diff --git a/Cargo.toml b/Cargo.toml
index e2835e252..e095f9efc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -110,10 +110,12 @@ include = [
     "examples/**/*.rs",
     "include/ring-core/aes.h",
     "include/ring-core/arm_arch.h",
+    "include/ring-core/asm_base.h",
     "include/ring-core/base.h",
     "include/ring-core/check.h",
     "include/ring-core/mem.h",
     "include/ring-core/poly1305.h",
+    "include/ring-core/target.h",
     "include/ring-core/type_check.h",
     "src/**/*.rs",
     "src/aead/poly1305_test.txt",
diff --git a/crypto/curve25519/asm/x25519-asm-arm.S b/crypto/curve25519/asm/x25519-asm-arm.S
index 04d0362bd..8a51bb9bd 100644
--- a/crypto/curve25519/asm/x25519-asm-arm.S
+++ b/crypto/curve25519/asm/x25519-asm-arm.S
@@ -17,15 +17,9 @@
  * domain licensed but the standard ISC license is included above to keep
  * licensing simple. */
 
-#if defined(__has_feature)
-#if __has_feature(memory_sanitizer) && !defined(OPENSSL_NO_ASM)
-#define OPENSSL_NO_ASM
-#endif
-#endif
+#include <ring-core/asm_base.h>
 
-#if !defined(OPENSSL_NO_ASM) && defined(__ARMEL__) && defined(__ELF__)
-
-#include "ring_core_generated/prefix_symbols_asm.h"
+#if !defined(OPENSSL_NO_ASM) && defined(OPENSSL_ARM) && defined(__ELF__)
 
 .fpu neon
 .text
@@ -2127,8 +2121,4 @@ mov sp,r12
 vpop {q4,q5,q6,q7}
 bx lr
 
-#endif  /* !OPENSSL_NO_ASM && __ARMEL__ && __ELF__ */
-
-#if defined(__ELF__)
-.section	.note.GNU-stack,"",%progbits
-#endif
+#endif  /* !OPENSSL_NO_ASM && OPENSSL_ARM && __ELF__ */
diff --git a/crypto/perlasm/arm-xlate.pl b/crypto/perlasm/arm-xlate.pl
index d15a0cb10..aa2f20f34 100755
--- a/crypto/perlasm/arm-xlate.pl
+++ b/crypto/perlasm/arm-xlate.pl
@@ -153,9 +153,9 @@ sub expand_line {
 
 my ($arch_defines, $target_defines);
 if ($flavour =~ /32/) {
-    $arch_defines = "defined(__ARMEL__)";
+    $arch_defines = "defined(OPENSSL_ARM)";
 } elsif ($flavour =~ /64/) {
-    $arch_defines = "defined(__AARCH64EL__)";
+    $arch_defines = "defined(OPENSSL_AARCH64)";
 } else {
     die "unknown architecture: $flavour";
 }
@@ -177,18 +177,11 @@ print <<___;
 // This file is generated from a similarly-named Perl script in the BoringSSL
 // source tree. Do not edit by hand.
 
-#if !defined(__has_feature)
-#define __has_feature(x) 0
-#endif
-#if __has_feature(memory_sanitizer) && !defined(OPENSSL_NO_ASM)
-#define OPENSSL_NO_ASM
-#endif
+#include <ring-core/asm_base.h>
 
 #if !defined(OPENSSL_NO_ASM) && $arch_defines && $target_defines
 ___
 
-print "#include \"ring_core_generated/prefix_symbols_asm.h\"\n";
-
 while(my $line=<>) {
 
     if ($line =~ m/^\s*(#|@|\/\/)/)	{ print $line; next; }
@@ -258,10 +251,6 @@ while(my $line=<>) {
 
 print <<___;
 #endif  // !OPENSSL_NO_ASM && $arch_defines && $target_defines
-#if defined(__ELF__)
-// See https://www.airs.com/blog/archives/518.
-.section .note.GNU-stack,"",\%progbits
-#endif
 ___
 
 close STDOUT or die "error closing STDOUT: $!";
diff --git a/crypto/perlasm/x86_64-xlate.pl b/crypto/perlasm/x86_64-xlate.pl
index 508cf4986..044a379da 100755
--- a/crypto/perlasm/x86_64-xlate.pl
+++ b/crypto/perlasm/x86_64-xlate.pl
@@ -1520,14 +1520,9 @@ if ($gas) {
         die "unknown target: $flavour";
     }
     print <<___;
-#if defined(__has_feature)
-#if __has_feature(memory_sanitizer) && !defined(OPENSSL_NO_ASM)
-#define OPENSSL_NO_ASM
-#endif
-#endif
+#include <ring-core/asm_base.h>
 
