X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fpk%2Fasn1%2Fder%2Foctet%2Fder_length_octet_string.c;fp=libtomcrypt%2Fsrc%2Fpk%2Fasn1%2Fder%2Foctet%2Fder_length_octet_string.c;h=10c9e892abea4d8a3be9d2c3f5868aecf3942143;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage

diff --git a/libtomcrypt/src/pk/asn1/der/octet/der_length_octet_string.c b/libtomcrypt/src/pk/asn1/der/octet/der_length_octet_string.c
new file mode 100644
index 0000000..10c9e89
--- /dev/null
+++ b/libtomcrypt/src/pk/asn1/der/octet/der_length_octet_string.c
@@ -0,0 +1,51 @@
+/* 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_length_octet_string.c
+  ASN.1 DER, get length of OCTET STRING, Tom St Denis
+*/
+
+#ifdef LTC_DER
+/**
+  Gets length of DER encoding of OCTET STRING
+  @param noctets  The number of octets in the string to encode
+  @param outlen   [out] The length of the DER encoding for the given string
+  @return CRYPT_OK if successful
+*/
+int der_length_octet_string(unsigned long noctets, unsigned long *outlen)
+{
+   LTC_ARGCHK(outlen != NULL);
+
+   if (noctets < 128) {
+      /* 04 LL DD DD DD ... */
+      *outlen = 2 + noctets;
+   } else if (noctets < 256) {
+      /* 04 81 LL DD DD DD ... */
+      *outlen = 3 + noctets;
+   } else if (noctets < 65536UL) {
+      /* 04 82 LL LL DD DD DD ... */
+      *outlen = 4 + noctets;
+   } else if (noctets < 16777216UL) {
+      /* 04 83 LL LL LL DD DD DD ... */
+      *outlen = 5 + noctets;
+   } else {
+      return CRYPT_INVALID_ARG;
+   }
+
+   return CRYPT_OK;
+}
+
+#endif
+
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */