[PATCH 09/18] crypto: Add generic 32-bit carry-less multiply routines

[Richard Henderson <richard.henderson@linaro.org>]

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 host/include/generic/host/crypto/clmul.h |  4 +++
 include/crypto/clmul.h                   | 23 ++++++++++++++++++
 crypto/clmul.c                           | 31 ++++++++++++++++++++++++
 3 files changed, 58 insertions(+)

diff --git a/host/include/generic/host/crypto/clmul.h b/host/include/generic/host/crypto/clmul.h
index cba8bbf3e4..3fbb1576cf 100644
--- a/host/include/generic/host/crypto/clmul.h
+++ b/host/include/generic/host/crypto/clmul.h
@@ -19,4 +19,8 @@
 #define clmul_16x4_even         clmul_16x4_even_gen
 #define clmul_16x4_odd          clmul_16x4_odd_gen
 
+#define clmul_32                clmul_32_gen
+#define clmul_32x2_even         clmul_32x2_even_gen
+#define clmul_32x2_odd          clmul_32x2_odd_gen
+
 #endif /* GENERIC_HOST_CRYPTO_CLMUL_H */
diff --git a/include/crypto/clmul.h b/include/crypto/clmul.h
index b701bac9d6..ce43c9aeb1 100644
--- a/include/crypto/clmul.h
+++ b/include/crypto/clmul.h
@@ -88,6 +88,29 @@ Int128 clmul_16x4_even_gen(Int128, Int128);
  */
 Int128 clmul_16x4_odd_gen(Int128, Int128);
 
+/**
+ * clmul_32:
+ *
+ * Perform a 32x32->64 carry-less multiply.
+ */
+uint64_t clmul_32_gen(uint32_t, uint32_t);
+
+/**
+ * clmul_32x2_even:
+ *
+ * Perform two 32x32->64 carry-less multiplies.
+ * The odd words of the inputs are ignored.
+ */
+Int128 clmul_32x2_even_gen(Int128, Int128);
+
+/**
+ * clmul_32x2_odd:
+ *
+ * Perform two 32x32->64 carry-less multiplies.
+ * The even words of the inputs are ignored.
+ */
+Int128 clmul_32x2_odd_gen(Int128, Int128);
+
 #include "host/crypto/clmul.h"
 
 #endif /* CRYPTO_CLMUL_H */
diff --git a/crypto/clmul.c b/crypto/clmul.c
index 69a3b6f7ff..c197cd5f21 100644
--- a/crypto/clmul.c
+++ b/crypto/clmul.c
@@ -113,3 +113,34 @@ Int128 clmul_16x4_odd_gen(Int128 n, Int128 m)
     rh = clmul_16x2_odd_gen(int128_gethi(n), int128_gethi(m));
     return int128_make128(rl, rh);
 }
+
+uint64_t clmul_32_gen(uint32_t n, uint32_t m32)
+{
+    uint64_t r = 0;
+    uint64_t m = m32;
+
+    for (int i = 0; i < 32; ++i) {
+        r ^= n & 1 ? m : 0;
+        n >>= 1;
+        m <<= 1;
+    }
+    return r;
+}
+
+Int128 clmul_32x2_even_gen(Int128 n, Int128 m)
+{
+    uint64_t rl, rh;
+
+    rl = clmul_32_gen(int128_getlo(n), int128_getlo(m));
+    rh = clmul_32_gen(int128_gethi(n), int128_gethi(m));
+    return int128_make128(rl, rh);
+}
+
+Int128 clmul_32x2_odd_gen(Int128 n, Int128 m)
+{
+    uint64_t rl, rh;
+
+    rl = clmul_32_gen(int128_getlo(n) >> 32, int128_getlo(m) >> 32);
+    rh = clmul_32_gen(int128_gethi(n) >> 32, int128_gethi(m) >> 32);
+    return int128_make128(rl, rh);
+}
-- 
2.34.1