28 files changed, 113 insertions, 1 deletions

diff --git a/src/lib/libcrypto/aes/asm/aes-x86_64.pl b/src/lib/libcrypto/aes/asm/aes-x86_64.pl
index b7399b552a..78ba20ca59 100755
--- a/src/lib/libcrypto/aes/asm/aes-x86_64.pl
+++ b/src/lib/libcrypto/aes/asm/aes-x86_64.pl
@@ -318,6 +318,7 @@ $code.=<<___;
 .type   _x86_64_AES_encrypt,\@abi-omnipotent
 .align  16
 _x86_64_AES_encrypt:
+        endbr64
         xor     0($key),$s0                     # xor with key
         xor     4($key),$s1
         xor     8($key),$s2
@@ -548,6 +549,7 @@ $code.=<<___;
 .type   _x86_64_AES_encrypt_compact,\@abi-omnipotent
 .align  16
 _x86_64_AES_encrypt_compact:
+        endbr64
         lea     128($sbox),$inp                 # size optimization
         mov     0-128($inp),$acc1               # prefetch Te4
         mov     32-128($inp),$acc2
@@ -593,6 +595,7 @@ $code.=<<___;
 .hidden asm_AES_encrypt
 asm_AES_encrypt:
 AES_encrypt:
+        endbr64
         push    %rbx
         push    %rbp
         push    %r12
@@ -884,6 +887,7 @@ $code.=<<___;
 .type   _x86_64_AES_decrypt,\@abi-omnipotent
 .align  16
 _x86_64_AES_decrypt:
+        endbr64
         xor     0($key),$s0                     # xor with key
         xor     4($key),$s1
         xor     8($key),$s2
@@ -1138,6 +1142,7 @@ $code.=<<___;
 .type   _x86_64_AES_decrypt_compact,\@abi-omnipotent
 .align  16
 _x86_64_AES_decrypt_compact:
+        endbr64
         lea     128($sbox),$inp                 # size optimization
         mov     0-128($inp),$acc1               # prefetch Td4
         mov     32-128($inp),$acc2
@@ -1192,6 +1197,7 @@ $code.=<<___;
 .hidden asm_AES_decrypt
 asm_AES_decrypt:
 AES_decrypt:
+        endbr64
         push    %rbx
         push    %rbp
         push    %r12
@@ -1291,6 +1297,7 @@ $code.=<<___;
 .type   AES_set_encrypt_key,\@function,3
 .align  16
 AES_set_encrypt_key:
+        endbr64
         push    %rbx
         push    %rbp
         push    %r12                    # redundant, but allows to share 
@@ -1316,6 +1323,7 @@ AES_set_encrypt_key:
 .type   _x86_64_AES_set_encrypt_key,\@abi-omnipotent
 .align  16
 _x86_64_AES_set_encrypt_key:
+        endbr64
         mov     %esi,%ecx                       # %ecx=bits
         mov     %rdi,%rsi                       # %rsi=userKey
         mov     %rdx,%rdi                       # %rdi=key
@@ -1561,6 +1569,7 @@ $code.=<<___;
 .type   AES_set_decrypt_key,\@function,3
 .align  16
 AES_set_decrypt_key:
+        endbr64
         push    %rbx
         push    %rbp
         push    %r12
@@ -1660,6 +1669,7 @@ $code.=<<___;
 .hidden asm_AES_cbc_encrypt
 asm_AES_cbc_encrypt:
 AES_cbc_encrypt:
+        endbr64
         cmp     \$0,%rdx        # check length
         je      .Lcbc_epilogue
         pushfq
@@ -2551,6 +2561,7 @@ $code.=<<___;
 .type   block_se_handler,\@abi-omnipotent
 .align  16
 block_se_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
@@ -2609,6 +2620,7 @@ block_se_handler:
 .type   key_se_handler,\@abi-omnipotent
 .align  16
 key_se_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
@@ -2666,6 +2678,7 @@ key_se_handler:
 .type   cbc_se_handler,\@abi-omnipotent
 .align  16
 cbc_se_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
