Add AES-NI key expansion for 256 bits
diff --git a/library/aesni.c b/library/aesni.c
index dc5f8fc..f303a28 100644
--- a/library/aesni.c
+++ b/library/aesni.c
@@ -248,6 +248,8 @@
"jmp 2f \n" // skip auxiliary routine
/*
+ * Finish generating the next round key.
+ *
* On entry xmm0 is r3:r2:r1:r0 and xmm1 is X:stuff:stuff:stuff
* with X = rot( sub( r3 ) ) ^ RCON.
*
@@ -286,6 +288,72 @@
}
/*
+ * Key expansion, 256-bit case
+ */
+void aesni_setkey_enc_256( unsigned char *rk,
+ const unsigned char *key )
+{
+ asm( "movdqu (%1), %%xmm0 \n"
+ "movdqu %%xmm0, (%0) \n"
+ "add $16, %0 \n"
+ "movdqu 16(%1), %%xmm1 \n"
+ "movdqu %%xmm1, (%0) \n"
+ "jmp 2f \n" // skip auxiliary routine
+
+ /*
+ * Finish generating the next two round keys.
+ *
+ * On entry xmm0 is r3:r2:r1:r0, xmm1 is r7:r6:r5:r4 and
+ * xmm2 is X:stuff:stuff:stuff with X = rot( sub( r7 )) ^ RCON
+ *
+ * On exit, xmm0 is r11:r10:r9:r8 and xmm1 is r15:r14:r13:r12
+ * and those have been written to the output buffer.
+ */
+ "1: \n"
+ "pshufd $0xff, %%xmm2, %%xmm2 \n"
+ "pxor %%xmm0, %%xmm2 \n"
+ "pslldq $4, %%xmm0 \n"
+ "pxor %%xmm0, %%xmm2 \n"
+ "pslldq $4, %%xmm0 \n"
+ "pxor %%xmm0, %%xmm2 \n"
+ "pslldq $4, %%xmm0 \n"
+ "pxor %%xmm2, %%xmm0 \n"
+ "add $16, %0 \n"
+ "movdqu %%xmm0, (%0) \n"
+
+ /* Set xmm2 to stuff:Y:stuff:stuff with Y = subword( r11 )
+ * and proceed to generate next round key from there */
+ "aeskeygenassist $0, %%xmm0, %%xmm2\n"
+ "pshufd $0xaa, %%xmm2, %%xmm2 \n"
+ "pxor %%xmm1, %%xmm2 \n"
+ "pslldq $4, %%xmm1 \n"
+ "pxor %%xmm1, %%xmm2 \n"
+ "pslldq $4, %%xmm1 \n"
+ "pxor %%xmm1, %%xmm2 \n"
+ "pslldq $4, %%xmm1 \n"
+ "pxor %%xmm2, %%xmm1 \n"
+ "add $16, %0 \n"
+ "movdqu %%xmm1, (%0) \n"
+ "ret \n"
+
+ /*
+ * Main "loop" - Generating one more key than necessary,
+ * see definition of aes_context.buf
+ */
+ "2: \n"
+ "aeskeygenassist $0x01, %%xmm1, %%xmm2 \ncall 1b \n"
+ "aeskeygenassist $0x02, %%xmm1, %%xmm2 \ncall 1b \n"
+ "aeskeygenassist $0x04, %%xmm1, %%xmm2 \ncall 1b \n"
+ "aeskeygenassist $0x08, %%xmm1, %%xmm2 \ncall 1b \n"
+ "aeskeygenassist $0x10, %%xmm1, %%xmm2 \ncall 1b \n"
+ "aeskeygenassist $0x20, %%xmm1, %%xmm2 \ncall 1b \n"
+ "aeskeygenassist $0x40, %%xmm1, %%xmm2 \ncall 1b \n"
+ :
+ : "r" (rk), "r" (key)
+ : "memory", "cc", "0" );
+}
+
+/*
* Key expansion, wrapper
*/
int aesni_setkey_enc( unsigned char *rk,
@@ -295,6 +363,7 @@
switch( bits )
{
case 128: aesni_setkey_enc_128( rk, key ); break;
+ case 256: aesni_setkey_enc_256( rk, key ); break;
default : return( POLARSSL_ERR_AES_INVALID_KEY_LENGTH );
}