Digi
/
meta-digi
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
meta-digi/meta-digi-arm/recipes-bsp/libubootenv/libubootenv/0001-Implement-support-for-...

607 lines
16 KiB
Diff
Raw Blame History

From 58977c4d6709f6ce4dc444e844b3665b031c556f Mon Sep 17 00:00:00 2001
From: Gabriel Valcazar <gabriel.valcazar@digi.com>
Date: Wed, 7 Apr 2021 09:15:07 +0200
Subject: [PATCH 1/3] Implement support for environment encryption by CAAM
Use the md5sum of HWID words (on the device tree) as key modifier. This is
based on the u-boot-fw-utils implementation of the CAAM encryption support.
Port a subset of U-Boot's md5 implementation.
https://jira.digi.com/browse/DEL-7410
https://jira.digi.com/browse/DEL-7185
https://jira.digi.com/browse/DEL-2836
Signed-off-by: Diaz de Grenu, Jose <Jose.DiazdeGrenu@digi.com>
Signed-off-by: Gonzalo Ruiz <Gonzalo.Ruiz@digi.com>
Signed-off-by: Hector Palacios <hector.palacios@digi.com>
Signed-off-by: Gabriel Valcazar <gabriel.valcazar@digi.com>
---
src/CMakeLists.txt | 2 +
src/caam_keyblob.h | 42 +++++++
src/md5.c | 275 ++++++++++++++++++++++++++++++++++++++++++++
src/md5.h | 24 ++++
src/uboot_env.c | 131 +++++++++++++++++++++
src/uboot_private.h | 4 +
6 files changed, 478 insertions(+)
create mode 100644 src/caam_keyblob.h
create mode 100644 src/md5.c
create mode 100644 src/md5.h
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a04dd11..659594a 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,6 +1,8 @@
cmake_minimum_required (VERSION 2.6)
# Sources and private headers
SET(libubootenv_SOURCES
+ md5.c
+ md5.h
uboot_env.c
uboot_private.h
)
diff --git a/src/caam_keyblob.h b/src/caam_keyblob.h
new file mode 100644
index 0000000..e313e87
--- /dev/null
+++ b/src/caam_keyblob.h
@@ -0,0 +1,42 @@
+/*
+ * CAAM public-level include definitions for the key blob
+ *
+ * Copyright (C) 2015 Freescale Semiconductor, Inc.
+ */
+
+#ifndef CAAM_KEYBLOB_H
+#define CAAM_KEYBLOB_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+struct caam_kb_data {
+ char *rawkey;
+ size_t rawkey_len;
+ char *keyblob;
+ size_t keyblob_len;
+ char *keymod;
+ size_t keymod_len;
+};
+
+#define CAAM_KB_MAGIC 'I'
+
+/**
+ * DOC: CAAM_KB_ENCRYPT - generate a key blob from raw key
+ *
+ * Takes an caam_kb_data struct and returns it with the key blob
+ */
+#define CAAM_KB_ENCRYPT _IOWR(CAAM_KB_MAGIC, 0, struct caam_kb_data)
+
+/**
+ * DOC: CAAM_KB_DECRYPT - get keys from a key blob
+ *
+ * Takes an caam_kb_data struct and returns it with the raw key.
+ */
+#define CAAM_KB_DECRYPT _IOWR(CAAM_KB_MAGIC, 1, struct caam_kb_data)
+
+#ifndef GENMEM_KEYMOD_LEN
+#define GENMEM_KEYMOD_LEN 16
+#endif
+
+#endif /* CAAM_KEYBLOB_H */
diff --git a/src/md5.c b/src/md5.c
new file mode 100644
index 0000000..47ae8bf
--- /dev/null
+++ b/src/md5.c
@@ -0,0 +1,275 @@
+/*
+ * This file was transplanted with slight modifications from Linux sources
+ * (fs/cifs/md5.c) into U-Boot by Bartlomiej Sieka <tur@semihalf.com>.
+ */
+
+/*
+ * This code implements the MD5 message-digest algorithm.
+ * The algorithm is due to Ron Rivest. This code was
+ * written by Colin Plumb in 1993, no copyright is claimed.
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Equivalent code is available from RSA Data Security, Inc.
+ * This code has been tested against that, and is equivalent,
+ * except that you don't need to include two pages of legalese
+ * with every copy.
+ *
+ * To compute the message digest of a chunk of bytes, declare an
+ * MD5Context structure, pass it to MD5Init, call MD5Update as
+ * needed on buffers full of bytes, and then call MD5Final, which
+ * will fill a supplied 16-byte array with the digest.
