crypto: rng - RNG interface and implementation

This patch adds a random number generator interface as well as a
cryptographic pseudo-random number generator based on AES.  It is
meant to be used in cases where a deterministic CPRNG is required.

One of the first applications will be as an input in the IPsec IV
generation process.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/Kconfig b/crypto/Kconfig
index a784c2dce57e2a3319e159cec2adf0583b545327..2274293e71e1162112ade645c41cc3aecba0daf1 100644 (file)
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -46,6 +46,10 @@ config CRYPTO_HASH
        tristate
        select CRYPTO_ALGAPI
 
+config CRYPTO_RNG
+       tristate
+       select CRYPTO_ALGAPI
+
 config CRYPTO_MANAGER
        tristate "Cryptographic algorithm manager"
        select CRYPTO_AEAD
@@ -689,6 +693,18 @@ config CRYPTO_LZO
        help
          This is the LZO algorithm.
 
+comment "Random Number Generation"
+
+config CRYPTO_ANSI_CPRNG
+       tristate "Pseudo Random Number Generation for Cryptographic modules"
+       select CRYPTO_AES
+       select CRYPTO_RNG
+       select CRYPTO_FIPS
+       help
+         This option enables the generic pseudo random number generator
+         for cryptographic modules.  Uses the Algorithm specified in
+         ANSI X9.31 A.2.4
+
 source "drivers/crypto/Kconfig"
 
 endif  # if CRYPTO

diff --git a/crypto/Makefile b/crypto/Makefile
index 8a27b834ea76356cef782aec1ed723f9caf6dda1..5862b807334e5c0f46fbad14bf01e058fe4e9939 100644 (file)
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -73,7 +73,9 @@ obj-$(CONFIG_CRYPTO_MICHAEL_MIC) += michael_mic.o
 obj-$(CONFIG_CRYPTO_CRC32C) += crc32c.o
 obj-$(CONFIG_CRYPTO_AUTHENC) += authenc.o
 obj-$(CONFIG_CRYPTO_LZO) += lzo.o
-
+obj-$(CONFIG_CRYPTO_RNG) += rng.o
+obj-$(CONFIG_CRYPTO_RNG) += krng.o
+obj-$(CONFIG_CRYPTO_ANSI_CPRNG) += ansi_cprng.o
 obj-$(CONFIG_CRYPTO_TEST) += tcrypt.o
 
 #

diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c
new file mode 100644 (file)
index 0000000..72db0fd
--- /dev/null
+++ b/crypto/ansi_cprng.c
@@ -0,0 +1,417 @@
+/*
+ * PRNG: Pseudo Random Number Generator
+ *       Based on NIST Recommended PRNG From ANSI X9.31 Appendix A.2.4 using
+ *       AES 128 cipher
+ *
+ *  (C) Neil Horman <nhorman@tuxdriver.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License as published by the
+ *  Free Software Foundation; either version 2 of the License, or (at your
+ *  any later version.
+ *
+ *
+ */
+
+#include <crypto/internal/rng.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/string.h>
+
+#include "internal.h"
+
+#define DEFAULT_PRNG_KEY "0123456789abcdef"
+#define DEFAULT_PRNG_KSZ 16
+#define DEFAULT_BLK_SZ 16
+#define DEFAULT_V_SEED "zaybxcwdveuftgsh"
+
+/*
+ * Flags for the prng_context flags field
+ */
+
+#define PRNG_FIXED_SIZE 0x1
+#define PRNG_NEED_RESET 0x2
+
+/*
+ * Note: DT is our counter value
+ *      I is our intermediate value
+ *      V is our seed vector
+ * See http://csrc.nist.gov/groups/STM/cavp/documents/rng/931rngext.pdf
+ * for implementation details
+ */
+
+
+struct prng_context {
+       spinlock_t prng_lock;
+       unsigned char rand_data[DEFAULT_BLK_SZ];
+       unsigned char last_rand_data[DEFAULT_BLK_SZ];
+       unsigned char DT[DEFAULT_BLK_SZ];
+       unsigned char I[DEFAULT_BLK_SZ];
+       unsigned char V[DEFAULT_BLK_SZ];
+       u32 rand_data_valid;
+       struct crypto_cipher *tfm;
+       u32 flags;
+};
+
+static int dbg;
+
+static void hexdump(char *note, unsigned char *buf, unsigned int len)
+{
+       if (dbg) {
+               printk(KERN_CRIT "%s", note);
+               print_hex_dump(KERN_CONT, "", DUMP_PREFIX_OFFSET,
+                               16, 1,
+                               buf, len, false);
+       }
+}
+
+#define dbgprint(format, args...) do {\
+if (dbg)\
+       printk(format, ##args);\
+} while (0)
+
+static void xor_vectors(unsigned char *in1, unsigned char *in2,
+                       unsigned char *out, unsigned int size)
+{
+       int i;
+
+       for (i = 0; i < size; i++)
+               out[i] = in1[i] ^ in2[i];
+
+}
+/*
+ * Returns DEFAULT_BLK_SZ bytes of random data per call
+ * returns 0 if generation succeded, <0 if something went wrong
+ */
+static int _get_more_prng_bytes(struct prng_context *ctx)
+{
+       int i;
+       unsigned char tmp[DEFAULT_BLK_SZ];
+       unsigned char *output = NULL;
+
+
+       dbgprint(KERN_CRIT "Calling _get_more_prng_bytes for context %p\n",
+               ctx);
+
+       hexdump("Input DT: ", ctx->DT, DEFAULT_BLK_SZ);
+       hexdump("Input I: ", ctx->I, DEFAULT_BLK_SZ);
+       hexdump("Input V: ", ctx->V, DEFAULT_BLK_SZ);
+
+       /*
+        * This algorithm is a 3 stage state machine
+        */
+       for (i = 0; i < 3; i++) {
+
+               switch (i) {
+               case 0:
+                       /*
+                        * Start by encrypting the counter value
+                        * This gives us an intermediate value I
+                        */
+                       memcpy(tmp, ctx->DT, DEFAULT_BLK_SZ);
+                       output = ctx->I;
+                       hexdump("tmp stage 0: ", tmp, DEFAULT_BLK_SZ);
+                       break;
+               case 1:
+
+                       /*
+                        * Next xor I with our secret vector V
+                        * encrypt that result to obtain our
+                        * pseudo random data which we output
+                        */
+                       xor_vectors(ctx->I, ctx->V, tmp, DEFAULT_BLK_SZ);
+                       hexdump("tmp stage 1: ", tmp, DEFAULT_BLK_SZ);
+                       output = ctx->rand_data;
+                       break;
+               case 2:
+                       /*
+                        * First check that we didn't produce the same
+                        * random data that we did last time around through this
+                        */
+                       if (!memcmp(ctx->rand_data, ctx->last_rand_data,
+                                       DEFAULT_BLK_SZ)) {
+                               printk(KERN_ERR
+                                       "ctx %p Failed repetition check!\n",
+                                       ctx);
+                               ctx->flags |= PRNG_NEED_RESET;
+                               return -EINVAL;
+                       }
+                       memcpy(ctx->last_rand_data, ctx->rand_data,
+                               DEFAULT_BLK_SZ);
+
+                       /*
+                        * Lastly xor the random data with I
+                        * and encrypt that to obtain a new secret vector V
+                        */
+                       xor_vectors(ctx->rand_data, ctx->I, tmp,
+                               DEFAULT_BLK_SZ);
+                       output = ctx->V;
+                       hexdump("tmp stage 2: ", tmp, DEFAULT_BLK_SZ);
+                       break;
+               }
+
+
+               /* do the encryption */
+               crypto_cipher_encrypt_one(ctx->tfm, output, tmp);
+
+       }
+
+       /*
+        * Now update our DT value
+        */
+       for (i = 0; i < DEFAULT_BLK_SZ; i++) {
+               ctx->DT[i] += 1;
+               if (ctx->DT[i] != 0)
+                       break;
+       }
+
+       dbgprint("Returning new block for context %p\n", ctx);
+       ctx->rand_data_valid = 0;
+
+       hexdump("Output DT: ", ctx->DT, DEFAULT_BLK_SZ);
+       hexdump("Output I: ", ctx->I, DEFAULT_BLK_SZ);
+       hexdump("Output V: ", ctx->V, DEFAULT_BLK_SZ);
+       hexdump("New Random Data: ", ctx->rand_data, DEFAULT_BLK_SZ);
+
+       return 0;
+}
+
+/* Our exported functions */
+static int get_prng_bytes(char *buf, size_t nbytes, struct prng_context *ctx)
+{
+       unsigned long flags;
+       unsigned char *ptr = buf;
+       unsigned int byte_count = (unsigned int)nbytes;
+       int err;
+
+
+       if (nbytes < 0)
+               return -EINVAL;
+
+       spin_lock_irqsave(&ctx->prng_lock, flags);
+
+       err = -EINVAL;
+       if (ctx->flags & PRNG_NEED_RESET)
+               goto done;
+
+       /*
+        * If the FIXED_SIZE flag is on, only return whole blocks of
