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-rw-r--r--lib/crypto/pkcs7_helper.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/lib/crypto/pkcs7_helper.c b/lib/crypto/pkcs7_helper.c
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+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PKCS7 helper functions
+ *
+ * Copyright (c) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+#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;
+}