X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fpk%2Fasn1%2Fder%2Fobject_identifier%2Fder_encode_object_identifier.c;fp=libtomcrypt%2Fsrc%2Fpk%2Fasn1%2Fder%2Fobject_identifier%2Fder_encode_object_identifier.c;h=b1ce62c9a6e7a8c0324b22b0db55818096286ffc;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage

diff --git a/libtomcrypt/src/pk/asn1/der/object_identifier/der_encode_object_identifier.c b/libtomcrypt/src/pk/asn1/der/object_identifier/der_encode_object_identifier.c
new file mode 100644
index 0000000..b1ce62c
--- /dev/null
+++ b/libtomcrypt/src/pk/asn1/der/object_identifier/der_encode_object_identifier.c
@@ -0,0 +1,109 @@
+/* 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_encode_object_identifier.c
+  ASN.1 DER, Encode Object Identifier, Tom St Denis
+*/
+
+#ifdef LTC_DER
+/**
+  Encode an OID
+  @param words   The words to encode  (upto 32-bits each)
+  @param nwords  The number of words in the OID
+  @param out     [out] Destination of OID data
+  @param outlen  [in/out] The max and resulting size of the OID
+  @return CRYPT_OK if successful
+*/
+int der_encode_object_identifier(unsigned long *words, unsigned long  nwords,
+                                 unsigned char *out,   unsigned long *outlen)
+{
+   unsigned long i, x, y, z, t, mask, wordbuf;
+   int           err;
+
+   LTC_ARGCHK(words  != NULL);
+   LTC_ARGCHK(out    != NULL);
+   LTC_ARGCHK(outlen != NULL);
+
+   /* check length */
+   if ((err = der_length_object_identifier(words, nwords, &x)) != CRYPT_OK) {
+      return err;
+   }
+   if (x > *outlen) {
+      *outlen = x;
+      return CRYPT_BUFFER_OVERFLOW;
+   }
+
+   /* compute length to store OID data */
+   z = 0;
+   wordbuf = words[0] * 40 + words[1];
+   for (y = 1; y < nwords; y++) {
+       t = der_object_identifier_bits(wordbuf);
+       z += t/7 + ((t%7) ? 1 : 0) + (wordbuf == 0 ? 1 : 0);
+       if (y < nwords - 1) {
+          wordbuf = words[y + 1];
+       }
+   }
+
+   /* store header + length */
+   x = 0;
+   out[x++] = 0x06;
+   if (z < 128) {
+      out[x++] = (unsigned char)z;
+   } else if (z < 256) {
+      out[x++] = 0x81;
+      out[x++] = (unsigned char)z;
+   } else if (z < 65536UL) {
+      out[x++] = 0x82;
+      out[x++] = (unsigned char)((z>>8)&255);
+      out[x++] = (unsigned char)(z&255);
+   } else {
+      return CRYPT_INVALID_ARG;
+   }
+
+   /* store first byte */
+   wordbuf = words[0] * 40 + words[1];
+   for (i = 1; i < nwords; i++) {
+      /* store 7 bit words in little endian */
+      t    = wordbuf & 0xFFFFFFFF;
+      if (t) {
+         y    = x;
+         mask = 0;
+         while (t) {
+            out[x++] = (unsigned char)((t & 0x7F) | mask);
+            t    >>= 7;
+            mask  |= 0x80;  /* upper bit is set on all but the last byte */
+         }
+         /* now swap bytes y...x-1 */
+         z = x - 1;
+         while (y < z) {
+            t = out[y]; out[y] = out[z]; out[z] = (unsigned char)t;
+            ++y;
+            --z;
+         }
+      } else {
+         /* zero word */
+         out[x++] = 0x00;
+      }
+
+      if (i < nwords - 1) {
+         wordbuf = words[i + 1];
+      }
+   }
+
+   *outlen = x;
+   return CRYPT_OK;
+}
+
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */