arm64: Add PAuth helpers for signing, stripping and authentication of pointers

CREDITS.TXT

@@ -81,3 +81,4 @@ Ziqiao Kong (lazymio): uc_context_free() API and various bug fix & improvement.
 Sven Almgren (blindmatrix): bug fix
 Chenxu Wu (kabeor): Documentation
 Philipp Takacs: virtual tlb, memory snapshots
+Daniel Roethlisberger (droe): ARM64 fixes & improvements

bindings/dotnet/UnicornEngine/Const/Arm64.fs

@@ -340,3 +340,12 @@ module Arm64 =
     let UC_ARM64_INS_WFI = 5
     let UC_ARM64_INS_ENDING = 6
 
+    // ARM64 PAuth keys
+
+    let UC_ARM64_PAUTH_KEY_IA = 0
+    let UC_ARM64_PAUTH_KEY_IB = 1
+    let UC_ARM64_PAUTH_KEY_DA = 2
+    let UC_ARM64_PAUTH_KEY_DB = 3
+    let UC_ARM64_PAUTH_KEY_GA = 4
+    let UC_ARM64_PAUTH_KEY_ENDING = 5
+

bindings/dotnet/UnicornEngine/Const/Common.fs

@@ -152,6 +152,9 @@ module Common =
     let UC_CTL_TLB_TYPE = 12
     let UC_CTL_TCG_BUFFER_SIZE = 13
     let UC_CTL_CONTEXT_MODE = 14
+    let UC_CTL_PAUTH_SIGN = 15
+    let UC_CTL_PAUTH_STRIP = 16
+    let UC_CTL_PAUTH_AUTH = 17
     let UC_CTL_CONTEXT_CPU = 1
     let UC_CTL_CONTEXT_MEMORY = 2
 

bindings/go/unicorn/arm64_const.go

@@ -334,4 +334,13 @@ const (
 	ARM64_INS_SYSL = 4
 	ARM64_INS_WFI = 5
 	ARM64_INS_ENDING = 6
+
+// ARM64 PAuth keys
+
+	ARM64_PAUTH_KEY_IA = 0
+	ARM64_PAUTH_KEY_IB = 1
+	ARM64_PAUTH_KEY_DA = 2
+	ARM64_PAUTH_KEY_DB = 3
+	ARM64_PAUTH_KEY_GA = 4
+	ARM64_PAUTH_KEY_ENDING = 5
 )

bindings/go/unicorn/unicorn_const.go

@@ -147,6 +147,9 @@ const (
 	CTL_TLB_TYPE = 12
 	CTL_TCG_BUFFER_SIZE = 13
 	CTL_CONTEXT_MODE = 14
+	CTL_PAUTH_SIGN = 15
+	CTL_PAUTH_STRIP = 16
+	CTL_PAUTH_AUTH = 17
 	CTL_CONTEXT_CPU = 1
 	CTL_CONTEXT_MEMORY = 2
 )

bindings/java/src/main/java/unicorn/Arm64Const.java

@@ -337,4 +337,13 @@ public interface Arm64Const {
     public static final int UC_ARM64_INS_WFI = 5;
     public static final int UC_ARM64_INS_ENDING = 6;
 
+    // ARM64 PAuth keys
+
+    public static final int UC_ARM64_PAUTH_KEY_IA = 0;
+    public static final int UC_ARM64_PAUTH_KEY_IB = 1;
+    public static final int UC_ARM64_PAUTH_KEY_DA = 2;
+    public static final int UC_ARM64_PAUTH_KEY_DB = 3;
+    public static final int UC_ARM64_PAUTH_KEY_GA = 4;
+    public static final int UC_ARM64_PAUTH_KEY_ENDING = 5;
+
 }