+ */
+
+/* This code slightly modified to fit into Samba by
+ abartlet@samba.org Jun 2001
+ and to fit the cifs vfs by
+ Steve French sfrench@us.ibm.com */
+
+#include <stdint.h>
+#include <string.h>
+
+#include "md5.h"
+
+static void
+MD5Transform(uint32_t buf[4], uint32_t const in[16]);
+
+/*
+ * Note: this code is harmless on little-endian machines.
+ */
+static void
+byteReverse(unsigned char *buf, unsigned longs)
+{
+ uint32_t t;
+ do {
+ t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
+ ((unsigned) buf[1] << 8 | buf[0]);
+ *(uint32_t *) buf = t;
+ buf += 4;
+ } while (--longs);
+}
+
+/*
+ * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
+ * initialization constants.
+ */
+static void
+MD5Init(struct MD5Context *ctx)
+{
+ ctx->buf[0] = 0x67452301;
+ ctx->buf[1] = 0xefcdab89;
+ ctx->buf[2] = 0x98badcfe;
+ ctx->buf[3] = 0x10325476;
+
+ ctx->bits[0] = 0;
+ ctx->bits[1] = 0;
+}
+
+/*
+ * Update context to reflect the concatenation of another buffer full
+ * of bytes.
+ */
+static void
+MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
+{
+ register uint32_t t;
+
+ /* Update bitcount */
+
+ t = ctx->bits[0];
+ if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
+ ctx->bits[1]++; /* Carry from low to high */
+ ctx->bits[1] += len >> 29;
+
+ t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
+
+ /* Handle any leading odd-sized chunks */
+
+ if (t) {
+ unsigned char *p = (unsigned char *) ctx->in + t;
+
+ t = 64 - t;
+ if (len < t) {
+ memmove(p, buf, len);
+ return;
+ }
+ memmove(p, buf, t);
+ byteReverse(ctx->in, 16);
+ MD5Transform(ctx->buf, (uint32_t *) ctx->in);
+ buf += t;
+ len -= t;
+ }
+ /* Process data in 64-byte chunks */
+
+ while (len >= 64) {
+ memmove(ctx->in, buf, 64);
+ byteReverse(ctx->in, 16);
+ MD5Transform(ctx->buf, (uint32_t *) ctx->in);
+ buf += 64;
+ len -= 64;
+ }
+
+ /* Handle any remaining bytes of data. */
+
+ memmove(ctx->in, buf, len);
+}
+
+/*
+ * Final wrapup - pad to 64-byte boundary with the bit pattern
+ * 1 0* (64-bit count of bits processed, MSB-first)
+ */
+static void
+MD5Final(unsigned char digest[16], struct MD5Context *ctx)
+{
+ unsigned int count;
+ unsigned char *p;
+
+ /* Compute number of bytes mod 64 */
+ count = (ctx->bits[0] >> 3) & 0x3F;
+
+ /* Set the first char of padding to 0x80. This is safe since there is
+ always at least one byte free */
+ p = ctx->in + count;
+ *p++ = 0x80;
+
+ /* Bytes of padding needed to make 64 bytes */
+ count = 64 - 1 - count;
+
+ /* Pad out to 56 mod 64 */
+ if (count < 8) {
+ /* Two lots of padding: Pad the first block to 64 bytes */
+ memset(p, 0, count);
+ byteReverse(ctx->in, 16);
+ MD5Transform(ctx->buf, (uint32_t *) ctx->in);
+
+ /* Now fill the next block with 56 bytes */
+ memset(ctx->in, 0, 56);
+ } else {
+ /* Pad block to 56 bytes */
+ memset(p, 0, count - 8);
+ }
+ byteReverse(ctx->in, 14);
+
+ /* Append length in bits and transform */
+ ctx->in32[14] = ctx->bits[0];
+ ctx->in32[15] = ctx->bits[1];
+
+ MD5Transform(ctx->buf, (uint32_t *) ctx->in);
+ byteReverse((unsigned char *) ctx->buf, 4);
+ memmove(digest, ctx->buf, 16);
+ memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
+}
+
+/* The four core functions - F1 is optimized somewhat */
+
+/* #define F1(x, y, z) (x & y | ~x & z) */
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+
+/* This is the central step in the MD5 algorithm. */
+#define MD5STEP(f, w, x, y, z, data, s) \
+ ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
+
+/*
+ * The core of the MD5 algorithm, this alters an existing MD5 hash to
+ * reflect the addition of 16 longwords of new data. MD5Update blocks
+ * the data and converts bytes into longwords for this routine.