-#if defined(__x86_64__) && !defined(OPENSSL_NO_ASM) && $target
-#include "ring_core_generated/prefix_symbols_asm.h"
+#if !defined(OPENSSL_NO_ASM) && defined(OPENSSL_X86_64) && $target
 ___
 }
 
@@ -1623,13 +1618,7 @@ print "\n$current_segment\tENDS\n"	if ($current_segment && $masm);
 if ($masm) {
     print "END\n";
 } elsif ($gas) {
-    print <<___;
-#endif
-#if defined(__ELF__)
-// See https://www.airs.com/blog/archives/518.
-.section .note.GNU-stack,"",\%progbits
-#endif
-___
+    print "#endif\n";
 } elsif ($nasm) {
     print <<___;
 \%else
diff --git a/crypto/perlasm/x86asm.pl b/crypto/perlasm/x86asm.pl
index f0abfb518..59fc975f2 100644
--- a/crypto/perlasm/x86asm.pl
+++ b/crypto/perlasm/x86asm.pl
@@ -305,22 +305,13 @@ ___
         }
 
         print <<___;
-#if defined(__has_feature)
-#if __has_feature(memory_sanitizer) && !defined(OPENSSL_NO_ASM)
-#define OPENSSL_NO_ASM
-#endif
-#endif
+#include <ring-core/asm_base.h>
 
-#if !defined(OPENSSL_NO_ASM) && defined(__i386__) && $target
-#include "ring_core_generated/prefix_symbols_asm.h"
+#if !defined(OPENSSL_NO_ASM) && defined(OPENSSL_X86) && $target
 ___
         print @out;
         print <<___;
-#endif  // !defined(OPENSSL_NO_ASM) && defined(__i386__) && $target
-#if defined(__ELF__)
-// See https://www.airs.com/blog/archives/518.
-.section .note.GNU-stack,"",\%progbits
-#endif
+#endif  // !defined(OPENSSL_NO_ASM) && defined(OPENSSL_X86) && $target
 ___
     }
 }
diff --git a/crypto/poly1305/poly1305_arm_asm.S b/crypto/poly1305/poly1305_arm_asm.S
index 93f46e811..df464d068 100644
--- a/crypto/poly1305/poly1305_arm_asm.S
+++ b/crypto/poly1305/poly1305_arm_asm.S
@@ -1,15 +1,9 @@
-#if defined(__has_feature)
-#if __has_feature(memory_sanitizer) && !defined(OPENSSL_NO_ASM)
-#define OPENSSL_NO_ASM
-#endif
-#endif
+#include <ring-core/asm_base.h>
 
-#if defined(__ARMEL__) && !defined(OPENSSL_NO_ASM) && defined(__ELF__)
+#if !defined(OPENSSL_NO_ASM) && defined(OPENSSL_ARM) && defined(__ELF__)
 
 #pragma GCC diagnostic ignored "-Wlanguage-extension-token"
 
-#include "ring_core_generated/prefix_symbols_asm.h"
-
 # This implementation was taken from the public domain, neon2 version in
 # SUPERCOP by D. J. Bernstein and Peter Schwabe.
 
@@ -2022,8 +2016,4 @@ vst1.8 d4,[r0,: 64]
 add sp,sp,#0
 bx lr
 
-#endif  /* __ARMEL__ && !OPENSSL_NO_ASM && __ELF__ */
-
-#if defined(__ELF__)
-.section	.note.GNU-stack,"",%progbits
-#endif
+#endif  /* !OPENSSL_NO_ASM && OPENSSL_ARM && __ELF__ */
diff --git a/include/ring-core/arm_arch.h b/include/ring-core/arm_arch.h
index 77229ddc8..2fc0fc042 100644
--- a/include/ring-core/arm_arch.h
+++ b/include/ring-core/arm_arch.h
@@ -53,12 +53,13 @@
 #ifndef OPENSSL_HEADER_ARM_ARCH_H
 #define OPENSSL_HEADER_ARM_ARCH_H
 
+#include <ring-core/target.h>
+
 // arm_arch.h contains symbols used by ARM assembly, and the C code that calls
 // it. It is included as a public header to simplify the build, but is not
 // intended for external use.
 
