crypto: Add generic 32-bit carry-less multiply routines
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/crypto/clmul.c b/crypto/clmul.c
index 2c87cfb..36ada1b 100644
--- a/crypto/clmul.c
+++ b/crypto/clmul.c
@@ -79,3 +79,16 @@
{
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;
+}
diff --git a/include/crypto/clmul.h b/include/crypto/clmul.h
index 72672b2..80de516 100644
--- a/include/crypto/clmul.h
+++ b/include/crypto/clmul.h
@@ -54,4 +54,11 @@
*/
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 */
