1 files changed, 91 insertions, 0 deletions
diff --git a/crypto/userspace/libtomcrypt/pk/asn1/der/octet/der_decode_octet_string.c b/crypto/userspace/libtomcrypt/pk/asn1/der/octet/der_decode_octet_string.c
new file mode 100644
index 00000000000..ab5bc10e3bd
--- /dev/null
+++ b/crypto/userspace/libtomcrypt/pk/asn1/der/octet/der_decode_octet_string.c
@@ -0,0 +1,91 @@
+/* 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.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
+ */
+#include "tomcrypt.h"
+
+/**
+  @file der_decode_octet_string.c
+  ASN.1 DER, encode a OCTET STRING, Tom St Denis
+*/
+
+
+#ifdef LTC_DER
+
+/**
+  Store a OCTET STRING
+  @param in      The DER encoded OCTET STRING
+  @param inlen   The size of the DER OCTET STRING
+  @param out     [out] The array of octets stored (one per char)
+  @param outlen  [in/out] The number of octets stored
+  @return CRYPT_OK if successful
+*/
+int der_decode_octet_string(const unsigned char *in, unsigned long inlen,
+                                  unsigned char *out, unsigned long *outlen)
+{
+   unsigned long x, y, len;
+
+   LTC_ARGCHK(in     != NULL);
+   LTC_ARGCHK(out    != NULL);
+   LTC_ARGCHK(outlen != NULL);
+
+   /* must have header at least */
+   if (inlen < 2) {
+      return CRYPT_INVALID_PACKET;
+   }
+
+   /* check for 0x04 */
+   if ((in[0] & 0x1F) != 0x04) {
+      return CRYPT_INVALID_PACKET;
+   }
+   x = 1;
+
+   /* decode the length */
+   if (in[x] & 0x80) {
+      /* valid # of bytes in length are 1,2,3 */
+      y = in[x] & 0x7F;
+      if ((y == 0) || (y > 3) || ((x + y) > inlen)) {
+         return CRYPT_INVALID_PACKET;
+      }
+
+      /* read the length in */
+      len = 0;
+      ++x;
+      while (y--) {
+         len = (len << 8) | in[x++];
+      }
+   } else {
+      len = in[x++] & 0x7F;
+   }
+
+   /* is it too long? */
+   if (len > *outlen) {
+      *outlen = len;
+      return CRYPT_BUFFER_OVERFLOW;
+   }
+
+   if (len + x > inlen) {
+      return CRYPT_INVALID_PACKET;
+   }
+
+   /* read the data */
+   for (y = 0; y < len; y++) {
+       out[y] = in[x++];
+   }
+
+   *outlen = y;
+
+   return CRYPT_OK;
+}
+ 
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/octet/der_decode_octet_string.c,v $ */
+/* $Revision: 1.4 $ */
+/* $Date: 2006/12/28 01:27:24 $ */