Hey-
Patch to expand the linux crypto api to allow for the registration and
allocation of various random number generators. Tested successfully by me.

Regards
Neil

Signed-off-by: Neil Horman


crypto/Makefile | 2 -
crypto/prng.c | 94 ++++++++++++++++++++++++++++++++++++++----------
crypto/rngapi.c | 77 +++++++++++++++++++++++++++++++++++++++
include/crypto/algapi.h | 1
include/crypto/rng.h | 63 ++++++++++++++++++++++++++++++++
include/linux/crypto.h | 28 +++++++++++++-
6 files changed, 244 insertions(+), 21 deletions(-)


diff --git a/crypto/Makefile b/crypto/Makefile
index 74dc264..4800a9d 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -3,7 +3,7 @@
#

obj-$(CONFIG_CRYPTO) += crypto.o
-crypto-objs := api.o cipher.o digest.o compress.o
+crypto-objs := api.o cipher.o digest.o compress.o rngapi.o

crypto_algapi-$(CONFIG_PROC_FS) += proc.o
crypto_algapi-objs := algapi.o scatterwalk.o $(crypto_algapi-y)
diff --git a/crypto/prng.c b/crypto/prng.c
index d860a3a..b203093 100644
--- a/crypto/prng.c
+++ b/crypto/prng.c
@@ -21,17 +21,16 @@
#include
#include
#include
-#include
#include
#include
#include
#include
#include
#include
+#include
+#include
#include "prng.h"

-#define TEST_PRNG_ON_START 0
-
#define DEFAULT_PRNG_KEY "0123456789abcdef"
#define DEFAULT_PRNG_KSZ 16
#define DEFAULT_BLK_SZ 16
@@ -360,31 +359,90 @@ out:
}
EXPORT_SYMBOL_GPL(reset_prng_context);

-/* Module initalization */
-static int __init prng_mod_init(void)
+ static int cprng_init(struct crypto_tfm *tfm)
{
+ struct rng_tfm *ctx = crypto_rng_crt(crypto_rng_cast(tfm));

-#if TEST_PRNG_ON_START
- int i;
- unsigned char tmpbuf[DEFAULT_BLK_SZ];
+ ctx->ctx_data = alloc_prng_context();
+
+ if (!ctx->ctx_data)
+ return -ENOMEM;
+
+ /*
+ * This tells useers how much data to pass in for
+ * reseeding when calling rng_reset
+ */
+ ctx->seedsize = DEFAULT_PRNG_KSZ + DEFAULT_BLK_SZ;
+
+ return 0;
+}
+
+static void cprng_exit(struct crypto_tfm *tfm)
+{
+ struct rng_tfm *ctx = crypto_rng_crt(crypto_rng_cast(tfm));
+
+ if (ctx->ctx_data)
+ free_prng_context(ctx->ctx_data);
+}
+
+ static int cprng_get_random(struct crypto_tfm *tfm, u8 *rdata,
+ unsigned int dlen)
+{
+ struct rng_tfm *ctx = crypto_rng_crt(crypto_rng_cast(tfm));
+ struct prng_context *prng = ctx->ctx_data;
+
+ return get_prng_bytes(rdata, dlen, prng);
+}

- struct prng_context *ctx = alloc_prng_context();
- if (ctx == NULL)
+static int cprng_reset(struct crypto_tfm *tfm,
+ u8 *seed, unsigned int slen)
+{
+ struct rng_tfm *ctx = crypto_rng_crt(crypto_rng_cast(tfm));
+ struct prng_context *prng = ctx->ctx_data;
+ u8 *key = seed + DEFAULT_PRNG_KSZ;
+
+ if (slen < ctx->seedsize)
+ return -EINVAL;
+
+ reset_prng_context(prng, key, DEFAULT_PRNG_KSZ, seed, NULL);
+
+ if (prng->flags & PRNG_NEED_RESET)
return -EFAULT;
- for (i = 0; i < 512; i++) {
- if (get_prng_bytes(tmpbuf, DEFAULT_BLK_SZ, ctx) < 0) {
- free_prng_context(ctx);
- return -EFAULT;
- }
- }
- free_prng_context(ctx);
-#endif
+ return 0;
+}
+
+static struct crypto_alg rng_alg = {
+ .cra_name = "ansi_cprng",
+ .cra_priority = 100,
+ .cra_flags = CRYPTO_ALG_TYPE_RNG,
+ .cra_ctxsize = 0,
+ .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 } }