diff --git a/src/lib/libcrypto/aes/asm/aesni-sha1-x86_64.pl b/src/lib/libcrypto/aes/asm/aesni-sha1-x86_64.pl
index bafa906a05..879d16793f 100644
--- a/src/lib/libcrypto/aes/asm/aesni-sha1-x86_64.pl
+++ b/src/lib/libcrypto/aes/asm/aesni-sha1-x86_64.pl
@@ -89,6 +89,7 @@ $code.=<<___;
 .type   aesni_cbc_sha1_enc,\@abi-omnipotent
 .align  16
 aesni_cbc_sha1_enc:
+        endbr64
         # caller should check for SSSE3 and AES-NI bits
         mov     OPENSSL_ia32cap_P+0(%rip),%r10d
         mov     OPENSSL_ia32cap_P+4(%rip),%r11d
@@ -132,6 +133,7 @@ $code.=<<___;
 .type   aesni_cbc_sha1_enc_ssse3,\@function,6
 .align  16
 aesni_cbc_sha1_enc_ssse3:
+        endbr64
         mov     `($win64?56:8)`(%rsp),$inp      # load 7th argument
         #shr    \$6,$len                        # debugging artefact
         #jz     .Lepilogue_ssse3                # debugging artefact
@@ -650,6 +652,7 @@ $code.=<<___;
 .type   aesni_cbc_sha1_enc_avx,\@function,6
 .align  16
 aesni_cbc_sha1_enc_avx:
+        endbr64
         mov     `($win64?56:8)`(%rsp),$inp      # load 7th argument
         #shr    \$6,$len                        # debugging artefact
         #jz     .Lepilogue_avx                  # debugging artefact
@@ -1100,6 +1103,7 @@ $code.=<<___;
 .type   ssse3_handler,\@abi-omnipotent
 .align  16
 ssse3_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
diff --git a/src/lib/libcrypto/aes/asm/aesni-x86_64.pl b/src/lib/libcrypto/aes/asm/aesni-x86_64.pl
index d394e6f696..c261a37958 100644
--- a/src/lib/libcrypto/aes/asm/aesni-x86_64.pl
+++ b/src/lib/libcrypto/aes/asm/aesni-x86_64.pl
@@ -242,6 +242,7 @@ $code.=<<___;
 .type   ${PREFIX}_encrypt,\@abi-omnipotent
 .align  16
 ${PREFIX}_encrypt:
+        endbr64
         movups  ($inp),$inout0          # load input
         mov     240($key),$rounds       # key->rounds
 ___
@@ -255,6 +256,7 @@ $code.=<<___;
 .type   ${PREFIX}_decrypt,\@abi-omnipotent
 .align  16
 ${PREFIX}_decrypt:
+        endbr64
         movups  ($inp),$inout0          # load input
         mov     240($key),$rounds       # key->rounds
 ___
@@ -284,6 +286,7 @@ $code.=<<___;
 .type   _aesni_${dir}rypt3,\@abi-omnipotent
 .align  16
 _aesni_${dir}rypt3:
+        endbr64
         $movkey ($key),$rndkey0
         shr     \$1,$rounds
         $movkey 16($key),$rndkey1
@@ -328,6 +331,7 @@ $code.=<<___;
 .type   _aesni_${dir}rypt4,\@abi-omnipotent
 .align  16
 _aesni_${dir}rypt4:
+        endbr64
         $movkey ($key),$rndkey0
         shr     \$1,$rounds
         $movkey 16($key),$rndkey1
@@ -373,6 +377,7 @@ $code.=<<___;
 .type   _aesni_${dir}rypt6,\@abi-omnipotent
 .align  16
 _aesni_${dir}rypt6:
+        endbr64
         $movkey         ($key),$rndkey0
         shr             \$1,$rounds
         $movkey         16($key),$rndkey1
@@ -437,6 +442,7 @@ $code.=<<___;
 .type   _aesni_${dir}rypt8,\@abi-omnipotent
 .align  16
 _aesni_${dir}rypt8:
+        endbr64
         $movkey         ($key),$rndkey0
         shr             \$1,$rounds
         $movkey         16($key),$rndkey1
@@ -525,6 +531,7 @@ $code.=<<___;
 .type   aesni_ecb_encrypt,\@function,5
 .align  16
 aesni_ecb_encrypt:
+        endbr64
         and     \$-16,$len
         jz      .Lecb_ret
 