+        * pseudo random data
+        */
+       err = -EINVAL;
+       if (ctx->flags & PRNG_FIXED_SIZE) {
+               if (nbytes < DEFAULT_BLK_SZ)
+                       goto done;
+               byte_count = DEFAULT_BLK_SZ;
+       }
+
+       err = byte_count;
+
+       dbgprint(KERN_CRIT "getting %d random bytes for context %p\n",
+               byte_count, ctx);
+
+
+remainder:
+       if (ctx->rand_data_valid == DEFAULT_BLK_SZ) {
+               if (_get_more_prng_bytes(ctx) < 0) {
+                       memset(buf, 0, nbytes);
+                       err = -EINVAL;
+                       goto done;
+               }
+       }
+
+       /*
+        * Copy up to the next whole block size
+        */
+       if (byte_count < DEFAULT_BLK_SZ) {
+               for (; ctx->rand_data_valid < DEFAULT_BLK_SZ;
+                       ctx->rand_data_valid++) {
+                       *ptr = ctx->rand_data[ctx->rand_data_valid];
+                       ptr++;
+                       byte_count--;
+                       if (byte_count == 0)
+                               goto done;
+               }
+       }
+
+       /*
+        * Now copy whole blocks
+        */
+       for (; byte_count >= DEFAULT_BLK_SZ; byte_count -= DEFAULT_BLK_SZ) {
+               if (_get_more_prng_bytes(ctx) < 0) {
+                       memset(buf, 0, nbytes);
+                       err = -EINVAL;
+                       goto done;
+               }
+               memcpy(ptr, ctx->rand_data, DEFAULT_BLK_SZ);
+               ctx->rand_data_valid += DEFAULT_BLK_SZ;
+               ptr += DEFAULT_BLK_SZ;
+       }
+
+       /*
+        * Now copy any extra partial data
+        */
+       if (byte_count)
+               goto remainder;
+
+done:
+       spin_unlock_irqrestore(&ctx->prng_lock, flags);
+       dbgprint(KERN_CRIT "returning %d from get_prng_bytes in context %p\n",
+               err, ctx);
+       return err;
+}
+
+static void free_prng_context(struct prng_context *ctx)
+{
+       crypto_free_cipher(ctx->tfm);
+}
+
+static int reset_prng_context(struct prng_context *ctx,
+                             unsigned char *key, size_t klen,
+                             unsigned char *V, unsigned char *DT)
+{
+       int ret;
+       int rc = -EINVAL;
+       unsigned char *prng_key;
+
+       spin_lock(&ctx->prng_lock);
+       ctx->flags |= PRNG_NEED_RESET;
+
+       prng_key = (key != NULL) ? key : (unsigned char *)DEFAULT_PRNG_KEY;
+
+       if (!key)
+               klen = DEFAULT_PRNG_KSZ;
+
+       if (V)
+               memcpy(ctx->V, V, DEFAULT_BLK_SZ);
+       else
+               memcpy(ctx->V, DEFAULT_V_SEED, DEFAULT_BLK_SZ);
+
+       if (DT)
+               memcpy(ctx->DT, DT, DEFAULT_BLK_SZ);
+       else
+               memset(ctx->DT, 0, DEFAULT_BLK_SZ);
+
+       memset(ctx->rand_data, 0, DEFAULT_BLK_SZ);
+       memset(ctx->last_rand_data, 0, DEFAULT_BLK_SZ);
+
+       if (ctx->tfm)
+               crypto_free_cipher(ctx->tfm);
+
+       ctx->tfm = crypto_alloc_cipher("aes", 0, 0);
+       if (IS_ERR(ctx->tfm)) {
+               dbgprint(KERN_CRIT "Failed to alloc tfm for context %p\n",
+                       ctx);
+               ctx->tfm = NULL;
+               goto out;
+       }
+
+       ctx->rand_data_valid = DEFAULT_BLK_SZ;
+
+       ret = crypto_cipher_setkey(ctx->tfm, prng_key, klen);
+       if (ret) {
+               dbgprint(KERN_CRIT "PRNG: setkey() failed flags=%x\n",
+                       crypto_cipher_get_flags(ctx->tfm));
+               crypto_free_cipher(ctx->tfm);
+               goto out;
+       }
+
+       rc = 0;
+       ctx->flags &= ~PRNG_NEED_RESET;
+out:
+       spin_unlock(&ctx->prng_lock);
+
+       return rc;
+
+}
+
+static int cprng_init(struct crypto_tfm *tfm)
+{
+       struct prng_context *ctx = crypto_tfm_ctx(tfm);
+
+       spin_lock_init(&ctx->prng_lock);
+
+       return reset_prng_context(ctx, NULL, DEFAULT_PRNG_KSZ, NULL, NULL);
+}
+
+static void cprng_exit(struct crypto_tfm *tfm)
+{
+       free_prng_context(crypto_tfm_ctx(tfm));
+}
+
+static int cprng_get_random(struct crypto_rng *tfm, u8 *rdata,
+                           unsigned int dlen)
+{
+       struct prng_context *prng = crypto_rng_ctx(tfm);
+
+       return get_prng_bytes(rdata, dlen, prng);
+}
+
+static int cprng_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
+{
+       struct prng_context *prng = crypto_rng_ctx(tfm);
+       u8 *key = seed + DEFAULT_PRNG_KSZ;
+
+       if (slen < DEFAULT_PRNG_KSZ + DEFAULT_BLK_SZ)
+               return -EINVAL;
+
+       reset_prng_context(prng, key, DEFAULT_PRNG_KSZ, seed, NULL);
+
+       if (prng->flags & PRNG_NEED_RESET)
+               return -EINVAL;
+       return 0;
+}
+
+static struct crypto_alg rng_alg = {
+       .cra_name               = "stdrng",
+       .cra_driver_name        = "ansi_cprng",
+       .cra_priority           = 100,
+       .cra_flags              = CRYPTO_ALG_TYPE_RNG,
+       .cra_ctxsize            = sizeof(struct prng_context),
+       .cra_type               = &crypto_rng_type,
+       .cra_module             = THIS_MODULE,
+       .cra_list               = LIST_HEAD_INIT(rng_alg.cra_list),
+       .cra_init               = cprng_init,
+       .cra_exit               = cprng_exit,
+       .cra_u                  = {
+               .rng = {
+                       .rng_make_random        = cprng_get_random,
+                       .rng_reset              = cprng_reset,
+                       .seedsize = DEFAULT_PRNG_KSZ + DEFAULT_BLK_SZ,
+               }
+       }
+};
+
+
+/* Module initalization */
+static int __init prng_mod_init(void)
+{
+       int ret = 0;
+
+       if (fips_enabled)
+               rng_alg.cra_priority += 200;
+
+       ret = crypto_register_alg(&rng_alg);
+
+       if (ret)
+               goto out;
+out:
+       return 0;
+}
+
+static void __exit prng_mod_fini(void)
+{
+       crypto_unregister_alg(&rng_alg);
+       return;
+}
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Software Pseudo Random Number Generator");
+MODULE_AUTHOR("Neil Horman <nhorman@tuxdriver.com>");
+module_param(dbg, int, 0);
+MODULE_PARM_DESC(dbg, "Boolean to enable debugging (0/1 == off/on)");
+module_init(prng_mod_init);
+module_exit(prng_mod_fini);
+MODULE_ALIAS("stdrng");

