Add an implementation of RC4. This will be used by Rockchip booting but may be useful in other situations.
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v3: None Changes in v2: None
include/rc4.h | 21 +++++++++++++++++++++ lib/Makefile | 1 + lib/rc4.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 71 insertions(+) create mode 100644 include/rc4.h create mode 100644 lib/rc4.c
diff --git a/include/rc4.h b/include/rc4.h new file mode 100644 index 0000000..ea409c2 --- /dev/null +++ b/include/rc4.h @@ -0,0 +1,21 @@ +/* + * (C) Copyright 2015 Google, Inc + * + * (C) Copyright 2008-2014 Rockchip Electronics + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef __RC4_H +#define __RC4_H + +/** + * rc4_encode() - encode a buf with the RC4 cipher + * + * @buf: Buffer to encode (it is overwrite in the process + * @len: Length of buffer in bytes + * @key: 16-byte key to use + */ +void rc4_encode(unsigned char *buf, unsigned int len, unsigned char key[16]); + +#endif diff --git a/lib/Makefile b/lib/Makefile index 1139f9b..fd106b9 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -37,6 +37,7 @@ obj-$(CONFIG_MD5) += md5.o obj-y += net_utils.o obj-$(CONFIG_PHYSMEM) += physmem.o obj-y += qsort.o +obj-y += rc4.o obj-$(CONFIG_SHA1) += sha1.o obj-$(CONFIG_SUPPORT_EMMC_RPMB) += sha256.o obj-$(CONFIG_SHA256) += sha256.o diff --git a/lib/rc4.c b/lib/rc4.c new file mode 100644 index 0000000..89d15f3 --- /dev/null +++ b/lib/rc4.c @@ -0,0 +1,49 @@ +/* + * (C) Copyright 2015 Google, Inc + * + * (C) Copyright 2008-2014 Rockchip Electronics + * + * Rivest Cipher 4 (RC4) implementation + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef USE_HOSTCC +#include <common.h> +#endif +#include <rc4.h> + +void rc4_encode(unsigned char *buf, unsigned int len, unsigned char key[16]) +{ + unsigned char s[256], k[256], temp; + unsigned short i, j, t; + int ptr; + + j = 0; + for (i = 0; i < 256; i++) { + s[i] = (unsigned char)i; + j &= 0x0f; + k[i] = key[j]; + j++; + } + + j = 0; + for (i = 0; i < 256; i++) { + j = (j + s[i] + k[i]) % 256; + temp = s[i]; + s[i] = s[j]; + s[j] = temp; + } + + i = 0; + j = 0; + for (ptr = 0; ptr < len; ptr++) { + i = (i + 1) % 256; + j = (j + s[i]) % 256; + temp = s[i]; + s[i] = s[j]; + s[j] = temp; + t = (s[i] + (s[j] % 256)) % 256; + buf[ptr] = buf[ptr] ^ s[t]; + } +}