@@ -830,6 +837,7 @@ $code.=<<___;
 .type   aesni_ccm64_encrypt_blocks,\@function,6
 .align  16
 aesni_ccm64_encrypt_blocks:
+        endbr64
 ___
 $code.=<<___ if ($win64);
         lea     -0x58(%rsp),%rsp
@@ -2478,6 +2486,7 @@ $code.=<<___;
 .type   ${PREFIX}_set_decrypt_key,\@abi-omnipotent
 .align  16
 ${PREFIX}_set_decrypt_key:
+        endbr64
         sub     \$8,%rsp
         call    __aesni_set_encrypt_key
         shl     \$4,$bits               # rounds-1 after _aesni_set_encrypt_key
@@ -2528,6 +2537,7 @@ $code.=<<___;
 .type   ${PREFIX}_set_encrypt_key,\@abi-omnipotent
 .align  16
 ${PREFIX}_set_encrypt_key:
+        endbr64
 __aesni_set_encrypt_key:
         sub     \$8,%rsp
         mov     \$-1,%rax
@@ -2749,6 +2759,7 @@ $code.=<<___ if ($PREFIX eq "aesni");
 .type   ecb_se_handler,\@abi-omnipotent
 .align  16
 ecb_se_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
@@ -2768,6 +2779,7 @@ ecb_se_handler:
 .type   ccm64_se_handler,\@abi-omnipotent
 .align  16
 ccm64_se_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
@@ -2809,6 +2821,7 @@ ccm64_se_handler:
 .type   ctr32_se_handler,\@abi-omnipotent
 .align  16
 ctr32_se_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
@@ -2844,6 +2857,7 @@ ctr32_se_handler:
 .type   xts_se_handler,\@abi-omnipotent
 .align  16
 xts_se_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
@@ -2885,6 +2899,7 @@ $code.=<<___;
 .type   cbc_se_handler,\@abi-omnipotent
 .align  16
 cbc_se_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
diff --git a/src/lib/libcrypto/aes/asm/bsaes-x86_64.pl b/src/lib/libcrypto/aes/asm/bsaes-x86_64.pl
index 20e9e1f71f..7098ba27f4 100644
--- a/src/lib/libcrypto/aes/asm/bsaes-x86_64.pl
+++ b/src/lib/libcrypto/aes/asm/bsaes-x86_64.pl
@@ -813,6 +813,7 @@ $code.=<<___;
 .type   _bsaes_encrypt8,\@abi-omnipotent
 .align  64
 _bsaes_encrypt8:
+        endbr64
         lea     .LBS0(%rip), $const     # constants table
 
         movdqa  ($key), @XMM[9]         # round 0 key
@@ -877,6 +878,7 @@ $code.=<<___;
 .type   _bsaes_decrypt8,\@abi-omnipotent
 .align  64
 _bsaes_decrypt8:
+        endbr64
         lea     .LBS0(%rip), $const     # constants table
 