+ */
+static void
+MD5Transform(uint32_t buf[4], uint32_t const in[16])
+{
+ register uint32_t a, b, c, d;
+
+ a = buf[0];
+ b = buf[1];
+ c = buf[2];
+ d = buf[3];
+
+ MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
+ MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
+ MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
+ MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
+ MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
+ MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
+ MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
+ MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
+ MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
+ MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
+ MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
+ MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
+ MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
+ MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
+ MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
+ MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
+
+ MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
+ MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
+ MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
+ MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
+ MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
+ MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
+ MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
+ MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
+ MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
+ MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
+ MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
+ MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
+ MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
+ MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
+ MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
+ MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
+
+ MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
+ MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
+ MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
+ MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
+ MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
+ MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
+ MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
+ MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
+ MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
+ MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
+ MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
+ MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
+ MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
+ MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
+ MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
+ MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
+
+ MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
+ MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
+ MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
+ MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
+ MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
+ MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
+ MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
+ MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
+ MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
+ MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
+ MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
+ MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
+ MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
+ MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
+ MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
+ MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
+
+ buf[0] += a;
+ buf[1] += b;
+ buf[2] += c;
+ buf[3] += d;
+}
+
+/*
+ * Calculate and store in 'output' the MD5 digest of 'len' bytes at
+ * 'input'. 'output' must have enough space to hold 16 bytes.
+ */
+void
+md5 (unsigned char *input, int len, unsigned char output[16])
+{
+ struct MD5Context context;
+
+ MD5Init(&context);
+ MD5Update(&context, input, len);
+ MD5Final(output, &context);
+}
diff --git a/src/md5.h b/src/md5.h
new file mode 100644
index 0000000..02a9a9d
--- /dev/null
+++ b/src/md5.h
@@ -0,0 +1,24 @@
+/*
+ * This file was transplanted with slight modifications from Linux sources
+ * (fs/cifs/md5.h) into U-Boot by Bartlomiej Sieka <tur@semihalf.com>.
+ */
+
+#ifndef _MD5_H
+#define _MD5_H
+
+struct MD5Context {
+ uint32_t buf[4];
+ uint32_t bits[2];
+ union {
+ unsigned char in[64];
+ uint32_t in32[16];
+ };
+};
+
+/*
+ * Calculate and store in 'output' the MD5 digest of 'len' bytes at
+ * 'input'. 'output' must have enough space to hold 16 bytes.
+ */
