15 files changed, 30 insertions, 24 deletions

diff --git a/src/lib/libcrypto/bn/arch/amd64/bignum_add.S b/src/lib/libcrypto/bn/arch/amd64/bignum_add.S
index 06298ca69e..5fe4aae7a1 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_add.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_add.S
@@ -49,7 +49,7 @@
 
 
 S2N_BN_SYMBOL(bignum_add):
-        endbr64
+        _CET_ENDBR
 
 #if WINDOWS_ABI
         push    rdi
diff --git a/src/lib/libcrypto/bn/arch/amd64/bignum_cmadd.S b/src/lib/libcrypto/bn/arch/amd64/bignum_cmadd.S
index 5ad712749f..25ba17bce2 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_cmadd.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_cmadd.S
@@ -54,7 +54,7 @@
 
 
 S2N_BN_SYMBOL(bignum_cmadd):
-        endbr64
+        _CET_ENDBR
 
 #if WINDOWS_ABI
         push    rdi
diff --git a/src/lib/libcrypto/bn/arch/amd64/bignum_cmul.S b/src/lib/libcrypto/bn/arch/amd64/bignum_cmul.S
index 9199c8f48b..12f785d63a 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_cmul.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_cmul.S
@@ -51,7 +51,7 @@
 
 
 S2N_BN_SYMBOL(bignum_cmul):
-        endbr64
+        _CET_ENDBR
 
 #if WINDOWS_ABI
         push    rdi
diff --git a/src/lib/libcrypto/bn/arch/amd64/bignum_mul.S b/src/lib/libcrypto/bn/arch/amd64/bignum_mul.S
index 2d7ed19091..a3552679a2 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_mul.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_mul.S
@@ -59,7 +59,7 @@
 
 
 S2N_BN_SYMBOL(bignum_mul):
-        endbr64
+        _CET_ENDBR
 
 #if WINDOWS_ABI
         push    rdi
diff --git a/src/lib/libcrypto/bn/arch/amd64/bignum_mul_4_8_alt.S b/src/lib/libcrypto/bn/arch/amd64/bignum_mul_4_8_alt.S
index f02b09b288..70ff69e372 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_mul_4_8_alt.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_mul_4_8_alt.S
@@ -72,7 +72,7 @@
         adc     h, rdx
 
 S2N_BN_SYMBOL(bignum_mul_4_8_alt):
-        endbr64
+        _CET_ENDBR
 
 #if WINDOWS_ABI
         push    rdi
diff --git a/src/lib/libcrypto/bn/arch/amd64/bignum_mul_8_16_alt.S b/src/lib/libcrypto/bn/arch/amd64/bignum_mul_8_16_alt.S
index 97be83e1f7..066403b074 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_mul_8_16_alt.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_mul_8_16_alt.S
@@ -72,7 +72,7 @@
         adc     h, rdx
 
 S2N_BN_SYMBOL(bignum_mul_8_16_alt):
-        endbr64
+        _CET_ENDBR
 
 #if WINDOWS_ABI
         push    rdi
diff --git a/src/lib/libcrypto/bn/arch/amd64/bignum_sqr.S b/src/lib/libcrypto/bn/arch/amd64/bignum_sqr.S
index c4a0cabf35..54e3f59442 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_sqr.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_sqr.S
@@ -62,7 +62,7 @@
 #define llshort ebp
 
 S2N_BN_SYMBOL(bignum_sqr):
-        endbr64
+        _CET_ENDBR
 
 #if WINDOWS_ABI
         push    rdi
diff --git a/src/lib/libcrypto/bn/arch/amd64/bignum_sqr_4_8_alt.S b/src/lib/libcrypto/bn/arch/amd64/bignum_sqr_4_8_alt.S
index b228414dce..7c534ae907 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_sqr_4_8_alt.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_sqr_4_8_alt.S
@@ -71,7 +71,7 @@
         adc     c, 0
 