         movdqa  ($key), @XMM[9]         # round 0 key
@@ -968,6 +970,7 @@ $code.=<<___;
 .type   _bsaes_key_convert,\@abi-omnipotent
 .align  16
 _bsaes_key_convert:
+        endbr64
         lea     .Lmasks(%rip), $const
         movdqu  ($inp), %xmm7           # load round 0 key
         lea     0x10($inp), $inp
@@ -1057,6 +1060,7 @@ $code.=<<___;
 .type   bsaes_enc_key_convert,\@function,2
 .align  16
 bsaes_enc_key_convert:
+        endbr64
         mov     240($inp),%r10d         # pass rounds
         mov     $inp,%rcx               # pass key
         mov     $out,%rax               # pass key schedule
@@ -1071,6 +1075,7 @@ bsaes_enc_key_convert:
 .align  16
 bsaes_encrypt_128:
 .Lenc128_loop:
+        endbr64
         movdqu  0x00($inp), @XMM[0]     # load input
         movdqu  0x10($inp), @XMM[1]
         movdqu  0x20($inp), @XMM[2]
@@ -1103,6 +1108,7 @@ bsaes_encrypt_128:
 .type   bsaes_dec_key_convert,\@function,2
 .align  16
 bsaes_dec_key_convert:
+        endbr64
         mov     240($inp),%r10d         # pass rounds
         mov     $inp,%rcx               # pass key
         mov     $out,%rax               # pass key schedule
@@ -1117,6 +1123,7 @@ bsaes_dec_key_convert:
 .type   bsaes_decrypt_128,\@function,4
 .align  16
 bsaes_decrypt_128:
+        endbr64
 .Ldec128_loop:
         movdqu  0x00($inp), @XMM[0]     # load input
         movdqu  0x10($inp), @XMM[1]
@@ -1162,6 +1169,7 @@ $code.=<<___;
 .type   bsaes_ecb_encrypt_blocks,\@abi-omnipotent
 .align  16
 bsaes_ecb_encrypt_blocks:
+        endbr64
         mov     %rsp, %rax
 .Lecb_enc_prologue:
         push    %rbp
@@ -1363,6 +1371,7 @@ $code.=<<___;
 .type   bsaes_ecb_decrypt_blocks,\@abi-omnipotent
 .align  16
 bsaes_ecb_decrypt_blocks:
+        endbr64
         mov     %rsp, %rax
 .Lecb_dec_prologue:
         push    %rbp
@@ -1568,6 +1577,7 @@ $code.=<<___;
 .type   bsaes_cbc_encrypt,\@abi-omnipotent
 .align  16
 bsaes_cbc_encrypt:
+        endbr64
 ___
 $code.=<<___ if ($win64);
         mov     48(%rsp),$arg6          # pull direction flag
@@ -1855,6 +1865,7 @@ $code.=<<___;
 .type   bsaes_ctr32_encrypt_blocks,\@abi-omnipotent
 .align  16
 bsaes_ctr32_encrypt_blocks:
+        endbr64
         mov     %rsp, %rax
 .Lctr_enc_prologue:
         push    %rbp
@@ -2096,6 +2107,7 @@ $code.=<<___;
 .type   bsaes_xts_encrypt,\@abi-omnipotent
 .align  16
 bsaes_xts_encrypt:
+        endbr64
         mov     %rsp, %rax
 .Lxts_enc_prologue:
         push    %rbp
@@ -2477,6 +2489,7 @@ $code.=<<___;
 .type   bsaes_xts_decrypt,\@abi-omnipotent
 .align  16
 bsaes_xts_decrypt:
+        endbr64
         mov     %rsp, %rax
 .Lxts_dec_prologue:
         push    %rbp
@@ -2953,6 +2966,7 @@ $code.=<<___;
 .type   se_handler,\@abi-omnipotent
 .align  16
 se_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
diff --git a/src/lib/libcrypto/aes/asm/vpaes-x86_64.pl b/src/lib/libcrypto/aes/asm/vpaes-x86_64.pl
index 3ffb1a3038..8ff8d8602b 100644
--- a/src/lib/libcrypto/aes/asm/vpaes-x86_64.pl
+++ b/src/lib/libcrypto/aes/asm/vpaes-x86_64.pl
@@ -82,6 +82,7 @@ $code.=<<___;
 .type   _vpaes_encrypt_core,\@abi-omnipotent
 .align 16
 _vpaes_encrypt_core:
+        endbr64
         mov     %rdx,   %r9
         mov     \$16,   %r11
         mov     240(%rdx),%eax