+void md5 (unsigned char *input, int len, unsigned char output[16]);
+
+#endif /* _MD5_H */
diff --git a/src/uboot_env.c b/src/uboot_env.c
index c9a900f..53b3576 100644
--- a/src/uboot_env.c
+++ b/src/uboot_env.c
@@ -33,11 +33,21 @@
#include <sys/wait.h>
#include <sys/ioctl.h>
#include <zlib.h>
+#include <arpa/inet.h>
#include <mtd/mtd-user.h>
#include <mtd/ubi-user.h>
+#include "caam_keyblob.h"
+#include "md5.h"
#include "uboot_private.h"
+/*
+ * The BLOB includes a random AES-256 key (32 bytes) and a
+ * Message Authentication Code (MAC) (16 bytes)
+ */
+#define BLOB_OVERHEAD 48
+#define CAAM_KEY_DEV "/dev/caam_kb"
+
#define UBI_MAX_VOLUME 128
#define DEVICE_MTD_NAME "/dev/mtd"
@@ -840,6 +850,105 @@ static int set_obsolete_flag(struct uboot_flash_env *dev)
return ret;
}
+static int is_env_encrypted(void)
+{
+ const char *dt_prop = "/proc/device-tree/digi,uboot-env,encrypted";
+
+ return access(dt_prop, F_OK) != -1;
+}
+
+#define MAX_HWID_WORDS 4
+static int env_caam_get_keymod(unsigned char output[16])
+{
+ int i;
+ int len;
+ int fd;
+ uint32_t ocotp_hwid[MAX_HWID_WORDS];
+ char dt_prop[32];
+
+ for (i = 0; i < MAX_HWID_WORDS; i++) {
+ sprintf(dt_prop, "/proc/device-tree/digi,hwid_%d", i);
+ if (access(dt_prop, F_OK) != -1) {
+ char buf[sizeof(uint32_t)];
+
+ fd = open(dt_prop, O_RDONLY);
+ if (fd < 0)
+ return fd;
+ len = read(fd, buf, sizeof(uint32_t));
+ if (len < 0) {
+ close(fd);
+ return -1;
+ }
+ ocotp_hwid[i] = ntohl(*(uint32_t *)buf);
+ close(fd);
+ } else {
+ break;
+ }
+ }
+
+ /* Calculate md5sum on the raw HWID array */
+ md5((unsigned char *)(&ocotp_hwid), sizeof(uint32_t) * i, output);
+
+ return 0;
+}
+
+static int env_caam_crypt(char *data, unsigned int size, const int enc)
+{
+ struct caam_kb_data enc_data;
+ int fd;
+ int ret = 0;
+ const int len = size;
+ int ioctl_mode;
+ char *buffer;
+ unsigned char key_modifier[16];
+
+ ret = env_caam_get_keymod(key_modifier);
+ if (ret)
+ return ret;
+
+ enc_data.keymod = (char *)key_modifier;
+ enc_data.keymod_len = sizeof(key_modifier);
+
+ enc_data.keyblob_len = len;
+ enc_data.rawkey_len = len - BLOB_OVERHEAD;
+
+ buffer = malloc(len);
+ if (!buffer) {
+ printf("Could not allocate memory\n");
+ return -1;
+ }
+
+ if (enc) {
+ enc_data.rawkey = data;
+ ioctl_mode = CAAM_KB_ENCRYPT;
+ enc_data.keyblob = buffer;
+ } else {
+ enc_data.keyblob = data;
+ ioctl_mode = CAAM_KB_DECRYPT;
+ enc_data.rawkey = buffer;
+ }
+
+ if ((fd = open(CAAM_KEY_DEV, O_RDWR)) < 0) {
+ ret = fd;
+ goto free;
+ }
+
+ ret = ioctl(fd, ioctl_mode, &enc_data);
+ if (ret) {
+ printf("CAAM_KEY_DEV ioctl failed: %d\n", ret);
+ goto out;
+ }
+
+ memcpy(data, buffer, enc ? len : len - BLOB_OVERHEAD);
+
+out:
+ close(fd);
+free:
+ free(buffer);
+
+ return ret;
+}
+
int libuboot_env_store(struct uboot_ctx *ctx)
{
struct var_entry *entry;
@@ -914,6 +1023,15 @@ int libuboot_env_store(struct uboot_ctx *ctx)
((struct uboot_env_redund *)image)->flags = flags;
}
+ if (ctx->encrypted) {
+ ret = env_caam_crypt(data, ctx->usable_size, 1);
+ if (ret) {
+ fprintf(stderr,
+ "Error: can't encrypt env for flash\n");
+ return ret;
+ }
+ }
+
*(uint32_t *)image = crc32(0, (uint8_t *)data, ctx->size - offsetdata);
copy = ctx->redundant ? (ctx->current ? 0 : 1) : 0;
@@ -978,6 +1096,13 @@ static int libuboot_load(struct uboot_ctx *ctx)
}
crc = *(uint32_t *)(buf[i] + offsetcrc);
dev->crc = crc32(0, (uint8_t *)data, ctx->size - offsetdata);
+ if (ctx->encrypted) {
+ ret = env_caam_crypt((char *)data, ctx->usable_size, 0);
+ if (ret) {
+ fprintf(stderr, "Error: can't decrypt environment\n");
+ return ret;
+ }
+ }
crcenv[i] = dev->crc == crc;
if (ctx->redundant)
dev->flags = *(uint8_t *)(buf[i] + offsetflags);
@@ -1258,6 +1383,11 @@ int libuboot_read_config(struct uboot_ctx *ctx, const char *config)
break;
}
}
+
+ ctx->usable_size = ctx->size - sizeof(uint32_t);
+ if (ctx->redundant)
+ ctx->usable_size -= sizeof(char);
+
if (ndev == 0)
retval = -EINVAL;
@@ -1446,6 +1576,7 @@ int libuboot_initialize(struct uboot_ctx **out,
return -ENOMEM;
ctx->valid = false;
+ ctx->encrypted = is_env_encrypted();
ret = libuboot_configure(ctx, envdevs);
if (ret < 0) {
diff --git a/src/uboot_private.h b/src/uboot_private.h
index 4b7a9f9..22c8c14 100644
--- a/src/uboot_private.h
+++ b/src/uboot_private.h
@@ -111,10 +111,14 @@ LIST_HEAD(vars, var_entry);
struct uboot_ctx {
/** true if the environment is redundant */
bool redundant;
+ /** true if the environment is encrypted */
+ bool encrypted;
/** set to valid after a successful load */
bool valid;
/** size of the environment */
size_t size;
+ /** usable environment size */
+ unsigned int usable_size;
/** devices where environment is stored */
struct uboot_flash_env envdevs[2];
/** Set which device contains the current(last valid) environment */
--
2.17.1
Reference in New Issue View Git Blame Copy Permalink