X.509: Add utility functions to render OIDs as strings

Add a pair of utility functions to render OIDs as strings. The first takes an encoded OID and turns it into a "a.b.c.d" form string: int sprint_oid(const void *data, size_t datasize, char *buffer, size_t bufsize); The second takes an OID enum index and calls the first on the data held therein: int sprint_OID(enum OID oid, char *buffer, size_t bufsize); Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

X.509: Add utility functions to render OIDs as strings
Add a pair of utility functions to render OIDs as strings. The first takes an encoded OID and turns it into a "a.b.c.d" form string: int sprint_oid(const void *data, size_t datasize, char *buffer, size_t bufsize); The second takes an OID enum index and calls the first on the data held therein: int sprint_OID(enum OID oid, char *buffer, size_t bufsize); Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
David Howells · Rusty Russell
1 parent a77ad6ea0b
Showing 2 changed files with 83 additions and 0 deletions Side-by-side Diff
include/linux/oid_registry.h
lib/oid_registry.c
@@ -86,6 +86,8 @@
 };
  
 extern enum OID look_up_OID(const void *data, size_t datasize);
+extern int sprint_oid(const void *, size_t, char *, size_t);
+extern int sprint_OID(enum OID, char *, size_t);
  
 #endif /* _LINUX_OID_REGISTRY_H */
@@ -11,6 +11,9 @@
  
 #include <linux/export.h>
 #include <linux/oid_registry.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/bug.h>
 #include "oid_registry_data.c"
  
