[CRYPTO] aes-generic: Make key generation exportable

This patch exports four tables and the set_key() routine. This ressources
can be shared by other AES implementations (aes-x86_64 for instance).
The decryption key has been turned around (deckey[0] is the first piece
of the key instead of deckey[keylen+20]). The encrypt/decrypt functions
are looking now identical (except they are using different tables and
key).

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 136 insertions, 129 deletions

diff --git a/crypto/aes_generic.c b/crypto/aes_generic.c
index df8df4d346d2..cf30af74480f 100644
--- a/crypto/aes_generic.c
+++ b/crypto/aes_generic.c
@@ -47,11 +47,6 @@
  * ---------------------------------------------------------------------------
  */
 
-/* Some changes from the Gladman version:
-    s/RIJNDAEL(e_key)/E_KEY/g
-    s/RIJNDAEL(d_key)/D_KEY/g
-*/
-
 #include <crypto/aes.h>
 #include <linux/module.h>
 #include <linux/init.h>
@@ -60,32 +55,26 @@
 #include <linux/crypto.h>
 #include <asm/byteorder.h>
 
-/*
- * #define byte(x, nr) ((unsigned char)((x) >> (nr*8))) 
- */
 static inline u8 byte(const u32 x, const unsigned n)
 {
         return x >> (n << 3);
 }
 
-struct aes_ctx {
-        int key_length;
-        u32 buf[120];
-};
-
-#define E_KEY (&ctx->buf[0])
-#define D_KEY (&ctx->buf[60])
-
 static u8 pow_tab[256] __initdata;
 static u8 log_tab[256] __initdata;
 static u8 sbx_tab[256] __initdata;
 static u8 isb_tab[256] __initdata;
 static u32 rco_tab[10];
-static u32 ft_tab[4][256];
-static u32 it_tab[4][256];
 
-static u32 fl_tab[4][256];
-static u32 il_tab[4][256];
+u32 crypto_ft_tab[4][256];
+u32 crypto_fl_tab[4][256];
+u32 crypto_it_tab[4][256];
+u32 crypto_il_tab[4][256];
+
+EXPORT_SYMBOL_GPL(crypto_ft_tab);
+EXPORT_SYMBOL_GPL(crypto_fl_tab);
+EXPORT_SYMBOL_GPL(crypto_it_tab);
+EXPORT_SYMBOL_GPL(crypto_il_tab);
 
 static inline u8 __init f_mult(u8 a, u8 b)
 {
@@ -134,37 +123,37 @@ static void __init gen_tabs(void)
                 p = sbx_tab[i];
 
                 t = p;
-                fl_tab[0][i] = t;
-                fl_tab[1][i] = rol32(t, 8);
-                fl_tab[2][i] = rol32(t, 16);
-                fl_tab[3][i] = rol32(t, 24);
+                crypto_fl_tab[0][i] = t;
+                crypto_fl_tab[1][i] = rol32(t, 8);
+                crypto_fl_tab[2][i] = rol32(t, 16);
+                crypto_fl_tab[3][i] = rol32(t, 24);
 
                 t = ((u32) ff_mult(2, p)) |
                     ((u32) p << 8) |
                     ((u32) p << 16) | ((u32) ff_mult(3, p) << 24);
 
-                ft_tab[0][i] = t;
-                ft_tab[1][i] = rol32(t, 8);
-                ft_tab[2][i] = rol32(t, 16);
-                ft_tab[3][i] = rol32(t, 24);
+                crypto_ft_tab[0][i] = t;
+                crypto_ft_tab[1][i] = rol32(t, 8);
+                crypto_ft_tab[2][i] = rol32(t, 16);
+                crypto_ft_tab[3][i] = rol32(t, 24);
 
                 p = isb_tab[i];
 
                 t = p;
-                il_tab[0][i] = t;
-                il_tab[1][i] = rol32(t, 8);
-                il_tab[2][i] = rol32(t, 16);
-                il_tab[3][i] = rol32(t, 24);
+                crypto_il_tab[0][i] = t;
+                crypto_il_tab[1][i] = rol32(t, 8);
+                crypto_il_tab[2][i] = rol32(t, 16);
+                crypto_il_tab[3][i] = rol32(t, 24);
 
                 t = ((u32) ff_mult(14, p)) |
                     ((u32) ff_mult(9, p) << 8) |
                     ((u32) ff_mult(13, p) << 16) |
                     ((u32) ff_mult(11, p) << 24);
 