@@ -172,6 +173,7 @@ _vpaes_encrypt_core:
 .type   _vpaes_decrypt_core,\@abi-omnipotent
 .align  16
 _vpaes_decrypt_core:
+        endbr64
         mov     %rdx,   %r9             # load key
         mov     240(%rdx),%eax
         movdqa  %xmm9,  %xmm1
@@ -279,6 +281,7 @@ _vpaes_decrypt_core:
 .type   _vpaes_schedule_core,\@abi-omnipotent
 .align  16
 _vpaes_schedule_core:
+        endbr64
         # rdi = key
         # rsi = size in bits
         # rdx = buffer
@@ -464,6 +467,7 @@ _vpaes_schedule_core:
 .type   _vpaes_schedule_192_smear,\@abi-omnipotent
 .align  16
 _vpaes_schedule_192_smear:
+        endbr64
         pshufd  \$0x80, %xmm6,  %xmm0   # d c 0 0 -> c 0 0 0
         pxor    %xmm0,  %xmm6           # -> c+d c 0 0
         pshufd  \$0xFE, %xmm7,  %xmm0   # b a _ _ -> b b b a
@@ -495,6 +499,7 @@ _vpaes_schedule_192_smear:
 .type   _vpaes_schedule_round,\@abi-omnipotent
 .align  16
 _vpaes_schedule_round:
+        endbr64
         # extract rcon from xmm8
         pxor    %xmm1,  %xmm1
         palignr \$15,   %xmm8,  %xmm1
@@ -562,6 +567,7 @@ _vpaes_schedule_low_round:
 .type   _vpaes_schedule_transform,\@abi-omnipotent
 .align  16
 _vpaes_schedule_transform:
+        endbr64
         movdqa  %xmm9,  %xmm1
         pandn   %xmm0,  %xmm1
         psrld   \$4,    %xmm1
@@ -600,6 +606,7 @@ _vpaes_schedule_transform:
 .type   _vpaes_schedule_mangle,\@abi-omnipotent
 .align  16
 _vpaes_schedule_mangle:
+        endbr64
         movdqa  %xmm0,  %xmm4   # save xmm0 for later
         movdqa  .Lk_mc_forward(%rip),%xmm5
         test    %rcx,   %rcx
@@ -673,6 +680,7 @@ _vpaes_schedule_mangle:
 .type   ${PREFIX}_set_encrypt_key,\@function,3
 .align  16
 ${PREFIX}_set_encrypt_key:
+        endbr64
 ___
 $code.=<<___ if ($win64);
         lea     -0xb8(%rsp),%rsp
@@ -721,6 +729,7 @@ $code.=<<___;
 .type   ${PREFIX}_set_decrypt_key,\@function,3
 .align  16
 ${PREFIX}_set_decrypt_key:
+        endbr64
 ___
 $code.=<<___ if ($win64);
         lea     -0xb8(%rsp),%rsp
@@ -774,6 +783,7 @@ $code.=<<___;
 .type   ${PREFIX}_encrypt,\@function,3
 .align  16
 ${PREFIX}_encrypt:
+        endbr64
 ___
 $code.=<<___ if ($win64);
         lea     -0xb8(%rsp),%rsp
@@ -817,6 +827,7 @@ $code.=<<___;
 .type   ${PREFIX}_decrypt,\@function,3
 .align  16
 ${PREFIX}_decrypt:
+        endbr64
 ___
 $code.=<<___ if ($win64);
         lea     -0xb8(%rsp),%rsp
@@ -866,6 +877,7 @@ $code.=<<___;
 .type   ${PREFIX}_cbc_encrypt,\@function,6
 .align  16
 ${PREFIX}_cbc_encrypt:
+        endbr64
         xchg    $key,$len
 ___
 ($len,$key)=($key,$len);
@@ -949,6 +961,7 @@ $code.=<<___;
 .type   _vpaes_preheat,\@abi-omnipotent
 .align  16
 _vpaes_preheat:
+        endbr64
         lea     .Lk_s0F(%rip), %r10
         movdqa  -0x20(%r10), %xmm10     # .Lk_inv
         movdqa  -0x10(%r10), %xmm11     # .Lk_inv+16
@@ -1079,6 +1092,7 @@ $code.=<<___;
 .type   se_handler,\@abi-omnipotent
 .align  16
 se_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
diff --git a/src/lib/libcrypto/bn/arch/amd64/bignum_add.S b/src/lib/libcrypto/bn/arch/amd64/bignum_add.S
index d56fa5e3a8..06298ca69e 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_add.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_add.S
@@ -49,6 +49,7 @@
 
