--- /dev/null
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+#include "tomcrypt.h"
+
+/**
+ @file der_decode_object_identifier.c
+ ASN.1 DER, Decode Object Identifier, Tom St Denis
+*/
+
+#ifdef LTC_DER
+/**
+ Decode OID data and store the array of integers in words
+ @param in The OID DER encoded data
+ @param inlen The length of the OID data
+ @param words [out] The destination of the OID words
+ @param outlen [in/out] The number of OID words
+ @return CRYPT_OK if successful
+*/
+int der_decode_object_identifier(const unsigned char *in, unsigned long inlen,
+ unsigned long *words, unsigned long *outlen)
+{
+ unsigned long x, y, t, len;
+ int err;
+
+ LTC_ARGCHK(in != NULL);
+ LTC_ARGCHK(words != NULL);
+ LTC_ARGCHK(outlen != NULL);
+
+ /* header is at least 3 bytes */
+ if (inlen < 3) {
+ return CRYPT_INVALID_PACKET;
+ }
+
+ /* must be room for at least two words */
+ if (*outlen < 2) {
+ *outlen = 2;
+ return CRYPT_BUFFER_OVERFLOW;
+ }
+
+ /* decode the packet header */
+ x = 0;
+ if ((in[x++] & 0x1F) != 0x06) {
+ return CRYPT_INVALID_PACKET;
+ }
+
+ /* get the length */
+ if (in[x] < 128) {
+ len = in[x++];
+ } else {
+ if (in[x] < 0x81 || in[x] > 0x82) {
+ return CRYPT_INVALID_PACKET;
+ }
+ y = in[x++] & 0x7F;
+ len = 0;
+ while (y--) {
+ len = (len << 8) | (unsigned long)in[x++];
+ }
+ }
+
+ if (len < 1 || (len + x) > inlen) {
+ return CRYPT_INVALID_PACKET;
+ }
+
+ /* decode words */
+ y = 0;
+ t = 0;
+ while (len--) {
+ t = (t << 7) | (in[x] & 0x7F);
+ if (!(in[x++] & 0x80)) {
+ /* store t */
+ if (y >= *outlen) {
+ y++;
+ } else {
+ if (y == 0) {
+ words[0] = t / 40;
+ words[1] = t % 40;
+ y = 2;
+ } else {
+ words[y++] = t;
+ }
+ }
+ t = 0;
+ }
+ }
+
+ if (y > *outlen) {
+ err = CRYPT_BUFFER_OVERFLOW;
+ } else {
+ err = CRYPT_OK;
+ }
+
+ *outlen = y;
+ return err;
+}
+
+#endif
+
+/* ref: $Format:%D$ */
+/* git commit: $Format:%H$ */
+/* commit time: $Format:%ai$ */