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 <dhowe...@redhat.com>
---

 include/linux/oid_registry.h |    2 +
 lib/oid_registry.c           |   81 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+)


diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
index 5928546..6926db7 100644
--- a/include/linux/oid_registry.h
+++ b/include/linux/oid_registry.h
@@ -86,5 +86,7 @@ enum OID {
 };
 
 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 */
diff --git a/lib/oid_registry.c b/lib/oid_registry.c
index 33cfd17..d8de11f 100644
--- a/lib/oid_registry.c
+++ b/lib/oid_registry.c
@@ -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"
 
 /**
@@ -87,3 +90,81 @@ enum OID look_up_OID(const void *data, size_t datasize)
        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);

--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to