+};
+
+
+/* Module initalization */
+static int __init prng_mod_init(void)
+{
+ int ret = 0;
+ 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;
}

diff --git a/crypto/rngapi.c b/crypto/rngapi.c
new file mode 100644
index 0000000..fc26bbd
--- /dev/null
+++ b/crypto/rngapi.c
@@ -0,0 +1,77 @@
+/*
+ * Cryptographic API.
+ *
+ * RNG operations.
+ *
+ * Copyright (c) 2008 Neil Horman
+ *
+ * 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
+#include
+#include
+#include
+#include
+#include "internal.h"
+
+static int crypto_gen_rng_data(struct crypto_tfm *tfm,
+ u8 *rdata, unsigned int dlen)
+{
+ return tfm->__crt_alg->cra_rng.rng_make_random(tfm, rdata, dlen);
+}
+
+static int crypto_rng_reset(struct crypto_tfm *tfm,
+ u8 *seed, unsigned int slen)
+{
+ if (!tfm->__crt_alg->cra_rng.rng_reset)
+ return -ENOTSUPP;
+
+ return tfm->__crt_alg->cra_rng.rng_reset(tfm, seed, slen);
+}
+
+static int crypto_init_rng_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
+{
+ struct rng_tfm *ops = &tfm->crt_rng;
+
+ ops->rng_gen_random = crypto_gen_rng_data;
+ ops->rng_reset = crypto_rng_reset;
+
+ return 0;
+}
+
+static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg)
+{
+ seq_printf(m, "type : rng\n");
+}
+
+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);
+
+
+struct crypto_rng *crypto_alloc_rng(const char *alg_name)
+{
+ u32 type, mask;
+
+ mask = CRYPTO_ALG_TYPE_MASK;
+ type = CRYPTO_ALG_TYPE_RNG;
+
+ return __crypto_rng_cast(crypto_alloc_base(alg_name, type, mask));
+}
+EXPORT_SYMBOL_GPL(crypto_alloc_rng);
+
diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h
index 60d06e7..8ce33ea 100644
--- a/include/crypto/algapi.h
+++ b/include/crypto/algapi.h
@@ -98,6 +98,7 @@ extern const struct crypto_type crypto_ablkcipher_type;
extern const struct crypto_type crypto_aead_type;
extern const struct crypto_type crypto_blkcipher_type;
extern const struct crypto_type crypto_hash_type;
+extern const struct crypto_type crypto_rng_type;

void crypto_mod_put(struct crypto_alg *alg);

diff --git a/include/crypto/rng.h b/include/crypto/rng.h
new file mode 100644
index 0000000..a1fca87
--- /dev/null
+++ b/include/crypto/rng.h
@@ -0,0 +1,63 @@
+/*
+ * RNG: Random Number Generator algorithms under the crypto API
+ *
+ * Copyright (c) 2008 Neil Horman
+ *
+ * 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
+
+struct crypto_rng *crypto_alloc_rng(const char *alg_name);
+
+static inline struct crypto_rng *__crypto_rng_cast(struct crypto_tfm *tfm)
+{
+ return (struct crypto_rng *)tfm;
+}
+
+static inline struct crypto_rng *crypto_rng_cast(struct crypto_tfm *tfm)
+{
+ BUG_ON((crypto_tfm_alg_type(tfm) ^ CRYPTO_ALG_TYPE_RNG) &
+ CRYPTO_ALG_TYPE_MASK);
+ return __crypto_rng_cast(tfm);
+}
+
+struct crypto_rng *crypto_alloc_rng(const char *alg_name);
+
+static inline struct crypto_tfm *crypto_rng_tfm(struct crypto_rng *tfm)
+{
+ return &tfm->base;
+}
+
+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_get_random_bytes(struct crypto_rng *tfm,
+ u8 *rdata, unsigned int dlen)
+{
+ return crypto_rng_crt(tfm)->rng_gen_random(crypto_rng_tfm(tfm),
+ rdata, dlen);
+}
+
+static inline int crypto_reset_rng(struct crypto_rng *tfm,
+ u8 *seed, unsigned int slen)
+{
+ return crypto_rng_crt(tfm)->rng_reset(crypto_rng_tfm(tfm),
+ seed, slen);
+}
+
+#endif
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 81d994a..598894f 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -38,7 +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
#define CRYPTO_ALG_TYPE_BLKCIPHER_MASK 0x0000000c
@@ -298,6 +298,14 @@ struct compress_alg {
unsigned int slen, u8 *dst, unsigned int *dlen);
};

+struct rng_alg {
+ int (*rng_make_random)(struct crypto_tfm *tfm, u8 *rdata,
+ unsigned int dlen);
+ int (*rng_reset)(struct crypto_tfm *tfm, u8 *seed,
+ unsigned int slen);
+};
+
+
#define cra_ablkcipher cra_u.ablkcipher
#define cra_aead cra_u.aead
#define cra_blkcipher cra_u.blkcipher
@@ -306,6 +314,7 @@ 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 +342,7 @@ 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 +448,15 @@ struct compress_tfm {
u8 *dst, unsigned int *dlen);
};

+struct rng_tfm {
+ int (*rng_gen_random)(struct crypto_tfm *tfm, u8 *rdata,
+ unsigned int dlen);
+ int (*rng_reset)(struct crypto_tfm *tfm, u8 *seed,
+ unsigned int slen);
+ void *ctx_data;
+ size_t seedsize;
+};
+
#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,
@@ -1313,6 +1338,5 @@ static inline int crypto_comp_decompress(struct crypto_comp *tfm,
return crypto_comp_crt(tfm)->cot_decompress(crypto_comp_tfm(tfm),
src, slen, dst, dlen);
}
-
#endif /* _LINUX_CRYPTO_H */

--
/************************************************** **
* Neil Horman
* Software Engineer, Red Hat
************************************************** **/
--
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