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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-6.1.114)


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

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