diff mbox series

[v5,06/16] Move accessors for keys in own file

Message ID 20250904115704.58413-7-Michael.Glembotzki@iris-sensing.com
State Changes Requested
Delegated to: Stefano Babic
Headers show
Series Add support for asymmetric decryption | expand

Commit Message

Michael Glembotzki Sept. 4, 2025, 11:49 a.m. UTC 
From: Stefano Babic <stefano.babic@swupdate.org>

Signed-off-by: Stefano Babic <stefano.babic@swupdate.org>
---
 core/Makefile       |   1 +
 core/cpio_utils.c   |   4 +-
 core/decrypt_keys.c | 150 ++++++++++++++++++++++++++++++++++++++++++++
 core/util.c         | 134 ---------------------------------------
 include/util.h      |   4 +-
 5 files changed, 155 insertions(+), 138 deletions(-)
 create mode 100644 core/decrypt_keys.c
diff mbox series

Patch

diff --git a/core/Makefile b/core/Makefile
index 1ef31136..2840f993 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -11,6 +11,7 @@ 
 obj-y += swupdate.o \
 	 cpio_utils.o \
 	 crypto.o \
+	 decrypt_keys.o \
 	 notifier.o \
 	 handler.o \
 	 bootloader.o \
diff --git a/core/cpio_utils.c b/core/cpio_utils.c
index 0768998a..e3a94c50 100644
--- a/core/cpio_utils.c
+++ b/core/cpio_utils.c
@@ -608,7 +608,7 @@  int copyfile(struct swupdate_copy *args)
 	}
 
 	if (args->encrypted) {
-		aes_key = (unsigned char *)get_aes_key();
+		aes_key = (unsigned char *)swupdate_get_decrypt_key();
 		if (args->imgivt && strlen(args->imgivt)) {
 			if (!is_hex_str(args->imgivt) || ascii_to_bin(ivtbuf, sizeof(ivtbuf), args->imgivt)) {
 				ERROR("Invalid image ivt");
@@ -617,7 +617,7 @@  int copyfile(struct swupdate_copy *args)
 			ivt = ivtbuf;
 		} else
 			ivt = get_aes_ivt();
-		decrypt_state.dcrypt = swupdate_DECRYPT_init(aes_key, get_aes_keylen(), ivt, AES_CBC);
+		decrypt_state.dcrypt = swupdate_DECRYPT_init(aes_key, swupdate_get_decrypt_keylen(), ivt, AES_CBC);
 		if (!decrypt_state.dcrypt) {
 			ERROR("decrypt initialization failure, aborting");
 			ret = -EFAULT;
diff --git a/core/decrypt_keys.c b/core/decrypt_keys.c
new file mode 100644
index 00000000..f5b6296d
--- /dev/null
+++ b/core/decrypt_keys.c
@@ -0,0 +1,150 @@ 
+/*
+ * (C) Copyright 2025
+ * Stefano Babic, stefano.babic@swupdate.org.
+ *
+ * SPDX-License-Identifier:     GPL-2.0-only
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#include "util.h"
+#include "generated/autoconf.h"
+
+/*
+ * key    is 256 bit for max aes_256
+ *	  or is a pkcs#11 URL
+ * keylen is the actual aes key length
+ * ivt    is 128 bit
+ */
+struct decryption_key {
+	char *key;
+	char keylen;
+	unsigned char ivt[AES_BLK_SIZE];
+};
+
+static struct decryption_key *decrypt_keys = NULL;
+
+int set_aes_key(const char *key, const char *ivt)
+{
+	int ret;
+	size_t keylen;
+	bool is_pkcs11 = false;
+
+	/*
+	 * Allocates the global structure just once
+	 */
+	if (!decrypt_keys) {
+		decrypt_keys = (struct decryption_key *)calloc(1, sizeof(*decrypt_keys));
+		if (!decrypt_keys)
+			return -ENOMEM;
+	}
+
+	if (strlen(ivt) != (AES_BLK_SIZE*2) || !is_hex_str(ivt)) {
+		ERROR("Invalid ivt");
+		return -EINVAL;
+	}
+
+	ret = ascii_to_bin(decrypt_keys->ivt, sizeof(decrypt_keys->ivt), ivt);
+	keylen = strlen(key);
+
+	if (!strcmp("pkcs11", key)) {
+		is_pkcs11 = true;
+		decrypt_keys->keylen = keylen;
+
+	} else {
+		switch (keylen) {
+		case AES_128_KEY_LEN * 2:
+		case AES_192_KEY_LEN * 2:
+		case AES_256_KEY_LEN * 2:
+			// valid hex string size for AES 128/192/256
+			decrypt_keys->keylen = keylen / 2;
+			break;
+		default:
+			ERROR("Invalid decrypt_keys length");
+			return -EINVAL;
+		}
+	}
+
+	if (decrypt_keys->key)
+		free(decrypt_keys->key);
+
+	decrypt_keys->key = calloc(1, keylen + 1);
+	if (!decrypt_keys->key)
+		return -ENOMEM;
+
+	if (is_pkcs11) {
+		strncpy(decrypt_keys->key, key, keylen);
+	} else {
+		ret |= !is_hex_str(key);
+		ret |= ascii_to_bin((unsigned char *)decrypt_keys->key, decrypt_keys->keylen, key);
+	}
+
+	if (ret) {
+		ERROR("Invalid decrypt_keys");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int load_decryption_key(char *fname)
+{
+	FILE *fp;
+	char *b1 = NULL, *b2 = NULL;
+	int ret;
+
+	fp = fopen(fname, "r");
+	if (!fp)
+		return -EBADF;
+
+	ret = fscanf(fp, "%ms %ms", &b1, &b2);
+	switch (ret) {
+		case 2:
+			DEBUG("Read decryption key and initialization vector from file %s.", fname);
+			break;
+		default:
+			if (b1 != NULL)
+				free(b1);
+			fprintf(stderr, "File with decryption key is not in the format <key> <ivt>\n");
+			fclose(fp);
+			return -EINVAL;
+	}
+	fclose(fp);
+
+	ret = set_aes_key(b1, b2);
+
+	if (b1 != NULL)
+		free(b1);
+	if (b2 != NULL)
+		free(b2);
+
+	if (ret) {
+		fprintf(stderr, "Keys are invalid\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+char *swupdate_get_decrypt_key(void) {
+	if (!decrypt_keys)
+		return NULL;
+	return decrypt_keys->key;
+}
+
+char swupdate_get_decrypt_keylen(void) {
+	if (!decrypt_keys)
+		return -1;
+	return decrypt_keys->keylen;
+}
+
+unsigned char *get_aes_ivt(void) {
+	if (!decrypt_keys)
+		return NULL;
+	return decrypt_keys->ivt;
+}
diff --git a/core/util.c b/core/util.c
index 9d87e04c..2534da31 100644
--- a/core/util.c
+++ b/core/util.c
@@ -37,20 +37,6 @@ 
 #include "util.h"
 #include "generated/autoconf.h"
 
-/*
- * key    is 256 bit for max aes_256
- *	  or is a pkcs#11 URL
- * keylen is the actual aes key length
- * ivt    is 128 bit
- */
-struct decryption_key {
-	char *key;
-	char keylen;
-	unsigned char ivt[AES_BLK_SIZE];
-};
-
-static struct decryption_key *aes_key = NULL;
-
 /*
  * Configuration file for fw_env.config
  */
@@ -506,63 +492,6 @@  int count_elem_list(struct imglist *list)
 	return count;
 }
 
-int load_decryption_key(char *fname)
-{
-	FILE *fp;
-	char *b1 = NULL, *b2 = NULL;
-	int ret;
-
-	fp = fopen(fname, "r");
-	if (!fp)
-		return -EBADF;
-
-	ret = fscanf(fp, "%ms %ms", &b1, &b2);
-	switch (ret) {
-		case 2:
-			DEBUG("Read decryption key and initialization vector from file %s.", fname);
-			break;
-		default:
-			if (b1 != NULL)
-				free(b1);
-			fprintf(stderr, "File with decryption key is not in the format <key> <ivt>\n");
-			fclose(fp);
-			return -EINVAL;
-	}
-	fclose(fp);
-
-	ret = set_aes_key(b1, b2);
-
-	if (b1 != NULL)
-		free(b1);
-	if (b2 != NULL)
-		free(b2);
-
-	if (ret) {
-		fprintf(stderr, "Keys are invalid\n");
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-char *get_aes_key(void) {
-	if (!aes_key)
-		return NULL;
-	return aes_key->key;
-}
-
-char get_aes_keylen(void) {
-	if (!aes_key)
-		return -1;
-	return aes_key->keylen;
-}
-
-unsigned char *get_aes_ivt(void) {
-	if (!aes_key)
-		return NULL;
-	return aes_key->ivt;
-}
-
 bool is_hex_str(const char *ascii) {
 	unsigned int i, size;
 
@@ -580,69 +509,6 @@  bool is_hex_str(const char *ascii) {
 	return true;
 }
 
-int set_aes_key(const char *key, const char *ivt)
-{
-	int ret;
-	size_t keylen;
-	bool is_pkcs11 = false;
-
-	/*
-	 * Allocates the global structure just once
-	 */
-	if (!aes_key) {
-		aes_key = (struct decryption_key *)calloc(1, sizeof(*aes_key));
-		if (!aes_key)
-			return -ENOMEM;
-	}
-
-	if (strlen(ivt) != (AES_BLK_SIZE*2) || !is_hex_str(ivt)) {
-		ERROR("Invalid ivt");
-		return -EINVAL;
-	}
-
-	ret = ascii_to_bin(aes_key->ivt, sizeof(aes_key->ivt), ivt);
-	keylen = strlen(key);
-
-	if (!strcmp("pkcs11", key)) {
-		is_pkcs11 = true;
-		aes_key->keylen = keylen;
-
-	} else {
-		switch (keylen) {
-		case AES_128_KEY_LEN * 2:
-		case AES_192_KEY_LEN * 2:
-		case AES_256_KEY_LEN * 2:
-			// valid hex string size for AES 128/192/256
-			aes_key->keylen = keylen / 2;
-			break;
-		default:
-			ERROR("Invalid aes_key length");
-			return -EINVAL;
-		}
-	}
-
-	if (aes_key->key)
-		free(aes_key->key);
-
-	aes_key->key = calloc(1, keylen + 1);
-	if (!aes_key->key)
-		return -ENOMEM;
-
-	if (is_pkcs11) {
-		strncpy(aes_key->key, key, keylen);
-	} else {
-		ret |= !is_hex_str(key);
-		ret |= ascii_to_bin((unsigned char *)aes_key->key, aes_key->keylen, key);
-	}
-
-	if (ret) {
-		ERROR("Invalid aes_key");
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
 const char *get_fwenv_config(void) {
 	if (!fwenv_config)
 #if defined(CONFIG_UBOOT)
diff --git a/include/util.h b/include/util.h
index 008ad79f..36c68b9d 100644
--- a/include/util.h
+++ b/include/util.h
@@ -289,8 +289,8 @@  void set_fwenv_config(const char *fname);
 
 /* Decryption key functions */
 int load_decryption_key(char *fname);
-char *get_aes_key(void);
-char get_aes_keylen(void);
+char *swupdate_get_decrypt_key(void);
+char swupdate_get_decrypt_keylen(void);
 unsigned char *get_aes_ivt(void);
 int set_aes_key(const char *key, const char *ivt);