 
 S2N_BN_SYMBOL(bignum_add):
+        endbr64
 
 #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 1dc1e58705..5ad712749f 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_cmadd.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_cmadd.S
@@ -54,6 +54,7 @@
 
 
 S2N_BN_SYMBOL(bignum_cmadd):
+        endbr64
 
 #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 c1a23ccea4..9199c8f48b 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_cmul.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_cmul.S
@@ -51,6 +51,7 @@
 
 
 S2N_BN_SYMBOL(bignum_cmul):
+        endbr64
 
 #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 42ac988a19..2d7ed19091 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_mul.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_mul.S
@@ -59,6 +59,7 @@
 
 
 S2N_BN_SYMBOL(bignum_mul):
+        endbr64
 
 #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 3b7848b285..f02b09b288 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
@@ -72,6 +72,7 @@
         adc     h, rdx
 
 S2N_BN_SYMBOL(bignum_mul_4_8_alt):
+        endbr64
 
 #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 1be37840df..97be83e1f7 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
@@ -72,6 +72,7 @@
         adc     h, rdx
 
 S2N_BN_SYMBOL(bignum_mul_8_16_alt):
+        endbr64
 
 #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 2e05b9c179..c4a0cabf35 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_sqr.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_sqr.S
@@ -62,6 +62,7 @@
 #define llshort ebp
 
 S2N_BN_SYMBOL(bignum_sqr):
+        endbr64
 
 #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 a635177c65..b228414dce 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
@@ -71,6 +71,7 @@
         adc     c, 0
 
 S2N_BN_SYMBOL(bignum_sqr_4_8_alt):
+        endbr64
 
 #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 f698202d29..04efeec7e2 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
@@ -103,6 +103,7 @@
         adc     c, 0
 
 S2N_BN_SYMBOL(bignum_sqr_8_16_alt):
+        endbr64
 
 #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 f8e1fe35a8..11a9bd7edd 100644
--- a/src/lib/libcrypto/bn/arch/amd64/bignum_sub.S
+++ b/src/lib/libcrypto/bn/arch/amd64/bignum_sub.S
@@ -49,6 +49,7 @@
 
 
 S2N_BN_SYMBOL(bignum_sub):
+        endbr64
 
 #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 025e98f9cb..464a9d90fc 100644
--- a/src/lib/libcrypto/bn/arch/amd64/word_clz.S
+++ b/src/lib/libcrypto/bn/arch/amd64/word_clz.S
@@ -30,6 +30,7 @@
         .text
 
 S2N_BN_SYMBOL(word_clz):
+        endbr64
 
 #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 2e71a7f03d..af78fff541 100644
--- a/src/lib/libcrypto/bn/asm/modexp512-x86_64.pl
+++ b/src/lib/libcrypto/bn/asm/modexp512-x86_64.pl
@@ -347,6 +347,7 @@ $code.=<<___;
 .type   MULADD_128x512,\@abi-omnipotent
 .align  16
 MULADD_128x512:
+        endbr64
 ___
         &MULSTEP_512([map("%r$_",(8..15))], "(+8*0)(%rcx)", "%rsi", "%rbp", "%rbx");
 $code.=<<___;
@@ -414,6 +415,7 @@ $code.=<<___;
 .type   mont_reduce,\@abi-omnipotent
 .align  16
 mont_reduce:
+        endbr64
 ___
 