-#if defined(__ARMEL__) || defined(_M_ARM) || defined(__AARCH64EL__) || \
-    defined(_M_ARM64)
+#if defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64)
 
 // ARMV7_NEON is true when a NEON unit is present in the current CPU.
 #define ARMV7_NEON (1 << 0)
@@ -91,124 +92,8 @@
 // will be included.
 #define __ARM_MAX_ARCH__ 8
 
-// Support macros for
-//   - Armv8.3-A Pointer Authentication and
-//   - Armv8.5-A Branch Target Identification
-// features which require emitting a .note.gnu.property section with the
-// appropriate architecture-dependent feature bits set.
-//
-// |AARCH64_SIGN_LINK_REGISTER| and |AARCH64_VALIDATE_LINK_REGISTER| expand to
-// PACIxSP and AUTIxSP, respectively. |AARCH64_SIGN_LINK_REGISTER| should be
-// used immediately before saving the LR register (x30) to the stack.
-// |AARCH64_VALIDATE_LINK_REGISTER| should be used immediately after restoring
-// it. Note |AARCH64_SIGN_LINK_REGISTER|'s modifications to LR must be undone
-// with |AARCH64_VALIDATE_LINK_REGISTER| before RET. The SP register must also
-// have the same value at the two points. For example:
-//
-//   .global f
-//   f:
-//     AARCH64_SIGN_LINK_REGISTER
-//     stp x29, x30, [sp, #-96]!
-//     mov x29, sp
-//     ...
-//     ldp x29, x30, [sp], #96
-//     AARCH64_VALIDATE_LINK_REGISTER
-//     ret
-//
-// |AARCH64_VALID_CALL_TARGET| expands to BTI 'c'. Either it, or
-// |AARCH64_SIGN_LINK_REGISTER|, must be used at every point that may be an
-// indirect call target. In particular, all symbols exported from a file must
-// begin with one of these macros. For example, a leaf function that does not
-// save LR can instead use |AARCH64_VALID_CALL_TARGET|:
-//
-//   .globl return_zero
-//   return_zero:
-//     AARCH64_VALID_CALL_TARGET
-//     mov x0, #0
-//     ret
-//
-// A non-leaf function which does not immediately save LR may need both macros
-// because |AARCH64_SIGN_LINK_REGISTER| appears late. For example, the function
-// may jump to an alternate implementation before setting up the stack:
-//
-//   .globl with_early_jump
-//   with_early_jump:
-//     AARCH64_VALID_CALL_TARGET
-//     cmp x0, #128
-//     b.lt .Lwith_early_jump_128
-//     AARCH64_SIGN_LINK_REGISTER
-//     stp x29, x30, [sp, #-96]!
-//     mov x29, sp
-//     ...
-//     ldp x29, x30, [sp], #96
-//     AARCH64_VALIDATE_LINK_REGISTER
-//     ret
-//
-//  .Lwith_early_jump_128:
-//     ...
-//     ret
-//
-// These annotations are only required with indirect calls. Private symbols that
-// are only the target of direct calls do not require annotations. Also note
-// that |AARCH64_VALID_CALL_TARGET| is only valid for indirect calls (BLR), not
-// indirect jumps (BR). Indirect jumps in assembly are currently not supported
-// and would require a macro for BTI 'j'.
-//
-// Although not necessary, it is safe to use these macros in 32-bit ARM
-// assembly. This may be used to simplify dual 32-bit and 64-bit files.
-//
-// References:
-// - "ELF for the Arm® 64-bit Architecture"
-//   https://github.com/ARM-software/abi-aa/blob/master/aaelf64/aaelf64.rst
-// - "Providing protection for complex software"
-//   https://developer.arm.com/architectures/learn-the-architecture/providing-protection-for-complex-software
-
-#if defined(__ARM_FEATURE_BTI_DEFAULT) && __ARM_FEATURE_BTI_DEFAULT == 1
-#define GNU_PROPERTY_AARCH64_BTI (1 << 0)   // Has Branch Target Identification
-#define AARCH64_VALID_CALL_TARGET hint #34  // BTI 'c'
-#else
-#define GNU_PROPERTY_AARCH64_BTI 0  // No Branch Target Identification
-#define AARCH64_VALID_CALL_TARGET
-#endif
-
-#if defined(__ARM_FEATURE_PAC_DEFAULT) && \
-    (__ARM_FEATURE_PAC_DEFAULT & 1) == 1  // Signed with A-key
-#define GNU_PROPERTY_AARCH64_POINTER_AUTH \
-  (1 << 1)                                       // Has Pointer Authentication
-#define AARCH64_SIGN_LINK_REGISTER hint #25      // PACIASP
-#define AARCH64_VALIDATE_LINK_REGISTER hint #29  // AUTIASP
-#elif defined(__ARM_FEATURE_PAC_DEFAULT) && \
-    (__ARM_FEATURE_PAC_DEFAULT & 2) == 2  // Signed with B-key
-#define GNU_PROPERTY_AARCH64_POINTER_AUTH \
-  (1 << 1)                                       // Has Pointer Authentication
-#define AARCH64_SIGN_LINK_REGISTER hint #27      // PACIBSP
-#define AARCH64_VALIDATE_LINK_REGISTER hint #31  // AUTIBSP
-#else
-#define GNU_PROPERTY_AARCH64_POINTER_AUTH 0  // No Pointer Authentication
-#if GNU_PROPERTY_AARCH64_BTI != 0
-#define AARCH64_SIGN_LINK_REGISTER AARCH64_VALID_CALL_TARGET
-#else
-#define AARCH64_SIGN_LINK_REGISTER
-#endif
-#define AARCH64_VALIDATE_LINK_REGISTER
-#endif
-
-#if GNU_PROPERTY_AARCH64_POINTER_AUTH != 0 || GNU_PROPERTY_AARCH64_BTI != 0
-.pushsection .note.gnu.property, "a";
-.balign 8;
-.long 4;
-.long 0x10;
-.long 0x5;
-.asciz "GNU";
-.long 0xc0000000; /* GNU_PROPERTY_AARCH64_FEATURE_1_AND */
-.long 4;
-.long (GNU_PROPERTY_AARCH64_POINTER_AUTH | GNU_PROPERTY_AARCH64_BTI);
-.long 0;
-.popsection;
-#endif
-
 #endif  // __ASSEMBLER__
 
-#endif  // __ARMEL__ || _M_ARM || __AARCH64EL__ || _M_ARM64
+#endif  // ARM || AARCH64
 
 #endif  // OPENSSL_HEADER_ARM_ARCH_H
diff --git a/include/ring-core/asm_base.h b/include/ring-core/asm_base.h
new file mode 100644
index 000000000..c905e998c
--- /dev/null
+++ b/include/ring-core/asm_base.h
@@ -0,0 +1,186 @@
+/* Copyright (c) 2023, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#ifndef OPENSSL_HEADER_ASM_BASE_H
+#define OPENSSL_HEADER_ASM_BASE_H
+
+#include <ring-core/target.h>
+
+
+// This header contains symbols and common sections used by assembly files. It
+// is included as a public header to simplify the build, but is not intended for
+// external use.
+//
+// Every assembly file must include this header. Some linker features require
+// all object files to be tagged with some section metadata. This header file,
+// when included in assembly, adds that metadata. It also makes defines like
+// |OPENSSL_X86_64| available and includes the prefixing macros.
+//
+// Including this header in an assembly file imples:
+//
+// - The file does not require an executable stack.
+//
+// - The file, on aarch64, uses the macros defined below to be compatible with
+//   BTI and PAC.
+
+#if defined(__ASSEMBLER__)
+
+#include <ring_core_generated/prefix_symbols_asm.h>
+
+#if defined(__ELF__)
+// Every ELF object file, even empty ones, should disable executable stacks. See
+// https://www.airs.com/blog/archives/518.
+.pushsection .note.GNU-stack, "", %progbits
+.popsection
+#endif
+
+#if defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64)
+
+// We require the ARM assembler provide |__ARM_ARCH| from Arm C Language
+// Extensions (ACLE). This is supported in GCC 4.8+ and Clang 3.2+. MSVC does
+// not implement ACLE, but we require Clang's assembler on Windows.
+#if !defined(__ARM_ARCH)
+#error "ARM assembler must define __ARM_ARCH"
+#endif
+
+// __ARM_ARCH__ is used by OpenSSL assembly to determine the minimum target ARM
+// version.
+//
+// TODO(davidben): Switch the assembly to use |__ARM_ARCH| directly.
+#define __ARM_ARCH__ __ARM_ARCH
+
+// Even when building for 32-bit ARM, support for aarch64 crypto instructions
+// will be included.
+#define __ARM_MAX_ARCH__ 8
+
+// Support macros for
+//   - Armv8.3-A Pointer Authentication and
+//   - Armv8.5-A Branch Target Identification
+// features which require emitting a .note.gnu.property section with the
+// appropriate architecture-dependent feature bits set.
+//
+// |AARCH64_SIGN_LINK_REGISTER| and |AARCH64_VALIDATE_LINK_REGISTER| expand to
+// PACIxSP and AUTIxSP, respectively. |AARCH64_SIGN_LINK_REGISTER| should be
+// used immediately before saving the LR register (x30) to the stack.
+// |AARCH64_VALIDATE_LINK_REGISTER| should be used immediately after restoring
+// it. Note |AARCH64_SIGN_LINK_REGISTER|'s modifications to LR must be undone
+// with |AARCH64_VALIDATE_LINK_REGISTER| before RET. The SP register must also
+// have the same value at the two points. For example:
+//
+//   .global f
+//   f:
+//     AARCH64_SIGN_LINK_REGISTER
+//     stp x29, x30, [sp, #-96]!
+//     mov x29, sp
+//     ...
+//     ldp x29, x30, [sp], #96
+//     AARCH64_VALIDATE_LINK_REGISTER
+//     ret
+//
+// |AARCH64_VALID_CALL_TARGET| expands to BTI 'c'. Either it, or
+// |AARCH64_SIGN_LINK_REGISTER|, must be used at every point that may be an
+// indirect call target. In particular, all symbols exported from a file must
+// begin with one of these macros. For example, a leaf function that does not
+// save LR can instead use |AARCH64_VALID_CALL_TARGET|:
