
399         int rc;                                   404         int rc;
400                                                   405 
401         struct prng_context *prng = crypto_rng    406         struct prng_context *prng = crypto_rng_ctx(tfm);
402                                                   407 
403         if (slen < DEFAULT_PRNG_KSZ + DEFAULT_    408         if (slen < DEFAULT_PRNG_KSZ + DEFAULT_BLK_SZ)
404                 return -EINVAL;                   409                 return -EINVAL;
405                                                   410 
406         /* fips strictly requires seed != key     411         /* fips strictly requires seed != key */
407         if (!memcmp(seed, key, DEFAULT_PRNG_KS    412         if (!memcmp(seed, key, DEFAULT_PRNG_KSZ))
408                 return -EINVAL;                   413                 return -EINVAL;
409                                                   414 
410         rc = cprng_reset(tfm, seed, slen);        415         rc = cprng_reset(tfm, seed, slen);
411                                                   416 
412         if (!rc)                                  417         if (!rc)
413                 goto out;                         418                 goto out;
414                                                   419 
415         /* this primes our continuity test */     420         /* this primes our continuity test */
416         rc = get_prng_bytes(rdata, DEFAULT_BLK    421         rc = get_prng_bytes(rdata, DEFAULT_BLK_SZ, prng, 0);
417         prng->rand_data_valid = DEFAULT_BLK_SZ    422         prng->rand_data_valid = DEFAULT_BLK_SZ;
418                                                   423 
419 out:                                              424 out:
420         return rc;                                425         return rc;
421 }                                                 426 }
422 #endif                                            427 #endif
423                                                   428 
424 static struct rng_alg rng_algs[] = { {            429 static struct rng_alg rng_algs[] = { {
425         .generate               = cprng_get_ra    430         .generate               = cprng_get_random,
426         .seed                   = cprng_reset,    431         .seed                   = cprng_reset,
427         .seedsize               = DEFAULT_PRNG    432         .seedsize               = DEFAULT_PRNG_KSZ + 2 * DEFAULT_BLK_SZ,
428         .base                   =       {         433         .base                   =       {
429                 .cra_name               = "std    434                 .cra_name               = "stdrng",
430                 .cra_driver_name        = "ans    435                 .cra_driver_name        = "ansi_cprng",
431                 .cra_priority           = 100,    436                 .cra_priority           = 100,
432                 .cra_ctxsize            = size    437                 .cra_ctxsize            = sizeof(struct prng_context),
433                 .cra_module             = THIS    438                 .cra_module             = THIS_MODULE,
434                 .cra_init               = cprn    439                 .cra_init               = cprng_init,
435                 .cra_exit               = cprn    440                 .cra_exit               = cprng_exit,
436         }                                         441         }
437 #ifdef CONFIG_CRYPTO_FIPS                         442 #ifdef CONFIG_CRYPTO_FIPS
438 }, {                                              443 }, {
439         .generate               = fips_cprng_g    444         .generate               = fips_cprng_get_random,
440         .seed                   = fips_cprng_r    445         .seed                   = fips_cprng_reset,
441         .seedsize               = DEFAULT_PRNG    446         .seedsize               = DEFAULT_PRNG_KSZ + 2 * DEFAULT_BLK_SZ,
442         .base                   =       {         447         .base                   =       {
443                 .cra_name               = "fip    448                 .cra_name               = "fips(ansi_cprng)",
444                 .cra_driver_name        = "fip    449                 .cra_driver_name        = "fips_ansi_cprng",
445                 .cra_priority           = 300,    450                 .cra_priority           = 300,
446                 .cra_ctxsize            = size    451                 .cra_ctxsize            = sizeof(struct prng_context),
447                 .cra_module             = THIS    452                 .cra_module             = THIS_MODULE,
448                 .cra_init               = cprn    453                 .cra_init               = cprng_init,
449                 .cra_exit               = cprn    454                 .cra_exit               = cprng_exit,
450         }                                         455         }
451 #endif                                            456 #endif
452 } };                                              457 } };
453                                                   458 
454 /* Module initalization */                        459 /* Module initalization */
455 static int __init prng_mod_init(void)             460 static int __init prng_mod_init(void)
456 {                                                 461 {
457         return crypto_register_rngs(rng_algs,     462         return crypto_register_rngs(rng_algs, ARRAY_SIZE(rng_algs));
458 }                                                 463 }
459                                                   464 
460 static void __exit prng_mod_fini(void)            465 static void __exit prng_mod_fini(void)
461 {                                                 466 {
462         crypto_unregister_rngs(rng_algs, ARRAY    467         crypto_unregister_rngs(rng_algs, ARRAY_SIZE(rng_algs));
463 }                                                 468 }
464                                                   469 
465 MODULE_LICENSE("GPL");                            470 MODULE_LICENSE("GPL");
466 MODULE_DESCRIPTION("Software Pseudo Random Num    471 MODULE_DESCRIPTION("Software Pseudo Random Number Generator");
467 MODULE_AUTHOR("Neil Horman <nhorman@tuxdriver.    472 MODULE_AUTHOR("Neil Horman <nhorman@tuxdriver.com>");
468 module_param(dbg, int, 0);                        473 module_param(dbg, int, 0);
469 MODULE_PARM_DESC(dbg, "Boolean to enable debug    474 MODULE_PARM_DESC(dbg, "Boolean to enable debugging (0/1 == off/on)");
470 subsys_initcall(prng_mod_init);                !! 475 module_init(prng_mod_init);
471 module_exit(prng_mod_fini);                       476 module_exit(prng_mod_fini);
472 MODULE_ALIAS_CRYPTO("stdrng");                    477 MODULE_ALIAS_CRYPTO("stdrng");
473 MODULE_ALIAS_CRYPTO("ansi_cprng");                478 MODULE_ALIAS_CRYPTO("ansi_cprng");
474 MODULE_IMPORT_NS(CRYPTO_INTERNAL);             << 
475                                                   479 

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