From 4f73175d0375a7c1b3ae625e76acee8b39741f28 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 21 Sep 2012 23:30:51 +0100 Subject: 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 Signed-off-by: Rusty Russell --- lib/oid_registry.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) (limited to 'lib') diff --git a/lib/oid_registry.c b/lib/oid_registry.c index 33cfd171f627..d8de11f45908 100644 --- a/lib/oid_registry.c +++ b/lib/oid_registry.c @@ -11,6 +11,9 @@ #include #include +#include +#include +#include #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); -- cgit v1.2.2