+//
+//   .globl return_zero
+//   return_zero:
+//     AARCH64_VALID_CALL_TARGET
+//     mov x0, #0
+//     ret
+//
+// A non-leaf function which does not immediately save LR may need both macros
+// because |AARCH64_SIGN_LINK_REGISTER| appears late. For example, the function
+// may jump to an alternate implementation before setting up the stack:
+//
+//   .globl with_early_jump
+//   with_early_jump:
+//     AARCH64_VALID_CALL_TARGET
+//     cmp x0, #128
+//     b.lt .Lwith_early_jump_128
+//     AARCH64_SIGN_LINK_REGISTER
+//     stp x29, x30, [sp, #-96]!
+//     mov x29, sp
+//     ...
+//     ldp x29, x30, [sp], #96
+//     AARCH64_VALIDATE_LINK_REGISTER
+//     ret
+//
+//  .Lwith_early_jump_128:
+//     ...
+//     ret
+//
+// These annotations are only required with indirect calls. Private symbols that
+// are only the target of direct calls do not require annotations. Also note
+// that |AARCH64_VALID_CALL_TARGET| is only valid for indirect calls (BLR), not
+// indirect jumps (BR). Indirect jumps in assembly are currently not supported
+// and would require a macro for BTI 'j'.
+//
+// Although not necessary, it is safe to use these macros in 32-bit ARM
+// assembly. This may be used to simplify dual 32-bit and 64-bit files.
+//
+// References:
+// - "ELF for the Arm® 64-bit Architecture"
+//   https://github.com/ARM-software/abi-aa/blob/master/aaelf64/aaelf64.rst
+// - "Providing protection for complex software"
+//   https://developer.arm.com/architectures/learn-the-architecture/providing-protection-for-complex-software
+
+#if defined(__ARM_FEATURE_BTI_DEFAULT) && __ARM_FEATURE_BTI_DEFAULT == 1
+#define GNU_PROPERTY_AARCH64_BTI (1 << 0)   // Has Branch Target Identification
+#define AARCH64_VALID_CALL_TARGET hint #34  // BTI 'c'
+#else
+#define GNU_PROPERTY_AARCH64_BTI 0  // No Branch Target Identification
+#define AARCH64_VALID_CALL_TARGET
+#endif
+
+#if defined(__ARM_FEATURE_PAC_DEFAULT) && \
+    (__ARM_FEATURE_PAC_DEFAULT & 1) == 1  // Signed with A-key
+#define GNU_PROPERTY_AARCH64_POINTER_AUTH \
+  (1 << 1)                                       // Has Pointer Authentication
+#define AARCH64_SIGN_LINK_REGISTER hint #25      // PACIASP
+#define AARCH64_VALIDATE_LINK_REGISTER hint #29  // AUTIASP
+#elif defined(__ARM_FEATURE_PAC_DEFAULT) && \
+    (__ARM_FEATURE_PAC_DEFAULT & 2) == 2  // Signed with B-key
+#define GNU_PROPERTY_AARCH64_POINTER_AUTH \
+  (1 << 1)                                       // Has Pointer Authentication
+#define AARCH64_SIGN_LINK_REGISTER hint #27      // PACIBSP
+#define AARCH64_VALIDATE_LINK_REGISTER hint #31  // AUTIBSP
+#else
+#define GNU_PROPERTY_AARCH64_POINTER_AUTH 0  // No Pointer Authentication
+#if GNU_PROPERTY_AARCH64_BTI != 0
+#define AARCH64_SIGN_LINK_REGISTER AARCH64_VALID_CALL_TARGET
+#else
+#define AARCH64_SIGN_LINK_REGISTER
+#endif
+#define AARCH64_VALIDATE_LINK_REGISTER
+#endif
+
+#if GNU_PROPERTY_AARCH64_POINTER_AUTH != 0 || GNU_PROPERTY_AARCH64_BTI != 0
+.pushsection .note.gnu.property, "a";
+.balign 8;
+.long 4;
+.long 0x10;
+.long 0x5;
+.asciz "GNU";
+.long 0xc0000000; /* GNU_PROPERTY_AARCH64_FEATURE_1_AND */
+.long 4;
+.long (GNU_PROPERTY_AARCH64_POINTER_AUTH | GNU_PROPERTY_AARCH64_BTI);
+.long 0;
+.popsection;
+#endif
+#endif  // ARM || AARCH64
+
+#endif  // __ASSEMBLER__
+
+#endif  // OPENSSL_HEADER_ASM_BASE_H
diff --git a/include/ring-core/base.h b/include/ring-core/base.h
index f1a027d1a..938c5b8c5 100644
--- a/include/ring-core/base.h
+++ b/include/ring-core/base.h
@@ -56,10 +56,6 @@
 