diff --git a/crypto/krng.c b/crypto/krng.c
new file mode 100644 (file)
index 0000000..4328bb3
--- /dev/null
+++ b/crypto/krng.c
@@ -0,0 +1,66 @@
+/*
+ * RNG implementation using standard kernel RNG.
+ *
+ * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * any later version.
+ *
+ */
+
+#include <crypto/internal/rng.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/random.h>
+
+static int krng_get_random(struct crypto_rng *tfm, u8 *rdata, unsigned int dlen)
+{
+       get_random_bytes(rdata, dlen);
+       return 0;
+}
+
+static int krng_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
+{
+       return 0;
+}
+
+static struct crypto_alg krng_alg = {
+       .cra_name               = "stdrng",
+       .cra_driver_name        = "krng",
+       .cra_priority           = 200,
+       .cra_flags              = CRYPTO_ALG_TYPE_RNG,
+       .cra_ctxsize            = 0,
+       .cra_type               = &crypto_rng_type,
+       .cra_module             = THIS_MODULE,
+       .cra_list               = LIST_HEAD_INIT(krng_alg.cra_list),
+       .cra_u                  = {
+               .rng = {
+                       .rng_make_random        = krng_get_random,
+                       .rng_reset              = krng_reset,
+                       .seedsize               = 0,
+               }
+       }
+};
+
+
+/* Module initalization */
+static int __init krng_mod_init(void)
+{
+       return crypto_register_alg(&krng_alg);
+}
+
+static void __exit krng_mod_fini(void)
+{
+       crypto_unregister_alg(&krng_alg);
+       return;
+}
+
+module_init(krng_mod_init);
+module_exit(krng_mod_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Kernel Random Number Generator");
+MODULE_ALIAS("stdrng");

