target-arm: crypto: fix BE host support

The crypto emulation code in target-arm/crypto_helper.c never worked
correctly on big endian hosts, due to the fact that it uses a union
of array types to convert between the native VFP register size (64
bits) and the types used in the algorithms (bytes and 32 bit words)

We cannot just swab between LE and BE when reading and writing the
registers, as the SHA code performs word additions, so instead, add
array accessors for the CRYPTO_STATE type whose LE and BE specific
implementations ensure that the correct array elements are referenced.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-id: 1420208303-24111-1-git-send-email-ard.biesheuvel@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 63 insertions, 51 deletions

diff --git a/target-arm/crypto_helper.c b/target-arm/crypto_helper.c
index dd60d0b81a..1fe975d0f1 100644
--- a/target-arm/crypto_helper.c
+++ b/target-arm/crypto_helper.c
@@ -22,6 +22,14 @@ union CRYPTO_STATE {
     uint64_t   l[2];
 };
 
+#ifdef HOST_WORDS_BIGENDIAN
+#define CR_ST_BYTE(state, i)   (state.bytes[(15 - (i)) ^ 8])
+#define CR_ST_WORD(state, i)   (state.words[(3 - (i)) ^ 2])
+#else
+#define CR_ST_BYTE(state, i)   (state.bytes[i])
+#define CR_ST_WORD(state, i)   (state.words[i])
+#endif
+
 void HELPER(crypto_aese)(CPUARMState *env, uint32_t rd, uint32_t rm,
                          uint32_t decrypt)
 {
@@ -46,7 +54,7 @@ void HELPER(crypto_aese)(CPUARMState *env, uint32_t rd, uint32_t rm,
 
     /* combine ShiftRows operation and sbox substitution */
     for (i = 0; i < 16; i++) {
-        st.bytes[i] = sbox[decrypt][rk.bytes[shift[decrypt][i]]];
+        CR_ST_BYTE(st, i) = sbox[decrypt][CR_ST_BYTE(rk, shift[decrypt][i])];
     }
 
     env->vfp.regs[rd] = make_float64(st.l[0]);
@@ -198,11 +206,11 @@ void HELPER(crypto_aesmc)(CPUARMState *env, uint32_t rd, uint32_t rm,
     assert(decrypt < 2);
 
     for (i = 0; i < 16; i += 4) {
-        st.words[i >> 2] = cpu_to_le32(
-            mc[decrypt][st.bytes[i]] ^
-            rol32(mc[decrypt][st.bytes[i + 1]], 8) ^
-            rol32(mc[decrypt][st.bytes[i + 2]], 16) ^
-            rol32(mc[decrypt][st.bytes[i + 3]], 24));
+        CR_ST_WORD(st, i >> 2) =
+            mc[decrypt][CR_ST_BYTE(st, i)] ^
+            rol32(mc[decrypt][CR_ST_BYTE(st, i + 1)], 8) ^
+            rol32(mc[decrypt][CR_ST_BYTE(st, i + 2)], 16) ^
+            rol32(mc[decrypt][CR_ST_BYTE(st, i + 3)], 24);
     }
 
     env->vfp.regs[rd] = make_float64(st.l[0]);
@@ -255,24 +263,25 @@ void HELPER(crypto_sha1_3reg)(CPUARMState *env, uint32_t rd, uint32_t rn,
 