 my $STACK_DEPTH         =  8;
@@ -676,6 +678,7 @@ $code.=<<___;
 .type   mont_mul_a3b,\@abi-omnipotent
 .align  16
 mont_mul_a3b:
+        endbr64
         #
         # multiply tmp = src1 * src2
         # For multiply: dst = rcx, src1 = rdi, src2 = rsi
@@ -1077,6 +1080,7 @@ $code.=<<___;
 .type   sqr_reduce,\@abi-omnipotent
 .align  16
 sqr_reduce:
+        endbr64
          mov    (+$pResult_offset+8)(%rsp), %rcx
 ___
         &SQR_512("%rsp+$tmp16_offset+8", "%rcx", [map("%r$_",(10..15,8..9))], "%rbx", "%rbp", "%rsi", "%rdi");
@@ -1106,6 +1110,7 @@ $code.=<<___;
 .globl  mod_exp_512
 .type   mod_exp_512,\@function,4
 mod_exp_512:
+        endbr64
          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 cae7309d5b..6f5ab331e2 100755
--- a/src/lib/libcrypto/bn/asm/x86_64-mont.pl
+++ b/src/lib/libcrypto/bn/asm/x86_64-mont.pl
@@ -63,6 +63,7 @@ $code=<<___;
 .type   bn_mul_mont,\@function,6
 .align  16
 bn_mul_mont:
+        endbr64
         test    \$3,${num}d
         jnz     .Lmul_enter
         cmp     \$8,${num}d
@@ -278,6 +279,7 @@ $code.=<<___;
 .align  16
 bn_mul4x_mont:
 .Lmul4x_enter:
+        endbr64
         push    %rbx
         push    %rbp
         push    %r12
@@ -705,6 +707,7 @@ $code.=<<___;
 .align  16
 bn_sqr4x_mont:
 .Lsqr4x_enter:
+        endbr64
         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 7b9c6df273..3b3325a6cc 100755
--- a/src/lib/libcrypto/bn/asm/x86_64-mont5.pl
+++ b/src/lib/libcrypto/bn/asm/x86_64-mont5.pl
@@ -57,6 +57,7 @@ $code=<<___;
 .type   bn_mul_mont_gather5,\@function,6
 .align  64
 bn_mul_mont_gather5:
+        endbr64
         test    \$3,${num}d
         jnz     .Lmul_enter
         cmp     \$8,${num}d
@@ -387,6 +388,7 @@ $code.=<<___;
 .type   bn_mul4x_mont_gather5,\@function,6
 .align  16
 bn_mul4x_mont_gather5:
+        endbr64
 .Lmul4x_enter:
         mov     ${num}d,${num}d
         movd    `($win64?56:8)`(%rsp),%xmm5     # load 7th argument
@@ -925,6 +927,7 @@ $code.=<<___;
 .type   bn_scatter5,\@abi-omnipotent
 .align  16
 bn_scatter5:
+        endbr64
         cmp     \$0, $num
         jz      .Lscatter_epilogue
         lea     ($tbl,$idx,8),$tbl
@@ -943,6 +946,7 @@ bn_scatter5:
 .type   bn_gather5,\@abi-omnipotent
 .align  16
 bn_gather5:
+        endbr64
 .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
@@ -1053,6 +1057,7 @@ $code.=<<___;
 .type   mul_handler,\@abi-omnipotent
 .align  16
 mul_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
diff --git a/src/lib/libcrypto/camellia/asm/cmll-x86_64.pl b/src/lib/libcrypto/camellia/asm/cmll-x86_64.pl
index 586e5d6e93..3ceed3e899 100644
--- a/src/lib/libcrypto/camellia/asm/cmll-x86_64.pl
+++ b/src/lib/libcrypto/camellia/asm/cmll-x86_64.pl
@@ -116,6 +116,7 @@ $code=<<___;
 .type   Camellia_EncryptBlock,\@abi-omnipotent
 .align  16
 Camellia_EncryptBlock:
+        endbr64
         movl    \$128,%eax
         subl    $arg0d,%eax
         movl    \$3,$arg0d
@@ -128,6 +129,7 @@ Camellia_EncryptBlock:
 .align  16
 .Lenc_rounds:
 Camellia_EncryptBlock_Rounds:
+        endbr64
         push    %rbx
         push    %rbp
         push    %r13
@@ -176,6 +178,7 @@ Camellia_EncryptBlock_Rounds:
 .type   _x86_64_Camellia_encrypt,\@abi-omnipotent
 .align  16
 _x86_64_Camellia_encrypt:
+        endbr64
         xor     0($key),@S[1]
         xor     4($key),@S[0]           # ^=key[0-3]
         xor     8($key),@S[3]
@@ -226,6 +229,7 @@ $code.=<<___;
 .type   Camellia_DecryptBlock,\@abi-omnipotent
 .align  16
 Camellia_DecryptBlock:
+        endbr64
         movl    \$128,%eax
         subl    $arg0d,%eax
         movl    \$3,$arg0d
@@ -238,6 +242,7 @@ Camellia_DecryptBlock:
 .align  16
 .Ldec_rounds:
 Camellia_DecryptBlock_Rounds:
+        endbr64
         push    %rbx
         push    %rbp
         push    %r13
@@ -286,6 +291,7 @@ Camellia_DecryptBlock_Rounds:
 .type   _x86_64_Camellia_decrypt,\@abi-omnipotent
 .align  16
 _x86_64_Camellia_decrypt:
+        endbr64
         xor     0($key),@S[1]
         xor     4($key),@S[0]           # ^=key[0-3]
         xor     8($key),@S[3]
@@ -400,6 +406,7 @@ $code.=<<___;
 .type   Camellia_Ekeygen,\@function,3
 .align  16
 Camellia_Ekeygen:
+        endbr64
         push    %rbx
         push    %rbp
         push    %r13
@@ -630,6 +637,7 @@ $code.=<<___;
 .type   Camellia_cbc_encrypt,\@function,6
 .align  16
 Camellia_cbc_encrypt:
+        endbr64
         cmp     \$0,%rdx
         je      .Lcbc_abort
         push    %rbx
diff --git a/src/lib/libcrypto/md5/asm/md5-x86_64.pl b/src/lib/libcrypto/md5/asm/md5-x86_64.pl
index c902a1b532..06d69094f4 100755
--- a/src/lib/libcrypto/md5/asm/md5-x86_64.pl
+++ b/src/lib/libcrypto/md5/asm/md5-x86_64.pl
@@ -128,6 +128,7 @@ $code .= <<EOF;
 .globl md5_block_asm_data_order
 .type md5_block_asm_data_order,\@function,3
 md5_block_asm_data_order:
+        endbr64
         push    %rbp
         push    %rbx
         push    %r12
diff --git a/src/lib/libcrypto/modes/asm/ghash-x86_64.pl b/src/lib/libcrypto/modes/asm/ghash-x86_64.pl
index 71d0822ac9..9ce0c38141 100644
--- a/src/lib/libcrypto/modes/asm/ghash-x86_64.pl
+++ b/src/lib/libcrypto/modes/asm/ghash-x86_64.pl
@@ -412,6 +412,7 @@ $code.=<<___;
 .type   gcm_init_clmul,\@abi-omnipotent
 .align  16
 gcm_init_clmul:
+        endbr64
         movdqu          ($Xip),$Hkey
         pshufd          \$0b01001110,$Hkey,$Hkey        # dword swap
 
