PIC patch to fix TEXTREL's in the library.

Patch by PaX team

--- nettle/x86/aes-encrypt.asm
+++ nettle/x86/aes-encrypt.asm
@@ -42,20 +42,29 @@
 	pushl	%esi		C  8(%esp)
 	pushl	%edi		C  4(%esp)
 
-	C ctx = 20(%esp)
-	C length = 24(%esp)
-	C dst = 28(%esp)
-	C src = 32(%esp)
+#ifdef __PIC__
+#undef __i686
+	call	___i686.get_pc_thunk.bx
+	addl	$_GLOBAL_OFFSET_TABLE_, %ebx
+	pushl	C_NAME(_nettle_aes_encrypt_table)@GOT(%ebx)
+#else
+	pushl	C_NAME(_nettle_aes_encrypt_table)
+#endif
+
+	C ctx = 24(%esp)
+	C length = 28(%esp)
+	C dst = 32(%esp)
+	C src = 36(%esp)
 
-	movl	24(%esp), %ebp
+	movl	28(%esp), %ebp
 	testl	%ebp,%ebp
 	jz	.Lend
 	
 .Lblock_loop:
-	movl	20(%esp),%esi	C  address of context struct ctx
-	movl	32(%esp),%ebp	C  address of plaintext
+	movl	24(%esp),%esi	C  address of context struct ctx
+	movl	36(%esp),%ebp	C  address of plaintext
 	AES_LOAD(%esi, %ebp)
-	addl	$16, 32(%esp)	C Increment src pointer
+	addl	$16, 36(%esp)	C Increment src pointer
 
 	C  get number of rounds to do from ctx struct	
 	movl	AES_NROUNDS (%esi),%ebp
@@ -65,16 +74,16 @@
 .Lround_loop:
 	pushl	%esi		C  save this first: we'll clobber it later
 
-	AES_ROUND(C_NAME(_nettle_aes_encrypt_table),a,b,c,d)
+	AES_ROUND(4(%esp),a,b,c,d)
 	pushl	%edi		C  save first on stack
 
-	AES_ROUND(C_NAME(_nettle_aes_encrypt_table),b,c,d,a)
+	AES_ROUND(8(%esp),b,c,d,a)
 	pushl	%edi		C  save first on stack
 
-	AES_ROUND(C_NAME(_nettle_aes_encrypt_table),c,d,a,b)
+	AES_ROUND(12(%esp),c,d,a,b)
 	pushl	%edi		C  save first on stack
 
-	AES_ROUND(C_NAME(_nettle_aes_encrypt_table),d,a,b,c)
+	AES_ROUND(16(%esp),d,a,b,c)
 	
 	movl	%edi,%edx
 	popl	%ecx
@@ -112,23 +121,24 @@
 	C S-box substitution
 	mov	$4,%edi
 .Lsubst:
-	AES_SUBST_BYTE(C_NAME(_nettle_aes_encrypt_table))
+	AES_SUBST_BYTE((%esp))
 
 	decl	%edi
 	jnz	.Lsubst
 
 	C Add last subkey, and store encrypted data
-	movl	28(%esp),%edi
+	movl	32(%esp),%edi
 	AES_STORE(%esi, %edi)
 	
-	addl	$16, 28(%esp)	C Increment destination pointer
-	subl	$16, 24(%esp)	C Length
+	addl	$16, 32(%esp)	C Increment destination pointer
+	subl	$16, 28(%esp)	C Length
 
 	C NOTE: Will loop forever if input data is not an
 	C integer number of blocks.
 	jnz	.Lblock_loop
 
 .Lend: 
+	addl	$4, %esp
 	popl	%edi
 	popl	%esi
 	popl	%ebp
@@ -136,6 +146,16 @@
 	ret
 EPILOGUE(nettle_aes_encrypt)
 
+#ifdef __PIC__
+	.section	.gnu.linkonce.t.___i686.get_pc_thunk.bx,"ax",@progbits
+.globl ___i686.get_pc_thunk.bx
+	.hidden	___i686.get_pc_thunk.bx
+	.type	___i686.get_pc_thunk.bx, @function
+___i686.get_pc_thunk.bx:
+	movl	(%esp), %ebx
+	ret
+#endif
+
 #ifdef __ELF__
 .section .note.GNU-stack,"",@progbits
 #endif
--- nettle/x86/aes-decrypt.asm
+++ nettle/x86/aes-decrypt.asm
@@ -31,20 +31,29 @@
 	pushl	%esi		C  8(%esp)
 	pushl	%edi		C  4(%esp)
 
-	C ctx = 20(%esp)
-	C length = 24(%esp)
-	C dst = 28(%esp)
-	C src = 32(%esp)
+#ifdef __PIC__
+#undef __i686
+	call	___i686.get_pc_thunk.bx
+	addl	$_GLOBAL_OFFSET_TABLE_, %ebx
+	pushl	C_NAME(_nettle_aes_decrypt_table)@GOT(%ebx)
+#else
+	pushl	C_NAME(_nettle_aes_decrypt_table)
+#endif
+
+	C ctx = 24(%esp)
+	C length = 28(%esp)
+	C dst = 32(%esp)
+	C src = 36(%esp)
 
-	movl	24(%esp), %ebp
+	movl	28(%esp), %ebp
 	testl	%ebp,%ebp
 	jz	.Lend
 	
 .Lblock_loop:
-	movl	20(%esp),%esi	C  address of context struct ctx
-	movl	32(%esp),%ebp	C  address of plaintext
+	movl	24(%esp),%esi	C  address of context struct ctx
+	movl	36(%esp),%ebp	C  address of plaintext
 	AES_LOAD(%esi, %ebp)
-	addl	$16, 32(%esp)	C Increment src pointer
+	addl	$16, 36(%esp)	C Increment src pointer
 
