Add spritz_crypt_inplace

Author: abderraouf-adjal

keywords.txt

@@ -14,6 +14,7 @@ spritz_random32	KEYWORD2
 spritz_random32_uniform	KEYWORD2
 spritz_add_entropy	KEYWORD2
 spritz_crypt	KEYWORD2
+spritz_crypt_inplace	KEYWORD2
 spritz_hash_setup	KEYWORD2
 spritz_hash_update	KEYWORD2
 spritz_hash_final	KEYWORD2

src/SpritzCipher.c

@@ -479,6 +479,26 @@ spritz_crypt(spritz_ctx *ctx,
   }
 }
 
+/** spritz_crypt_inplace()
+ * Encrypt or decrypt data chunk by XOR-ing it with the spritz keystream
+ * and put the output in the same buffer `data`.
+ * Usable only after calling spritz_setup() or spritz_setup_withiv().
+ *
+ * Parameter ctx:     The context.
+ * Parameter data:    The data to encrypt or decrypt, also the output.
+ * Parameter datalen: Length of the data in bytes.
+ */
+void
+spritz_crypt_inplace(spritz_ctx *ctx,
+                     uint8_t *data, uint16_t dataLen)
+{
+  uint16_t i;
+
+  for (i = 0; i < dataLen; i++) {
+    data[i] ^= drip(ctx);
+  }
+}
+
 
 /** spritz_hash_setup()
  * Setup the spritz hash state `spritz_ctx`.

src/SpritzCipher.h

@@ -33,7 +33,7 @@ extern "C" {
  */
 #if 0
 # define SPRITZ_USE_LIBC
-# include <string.h>
+# include <string.h> /* For `memset()` */
 # if !defined(__GNUC__) && !defined(__clang__) /* Not GCC or Clang. */
 #  warning "SPRITZ_USE_LIBC warning: Code optimization isn't off in some security functions."
 # endif /* Not GCC or Clang. */
@@ -231,6 +231,19 @@ spritz_crypt(spritz_ctx *ctx,
              const uint8_t *data, uint16_t dataLen,
              uint8_t *dataOut);
 
+/** spritz_crypt_inplace()
+ * Encrypt or decrypt data chunk by XOR-ing it with the spritz keystream
+ * and put the output in the same buffer `data`.
+ * Usable only after calling spritz_setup() or spritz_setup_withiv().
+ *
+ * Parameter ctx:     The context.
+ * Parameter data:    The data to encrypt or decrypt, also the output.
+ * Parameter datalen: Length of the data in bytes.
+ */
+void
+spritz_crypt_inplace(spritz_ctx *ctx,
+                     uint8_t *data, uint16_t dataLen);
+
 
 /** spritz_hash_setup()
  * Setup the spritz hash state `spritz_ctx`.