bindings/java/src/main/java/unicorn/UnicornConst.java

@@ -149,6 +149,9 @@ public interface UnicornConst {
     public static final int UC_CTL_TLB_TYPE = 12;
     public static final int UC_CTL_TCG_BUFFER_SIZE = 13;
     public static final int UC_CTL_CONTEXT_MODE = 14;
+    public static final int UC_CTL_PAUTH_SIGN = 15;
+    public static final int UC_CTL_PAUTH_STRIP = 16;
+    public static final int UC_CTL_PAUTH_AUTH = 17;
     public static final int UC_CTL_CONTEXT_CPU = 1;
     public static final int UC_CTL_CONTEXT_MEMORY = 2;
 

bindings/pascal/unicorn/Arm64Const.pas

@@ -338,5 +338,14 @@ interface
   UC_ARM64_INS_WFI = 5;
   UC_ARM64_INS_ENDING = 6;
 
+// ARM64 PAuth keys
+
+  UC_ARM64_PAUTH_KEY_IA = 0;
+  UC_ARM64_PAUTH_KEY_IB = 1;
+  UC_ARM64_PAUTH_KEY_DA = 2;
+  UC_ARM64_PAUTH_KEY_DB = 3;
+  UC_ARM64_PAUTH_KEY_GA = 4;
+  UC_ARM64_PAUTH_KEY_ENDING = 5;
+
 implementation
 end.

bindings/pascal/unicorn/UnicornConst.pas

@@ -150,6 +150,9 @@ interface
   UC_CTL_TLB_TYPE = 12;
   UC_CTL_TCG_BUFFER_SIZE = 13;
   UC_CTL_CONTEXT_MODE = 14;
+  UC_CTL_PAUTH_SIGN = 15;
+  UC_CTL_PAUTH_STRIP = 16;
+  UC_CTL_PAUTH_AUTH = 17;
   UC_CTL_CONTEXT_CPU = 1;
   UC_CTL_CONTEXT_MEMORY = 2;
 

bindings/python/unicorn/arm64_const.py

@@ -332,3 +332,12 @@
 UC_ARM64_INS_SYSL = 4
 UC_ARM64_INS_WFI = 5
 UC_ARM64_INS_ENDING = 6
+
+# ARM64 PAuth keys
+
+UC_ARM64_PAUTH_KEY_IA = 0
+UC_ARM64_PAUTH_KEY_IB = 1
+UC_ARM64_PAUTH_KEY_DA = 2
+UC_ARM64_PAUTH_KEY_DB = 3
+UC_ARM64_PAUTH_KEY_GA = 4
+UC_ARM64_PAUTH_KEY_ENDING = 5

bindings/python/unicorn/unicorn_const.py

@@ -145,5 +145,8 @@
 UC_CTL_TLB_TYPE = 12
 UC_CTL_TCG_BUFFER_SIZE = 13
 UC_CTL_CONTEXT_MODE = 14
+UC_CTL_PAUTH_SIGN = 15
+UC_CTL_PAUTH_STRIP = 16
+UC_CTL_PAUTH_AUTH = 17
 UC_CTL_CONTEXT_CPU = 1
 UC_CTL_CONTEXT_MEMORY = 2

bindings/python/unicorn/unicorn_py3/unicorn.py

@@ -1253,16 +1253,15 @@ def __ctl_w(self, ctl: int, *args: Arg):
 
         self.ctl(ctl, uc.UC_CTL_IO_WRITE, *cargs)
 
-    def __ctl_wr(self, ctl: int, arg0: Arg, arg1: Arg):
-        atype, avalue = arg0
-        carg0 = atype(avalue)
+    def __ctl_wr(self, ctl: int, *args: Arg):
+        cargs = (atype(avalue) for atype, avalue in args[:-1])
 
-        atype, _ = arg1
-        carg1 = atype()
+        atype, _ = args[-1]
+        cretv = atype()
 
-        self.ctl(ctl, uc.UC_CTL_IO_READ_WRITE, carg0, ctypes.byref(carg1))
+        self.ctl(ctl, uc.UC_CTL_IO_READ_WRITE, *cargs, ctypes.byref(cretv))
 