-                it_tab[0][i] = t;
-                it_tab[1][i] = rol32(t, 8);
-                it_tab[2][i] = rol32(t, 16);
-                it_tab[3][i] = rol32(t, 24);
+                crypto_it_tab[0][i] = t;
+                crypto_it_tab[1][i] = rol32(t, 8);
+                crypto_it_tab[2][i] = rol32(t, 16);
+                crypto_it_tab[3][i] = rol32(t, 24);
         }
 }
 
@@ -184,69 +173,69 @@ static void __init gen_tabs(void)
 } while (0)
 
 #define ls_box(x)               \
-        fl_tab[0][byte(x, 0)] ^ \
-        fl_tab[1][byte(x, 1)] ^ \
-        fl_tab[2][byte(x, 2)] ^ \
-        fl_tab[3][byte(x, 3)]
+        crypto_fl_tab[0][byte(x, 0)] ^  \
+        crypto_fl_tab[1][byte(x, 1)] ^  \
+        crypto_fl_tab[2][byte(x, 2)] ^  \
+        crypto_fl_tab[3][byte(x, 3)]
 
 #define loop4(i)        do {            \
         t = ror32(t, 8);                \
         t = ls_box(t) ^ rco_tab[i];     \
-        t ^= E_KEY[4 * i];              \
-        E_KEY[4 * i + 4] = t;           \
-        t ^= E_KEY[4 * i + 1];          \
-        E_KEY[4 * i + 5] = t;           \
-        t ^= E_KEY[4 * i + 2];          \
-        E_KEY[4 * i + 6] = t;           \
-        t ^= E_KEY[4 * i + 3];          \
-        E_KEY[4 * i + 7] = t;           \
+        t ^= ctx->key_enc[4 * i];               \
+        ctx->key_enc[4 * i + 4] = t;            \
+        t ^= ctx->key_enc[4 * i + 1];           \
+        ctx->key_enc[4 * i + 5] = t;            \
+        t ^= ctx->key_enc[4 * i + 2];           \
+        ctx->key_enc[4 * i + 6] = t;            \
+        t ^= ctx->key_enc[4 * i + 3];           \
+        ctx->key_enc[4 * i + 7] = t;            \
 } while (0)
 
 #define loop6(i)        do {            \
         t = ror32(t, 8);                \
         t = ls_box(t) ^ rco_tab[i];     \
-        t ^= E_KEY[6 * i];              \
-        E_KEY[6 * i + 6] = t;           \
-        t ^= E_KEY[6 * i + 1];          \
-        E_KEY[6 * i + 7] = t;           \
-        t ^= E_KEY[6 * i + 2];          \
-        E_KEY[6 * i + 8] = t;           \
-        t ^= E_KEY[6 * i + 3];          \
-        E_KEY[6 * i + 9] = t;           \
-        t ^= E_KEY[6 * i + 4];          \
-        E_KEY[6 * i + 10] = t;          \
-        t ^= E_KEY[6 * i + 5];          \
-        E_KEY[6 * i + 11] = t;          \
+        t ^= ctx->key_enc[6 * i];               \
+        ctx->key_enc[6 * i + 6] = t;            \
+        t ^= ctx->key_enc[6 * i + 1];           \
+        ctx->key_enc[6 * i + 7] = t;            \
+        t ^= ctx->key_enc[6 * i + 2];           \
+        ctx->key_enc[6 * i + 8] = t;            \
+        t ^= ctx->key_enc[6 * i + 3];           \
+        ctx->key_enc[6 * i + 9] = t;            \
+        t ^= ctx->key_enc[6 * i + 4];           \
+        ctx->key_enc[6 * i + 10] = t;           \
+        t ^= ctx->key_enc[6 * i + 5];           \
+        ctx->key_enc[6 * i + 11] = t;           \
 } while (0)
 