diff --git a/crypto/rng.c b/crypto/rng.c
new file mode 100644 (file)
index 0000000..6e94bc7
--- /dev/null
+++ b/crypto/rng.c
@@ -0,0 +1,126 @@
+/*
+ * Cryptographic API.
+ *
+ * RNG operations.
+ *
+ * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#include <asm/atomic.h>
+#include <crypto/internal/rng.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/random.h>
+#include <linux/seq_file.h>
+#include <linux/string.h>
+
+static DEFINE_MUTEX(crypto_default_rng_lock);
+struct crypto_rng *crypto_default_rng;
+EXPORT_SYMBOL_GPL(crypto_default_rng);
+static int crypto_default_rng_refcnt;
+
+static int rngapi_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
+{
+       u8 *buf = NULL;
+       int err;
+
+       if (!seed && slen) {
+               buf = kmalloc(slen, GFP_KERNEL);
+               if (!buf)
+                       return -ENOMEM;
+
+               get_random_bytes(buf, slen);
+               seed = buf;
+       }
+
+       err = crypto_rng_alg(tfm)->rng_reset(tfm, seed, slen);
+
+       kfree(buf);
+       return err;
+}
+
+static int crypto_init_rng_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
+{
+       struct rng_alg *alg = &tfm->__crt_alg->cra_rng;
+       struct rng_tfm *ops = &tfm->crt_rng;
+
+       ops->rng_gen_random = alg->rng_make_random;
+       ops->rng_reset = rngapi_reset;
+
+       return 0;
+}
+
+static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
+       __attribute__ ((unused));
+static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
+{
+       seq_printf(m, "type         : rng\n");
+       seq_printf(m, "seedsize     : %u\n", alg->cra_rng.seedsize);
+}
+
+static unsigned int crypto_rng_ctxsize(struct crypto_alg *alg, u32 type,
+                                      u32 mask)
+{
+       return alg->cra_ctxsize;
+}
+
+const struct crypto_type crypto_rng_type = {
+       .ctxsize = crypto_rng_ctxsize,
+       .init = crypto_init_rng_ops,
+#ifdef CONFIG_PROC_FS
+       .show = crypto_rng_show,
+#endif
+};
+EXPORT_SYMBOL_GPL(crypto_rng_type);
+
+int crypto_get_default_rng(void)
+{
+       struct crypto_rng *rng;
+       int err;
+
+       mutex_lock(&crypto_default_rng_lock);
+       if (!crypto_default_rng) {
+               rng = crypto_alloc_rng("stdrng", 0, 0);
+               err = PTR_ERR(rng);
+               if (IS_ERR(rng))
+                       goto unlock;
+
+               err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng));
+               if (err) {
+                       crypto_free_rng(rng);
+                       goto unlock;
+               }
+
+               crypto_default_rng = rng;
+       }
+
+       crypto_default_rng_refcnt++;
+       err = 0;
+
+unlock:
+       mutex_unlock(&crypto_default_rng_lock);
+
+       return err;
+}
+EXPORT_SYMBOL_GPL(crypto_get_default_rng);
+
+void crypto_put_default_rng(void)
+{
+       mutex_lock(&crypto_default_rng_lock);
+       if (!--crypto_default_rng_refcnt) {
+               crypto_free_rng(crypto_default_rng);
+               crypto_default_rng = NULL;
+       }
+       mutex_unlock(&crypto_default_rng_lock);
+}
+EXPORT_SYMBOL_GPL(crypto_put_default_rng);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Random Number Genertor");

