Consumers of the ASN.1 encoder occasionally need to insert OIDs into
the ASN.1 stream. The existing interface in lib/asn1_encoder.c is
clunky in that it directly encodes the u32 array form of the OID.
Instead introduce a function, encode_OID() which takes the OID enum
and returns the ASN.1 encoding. This is easy because the OID registry
table already has the binary encoded form for comparison.
Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
---
include/linux/oid_registry.h | 1 +
lib/oid_registry.c | 29 +++++++++++++++++++++++++++++
2 files changed, 30 insertions(+)
diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
index 51421fdbb0ba..87a6bcb2f5c0 100644
--- a/include/linux/oid_registry.h
+++ b/include/linux/oid_registry.h
@@ -151,5 +151,6 @@ extern enum OID look_up_OID(const void *data, size_t datasize);
extern int parse_OID(const void *data, size_t datasize, enum OID *oid);
extern int sprint_oid(const void *, size_t, char *, size_t);
extern int sprint_OID(enum OID, char *, size_t);
+extern ssize_t encode_OID(enum OID, u8 *, size_t);
#endif /* _LINUX_OID_REGISTRY_H */
diff --git a/lib/oid_registry.c b/lib/oid_registry.c
index fe6705cfd780..adbc287875c1 100644
--- a/lib/oid_registry.c
+++ b/lib/oid_registry.c
@@ -12,6 +12,7 @@
#include <linux/errno.h>
#include <linux/bug.h>
#include <linux/asn1.h>
+#include <linux/asn1_ber_bytecode.h>
#include "oid_registry_data.c"
MODULE_DESCRIPTION("OID Registry");
@@ -196,3 +197,31 @@ int sprint_OID(enum OID oid, char *buffer, size_t bufsize)
return ret;
}
EXPORT_SYMBOL_GPL(sprint_OID);
+
+/**
+ * encode_OID - embed an ASN.1 encoded OID in the provide buffer
+ * @oid: The OID to encode
+ * @buffer: The buffer to encode to
+ * @bufsize: the maximum size of the buffer
+ *
+ * Returns: negative error or encoded size in the buffer.
+ */
+ssize_t encode_OID(enum OID oid, u8 *buffer, size_t bufsize)
+{
+ int oid_size;
+
+ BUG_ON(oid >= OID__NR);
+
+ oid_size = oid_index[oid + 1] - oid_index[oid];
+
+ if (bufsize < oid_size + 2)
+ return -EINVAL;
+
+ buffer[0] = _tag(UNIV, PRIM, OID);
+ buffer[1] = oid_size;
+
+ memcpy(&buffer[2], &oid_data[oid_index[oid]], oid_size);
+
+ return oid_size + 2;
+}
+EXPORT_SYMBOL_GPL(encode_OID);
--
2.35.3