 #define loop8(i)        do {                    \
         t = ror32(t, 8);                        \
         t = ls_box(t) ^ rco_tab[i];             \
-        t ^= E_KEY[8 * i];                      \
-        E_KEY[8 * i + 8] = t;                   \
-        t ^= E_KEY[8 * i + 1];                  \
-        E_KEY[8 * i + 9] = t;                   \
-        t ^= E_KEY[8 * i + 2];                  \
-        E_KEY[8 * i + 10] = t;                  \
-        t ^= E_KEY[8 * i + 3];                  \
-        E_KEY[8 * i + 11] = t;                  \
-        t  = E_KEY[8 * i + 4] ^ ls_box(t);      \
-        E_KEY[8 * i + 12] = t;                  \
-        t ^= E_KEY[8 * i + 5];                  \
-        E_KEY[8 * i + 13] = t;                  \
-        t ^= E_KEY[8 * i + 6];                  \
-        E_KEY[8 * i + 14] = t;                  \
-        t ^= E_KEY[8 * i + 7];                  \
-        E_KEY[8 * i + 15] = t;                  \
+        t ^= ctx->key_enc[8 * i];                       \
+        ctx->key_enc[8 * i + 8] = t;                    \
+        t ^= ctx->key_enc[8 * i + 1];                   \
+        ctx->key_enc[8 * i + 9] = t;                    \
+        t ^= ctx->key_enc[8 * i + 2];                   \
+        ctx->key_enc[8 * i + 10] = t;                   \
+        t ^= ctx->key_enc[8 * i + 3];                   \
+        ctx->key_enc[8 * i + 11] = t;                   \
+        t  = ctx->key_enc[8 * i + 4] ^ ls_box(t);       \
+        ctx->key_enc[8 * i + 12] = t;                   \
+        t ^= ctx->key_enc[8 * i + 5];                   \
+        ctx->key_enc[8 * i + 13] = t;                   \
+        t ^= ctx->key_enc[8 * i + 6];                   \
+        ctx->key_enc[8 * i + 14] = t;                   \
+        t ^= ctx->key_enc[8 * i + 7];                   \
+        ctx->key_enc[8 * i + 15] = t;                   \
 } while (0)
 
-static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
+int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
                 unsigned int key_len)
 {
-        struct aes_ctx *ctx = crypto_tfm_ctx(tfm);
+        struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
         const __le32 *key = (const __le32 *)in_key;
         u32 *flags = &tfm->crt_flags;
-        u32 i, t, u, v, w;
+        u32 i, t, u, v, w, j;
 
         if (key_len % 8) {
                 *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
@@ -255,54 +244,55 @@ static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 
         ctx->key_length = key_len;
 
-        E_KEY[0] = le32_to_cpu(key[0]);
-        E_KEY[1] = le32_to_cpu(key[1]);
-        E_KEY[2] = le32_to_cpu(key[2]);
-        E_KEY[3] = le32_to_cpu(key[3]);
+        ctx->key_dec[key_len + 24] = ctx->key_enc[0] = le32_to_cpu(key[0]);
+        ctx->key_dec[key_len + 25] = ctx->key_enc[1] = le32_to_cpu(key[1]);
+        ctx->key_dec[key_len + 26] = ctx->key_enc[2] = le32_to_cpu(key[2]);
+        ctx->key_dec[key_len + 27] = ctx->key_enc[3] = le32_to_cpu(key[3]);
 
         switch (key_len) {
         case 16:
-                t = E_KEY[3];
+                t = ctx->key_enc[3];
                 for (i = 0; i < 10; ++i)
                         loop4(i);
                 break;
 
         case 24:
-                E_KEY[4] = le32_to_cpu(key[4]);
-                t = E_KEY[5] = le32_to_cpu(key[5]);
+                ctx->key_enc[4] = le32_to_cpu(key[4]);
+                t = ctx->key_enc[5] = le32_to_cpu(key[5]);
                 for (i = 0; i < 8; ++i)
                         loop6(i);
                 break;
 
         case 32:
-                E_KEY[4] = le32_to_cpu(key[4]);
-                E_KEY[5] = le32_to_cpu(key[5]);
-                E_KEY[6] = le32_to_cpu(key[6]);
-                t = E_KEY[7] = le32_to_cpu(key[7]);
+                ctx->key_enc[4] = le32_to_cpu(key[4]);
+                ctx->key_enc[5] = le32_to_cpu(key[5]);
+                ctx->key_enc[6] = le32_to_cpu(key[6]);
+                t = ctx->key_enc[7] = le32_to_cpu(key[7]);
                 for (i = 0; i < 7; ++i)
                         loop8(i);
                 break;
         }
 
-        D_KEY[0] = E_KEY[0];
-        D_KEY[1] = E_KEY[1];
-        D_KEY[2] = E_KEY[2];
-        D_KEY[3] = E_KEY[3];
+        ctx->key_dec[0] = ctx->key_enc[key_len + 24];
+        ctx->key_dec[1] = ctx->key_enc[key_len + 25];
+        ctx->key_dec[2] = ctx->key_enc[key_len + 26];
+        ctx->key_dec[3] = ctx->key_enc[key_len + 27];
 
         for (i = 4; i < key_len + 24; ++i) {
-                imix_col(D_KEY[i], E_KEY[i]);
+                j = key_len + 24 - (i & ~3) + (i & 3);
+                imix_col(ctx->key_dec[j], ctx->key_enc[i]);
         }
-
         return 0;
 }
+EXPORT_SYMBOL_GPL(crypto_aes_set_key);
 