             switch (op) {
             case 0: /* sha1c */
-                t = cho(d.words[1], d.words[2], d.words[3]);
+                t = cho(CR_ST_WORD(d, 1), CR_ST_WORD(d, 2), CR_ST_WORD(d, 3));
                 break;
             case 1: /* sha1p */
-                t = par(d.words[1], d.words[2], d.words[3]);
+                t = par(CR_ST_WORD(d, 1), CR_ST_WORD(d, 2), CR_ST_WORD(d, 3));
                 break;
             case 2: /* sha1m */
-                t = maj(d.words[1], d.words[2], d.words[3]);
+                t = maj(CR_ST_WORD(d, 1), CR_ST_WORD(d, 2), CR_ST_WORD(d, 3));
                 break;
             default:
                 g_assert_not_reached();
             }
-            t += rol32(d.words[0], 5) + n.words[0] + m.words[i];
-
-            n.words[0] = d.words[3];
-            d.words[3] = d.words[2];
-            d.words[2] = ror32(d.words[1], 2);
-            d.words[1] = d.words[0];
-            d.words[0] = t;
+            t += rol32(CR_ST_WORD(d, 0), 5) + CR_ST_WORD(n, 0)
+                 + CR_ST_WORD(m, i);
+
+            CR_ST_WORD(n, 0) = CR_ST_WORD(d, 3);
+            CR_ST_WORD(d, 3) = CR_ST_WORD(d, 2);
+            CR_ST_WORD(d, 2) = ror32(CR_ST_WORD(d, 1), 2);
+            CR_ST_WORD(d, 1) = CR_ST_WORD(d, 0);
+            CR_ST_WORD(d, 0) = t;
         }
     }
     env->vfp.regs[rd] = make_float64(d.l[0]);
@@ -286,8 +295,8 @@ void HELPER(crypto_sha1h)(CPUARMState *env, uint32_t rd, uint32_t rm)
         float64_val(env->vfp.regs[rm + 1])
     } };
 
-    m.words[0] = ror32(m.words[0], 2);
-    m.words[1] = m.words[2] = m.words[3] = 0;
+    CR_ST_WORD(m, 0) = ror32(CR_ST_WORD(m, 0), 2);
+    CR_ST_WORD(m, 1) = CR_ST_WORD(m, 2) = CR_ST_WORD(m, 3) = 0;
 
     env->vfp.regs[rd] = make_float64(m.l[0]);
     env->vfp.regs[rd + 1] = make_float64(m.l[1]);
@@ -304,10 +313,10 @@ void HELPER(crypto_sha1su1)(CPUARMState *env, uint32_t rd, uint32_t rm)
         float64_val(env->vfp.regs[rm + 1])
     } };
 
-    d.words[0] = rol32(d.words[0] ^ m.words[1], 1);
-    d.words[1] = rol32(d.words[1] ^ m.words[2], 1);
-    d.words[2] = rol32(d.words[2] ^ m.words[3], 1);
-    d.words[3] = rol32(d.words[3] ^ d.words[0], 1);
+    CR_ST_WORD(d, 0) = rol32(CR_ST_WORD(d, 0) ^ CR_ST_WORD(m, 1), 1);
+    CR_ST_WORD(d, 1) = rol32(CR_ST_WORD(d, 1) ^ CR_ST_WORD(m, 2), 1);
+    CR_ST_WORD(d, 2) = rol32(CR_ST_WORD(d, 2) ^ CR_ST_WORD(m, 3), 1);
+    CR_ST_WORD(d, 3) = rol32(CR_ST_WORD(d, 3) ^ CR_ST_WORD(d, 0), 1);
 
     env->vfp.regs[rd] = make_float64(d.l[0]);
     env->vfp.regs[rd + 1] = make_float64(d.l[1]);
@@ -356,20 +365,22 @@ void HELPER(crypto_sha256h)(CPUARMState *env, uint32_t rd, uint32_t rn,
     int i;
 
     for (i = 0; i < 4; i++) {
-        uint32_t t = cho(n.words[0], n.words[1], n.words[2]) + n.words[3]
-                     + S1(n.words[0]) + m.words[i];
-
-        n.words[3] = n.words[2];
-        n.words[2] = n.words[1];
-        n.words[1] = n.words[0];
-        n.words[0] = d.words[3] + t;
-
-        t += maj(d.words[0], d.words[1], d.words[2]) + S0(d.words[0]);
-
-        d.words[3] = d.words[2];
-        d.words[2] = d.words[1];
-        d.words[1] = d.words[0];
-        d.words[0] = t;
+        uint32_t t = cho(CR_ST_WORD(n, 0), CR_ST_WORD(n, 1), CR_ST_WORD(n, 2))
+                     + CR_ST_WORD(n, 3) + S1(CR_ST_WORD(n, 0))
+                     + CR_ST_WORD(m, i);
+
+        CR_ST_WORD(n, 3) = CR_ST_WORD(n, 2);
+        CR_ST_WORD(n, 2) = CR_ST_WORD(n, 1);
+        CR_ST_WORD(n, 1) = CR_ST_WORD(n, 0);
+        CR_ST_WORD(n, 0) = CR_ST_WORD(d, 3) + t;
+
+        t += maj(CR_ST_WORD(d, 0), CR_ST_WORD(d, 1), CR_ST_WORD(d, 2))
+             + S0(CR_ST_WORD(d, 0));
+
+        CR_ST_WORD(d, 3) = CR_ST_WORD(d, 2);
+        CR_ST_WORD(d, 2) = CR_ST_WORD(d, 1);
+        CR_ST_WORD(d, 1) = CR_ST_WORD(d, 0);
+        CR_ST_WORD(d, 0) = t;
     }
 
