[PATCH v3 11/37] crypto: Add aesdec_ISB_ISR_AK

[Richard Henderson]

Add a primitive for InvSubBytes + InvShiftRows + AddRoundKey.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 host/include/generic/host/crypto/aes-round.h |  4 ++
 include/crypto/aes-round.h                   | 21 +++++++++
 crypto/aes.c                                 | 45 ++++++++++++++++++++
 3 files changed, 70 insertions(+)

diff --git a/host/include/generic/host/crypto/aes-round.h 
b/host/include/generic/host/crypto/aes-round.h
index c5d8066179..c9b9d732f0 100644
--- a/host/include/generic/host/crypto/aes-round.h
+++ b/host/include/generic/host/crypto/aes-round.h
@@ -13,4 +13,8 @@ void aesenc_SB_SR_AK_accel(AESState *, const AESState *,
                            const AESState *, bool)
     QEMU_ERROR("unsupported accel");
 
+void aesdec_ISB_ISR_AK_accel(AESState *, const AESState *,
+                             const AESState *, bool)
+    QEMU_ERROR("unsupported accel");
+
 #endif /* GENERIC_HOST_CRYPTO_AES_ROUND_H */
diff --git a/include/crypto/aes-round.h b/include/crypto/aes-round.h
index d675d2468f..f917339104 100644
--- a/include/crypto/aes-round.h
+++ b/include/crypto/aes-round.h
@@ -41,4 +41,25 @@ static inline void aesenc_SB_SR_AK(AESState *r, const 
AESState *st,
     }
 }
 
+/*
+ * Perform InvSubBytes + InvShiftRows + AddRoundKey.
+ */
+
+void aesdec_ISB_ISR_AK_gen(AESState *ret, const AESState *st,
+                           const AESState *rk);
+void aesdec_ISB_ISR_AK_genrev(AESState *ret, const AESState *st,
+                              const AESState *rk);
+
+static inline void aesdec_ISB_ISR_AK(AESState *r, const AESState *st,
+                                     const AESState *rk, bool be)
+{
+    if (HAVE_AES_ACCEL) {
+        aesdec_ISB_ISR_AK_accel(r, st, rk, be);
+    } else if (HOST_BIG_ENDIAN == be) {
+        aesdec_ISB_ISR_AK_gen(r, st, rk);
+    } else {
+        aesdec_ISB_ISR_AK_genrev(r, st, rk);
+    }
+}
+
 #endif /* CRYPTO_AES_ROUND_H */
diff --git a/crypto/aes.c b/crypto/aes.c
index c00f10bad1..3d24781858 100644
--- a/crypto/aes.c
+++ b/crypto/aes.c
@@ -1295,6 +1295,51 @@ void aesenc_SB_SR_AK_genrev(AESState *r, const AESState 
*s, const AESState *k)
     aesenc_SB_SR_AK_swap(r, s, k, true);
 }
 
+/*
+ * Perform InvSubBytes + InvShiftRows + AddRoundKey.
+ */
+static inline void
+aesdec_ISB_ISR_AK_swap(AESState *ret, const AESState *st,
+                       const AESState *rk, bool swap)
+{
+    const int swap_b = swap ? 15 : 0;
+    AESState t;
+
+    t.b[swap_b ^ 0x0] = AES_isbox[st->b[swap_b ^ AES_ISH_0]];
+    t.b[swap_b ^ 0x1] = AES_isbox[st->b[swap_b ^ AES_ISH_1]];
+    t.b[swap_b ^ 0x2] = AES_isbox[st->b[swap_b ^ AES_ISH_2]];
+    t.b[swap_b ^ 0x3] = AES_isbox[st->b[swap_b ^ AES_ISH_3]];
+    t.b[swap_b ^ 0x4] = AES_isbox[st->b[swap_b ^ AES_ISH_4]];
+    t.b[swap_b ^ 0x5] = AES_isbox[st->b[swap_b ^ AES_ISH_5]];
+    t.b[swap_b ^ 0x6] = AES_isbox[st->b[swap_b ^ AES_ISH_6]];
+    t.b[swap_b ^ 0x7] = AES_isbox[st->b[swap_b ^ AES_ISH_7]];
+    t.b[swap_b ^ 0x8] = AES_isbox[st->b[swap_b ^ AES_ISH_8]];
+    t.b[swap_b ^ 0x9] = AES_isbox[st->b[swap_b ^ AES_ISH_9]];
+    t.b[swap_b ^ 0xa] = AES_isbox[st->b[swap_b ^ AES_ISH_A]];
+    t.b[swap_b ^ 0xb] = AES_isbox[st->b[swap_b ^ AES_ISH_B]];
+    t.b[swap_b ^ 0xc] = AES_isbox[st->b[swap_b ^ AES_ISH_C]];
+    t.b[swap_b ^ 0xd] = AES_isbox[st->b[swap_b ^ AES_ISH_D]];
+    t.b[swap_b ^ 0xe] = AES_isbox[st->b[swap_b ^ AES_ISH_E]];
+    t.b[swap_b ^ 0xf] = AES_isbox[st->b[swap_b ^ AES_ISH_F]];
+
+    /*
+     * Perform the AddRoundKey with generic vectors.
+     * This may be expanded to either host integer or host vector code.
+     * The key and output endianness match, so no bswap required.
+     */
+    ret->v = t.v ^ rk->v;
+}
+
+void aesdec_ISB_ISR_AK_gen(AESState *r, const AESState *s, const AESState *k)
+{
+    aesdec_ISB_ISR_AK_swap(r, s, k, false);
+}
+
+void aesdec_ISB_ISR_AK_genrev(AESState *r, const AESState *s, const AESState 
*k)
+{
+    aesdec_ISB_ISR_AK_swap(r, s, k, true);
+}
+
 /**
  * Expand the cipher key into the encryption key schedule.
  */
-- 
2.34.1