 /* encrypt a block of text */
 
 #define f_rn(bo, bi, n, k)      do {                            \
-        bo[n] = ft_tab[0][byte(bi[n], 0)] ^                     \
-                ft_tab[1][byte(bi[(n + 1) & 3], 1)] ^           \
-                ft_tab[2][byte(bi[(n + 2) & 3], 2)] ^           \
-                ft_tab[3][byte(bi[(n + 3) & 3], 3)] ^ *(k + n); \
+        bo[n] = crypto_ft_tab[0][byte(bi[n], 0)] ^                      \
+                crypto_ft_tab[1][byte(bi[(n + 1) & 3], 1)] ^            \
+                crypto_ft_tab[2][byte(bi[(n + 2) & 3], 2)] ^            \
+                crypto_ft_tab[3][byte(bi[(n + 3) & 3], 3)] ^ *(k + n);  \
 } while (0)
 
 #define f_nround(bo, bi, k)     do {\
@@ -314,10 +304,10 @@ static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 } while (0)
 
 #define f_rl(bo, bi, n, k)      do {                            \
-        bo[n] = fl_tab[0][byte(bi[n], 0)] ^                     \
-                fl_tab[1][byte(bi[(n + 1) & 3], 1)] ^           \
-                fl_tab[2][byte(bi[(n + 2) & 3], 2)] ^           \
-                fl_tab[3][byte(bi[(n + 3) & 3], 3)] ^ *(k + n); \
+        bo[n] = crypto_fl_tab[0][byte(bi[n], 0)] ^                      \
+                crypto_fl_tab[1][byte(bi[(n + 1) & 3], 1)] ^            \
+                crypto_fl_tab[2][byte(bi[(n + 2) & 3], 2)] ^            \
+                crypto_fl_tab[3][byte(bi[(n + 3) & 3], 3)] ^ *(k + n);  \
 } while (0)
 
 #define f_lround(bo, bi, k)     do {\
@@ -329,23 +319,24 @@ static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 
 static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 {
-        const struct aes_ctx *ctx = crypto_tfm_ctx(tfm);
+        const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
         const __le32 *src = (const __le32 *)in;
         __le32 *dst = (__le32 *)out;
         u32 b0[4], b1[4];
-        const u32 *kp = E_KEY + 4;
+        const u32 *kp = ctx->key_enc + 4;
+        const int key_len = ctx->key_length;
 
-        b0[0] = le32_to_cpu(src[0]) ^ E_KEY[0];
-        b0[1] = le32_to_cpu(src[1]) ^ E_KEY[1];
-        b0[2] = le32_to_cpu(src[2]) ^ E_KEY[2];
-        b0[3] = le32_to_cpu(src[3]) ^ E_KEY[3];
+        b0[0] = le32_to_cpu(src[0]) ^ ctx->key_enc[0];
+        b0[1] = le32_to_cpu(src[1]) ^ ctx->key_enc[1];
+        b0[2] = le32_to_cpu(src[2]) ^ ctx->key_enc[2];
+        b0[3] = le32_to_cpu(src[3]) ^ ctx->key_enc[3];
 
-        if (ctx->key_length > 24) {
+        if (key_len > 24) {
                 f_nround(b1, b0, kp);
                 f_nround(b0, b1, kp);
         }
 
-        if (ctx->key_length > 16) {
+        if (key_len > 16) {
                 f_nround(b1, b0, kp);
                 f_nround(b0, b1, kp);
         }
@@ -370,10 +361,10 @@ static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 /* decrypt a block of text */
 
 #define i_rn(bo, bi, n, k)      do {                            \
-        bo[n] = it_tab[0][byte(bi[n], 0)] ^                     \
-                it_tab[1][byte(bi[(n + 3) & 3], 1)] ^           \
-                it_tab[2][byte(bi[(n + 2) & 3], 2)] ^           \
-                it_tab[3][byte(bi[(n + 1) & 3], 3)] ^ *(k + n); \
+        bo[n] = crypto_it_tab[0][byte(bi[n], 0)] ^                      \
+                crypto_it_tab[1][byte(bi[(n + 3) & 3], 1)] ^            \
+                crypto_it_tab[2][byte(bi[(n + 2) & 3], 2)] ^            \
+                crypto_it_tab[3][byte(bi[(n + 1) & 3], 3)] ^ *(k + n);  \
 } while (0)
 