 // This file should be the first included by all BoringSSL headers.
 
-#include <ring_core_generated/prefix_symbols.h>
-
-#include <ring-core/type_check.h>
-
 #if defined(_MSC_VER) && !defined(__clang__)
 #pragma warning(push, 3)
 #endif
@@ -71,40 +67,25 @@
 #pragma warning(pop)
 #endif
 
-#if defined(__x86_64) || defined(_M_AMD64) || defined(_M_X64)
-#define OPENSSL_64_BIT
-#define OPENSSL_X86_64
-#elif defined(__x86) || defined(__i386) || defined(__i386__) || defined(_M_IX86)
-#define OPENSSL_32_BIT
-#define OPENSSL_X86
-#elif defined(__AARCH64EL__) || defined(_M_ARM64)
-#define OPENSSL_64_BIT
-#define OPENSSL_AARCH64
-#elif defined(__ARMEL__) || defined(_M_ARM)
-#define OPENSSL_32_BIT
-#define OPENSSL_ARM
-#elif defined(__MIPSEL__) && !defined(__LP64__)
-#define OPENSSL_32_BIT
-#define OPENSSL_MIPS
-#elif defined(__MIPSEL__) && defined(__LP64__)
-#define OPENSSL_64_BIT
-#define OPENSSL_MIPS64
-#elif defined(__wasm__)
-#define OPENSSL_32_BIT
-#else
-// Note BoringSSL only supports standard 32-bit and 64-bit two's-complement,
-// little-endian architectures. Functions will not produce the correct answer
-// on other systems. Run the crypto_test binary, notably
-// crypto/compiler_test.cc, before adding a new architecture.
-#error "Unknown target CPU"
+#if defined(__APPLE__)
+#include <TargetConditionals.h>
 #endif
 