diff --git a/include/crypto/internal/rng.h b/include/crypto/internal/rng.h
new file mode 100644 (file)
index 0000000..8969733
--- /dev/null
+++ b/include/crypto/internal/rng.h
@@ -0,0 +1,26 @@
+/*
+ * RNG: Random Number Generator  algorithms under the crypto API
+ *
+ * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#ifndef _CRYPTO_INTERNAL_RNG_H
+#define _CRYPTO_INTERNAL_RNG_H
+
+#include <crypto/algapi.h>
+#include <crypto/rng.h>
+
+extern const struct crypto_type crypto_rng_type;
+
+static inline void *crypto_rng_ctx(struct crypto_rng *tfm)
+{
+       return crypto_tfm_ctx(&tfm->base);
+}
+
+#endif

diff --git a/include/crypto/rng.h b/include/crypto/rng.h
new file mode 100644 (file)
index 0000000..c93f9b9
--- /dev/null
+++ b/include/crypto/rng.h
@@ -0,0 +1,75 @@
+/*
+ * RNG: Random Number Generator  algorithms under the crypto API
+ *
+ * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#ifndef _CRYPTO_RNG_H
+#define _CRYPTO_RNG_H
+
+#include <linux/crypto.h>
+
+extern struct crypto_rng *crypto_default_rng;
+
+int crypto_get_default_rng(void);
+void crypto_put_default_rng(void);
+
+static inline struct crypto_rng *__crypto_rng_cast(struct crypto_tfm *tfm)
+{
+       return (struct crypto_rng *)tfm;
+}
+
+static inline struct crypto_rng *crypto_alloc_rng(const char *alg_name,
+                                                 u32 type, u32 mask)
+{
+       type &= ~CRYPTO_ALG_TYPE_MASK;
+       type |= CRYPTO_ALG_TYPE_RNG;
+       mask |= CRYPTO_ALG_TYPE_MASK;
+
+       return __crypto_rng_cast(crypto_alloc_base(alg_name, type, mask));
+}
+
+static inline struct crypto_tfm *crypto_rng_tfm(struct crypto_rng *tfm)
+{
+       return &tfm->base;
+}
+
+static inline struct rng_alg *crypto_rng_alg(struct crypto_rng *tfm)
+{
+       return &crypto_rng_tfm(tfm)->__crt_alg->cra_rng;
+}
+
+static inline struct rng_tfm *crypto_rng_crt(struct crypto_rng *tfm)
+{
+       return &crypto_rng_tfm(tfm)->crt_rng;
+}
+
+static inline void crypto_free_rng(struct crypto_rng *tfm)
+{
+       crypto_free_tfm(crypto_rng_tfm(tfm));
+}
+
+static inline int crypto_rng_get_bytes(struct crypto_rng *tfm,
+                                      u8 *rdata, unsigned int dlen)
+{
+       return crypto_rng_crt(tfm)->rng_gen_random(tfm, rdata, dlen);
+}
+
+static inline int crypto_rng_reset(struct crypto_rng *tfm,
+                                  u8 *seed, unsigned int slen)
+{
+       return crypto_rng_crt(tfm)->rng_reset(tfm, seed, slen);
+}
+
+static inline int crypto_rng_seedsize(struct crypto_rng *tfm)
+{
+       return crypto_rng_alg(tfm)->seedsize;
+}
+
+#endif

diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 81d994a3bdaf1395db837a4ce2454ae733cc12c2..3d2317e4af2e4b4475c2fc18ff1db3b475ae1d52 100644 (file)
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -38,6 +38,7 @@
 #define CRYPTO_ALG_TYPE_DIGEST         0x00000008
 #define CRYPTO_ALG_TYPE_HASH           0x00000009
 #define CRYPTO_ALG_TYPE_AHASH          0x0000000a
+#define CRYPTO_ALG_TYPE_RNG            0x0000000c
 
 #define CRYPTO_ALG_TYPE_HASH_MASK      0x0000000e
 #define CRYPTO_ALG_TYPE_AHASH_MASK     0x0000000c
@@ -113,6 +114,7 @@ struct crypto_aead;
 struct crypto_blkcipher;
 struct crypto_hash;
 struct crypto_ahash;
+struct crypto_rng;
 struct crypto_tfm;
 struct crypto_type;
 struct aead_givcrypt_request;
@@ -298,6 +300,15 @@ struct compress_alg {
                              unsigned int slen, u8 *dst, unsigned int *dlen);
 };
 
+struct rng_alg {
+       int (*rng_make_random)(struct crypto_rng *tfm, u8 *rdata,
+                              unsigned int dlen);
+       int (*rng_reset)(struct crypto_rng *tfm, u8 *seed, unsigned int slen);
+
+       unsigned int seedsize;
+};
+
+
 #define cra_ablkcipher cra_u.ablkcipher
 #define cra_aead       cra_u.aead
 #define cra_blkcipher  cra_u.blkcipher
@@ -306,6 +317,7 @@ struct compress_alg {
 #define cra_hash       cra_u.hash
 #define cra_ahash      cra_u.ahash
 #define cra_compress   cra_u.compress
+#define cra_rng                cra_u.rng
 
 struct crypto_alg {
        struct list_head cra_list;
@@ -333,6 +345,7 @@ struct crypto_alg {
                struct hash_alg hash;
                struct ahash_alg ahash;
                struct compress_alg compress;
+               struct rng_alg rng;
        } cra_u;
 
        int (*cra_init)(struct crypto_tfm *tfm);
@@ -438,6 +451,12 @@ struct compress_tfm {
                              u8 *dst, unsigned int *dlen);
 };
 
+struct rng_tfm {
+       int (*rng_gen_random)(struct crypto_rng *tfm, u8 *rdata,
+                             unsigned int dlen);
+       int (*rng_reset)(struct crypto_rng *tfm, u8 *seed, unsigned int slen);
+};
+
 #define crt_ablkcipher crt_u.ablkcipher
 #define crt_aead       crt_u.aead
 #define crt_blkcipher  crt_u.blkcipher
@@ -445,6 +464,7 @@ struct compress_tfm {
 #define crt_hash       crt_u.hash
 #define crt_ahash      crt_u.ahash
 #define crt_compress   crt_u.compress
+#define crt_rng                crt_u.rng
 
 struct crypto_tfm {
 
@@ -458,6 +478,7 @@ struct crypto_tfm {
                struct hash_tfm hash;
                struct ahash_tfm ahash;
                struct compress_tfm compress;
+               struct rng_tfm rng;
        } crt_u;
        
        struct crypto_alg *__crt_alg;
@@ -489,6 +510,10 @@ struct crypto_hash {
        struct crypto_tfm base;
 };
 
+struct crypto_rng {
+       struct crypto_tfm base;
+};
+
 enum {
        CRYPTOA_UNSPEC,
        CRYPTOA_ALG,