 #define i_nround(bo, bi, k)     do {\
@@ -381,14 +372,14 @@ static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
         i_rn(bo, bi, 1, k);     \
         i_rn(bo, bi, 2, k);     \
         i_rn(bo, bi, 3, k);     \
-        k -= 4;                 \
+        k += 4;                 \
 } while (0)
 
 #define i_rl(bo, bi, n, k)      do {                    \
-        bo[n] = il_tab[0][byte(bi[n], 0)] ^             \
-        il_tab[1][byte(bi[(n + 3) & 3], 1)] ^           \
-        il_tab[2][byte(bi[(n + 2) & 3], 2)] ^           \
-        il_tab[3][byte(bi[(n + 1) & 3], 3)] ^ *(k + n); \
+        bo[n] = crypto_il_tab[0][byte(bi[n], 0)] ^              \
+        crypto_il_tab[1][byte(bi[(n + 3) & 3], 1)] ^            \
+        crypto_il_tab[2][byte(bi[(n + 2) & 3], 2)] ^            \
+        crypto_il_tab[3][byte(bi[(n + 1) & 3], 3)] ^ *(k + n);  \
 } while (0)
 
 #define i_lround(bo, bi, k)     do {\
@@ -400,17 +391,17 @@ static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 
 static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 {
-        const struct aes_ctx *ctx = crypto_tfm_ctx(tfm);
+        const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
         const __le32 *src = (const __le32 *)in;
         __le32 *dst = (__le32 *)out;
         u32 b0[4], b1[4];
         const int key_len = ctx->key_length;
-        const u32 *kp = D_KEY + key_len + 20;
+        const u32 *kp = ctx->key_dec + 4;
 
-        b0[0] = le32_to_cpu(src[0]) ^ E_KEY[key_len + 24];
-        b0[1] = le32_to_cpu(src[1]) ^ E_KEY[key_len + 25];
-        b0[2] = le32_to_cpu(src[2]) ^ E_KEY[key_len + 26];
-        b0[3] = le32_to_cpu(src[3]) ^ E_KEY[key_len + 27];
+        b0[0] = le32_to_cpu(src[0]) ^  ctx->key_dec[0];
+        b0[1] = le32_to_cpu(src[1]) ^  ctx->key_dec[1];
+        b0[2] = le32_to_cpu(src[2]) ^  ctx->key_dec[2];
+        b0[3] = le32_to_cpu(src[3]) ^  ctx->key_dec[3];
 
         if (key_len > 24) {
                 i_nround(b1, b0, kp);
@@ -445,7 +436,7 @@ static struct crypto_alg aes_alg = {
         .cra_priority           =       100,
         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
         .cra_blocksize          =       AES_BLOCK_SIZE,
-        .cra_ctxsize            =       sizeof(struct aes_ctx),
+        .cra_ctxsize            =       sizeof(struct crypto_aes_ctx),
         .cra_alignmask          =       3,
         .cra_module             =       THIS_MODULE,
         .cra_list               =       LIST_HEAD_INIT(aes_alg.cra_list),
@@ -453,7 +444,7 @@ static struct crypto_alg aes_alg = {
                 .cipher = {
                         .cia_min_keysize        =       AES_MIN_KEY_SIZE,
                         .cia_max_keysize        =       AES_MAX_KEY_SIZE,
-                        .cia_setkey             =       aes_set_key,
+                        .cia_setkey             =       crypto_aes_set_key,
                         .cia_encrypt            =       aes_encrypt,
                         .cia_decrypt            =       aes_decrypt
                 }
diff --git a/include/crypto/aes.h b/include/crypto/aes.h
index 9ff842fc6b89..d480b76715a8 100644
--- a/include/crypto/aes.h
+++ b/include/crypto/aes.h
@@ -5,6 +5,9 @@
 #ifndef _CRYPTO_AES_H
 #define _CRYPTO_AES_H
 
+#include <linux/types.h>
+#include <linux/crypto.h>
+
 #define AES_MIN_KEY_SIZE        16
 #define AES_MAX_KEY_SIZE        32
 #define AES_KEYSIZE_128         16
@@ -12,4 +15,17 @@
 #define AES_KEYSIZE_256         32
 #define AES_BLOCK_SIZE          16
 
+struct crypto_aes_ctx {
+        u32 key_length;
+        u32 key_enc[60];
+        u32 key_dec[60];
+};
+
+extern u32 crypto_ft_tab[4][256];
+extern u32 crypto_fl_tab[4][256];
+extern u32 crypto_it_tab[4][256];
+extern u32 crypto_il_tab[4][256];
+
+int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
+                unsigned int key_len);
 #endif