     env->vfp.regs[rd] = make_float64(d.l[0]);
@@ -394,13 +405,14 @@ void HELPER(crypto_sha256h2)(CPUARMState *env, uint32_t rd, uint32_t rn,
     int i;
 
     for (i = 0; i < 4; i++) {
-        uint32_t t = cho(d.words[0], d.words[1], d.words[2]) + d.words[3]
-                     + S1(d.words[0]) + m.words[i];
-
-        d.words[3] = d.words[2];
-        d.words[2] = d.words[1];
-        d.words[1] = d.words[0];
-        d.words[0] = n.words[3 - i] + t;
+        uint32_t t = cho(CR_ST_WORD(d, 0), CR_ST_WORD(d, 1), CR_ST_WORD(d, 2))
+                     + CR_ST_WORD(d, 3) + S1(CR_ST_WORD(d, 0))
+                     + CR_ST_WORD(m, i);
+
+        CR_ST_WORD(d, 3) = CR_ST_WORD(d, 2);
+        CR_ST_WORD(d, 2) = CR_ST_WORD(d, 1);
+        CR_ST_WORD(d, 1) = CR_ST_WORD(d, 0);
+        CR_ST_WORD(d, 0) = CR_ST_WORD(n, 3 - i) + t;
     }
 
     env->vfp.regs[rd] = make_float64(d.l[0]);
@@ -418,10 +430,10 @@ void HELPER(crypto_sha256su0)(CPUARMState *env, uint32_t rd, uint32_t rm)
         float64_val(env->vfp.regs[rm + 1])
     } };
 
-    d.words[0] += s0(d.words[1]);
-    d.words[1] += s0(d.words[2]);
-    d.words[2] += s0(d.words[3]);
-    d.words[3] += s0(m.words[0]);
+    CR_ST_WORD(d, 0) += s0(CR_ST_WORD(d, 1));
+    CR_ST_WORD(d, 1) += s0(CR_ST_WORD(d, 2));
+    CR_ST_WORD(d, 2) += s0(CR_ST_WORD(d, 3));
+    CR_ST_WORD(d, 3) += s0(CR_ST_WORD(m, 0));
 
     env->vfp.regs[rd] = make_float64(d.l[0]);
     env->vfp.regs[rd + 1] = make_float64(d.l[1]);
@@ -443,10 +455,10 @@ void HELPER(crypto_sha256su1)(CPUARMState *env, uint32_t rd, uint32_t rn,
         float64_val(env->vfp.regs[rm + 1])
     } };
 
-    d.words[0] += s1(m.words[2]) + n.words[1];
-    d.words[1] += s1(m.words[3]) + n.words[2];
-    d.words[2] += s1(d.words[0]) + n.words[3];
-    d.words[3] += s1(d.words[1]) + m.words[0];
+    CR_ST_WORD(d, 0) += s1(CR_ST_WORD(m, 2)) + CR_ST_WORD(n, 1);
+    CR_ST_WORD(d, 1) += s1(CR_ST_WORD(m, 3)) + CR_ST_WORD(n, 2);
+    CR_ST_WORD(d, 2) += s1(CR_ST_WORD(d, 0)) + CR_ST_WORD(n, 3);
+    CR_ST_WORD(d, 3) += s1(CR_ST_WORD(d, 1)) + CR_ST_WORD(m, 0);
 
     env->vfp.regs[rd] = make_float64(d.l[0]);
     env->vfp.regs[rd + 1] = make_float64(d.l[1]);