 /**
@@ -87,4 +90,82 @@
 	return OID__NR;
 }
 EXPORT_SYMBOL_GPL(look_up_OID);
+
+/*
+ * sprint_OID - Print an Object Identifier into a buffer
+ * @data: The encoded OID to print
+ * @datasize: The size of the encoded OID
+ * @buffer: The buffer to render into
+ * @bufsize: The size of the buffer
+ *
+ * The OID is rendered into the buffer in "a.b.c.d" format and the number of
+ * bytes is returned.  -EBADMSG is returned if the data could not be intepreted
+ * and -ENOBUFS if the buffer was too small.
+ */
+int sprint_oid(const void *data, size_t datasize, char *buffer, size_t bufsize)
+{
+	const unsigned char *v = data, *end = v + datasize;
+	unsigned long num;
+	unsigned char n;
+	size_t ret;
+	int count;
+
+	if (v >= end)
+		return -EBADMSG;
+
+	n = *v++;
+	ret = count = snprintf(buffer, bufsize, "%u.%u", n / 40, n % 40);
+	buffer += count;
+	bufsize -= count;
+	if (bufsize == 0)
+		return -ENOBUFS;
+
+	while (v < end) {
+		num = 0;
+		n = *v++;
+		if (!(n & 0x80)) {
+			num = n;
+		} else {
+			num = n & 0x7f;
+			do {
+				if (v >= end)
+					return -EBADMSG;
+				n = *v++;
+				num <<= 7;
+				num |= n & 0x7f;
+			} while (n & 0x80);
+		}
+		ret += count = snprintf(buffer, bufsize, ".%lu", num);
+		buffer += count;
+		bufsize -= count;
+		if (bufsize == 0)
+			return -ENOBUFS;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(sprint_oid);
+
+/**
+ * sprint_OID - Print an Object Identifier into a buffer
+ * @oid: The OID to print
+ * @buffer: The buffer to render into
+ * @bufsize: The size of the buffer
+ *
+ * The OID is rendered into the buffer in "a.b.c.d" format and the number of
+ * bytes is returned.
+ */
+int sprint_OID(enum OID oid, char *buffer, size_t bufsize)
+{
+	int ret;
+
+	BUG_ON(oid >= OID__NR);
+
+	ret = sprint_oid(oid_data + oid_index[oid],
+			 oid_index[oid + 1] - oid_index[oid],
+			 buffer, bufsize);
+	BUG_ON(ret == -EBADMSG);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(sprint_OID);
...	...	@@ -86,6 +86,8 @@
86	86	};
87	87
88	88	extern enum OID look_up_OID(const void *data, size_t datasize);
	89	+extern int sprint_oid(const void , size_t, char , size_t);
	90	+extern int sprint_OID(enum OID, char *, size_t);
89	91
90	92	#endif /* _LINUX_OID_REGISTRY_H */
...	...	@@ -11,6 +11,9 @@
11	11
12	12	#include <linux/export.h>
13	13	#include <linux/oid_registry.h>
	14	+#include <linux/kernel.h>
	15	+#include <linux/errno.h>
	16	+#include <linux/bug.h>
14	17	#include "oid_registry_data.c"
15	18
16	19	/**
...	...	@@ -87,4 +90,82 @@
87	90	return OID__NR;
88	91	}
89	92	EXPORT_SYMBOL_GPL(look_up_OID);
	93	+
	94	+/*
	95	+ * sprint_OID - Print an Object Identifier into a buffer
	96	+ * @data: The encoded OID to print
	97	+ * @datasize: The size of the encoded OID
	98	+ * @buffer: The buffer to render into
	99	+ * @bufsize: The size of the buffer
	100	+ *
	101	+ * The OID is rendered into the buffer in "a.b.c.d" format and the number of
	102	+ * bytes is returned. -EBADMSG is returned if the data could not be intepreted
	103	+ * and -ENOBUFS if the buffer was too small.
	104	+ */
	105	+int sprint_oid(const void data, size_t datasize, char buffer, size_t bufsize)
	106	+{
	107	+ const unsigned char v = data, end = v + datasize;
	108	+ unsigned long num;
	109	+ unsigned char n;
	110	+ size_t ret;
	111	+ int count;
	112	+
	113	+ if (v >= end)
	114	+ return -EBADMSG;
	115	+
	116	+ n = *v++;
	117	+ ret = count = snprintf(buffer, bufsize, "%u.%u", n / 40, n % 40);
	118	+ buffer += count;
	119	+ bufsize -= count;
	120	+ if (bufsize == 0)
	121	+ return -ENOBUFS;
	122	+
	123	+ while (v < end) {
	124	+ num = 0;
	125	+ n = *v++;
	126	+ if (!(n & 0x80)) {
	127	+ num = n;
	128	+ } else {
	129	+ num = n & 0x7f;
	130	+ do {
	131	+ if (v >= end)
	132	+ return -EBADMSG;
	133	+ n = *v++;
	134	+ num <<= 7;
	135	+ num \|= n & 0x7f;
	136	+ } while (n & 0x80);
	137	+ }
	138	+ ret += count = snprintf(buffer, bufsize, ".%lu", num);
	139	+ buffer += count;
	140	+ bufsize -= count;
	141	+ if (bufsize == 0)
	142	+ return -ENOBUFS;
	143	+ }
	144	+
	145	+ return ret;
	146	+}
	147	+EXPORT_SYMBOL_GPL(sprint_oid);
	148	+
	149	+/**
	150	+ * sprint_OID - Print an Object Identifier into a buffer
	151	+ * @oid: The OID to print
	152	+ * @buffer: The buffer to render into
	153	+ * @bufsize: The size of the buffer
	154	+ *
	155	+ * The OID is rendered into the buffer in "a.b.c.d" format and the number of
	156	+ * bytes is returned.
	157	+ */
	158	+int sprint_OID(enum OID oid, char *buffer, size_t bufsize)
	159	+{
	160	+ int ret;
	161	+
	162	+ BUG_ON(oid >= OID__NR);
	163	+
	164	+ ret = sprint_oid(oid_data + oid_index[oid],
	165	+ oid_index[oid + 1] - oid_index[oid],
	166	+ buffer, bufsize);
	167	+ BUG_ON(ret == -EBADMSG);
	168	+ return ret;
	169	+}
	170	+EXPORT_SYMBOL_GPL(sprint_OID);