-        return carg1.value
+        return cretv.value
 
     def ctl_get_mode(self) -> int:
         """Retrieve current processor mode.
@@ -1475,6 +1474,58 @@ def ctl_set_tcg_buffer_size(self, size: int) -> None:
             (ctypes.c_uint32, size)
         )
 
+    def ctl_pauth_sign(self, ptr: int, key: int, diversifier: int) -> int:
+        """Sign a pointer with a key and discriminator.
+
+        Args:
+            ptr: pointer to sign
+            key: architecture-specific constant indicating the key to use
+            diversifier: discriminator to use
+
+        Returns: the signed pointer
+        """
+
+        return self.__ctl_wr(uc.UC_CTL_PAUTH_SIGN,
+            (ctypes.c_uint64, ptr),
+            (ctypes.c_uint32, key),
+            (ctypes.c_uint64, diversifier),
+            (ctypes.c_uint64, None),
+        )
+
+    def ctl_pauth_strip(self, ptr: int, key: int) -> int:
+        """Strip the PAC from a possibly signed pointer.
+
+        Args:
+            ptr: pointer to strip PAC from
+            key: architecture-specific constant indicating the key to use
+
+        Returns: the stripped pointer
+        """
+
+        return self.__ctl_wr(uc.UC_CTL_PAUTH_STRIP,
+            (ctypes.c_uint64, ptr),
+            (ctypes.c_uint32, key),
+            (ctypes.c_uint64, None),
+        )
+
+    def ctl_pauth_auth(self, ptr: int, key: int, diversifier: int) -> bool:
+        """Authenticate a pointer with a key and discriminator.
+
+        Args:
+            ptr: signed pointer to authenticate
+            key: architecture-specific constant indicating the key to use
+            diversifier: discriminator to use
+
+        Returns: True if signature is valid, False othewise
+        """
+
+        return self.__ctl_wr(uc.UC_CTL_PAUTH_AUTH,
+            (ctypes.c_uint64, ptr),
+            (ctypes.c_uint32, key),
+            (ctypes.c_uint64, diversifier),
+            (ctypes.c_bool, None),
+        )
+
 
 class UcContext(RegStateManager):
     """Unicorn internal context.

bindings/ruby/unicorn_gem/lib/unicorn_engine/arm64_const.rb

@@ -334,4 +334,13 @@ module UnicornEngine
 	UC_ARM64_INS_SYSL = 4
 	UC_ARM64_INS_WFI = 5
 	UC_ARM64_INS_ENDING = 6
+
+# ARM64 PAuth keys
+
+	UC_ARM64_PAUTH_KEY_IA = 0
+	UC_ARM64_PAUTH_KEY_IB = 1
+	UC_ARM64_PAUTH_KEY_DA = 2
+	UC_ARM64_PAUTH_KEY_DB = 3
+	UC_ARM64_PAUTH_KEY_GA = 4
+	UC_ARM64_PAUTH_KEY_ENDING = 5
 end

bindings/ruby/unicorn_gem/lib/unicorn_engine/unicorn_const.rb

@@ -147,6 +147,9 @@ module UnicornEngine
 	UC_CTL_TLB_TYPE = 12
 	UC_CTL_TCG_BUFFER_SIZE = 13
 	UC_CTL_CONTEXT_MODE = 14
+	UC_CTL_PAUTH_SIGN = 15
+	UC_CTL_PAUTH_STRIP = 16
+	UC_CTL_PAUTH_AUTH = 17
 	UC_CTL_CONTEXT_CPU = 1
 	UC_CTL_CONTEXT_MEMORY = 2
 end

bindings/zig/unicorn/arm64_const.zig

@@ -335,4 +335,13 @@ pub const arm64Const = enum(c_int) {
 	ARM64_INS_WFI = 5,
 	ARM64_INS_ENDING = 6,
 