+#include <ring-core/target.h>  // IWYU pragma: export
+
+#include <ring_core_generated/prefix_symbols.h>
+
+#include <ring-core/type_check.h>
+
 #if defined(__APPLE__)
-#define OPENSSL_APPLE
+// Note |TARGET_OS_MAC| is set for all Apple OS variants. |TARGET_OS_OSX|
+// targets macOS specifically.
+#if defined(TARGET_OS_OSX) && TARGET_OS_OSX
+#define OPENSSL_MACOS
+#endif
+#if defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE
+#define OPENSSL_IOS
 #endif
-
-#if defined(_WIN32)
-#define OPENSSL_WINDOWS
 #endif
 
 // *ring* doesn't support the `BORINGSSL_SHARED_LIBRARY` configuration, so
diff --git a/include/ring-core/target.h b/include/ring-core/target.h
new file mode 100644
index 000000000..0213d5c63
--- /dev/null
+++ b/include/ring-core/target.h
@@ -0,0 +1,139 @@
+/* Copyright (c) 2023, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#ifndef OPENSSL_HEADER_TARGET_H
+#define OPENSSL_HEADER_TARGET_H
+
+// Preprocessor symbols that define the target platform.
+//
+// This file may be included in C, C++, and assembler and must be compatible
+// with each environment. It is separated out only to share code between
+// <ring-core/base.h> and <ring-core/asm_base.h>. Prefer to include those headers
+// instead.
+
+#if defined(__x86_64) || defined(_M_AMD64) || defined(_M_X64)
+#define OPENSSL_64_BIT
+#define OPENSSL_X86_64
+#elif defined(__x86) || defined(__i386) || defined(__i386__) || defined(_M_IX86)
+#define OPENSSL_32_BIT
+#define OPENSSL_X86
+#elif defined(__AARCH64EL__) || defined(_M_ARM64)
+#define OPENSSL_64_BIT
+#define OPENSSL_AARCH64
+#elif defined(__ARMEL__) || defined(_M_ARM)
+#define OPENSSL_32_BIT
+#define OPENSSL_ARM
+#elif defined(__MIPSEL__) && !defined(__LP64__)
+#define OPENSSL_32_BIT
+#define OPENSSL_MIPS
+#elif defined(__MIPSEL__) && defined(__LP64__)
+#define OPENSSL_64_BIT
+#define OPENSSL_MIPS64
+#elif defined(__wasm__)
+#define OPENSSL_32_BIT
+#else
+// Note BoringSSL only supports standard 32-bit and 64-bit two's-complement,
+// little-endian architectures. Functions will not produce the correct answer
+// on other systems. Run the crypto_test binary, notably
+// crypto/compiler_test.cc, before adding a new architecture.
+#error "Unknown target CPU"
+#endif
+
+#if defined(__APPLE__)
+#define OPENSSL_APPLE
+#endif
+
+#if defined(_WIN32)
+#define OPENSSL_WINDOWS
+#endif
+
+// Trusty isn't Linux but currently defines __linux__. As a workaround, we
+// exclude it here.
+// TODO(b/169780122): Remove this workaround once Trusty no longer defines it.
+#if defined(__linux__) && !defined(__TRUSTY__)
+#define OPENSSL_LINUX
+#endif
+
+#if defined(__Fuchsia__)
+#define OPENSSL_FUCHSIA
+#endif
+
+#if defined(__TRUSTY__)
+#define OPENSSL_TRUSTY
+#define OPENSSL_NO_POSIX_IO
+#define OPENSSL_NO_SOCK
+#define OPENSSL_NO_THREADS_CORRUPT_MEMORY_AND_LEAK_SECRETS_IF_THREADED
+#endif
+
+#if defined(OPENSSL_NANOLIBC)
+#define OPENSSL_NO_POSIX_IO
+#define OPENSSL_NO_SOCK
+#define OPENSSL_NO_THREADS_CORRUPT_MEMORY_AND_LEAK_SECRETS_IF_THREADED
+#endif
+
+#if defined(__ANDROID_API__)
+#define OPENSSL_ANDROID
+#endif
+
+#if defined(__FreeBSD__)
+#define OPENSSL_FREEBSD
+#endif
+
+#if defined(__OpenBSD__)
+#define OPENSSL_OPENBSD
+#endif
+
+// BoringSSL requires platform's locking APIs to make internal global state
+// thread-safe, including the PRNG. On some single-threaded embedded platforms,
+// locking APIs may not exist, so this dependency may be disabled with the
+// following build flag.
+//
+// IMPORTANT: Doing so means the consumer promises the library will never be
+// used in any multi-threaded context. It causes BoringSSL to be globally
+// thread-unsafe. Setting it inappropriately will subtly and unpredictably
+// corrupt memory and leak secret keys.
+//
+// Do not set this flag on any platform where threads are possible. BoringSSL
+// maintainers will not provide support for any consumers that do so. Changes
+// which break such unsupported configurations will not be reverted.
+#if !defined(OPENSSL_NO_THREADS_CORRUPT_MEMORY_AND_LEAK_SECRETS_IF_THREADED)
+#define OPENSSL_THREADS
+#endif
+
+#if defined(BORINGSSL_UNSAFE_FUZZER_MODE) && \
+    !defined(BORINGSSL_UNSAFE_DETERMINISTIC_MODE)
+#define BORINGSSL_UNSAFE_DETERMINISTIC_MODE
+#endif
+
+#if defined(__has_feature)
+#if __has_feature(address_sanitizer)
+#define OPENSSL_ASAN
+#endif
+#if __has_feature(thread_sanitizer)
+#define OPENSSL_TSAN
+#endif
+#if __has_feature(memory_sanitizer)
+#define OPENSSL_MSAN
+#define OPENSSL_ASM_INCOMPATIBLE
+#endif
+#endif
+
+#if defined(OPENSSL_ASM_INCOMPATIBLE)
+#undef OPENSSL_ASM_INCOMPATIBLE
+#if !defined(OPENSSL_NO_ASM)
+#define OPENSSL_NO_ASM
+#endif
+#endif  // OPENSSL_ASM_INCOMPATIBLE
+
+#endif  // OPENSSL_HEADER_TARGET_H
diff --git a/include/ring-core/type_check.h b/include/ring-core/type_check.h
index d7e039345..67df7bc68 100644
--- a/include/ring-core/type_check.h
+++ b/include/ring-core/type_check.h
@@ -71,5 +71,4 @@
 #define OPENSSL_STATIC_ASSERT(cond, msg) _Static_assert(cond, msg)
 #endif
 