 S2N_BN_SYMBOL(bignum_sqr_4_8_alt):
-        endbr64
+        _CET_ENDBR
 
 #if WINDOWS_ABI
         push    rdi
diff --git a/src/lib/libcrypto/bn/arch/amd64/bignum_sqr_8_16_alt.S b/src/lib/libcrypto/bn/arch/amd64/bignum_sqr_8_16_alt.S
index 04efeec7e2..ac0b6f96c2 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_sqr_8_16_alt.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_sqr_8_16_alt.S
@@ -103,7 +103,7 @@
         adc     c, 0
 
 S2N_BN_SYMBOL(bignum_sqr_8_16_alt):
-        endbr64
+        _CET_ENDBR
 
 #if WINDOWS_ABI
         push    rdi
diff --git a/src/lib/libcrypto/bn/arch/amd64/bignum_sub.S b/src/lib/libcrypto/bn/arch/amd64/bignum_sub.S
index 11a9bd7edd..3ff8a30510 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_sub.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_sub.S
@@ -49,7 +49,7 @@
 
 
 S2N_BN_SYMBOL(bignum_sub):
-        endbr64
+        _CET_ENDBR
 
 #if WINDOWS_ABI
         push    rdi
diff --git a/src/lib/libcrypto/bn/arch/amd64/word_clz.S b/src/lib/libcrypto/bn/arch/amd64/word_clz.S
index 464a9d90fc..3926fcd4b0 100644
--- a/src/lib/libcrypto/bn/arch/amd64/word_clz.S
+++ b/src/lib/libcrypto/bn/arch/amd64/word_clz.S
@@ -30,7 +30,7 @@
         .text
 
 S2N_BN_SYMBOL(word_clz):
-        endbr64
+        _CET_ENDBR
 
 #if WINDOWS_ABI
         push    rdi
diff --git a/src/lib/libcrypto/bn/asm/modexp512-x86_64.pl b/src/lib/libcrypto/bn/asm/modexp512-x86_64.pl
index af78fff541..8645d5adcc 100644
--- a/src/lib/libcrypto/bn/asm/modexp512-x86_64.pl
+++ b/src/lib/libcrypto/bn/asm/modexp512-x86_64.pl
@@ -347,7 +347,7 @@ $code.=<<___;
 .type   MULADD_128x512,\@abi-omnipotent
 .align  16
 MULADD_128x512:
-        endbr64
+        _CET_ENDBR
 ___
         &MULSTEP_512([map("%r$_",(8..15))], "(+8*0)(%rcx)", "%rsi", "%rbp", "%rbx");
 $code.=<<___;
@@ -415,7 +415,7 @@ $code.=<<___;
 .type   mont_reduce,\@abi-omnipotent
 .align  16
 mont_reduce:
-        endbr64
+        _CET_ENDBR
 ___
 
 my $STACK_DEPTH         =  8;
@@ -678,7 +678,7 @@ $code.=<<___;
 .type   mont_mul_a3b,\@abi-omnipotent
 .align  16
 mont_mul_a3b:
-        endbr64
+        _CET_ENDBR
         #
         # multiply tmp = src1 * src2
         # For multiply: dst = rcx, src1 = rdi, src2 = rsi
@@ -1080,7 +1080,7 @@ $code.=<<___;
 .type   sqr_reduce,\@abi-omnipotent
 .align  16
 sqr_reduce:
-        endbr64
+        _CET_ENDBR
          mov    (+$pResult_offset+8)(%rsp), %rcx
 ___
         &SQR_512("%rsp+$tmp16_offset+8", "%rcx", [map("%r$_",(10..15,8..9))], "%rbx", "%rbp", "%rsi", "%rdi");
@@ -1110,7 +1110,7 @@ $code.=<<___;
 .globl  mod_exp_512
 .type   mod_exp_512,\@function,4
 mod_exp_512:
-        endbr64
+        _CET_ENDBR
          push   %rbp
          push   %rbx
          push   %r12
diff --git a/src/lib/libcrypto/bn/asm/x86_64-mont.pl b/src/lib/libcrypto/bn/asm/x86_64-mont.pl
index 6f5ab331e2..30cfab4fce 100755
--- a/src/lib/libcrypto/bn/asm/x86_64-mont.pl
+++ b/src/lib/libcrypto/bn/asm/x86_64-mont.pl
@@ -63,7 +63,7 @@ $code=<<___;
 .type   bn_mul_mont,\@function,6
 .align  16
 bn_mul_mont:
-        endbr64
+        _CET_ENDBR
         test    \$3,${num}d
         jnz     .Lmul_enter
         cmp     \$8,${num}d
@@ -279,7 +279,7 @@ $code.=<<___;
 .align  16
 bn_mul4x_mont:
 .Lmul4x_enter:
-        endbr64
+        _CET_ENDBR
         push    %rbx
         push    %rbp
         push    %r12
@@ -707,7 +707,7 @@ $code.=<<___;
 .align  16
 bn_sqr4x_mont:
 .Lsqr4x_enter:
-        endbr64
+        _CET_ENDBR
         push    %rbx
         push    %rbp
         push    %r12
diff --git a/src/lib/libcrypto/bn/asm/x86_64-mont5.pl b/src/lib/libcrypto/bn/asm/x86_64-mont5.pl
index 3b3325a6cc..38751ec5de 100755
--- a/src/lib/libcrypto/bn/asm/x86_64-mont5.pl
+++ b/src/lib/libcrypto/bn/asm/x86_64-mont5.pl
@@ -57,7 +57,7 @@ $code=<<___;
 .type   bn_mul_mont_gather5,\@function,6
 .align  64
 bn_mul_mont_gather5:
-        endbr64
+        _CET_ENDBR
         test    \$3,${num}d
         jnz     .Lmul_enter
         cmp     \$8,${num}d
@@ -388,7 +388,7 @@ $code.=<<___;
 .type   bn_mul4x_mont_gather5,\@function,6
 .align  16
 bn_mul4x_mont_gather5:
-        endbr64
+        _CET_ENDBR
 .Lmul4x_enter:
         mov     ${num}d,${num}d
         movd    `($win64?56:8)`(%rsp),%xmm5     # load 7th argument
@@ -927,7 +927,7 @@ $code.=<<___;
 .type   bn_scatter5,\@abi-omnipotent
 .align  16
 bn_scatter5:
-        endbr64
+        _CET_ENDBR
         cmp     \$0, $num
         jz      .Lscatter_epilogue
         lea     ($tbl,$idx,8),$tbl
@@ -946,7 +946,7 @@ bn_scatter5:
 .type   bn_gather5,\@abi-omnipotent
 .align  16
 bn_gather5:
-        endbr64
+        _CET_ENDBR
 .LSEH_begin_bn_gather5:                 # Win64 thing, but harmless in other cases
         # I can't trust assembler to use specific encoding:-(
         .byte   0x4c,0x8d,0x14,0x24                     # lea    (%rsp),%r10
@@ -1057,7 +1057,7 @@ $code.=<<___;
 .type   mul_handler,\@abi-omnipotent
 .align  16
 mul_handler:
-        endbr64
+        _CET_ENDBR
         push    %rsi
         push    %rdi
         push    %rbx
diff --git a/src/lib/libcrypto/bn/s2n_bignum_internal.h b/src/lib/libcrypto/bn/s2n_bignum_internal.h
index f413688338..b82db7d019 100644
--- a/src/lib/libcrypto/bn/s2n_bignum_internal.h
+++ b/src/lib/libcrypto/bn/s2n_bignum_internal.h
@@ -18,6 +18,12 @@
 #   define S2N_BN_SYMBOL(name) name
 #endif
 
+#ifdef __CET__
+#   include <cet.h>
+#else
+#   define _CET_ENDBR
+#endif
+
 #define S2N_BN_SYM_VISIBILITY_DIRECTIVE(name) .globl S2N_BN_SYMBOL(name)
 #ifdef S2N_BN_HIDE_SYMBOLS
 #   ifdef __APPLE__