From aadb9e2e90925a187877241e50110e4ce7ea80a1 Mon Sep 17 00:00:00 2001
From: Benjamin Barenblat <bbaren@mit.edu>
Date: Sat, 14 Mar 2015 19:47:09 -0400
Subject: Imported Upstream version 1.3

---
 secure_random_openssl.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 secure_random_openssl.c

(limited to 'secure_random_openssl.c')

diff --git a/secure_random_openssl.c b/secure_random_openssl.c
new file mode 100644
index 0000000..fe29165
--- /dev/null
+++ b/secure_random_openssl.c
@@ -0,0 +1,108 @@
+/*
+  secure_random_openssl.c - secure random number generator using OpenSSL
+  (c) 2004-2005 Zeljko Vrba <zvrba@globalnet.hr>
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+  CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+  TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+#include <stdlib.h>
+#include <string.h>
+#include <openssl/err.h>
+#include <openssl/rand.h>
+#include <openssl/blowfish.h>
+#include "exceptions.h"
+
+static char rcsid[] = "$Id: secure_random_openssl.c 1 2005-11-13 20:23:40Z zvrba $";
+
+/**
+	@file
+	This implementation uses the Blowfish cipher and low-level interfaces
+	usable both in SSLEay and OpenSSL (the latter is interesting in porting
+	to e.g. PalmOS).
+	
+	The generator gathers a small amount of true randomness from the system and
+	uses it to initialize the blowfish key and the randomness buffer. Further
+	random bytes are obtained by encrypting the previous contents of the
+	random buffer.
+*/
+
+/* Blowfish parameters. */
+#define	KEY_SIZE	16	/* 128-bit key size */
+#define BLOCK_SIZE	8	/* 64-bit block size */
+
+struct SRNG_st {
+	BF_KEY key;
+	unsigned char rnd[2*BLOCK_SIZE];
+	unsigned int idx;
+	unsigned char keydata[KEY_SIZE];
+};
+
+unsigned int SRNG_init(struct SRNG_st *st)
+{
+	if(!st)
+		goto end;
+
+	if(!RAND_bytes(st->keydata, sizeof(st->keydata))
+	|| !RAND_bytes(st->rnd, sizeof(st->rnd))) {
+		ERR_print_errors_fp(stderr);
+		Throw(lib_crypto_exception);
+	}
+
+	BF_set_key(&st->key, sizeof(st->keydata), st->keydata);
+	st->idx = 0;
+
+end:
+	return sizeof(struct SRNG_st);
+}
+
+void SRNG_bytes(
+	struct SRNG_st *st,
+	void *buf,
+	unsigned int n)
+{
+	unsigned char *out = buf, *src, *dst;
+
+	while(1) {
+		/*
+		 * this swaps src and dst to point to differenct halves of st->rnd on
+		 * each iteration. st->idx is either 0 or BLOCK_SIZE. it is initialized
+		 * to 0 in SRNG_init.
+		 */
+		src = st->rnd + st->idx;
+		dst = st->rnd + (BLOCK_SIZE - st->idx);
+		st->idx = BLOCK_SIZE - st->idx;
+
+		BF_ecb_encrypt(src, dst, &st->key, BF_ENCRYPT);
+
+		if(n < BLOCK_SIZE) {
+			memcpy(out, dst, n);
+			break;
+		}
+
+		memcpy(out, dst, BLOCK_SIZE);
+		n -= BLOCK_SIZE; out += BLOCK_SIZE;
+	}
+}
+
+void SRNG_destroy(struct SRNG_st *st)
+{
+	printf("INFO: destroying random number generator.\n");
+	memset(st, 0, sizeof(*st));
+}
+
-- 
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