diff options
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/Kconfig | 16 | ||||
| -rw-r--r-- | crypto/Makefile | 4 | ||||
| -rw-r--r-- | crypto/ansi_cprng.c | 417 | ||||
| -rw-r--r-- | crypto/krng.c | 66 | ||||
| -rw-r--r-- | crypto/rng.c | 126 |
5 files changed, 628 insertions, 1 deletions
diff --git a/crypto/Kconfig b/crypto/Kconfig index a784c2dce57e..2274293e71e1 100644 --- 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 8a27b834ea76..5862b807334e 100644 --- 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 index 000000000000..72db0fd763cc --- /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 index 000000000000..4328bb3430ed --- /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 index 000000000000..6e94bc735578 --- /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"); |