Reviewed-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Richard Henderson <[email protected]>
---
include/crypto/clmul.h | 7 +++++++
crypto/clmul.c | 13 +++++++++++++
2 files changed, 20 insertions(+)
diff --git a/include/crypto/clmul.h b/include/crypto/clmul.h
index 72672b237c..80de516464 100644
--- a/include/crypto/clmul.h
+++ b/include/crypto/clmul.h
@@ -54,4 +54,11 @@ uint64_t clmul_16x2_even(uint64_t, uint64_t);
*/
uint64_t clmul_16x2_odd(uint64_t, uint64_t);
+/**
+ * clmul_32:
+ *
+ * Perform a 32x32->64 carry-less multiply.
+ */
+uint64_t clmul_32(uint32_t, uint32_t);
+
#endif /* CRYPTO_CLMUL_H */
diff --git a/crypto/clmul.c b/crypto/clmul.c
index 2c87cfbf8a..36ada1be9d 100644
--- a/crypto/clmul.c
+++ b/crypto/clmul.c
@@ -79,3 +79,16 @@ uint64_t clmul_16x2_odd(uint64_t n, uint64_t m)
{
return clmul_16x2_even(n >> 16, m >> 16);
}
+
+uint64_t clmul_32(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;
+}
--
2.34.1