-
 #endif  // OPENSSL_HEADER_TYPE_CHECK_H
diff --git a/third_party/fiat/asm/fiat_curve25519_adx_mul.S b/third_party/fiat/asm/fiat_curve25519_adx_mul.S
index 28b174560..f4c70dd41 100644
--- a/third_party/fiat/asm/fiat_curve25519_adx_mul.S
+++ b/third_party/fiat/asm/fiat_curve25519_adx_mul.S
@@ -1,9 +1,7 @@
-#if !defined(OPENSSL_NO_ASM) && defined(__x86_64__) && \
-    (defined(__APPLE__) || defined(__ELF__))
+#include <ring-core/asm_base.h>
 
-#if defined(BORINGSSL_PREFIX)
-#include <boringssl_prefix_symbols_asm.h>
-#endif
+#if !defined(OPENSSL_NO_ASM) && defined(OPENSSL_X86_64) && \
+    (defined(__APPLE__) || defined(__ELF__))
 
 .intel_syntax noprefix
 .text
@@ -169,7 +167,3 @@ ret
 #endif
 
 #endif
-
-#if defined(__ELF__)
-.section	.note.GNU-stack,"",%progbits
-#endif
diff --git a/third_party/fiat/asm/fiat_curve25519_adx_square.S b/third_party/fiat/asm/fiat_curve25519_adx_square.S
index 88818217b..9b1fdb9cf 100644
--- a/third_party/fiat/asm/fiat_curve25519_adx_square.S
+++ b/third_party/fiat/asm/fiat_curve25519_adx_square.S
@@ -1,9 +1,7 @@
-#if !defined(OPENSSL_NO_ASM) && defined(__x86_64__) && \
-    (defined(__APPLE__) || defined(__ELF__))
+#include <ring-core/asm_base.h>
 
-#if defined(BORINGSSL_PREFIX)
-#include <boringssl_prefix_symbols_asm.h>
-#endif
+#if !defined(OPENSSL_NO_ASM) && defined(OPENSSL_X86_64) && \
+    (defined(__APPLE__) || defined(__ELF__))
 
 .intel_syntax noprefix
 .text
@@ -137,7 +135,3 @@ ret
 #endif
 
 #endif
-
-#if defined(__ELF__)
-.section	.note.GNU-stack,"",%progbits
-#endif