sha3.[hc]: add turboshake{128,256}_custom()

2 files changed, 41 insertions, 1 deletions

diff --git a/sha3.c b/sha3.c
index 8dbc60b..88c83cb 100644
--- a/sha3.c
+++ b/sha3.c
@@ -1695,7 +1695,7 @@ void parallelhash256_xof_once(const parallelhash_params_t params, const uint8_t
 // default turboshake pad byte (can be customized for domain separation)
 #define TURBOSHAKE_PAD 0x1f
 
-// init turboeshake context with given pad byte.  returns false if the
+// init turboshake context with given pad byte.  returns false if the
 // pad byte is out of range.
 static inline _Bool turboshake_init(turboshake_t * const ts, const uint8_t pad) {
   // check for valid pad
@@ -1736,6 +1736,10 @@ void turboshake128(const uint8_t * const src, const size_t src_len, uint8_t * co
   xof_once(SHAKE128_XOF_RATE, TURBOSHAKE_NUM_ROUNDS, TURBOSHAKE_PAD, src, src_len, dst, dst_len);
 }
 
+void turboshake128_custom(const uint8_t pad, const uint8_t * const src, const size_t src_len, uint8_t * const dst, const size_t dst_len) {
+  xof_once(SHAKE128_XOF_RATE, TURBOSHAKE_NUM_ROUNDS, pad, src, src_len, dst, dst_len);
+}
+
 _Bool turboshake256_init_custom(turboshake_t * const ts, const uint8_t pad) {
   return turboshake_init(ts, pad);
 }
@@ -1756,6 +1760,10 @@ void turboshake256(const uint8_t * const src, const size_t src_len, uint8_t * co
   xof_once(SHAKE256_XOF_RATE, TURBOSHAKE_NUM_ROUNDS, TURBOSHAKE_PAD, src, src_len, dst, dst_len);
 }
 
+void turboshake256_custom(const uint8_t pad, const uint8_t * const src, const size_t src_len, uint8_t * const dst, const size_t dst_len) {
+  xof_once(SHAKE256_XOF_RATE, TURBOSHAKE_NUM_ROUNDS, pad, src, src_len, dst, dst_len);
+}
+
 #ifdef SHA3_TEST
 #include <stdio.h> // printf()
 
diff --git a/sha3.h b/sha3.h
index 6ca8922..4f1ce06 100644
--- a/sha3.h
+++ b/sha3.h
@@ -1156,6 +1156,22 @@ void parallelhash256_xof_once(const parallelhash_params_t params, const uint8_t
 void turboshake128(const uint8_t *src, const size_t src_len, uint8_t *dst, const size_t dst_len);
 
 /**
+ * Initialize internal TurboSHAKE128 context with custom padding byte
+ * `pad`, absorb `src_len` bytes of input from in source buffer `src`,
+ * then squeeze `dst_len` bytes of output into destination buffer `dst`.
+ *
+ * Note: The padding byte value must be in the range [0x01, 0x7F] and
+ * can be used for domain separation.
+ *
+ * @param[in] pad Padding byte.
+ * @param[in] src Source buffer.
+ * @param[in] src_len Source buffer length, in bytes.
+ * @param[out] dst Destination buffer.
+ * @param[in] dst_len Destination buffer length, in bytes.
+ */
+void turboshake128_custom(const uint8_t pad, const uint8_t *src, const size_t src_len, uint8_t *dst, const size_t dst_len);
+
+/**
  * Initialize internal TurboSHAKE256 context, absorb `src_len` bytes of
  * input from in source buffer `src`, then squeeze `dst_len` bytes of output
  * into destination buffer `dst`.
@@ -1167,6 +1183,22 @@ void turboshake128(const uint8_t *src, const size_t src_len, uint8_t *dst, const
  */
 void turboshake256(const uint8_t *src, const size_t src_len, uint8_t *dst, const size_t dst_len);
 
+/**
+ * Initialize internal TurboSHAKE256 context with custom padding byte
+ * `pad`, absorb `src_len` bytes of input from in source buffer `src`,
+ * then squeeze `dst_len` bytes of output into destination buffer `dst`.
+ *
+ * Note: The padding byte value must be in the range [0x01, 0x7F] and
+ * can be used for domain separation.
+ *
+ * @param[in] pad Padding byte.
+ * @param[in] src Source buffer.
+ * @param[in] src_len Source buffer length, in bytes.
+ * @param[out] dst Destination buffer.
+ * @param[in] dst_len Destination buffer length, in bytes.
+ */
+void turboshake256_custom(const uint8_t pad, const uint8_t *src, const size_t src_len, uint8_t *dst, const size_t dst_len);
+
 // TurboShake XOF context.
 typedef struct {
   sha3_xof_t xof;