X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fstream%2Fchacha%2Fchacha_ivctr64.c;fp=libtomcrypt%2Fsrc%2Fstream%2Fchacha%2Fchacha_ivctr64.c;h=643d11fee1a087c2292c8e38846c3c38df0eb043;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage

diff --git a/libtomcrypt/src/stream/chacha/chacha_ivctr64.c b/libtomcrypt/src/stream/chacha/chacha_ivctr64.c
new file mode 100644
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--- /dev/null
+++ b/libtomcrypt/src/stream/chacha/chacha_ivctr64.c
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+/* 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.
+ */
+
+/* The implementation is based on:
+ * chacha-ref.c version 20080118
+ * Public domain from D. J. Bernstein
+ */
+
+#include "tomcrypt.h"
+
+#ifdef LTC_CHACHA
+
+/**
+  Set IV + counter data to the ChaCha state
+  @param st      The ChaCha20 state
+  @param iv      The IV data to add
+  @param ivlen   The length of the IV (must be 8)
+  @param counter 64bit (unsigned) initial counter value
+  @return CRYPT_OK on success
+ */
+int chacha_ivctr64(chacha_state *st, const unsigned char *iv, unsigned long ivlen, ulong64 counter)
+{
+   LTC_ARGCHK(st != NULL);
+   LTC_ARGCHK(iv != NULL);
+   /* 64bit IV + 64bit counter */
+   LTC_ARGCHK(ivlen == 8);
+
+   st->input[12] = (ulong32)(counter & 0xFFFFFFFF);
+   st->input[13] = (ulong32)(counter >> 32);
+   LOAD32L(st->input[14], iv + 0);
+   LOAD32L(st->input[15], iv + 4);
+   st->ksleft = 0;
+   st->ivlen = ivlen;
+   return CRYPT_OK;
+}
+
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */