[PATCH v4 16/29] pkcs7: move common functions to PKCS7 helper

[Raymond Mao]

Move pkcs7_get_content_data as a helper function that can be
shared by legacy crypto lib and MbedTLS implementation.

Signed-off-by: Raymond Mao <raymond.mao at linaro.org>
---
Changes in v4
- Initial patch.

 lib/crypto/Makefile       |  1 +
 lib/crypto/pkcs7_helper.c | 40 +++++++++++++++++++++++++++++++++++++++
 lib/crypto/pkcs7_parser.c | 28 ---------------------------
 3 files changed, 41 insertions(+), 28 deletions(-)
 create mode 100644 lib/crypto/pkcs7_helper.c

diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
index 946cc3a7b59..16059088f26 100644
--- a/lib/crypto/Makefile
+++ b/lib/crypto/Makefile
@@ -53,6 +53,7 @@ $(obj)/x509_akid.asn1.o: $(obj)/x509_akid.asn1.c $(obj)/x509_akid.asn1.h
 obj-$(CONFIG_$(SPL_)PKCS7_MESSAGE_PARSER) += pkcs7_message.o
 pkcs7_message-y := \
 	pkcs7.asn1.o \
+	pkcs7_helper.o \
 	pkcs7_parser.o
 obj-$(CONFIG_$(SPL_)PKCS7_VERIFY) += pkcs7_verify.o
 
diff --git a/lib/crypto/pkcs7_helper.c b/lib/crypto/pkcs7_helper.c
new file mode 100644
index 00000000000..6c8dcd1a935
--- /dev/null
+++ b/lib/crypto/pkcs7_helper.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PKCS7 helper functions
+ *
+ * Copyright (c) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells at redhat.com)
+ *
+ * Copyright (c) 2024 Linaro Limited
+ * Author: Raymond Mao <raymond.mao at linaro.org>
+ */
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <crypto/pkcs7_parser.h>
+
+/**
+ * pkcs7_get_content_data - Get access to the PKCS#7 content
+ * @pkcs7: The preparsed PKCS#7 message to access
+ * @_data: Place to return a pointer to the data
+ * @_data_len: Place to return the data length
+ * @_headerlen: Size of ASN.1 header not included in _data
+ *
+ * Get access to the data content of the PKCS#7 message.  The size of the
+ * header of the ASN.1 object that contains it is also provided and can be used
+ * to adjust *_data and *_data_len to get the entire object.
+ *
+ * Returns -ENODATA if the data object was missing from the message.
+ */
+int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
+			   const void **_data, size_t *_data_len,
+			   size_t *_headerlen)
+{
+	if (!pkcs7->data)
+		return -ENODATA;
+
+	*_data = pkcs7->data;
+	*_data_len = pkcs7->data_len;
+	if (_headerlen)
+		*_headerlen = pkcs7->data_hdrlen;
+	return 0;
+}
diff --git a/lib/crypto/pkcs7_parser.c b/lib/crypto/pkcs7_parser.c
index d5efa828d6a..c849dc0d92d 100644
--- a/lib/crypto/pkcs7_parser.c
+++ b/lib/crypto/pkcs7_parser.c
@@ -182,34 +182,6 @@ out_no_ctx:
 }
 EXPORT_SYMBOL_GPL(pkcs7_parse_message);
 
-/**
- * pkcs7_get_content_data - Get access to the PKCS#7 content
- * @pkcs7: The preparsed PKCS#7 message to access
- * @_data: Place to return a pointer to the data
- * @_data_len: Place to return the data length
- * @_headerlen: Size of ASN.1 header not included in _data
- *
- * Get access to the data content of the PKCS#7 message.  The size of the
- * header of the ASN.1 object that contains it is also provided and can be used
- * to adjust *_data and *_data_len to get the entire object.
- *
- * Returns -ENODATA if the data object was missing from the message.
- */
-int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
-			   const void **_data, size_t *_data_len,
-			   size_t *_headerlen)
-{
-	if (!pkcs7->data)
-		return -ENODATA;
-
-	*_data = pkcs7->data;
-	*_data_len = pkcs7->data_len;
-	if (_headerlen)
-		*_headerlen = pkcs7->data_hdrlen;
-	return 0;
-}
-EXPORT_SYMBOL_GPL(pkcs7_get_content_data);
-
 /*
  * Note an OID when we find one for later processing when we know how
  * to interpret it.
-- 
2.25.1