Revert crypto: prng - Deterministic CPRNG

This patch is clearly not ready yet for prime time.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

4 files changed, 1 insertions, 447 deletions

diff --git a/crypto/Kconfig b/crypto/Kconfig
index ea503572fcbe..d83185915eee 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -666,15 +666,6 @@ config CRYPTO_LZO
         help
           This is the LZO algorithm.
 
-comment "Random Number Generation"
-
-config CRYPTO_PRNG
-        tristate "Pseudo Random Number Generation for Cryptographic modules"
-        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 ef61b3b64660..d4f3ed857df0 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -69,7 +69,7 @@ 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-$(CONFIG_CRYPTO_PRNG) += prng.o
+
 obj-$(CONFIG_CRYPTO_TEST) += tcrypt.o
 
 #
diff --git a/crypto/prng.c b/crypto/prng.c
deleted file mode 100644
index 24e4f3282c56..000000000000
--- a/crypto/prng.c
+++ /dev/null
@@ -1,410 +0,0 @@
-/*
- * PRNG: Pseudo Random Number Generator
- *       Based on NIST Recommended PRNG From ANSI X9.31 Appendix A.2.4 using
- *       AES 128 cipher in RFC3686 ctr mode
- *
- *  (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 <linux/err.h>
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/mm.h>
-#include <linux/slab.h>
-#include <linux/fs.h>
-#include <linux/scatterlist.h>
-#include <linux/string.h>
-#include <linux/crypto.h>
-#include <linux/highmem.h>
-#include <linux/moduleparam.h>
-#include <linux/jiffies.h>
-#include <linux/timex.h>
-#include <linux/interrupt.h>
-#include <linux/miscdevice.h>
-#include "prng.h"
-
-#define TEST_PRNG_ON_START 0
-
-#define DEFAULT_PRNG_KEY "0123456789abcdef1011"
-#define DEFAULT_PRNG_KSZ 20
-#define DEFAULT_PRNG_IV "defaultv"
-#define DEFAULT_PRNG_IVSZ 8
-#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 {
-        char *prng_key;
-        char *prng_iv;
-        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_blkcipher *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;
-        struct blkcipher_desc desc;
-        struct scatterlist sg_in, sg_out;
-        int ret;
-        unsigned char tmp[DEFAULT_BLK_SZ];
-
-        desc.tfm = ctx->tfm;
-        desc.flags = 0;
-
-
-        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++) {
-
-                desc.tfm = ctx->tfm;
-                desc.flags = 0;
-                switch (i) {
-                        case 0:
-                                /*
-                                 * Start by encrypting the counter value
-                                 * This gives us an intermediate value I
-                                 */
-                                memcpy(tmp, ctx->DT, DEFAULT_BLK_SZ);
-                                sg_init_one(&sg_out, &ctx->I[0], DEFAULT_BLK_SZ);
-                                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);
-                                sg_init_one(&sg_out, &ctx->rand_data[0], DEFAULT_BLK_SZ);
-                                hexdump("tmp stage 1: ", tmp, DEFAULT_BLK_SZ);
-                                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 -1;
-                                }
-                                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);
-                                sg_init_one(&sg_out, &ctx->V[0], DEFAULT_BLK_SZ);
-                                hexdump("tmp stage 2: ", tmp, DEFAULT_BLK_SZ);
-                                break;
-                }
-
-                /* Initialize our input buffer */
-                sg_init_one(&sg_in, &tmp[0], DEFAULT_BLK_SZ);
-
-                /* do the encryption */
-                ret = crypto_blkcipher_encrypt(&desc, &sg_out, &sg_in, DEFAULT_BLK_SZ);
-
-                /* And check the result */
-                if (ret) {
-                        dbgprint(KERN_CRIT "Encryption of new block failed for context %p\n",ctx);
-                        ctx->rand_data_valid = DEFAULT_BLK_SZ;
-                        return -1;
-                }
-
-        }
-