+// ARM64 PAuth keys
+
+	ARM64_PAUTH_KEY_IA = 0,
+	ARM64_PAUTH_KEY_IB = 1,
+	ARM64_PAUTH_KEY_DA = 2,
+	ARM64_PAUTH_KEY_DB = 3,
+	ARM64_PAUTH_KEY_GA = 4,
+	ARM64_PAUTH_KEY_ENDING = 5,
+
 };

bindings/zig/unicorn/unicorn_const.zig

@@ -147,6 +147,9 @@ pub const unicornConst = enum(c_int) {
 	CTL_TLB_TYPE = 12,
 	CTL_TCG_BUFFER_SIZE = 13,
 	CTL_CONTEXT_MODE = 14,
+	CTL_PAUTH_SIGN = 15,
+	CTL_PAUTH_STRIP = 16,
+	CTL_PAUTH_AUTH = 17,
 	CTL_CONTEXT_CPU = 1,
 	CTL_CONTEXT_MEMORY = 2,
 

include/uc_priv.h

@@ -157,6 +157,11 @@ typedef uc_tcg_flush_tlb uc_tb_flush_t;
 
 typedef uc_err (*uc_set_tlb_t)(struct uc_struct *uc, int mode);
 
+// PAuth sign and strip
+typedef uc_err (*uc_pauth_sign_t)(struct uc_struct *uc, uint64_t ptr, int key, uint64_t diversifier, uint64_t *signed_ptr);
+typedef uc_err (*uc_pauth_strip_t)(struct uc_struct *uc, uint64_t ptr, int key, uint64_t *stripped_ptr);
+typedef uc_err (*uc_pauth_auth_t)(struct uc_struct *uc, uint64_t ptr, int key, uint64_t diversifier, bool *valid);
+
 struct hook {
     int type;       // UC_HOOK_*
     int insn;       // instruction for HOOK_INSN
@@ -313,6 +318,9 @@ struct uc_struct {
     uc_tb_flush_t tb_flush;
     uc_add_inline_hook_t add_inline_hook;
     uc_del_inline_hook_t del_inline_hook;
+    uc_pauth_sign_t pauth_sign;
+    uc_pauth_strip_t pauth_strip;
+    uc_pauth_auth_t pauth_auth;
 
     uc_context_size_t context_size;
     uc_context_save_t context_save;

include/unicorn/arm64.h

@@ -387,6 +387,16 @@ typedef enum uc_arm64_insn {
     UC_ARM64_INS_ENDING
 } uc_arm64_insn;
 
+//> ARM64 PAuth keys
+typedef enum uc_arm64_pauth_key {
+    UC_ARM64_PAUTH_KEY_IA = 0,
+    UC_ARM64_PAUTH_KEY_IB,
+    UC_ARM64_PAUTH_KEY_DA,
+    UC_ARM64_PAUTH_KEY_DB,
+    UC_ARM64_PAUTH_KEY_GA,
+    UC_ARM64_PAUTH_KEY_ENDING,
+} uc_arm64_pauth_key;
+
 #ifdef __cplusplus
 }
 #endif

include/unicorn/unicorn.h

@@ -605,6 +605,46 @@ typedef enum uc_control_type {
     // controle if context_save/restore should work with snapshots
     // Write: @args = (int)
     UC_CTL_CONTEXT_MODE,
+
+    // Sign a pointer with a given architecture-specific key and a diversifier
+    // (also known as modifier, extra data, or discriminator).  If the key is
+    // currently disabled, the operation returns the unsigned ptr.
+    // ABI-specific string hashing or address blending is up to the caller to
+    // implement.
+    //
+    // Pointer authentication needs to have been set up properly beforehand.
+    // Depending on architecture, current CPU state may determine pointer
+    // layout and other aspects of the operation not explicitly specified as
+    // parameters.
+    //
+    // Read/write: @args = (uint64_t ptr, int key, uint64_t diversifier,
+    //                      uint64_t *signed_ptr)
+    UC_CTL_PAUTH_SIGN,
+
+    // Strip a possibly signed pointer of all PAC bits without authenticating,
+    // returning an unsigned pointer.
+    //
+    // Pointer authentication needs to have been set up properly beforehand.
+    // Depending on architecture, current CPU state may determine pointer
+    // layout and other aspects of the operation not explicitly specified as
+    // parameters.
+    //
+    // Read/write: @args = (uint64_t ptr, int key, uint64_t *stripped_ptr)
+    UC_CTL_PAUTH_STRIP,
+
+    // Authenticate a signed pointer with a given architecture-specific key and
+    // diversifier (also known as modifier, extra data, or discriminator).
+    // ABI-specific string hashing or address blending is up to the caller to
+    // implement.
+    //
+    // Pointer authentication needs to have been set up properly beforehand.
+    // Depending on architecture, current CPU state may determine pointer
+    // layout and other aspects of the operation not explicitly specified as
+    // parameters.
+    //
+    // Read/write: @args = (uint64_t ptr, int key, uint64_t diversifier,
+    //                      bool *valid)
+    UC_CTL_PAUTH_AUTH,
 } uc_control_type;
 