 	C  get number of rounds to do from struct	
 	movl	AES_NROUNDS (%esi),%ebp	
@@ -57,16 +66,16 @@
 	C In these patterns, note that each row, like
 	C "a,d,c,b" corresponds to one *column* of the 
 	C array _aes_decrypt_table.idx.
-	AES_ROUND(C_NAME(_nettle_aes_decrypt_table),a,d,c,b)
+	AES_ROUND(4(%esp),a,d,c,b)
 	pushl	%edi		C  save first on stack
 
-	AES_ROUND(C_NAME(_nettle_aes_decrypt_table),b,a,d,c)
+	AES_ROUND(8(%esp),b,a,d,c)
 	pushl	%edi
 
-	AES_ROUND(C_NAME(_nettle_aes_decrypt_table),c,b,a,d)
+	AES_ROUND(12(%esp),c,b,a,d)
 	pushl	%edi		C  save first on stack
 
-	AES_ROUND(C_NAME(_nettle_aes_decrypt_table),d,c,b,a)
+	AES_ROUND(16(%esp),d,c,b,a)
 
 	movl	%edi,%edx
 	popl	%ecx
@@ -104,23 +113,24 @@
 	C inverse S-box substitution
 	mov	$4,%edi
 .Lsubst:
-	AES_SUBST_BYTE(C_NAME(_nettle_aes_decrypt_table))
+	AES_SUBST_BYTE((%esp))
 
 	decl	%edi
 	jnz	.Lsubst
 
 	C Add last subkey, and store encrypted data
-	movl	28(%esp),%edi
+	movl	32(%esp),%edi
 	AES_STORE(%esi, %edi)
 	
-	addl	$16, 28(%esp)	C Increment destination pointer
-	subl	$16, 24(%esp)	C Length
+	addl	$16, 32(%esp)	C Increment destination pointer
+	subl	$16, 28(%esp)	C Length
 
 	C NOTE: Will loop forever if input data is not an
 	C integer number of blocks.
 	jnz	.Lblock_loop
 
 .Lend: 
+	addl	$4, %esp
 	popl	%edi
 	popl	%esi
 	popl	%ebp
@@ -128,6 +138,16 @@
 	ret
 EPILOGUE(nettle_aes_decrypt)
 
+#ifdef __PIC__
+	.section	.gnu.linkonce.t.___i686.get_pc_thunk.bx,"ax",@progbits
+.globl ___i686.get_pc_thunk.bx
+	.hidden	___i686.get_pc_thunk.bx
+	.type	___i686.get_pc_thunk.bx, @function
+___i686.get_pc_thunk.bx:
+	movl	(%esp), %ebx
+	ret
+#endif
+
 #ifdef __ELF__
 .section .note.GNU-stack,"",@progbits
 #endif
--- nettle/x86/machine.m4
+++ nettle/x86/machine.m4
@@ -36,19 +36,23 @@ define(<AES_ROUND>, <
 	movl	%e<>$2<>x, %esi
 	andl	<$>0xff, %esi
 	shll	<$>2,%esi		C  index in table
-	movl	AES_TABLE0 + $1 (%esi),%edi
+	addl	$1, %esi
+	movl	AES_TABLE0 (%esi),%edi
 	movl	%e<>$3<>x, %esi
 	shrl	<$>6,%esi
 	andl	<$>0x000003fc,%esi C  clear all but offset bytes
-	xorl	AES_TABLE1 + $1 (%esi),%edi
+	addl	$1, %esi
+	xorl	AES_TABLE1 (%esi),%edi
 	movl	%e<>$4<>x,%esi	C  third one
 	shrl	<$>14,%esi
 	andl	<$>0x000003fc,%esi
-	xorl	AES_TABLE2 + $1 (%esi),%edi
+	addl	$1, %esi
+	xorl	AES_TABLE2 (%esi),%edi
 	movl	%e<>$5<>x,%esi	C  fourth one
 	shrl	<$>22,%esi
 	andl	<$>0x000003fc,%esi
-	xorl	AES_TABLE3 + $1 (%esi),%edi>)dnl
+	addl	$1, %esi
+	xorl	AES_TABLE3 (%esi),%edi>)dnl
 
 dnl AES_FINAL_ROUND(a, b, c, d)
 dnl Computes one word of the final round. Leaves result in %edi.
@@ -75,20 +79,24 @@ dnl the words one byte to the left.
 define(<AES_SUBST_BYTE>, <
 	movl	%eax,%ebp
 	andl	<$>0x000000ff,%ebp
-	movb	AES_SBOX + $1 (%ebp),%al
+	addl	$1, %ebp
+	movb	AES_SBOX (%ebp),%al
 	roll	<$>8,%eax
 
 	movl	%ebx,%ebp
 	andl	<$>0x000000ff,%ebp
-	movb	AES_SBOX + $1 (%ebp),%bl
+	addl	$1, %ebp
+	movb	AES_SBOX (%ebp),%bl
 	roll	<$>8,%ebx
 
 	movl	%ecx,%ebp
 	andl	<$>0x000000ff,%ebp
-	movb	AES_SBOX + $1 (%ebp),%cl
+	addl	$1, %ebp
+	movb	AES_SBOX (%ebp),%cl
 	roll	<$>8,%ecx
 
 	movl	%edx,%ebp
 	andl	<$>0x000000ff,%ebp
-	movb	AES_SBOX + $1 (%ebp),%dl
+	addl	$1, %ebp
+	movb	AES_SBOX (%ebp),%dl
 	roll	<$>8,%edx>)dnl