-        /*
-         * Now update our DT value
-         */
-        for (i=DEFAULT_BLK_SZ-1;i>0;i--) {
-                ctx->DT[i] = ctx->DT[i-1];
-        }
-        ctx->DT[0] += 1;
-
-        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 */
-int get_prng_bytes(char *buf, int 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 = -EFAULT;
-        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 = -EFAULT;
-                        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 = -1;
-                        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;
-}
-EXPORT_SYMBOL_GPL(get_prng_bytes);
-
-struct prng_context *alloc_prng_context(void)
-{
-        struct prng_context *ctx=kzalloc(sizeof(struct prng_context), GFP_KERNEL);
-
-        spin_lock_init(&ctx->prng_lock);
-
-        if (reset_prng_context(ctx, NULL, NULL, NULL, NULL)) {
-                kfree(ctx);
-                ctx = NULL;
-        }
-
-        dbgprint(KERN_CRIT "returning context %p\n",ctx);
-        return ctx;
-}
-
-EXPORT_SYMBOL_GPL(alloc_prng_context);
-
-void free_prng_context(struct prng_context *ctx)
-{
-        crypto_free_blkcipher(ctx->tfm);
-        kfree(ctx);
-}
-EXPORT_SYMBOL_GPL(free_prng_context);
-
-int reset_prng_context(struct prng_context *ctx,
-                       unsigned char *key, unsigned char *iv,
-                       unsigned char *V, unsigned char *DT)
-{
-        int ret;
-        int iv_len;
-        int rc = -EFAULT;
-
-        spin_lock(&ctx->prng_lock);
-        ctx->flags |= PRNG_NEED_RESET;
-
-        if (key)
-                memcpy(ctx->prng_key,key,strlen(ctx->prng_key));
-        else
-                ctx->prng_key = DEFAULT_PRNG_KEY;
-
-        if (iv)
-                memcpy(ctx->prng_iv,iv, strlen(ctx->prng_iv));
-        else
-                ctx->prng_iv = DEFAULT_PRNG_IV;
-
-        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_blkcipher(ctx->tfm);
-
-        ctx->tfm = crypto_alloc_blkcipher("rfc3686(ctr(aes))",0,0);
-        if (!ctx->tfm) {
-                dbgprint(KERN_CRIT "Failed to alloc crypto tfm for context %p\n",ctx->tfm);
-                goto out;
-        }
-
-        ctx->rand_data_valid = DEFAULT_BLK_SZ;
-
-        ret = crypto_blkcipher_setkey(ctx->tfm, ctx->prng_key, strlen(ctx->prng_key));
-        if (ret) {
-                dbgprint(KERN_CRIT "PRNG: setkey() failed flags=%x\n",
-                        crypto_blkcipher_get_flags(ctx->tfm));
-                crypto_free_blkcipher(ctx->tfm);
-                goto out;
-        }
-
-        iv_len = crypto_blkcipher_ivsize(ctx->tfm);
-        if (iv_len) {
-                crypto_blkcipher_set_iv(ctx->tfm, ctx->prng_iv, iv_len);
-        }
-        rc = 0;
-        ctx->flags &= ~PRNG_NEED_RESET;
-out:
-        spin_unlock(&ctx->prng_lock);
-
-        return rc;
-
-}
-EXPORT_SYMBOL_GPL(reset_prng_context);
-
-/* Module initalization */
-static int __init prng_mod_init(void)
-{
-
-#ifdef TEST_PRNG_ON_START
-        int i;
-        unsigned char tmpbuf[DEFAULT_BLK_SZ];
-
-        struct prng_context *ctx = alloc_prng_context();
-        if (ctx == NULL)
-                return -EFAULT;
-        for (i=0;i<16;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 void __exit prng_mod_fini(void)
-{
-        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);
diff --git a/crypto/prng.h b/crypto/prng.h
deleted file mode 100644
index 1ac9be5009b7..000000000000
--- a/crypto/prng.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
- * PRNG: Pseudo Random Number Generator
- *
- *  (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.
- *
- *
- */
-
-#ifndef _PRNG_H_
-#define _PRNG_H_
-struct prng_context;
-
-int get_prng_bytes(char *buf, int nbytes, struct prng_context *ctx);
-struct prng_context *alloc_prng_context(void);
-int reset_prng_context(struct prng_context *ctx,
-                        unsigned char *key, unsigned char *iv,
-                        unsigned char *V,
-                        unsigned char *DT);
-void free_prng_context(struct prng_context *ctx);
-
-#endif
-