 /*
@@ -688,6 +728,12 @@ See sample_ctl.c for a detailed example.
     uc_ctl(uc, UC_CTL_WRITE(UC_CTL_TCG_BUFFER_SIZE, 1), (size))
 #define uc_ctl_context_mode(uc, mode)                                          \
     uc_ctl(uc, UC_CTL_WRITE(UC_CTL_CONTEXT_MODE, 1), (mode))
+#define uc_ctl_pauth_sign(uc, ptr, key, diversifier, signed_ptr)               \
+    uc_ctl(uc, UC_CTL_READ_WRITE(UC_CTL_PAUTH_SIGN, 4), (uint64_t)(ptr), (int)(key), (uint64_t)(diversifier), (uint64_t *)(signed_ptr))
+#define uc_ctl_pauth_strip(uc, ptr, key, stripped_ptr)                         \
+    uc_ctl(uc, UC_CTL_READ_WRITE(UC_CTL_PAUTH_STRIP, 3), (uint64_t)(ptr), (int)(key), (uint64_t *)(stripped_ptr))
+#define uc_ctl_pauth_auth(uc, ptr, key, diversifier, valid)                    \
+    uc_ctl(uc, UC_CTL_READ_WRITE(UC_CTL_PAUTH_AUTH, 4), (uint64_t)(ptr), (int)(key), (uint64_t)(diversifier), (uint64_t *)(valid))
 
 // Opaque storage for CPU context, used with uc_context_*()
 struct uc_context;

qemu/target/arm/pauth_helper.c

@@ -492,3 +492,33 @@ uint64_t HELPER(xpacd)(CPUARMState *env, uint64_t a)
 {
     return pauth_strip(env, a, true);
 }
+
+uint64_t _uc_pauth_sign(CPUARMState *env, uint64_t ptr, uint64_t diversifier, uint32_t sctlr_bit, ARMPACKey *key, bool data)
+{
+    int el = arm_current_el(env);
+    if (!pauth_key_enabled(env, el, sctlr_bit)) {
+        return ptr;
+    } else {
+        return pauth_addpac(env, ptr, diversifier, key, data);
+    }
+}
+
+uint64_t _uc_pauth_sign_ga(CPUARMState *env, uint64_t ptr, uint64_t diversifier)
+{
+    return pauth_computepac(ptr, diversifier, env->keys.apga) & 0xffffffff00000000ull;
+}
+
+uint64_t _uc_pauth_strip(CPUARMState *env, uint64_t ptr, bool data)
+{
+    return pauth_strip(env, ptr, data);
+}
+
+bool _uc_pauth_auth(CPUARMState *env, uint64_t ptr, uint64_t diversifier, uint32_t sctlr_bit, ARMPACKey *key, bool data)
+{
+    int el = arm_current_el(env);
+    if (!pauth_key_enabled(env, el, sctlr_bit)) {
+        return false;
+    }
+    uint64_t maybe_corrupted_ptr = pauth_auth(env, ptr, diversifier, key, data, 0);
+    return maybe_corrupted_ptr == pauth_strip(env, ptr, data);
+}