@@ -449,6 +450,7 @@ $code.=<<___;
 .type   gcm_gmult_clmul,\@abi-omnipotent
 .align  16
 gcm_gmult_clmul:
+        endbr64
         movdqu          ($Xip),$Xi
         movdqa          .Lbswap_mask(%rip),$T3
         movdqu          ($Htbl),$Hkey
@@ -476,6 +478,7 @@ $code.=<<___;
 .type   gcm_ghash_clmul,\@abi-omnipotent
 .align  16
 gcm_ghash_clmul:
+        endbr64
 ___
 $code.=<<___ if ($win64);
 .LSEH_begin_gcm_ghash_clmul:
@@ -686,6 +689,7 @@ $code.=<<___;
 .type   se_handler,\@abi-omnipotent
 .align  16
 se_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
diff --git a/src/lib/libcrypto/rc4/asm/rc4-md5-x86_64.pl b/src/lib/libcrypto/rc4/asm/rc4-md5-x86_64.pl
index 501d9e936b..6d058bd9d4 100644
--- a/src/lib/libcrypto/rc4/asm/rc4-md5-x86_64.pl
+++ b/src/lib/libcrypto/rc4/asm/rc4-md5-x86_64.pl
@@ -109,6 +109,7 @@ $code.=<<___;
 .globl  $func
 .type   $func,\@function,$nargs
 $func:
+        endbr64
         cmp     \$0,$len
         je      .Labort
         push    %rbx
@@ -453,6 +454,7 @@ $code.=<<___;
 .type   RC4_set_key,\@function,3
 .align  16
 RC4_set_key:
+        endbr64
         lea     8($dat),$dat
         lea     ($inp,$len),$inp
         neg     $len
@@ -494,6 +496,7 @@ RC4_set_key:
 .type   RC4_options,\@abi-omnipotent
 .align  16
 RC4_options:
+        endbr64
         lea     .Lopts(%rip),%rax
         ret
 .align  64
diff --git a/src/lib/libcrypto/rc4/asm/rc4-x86_64.pl b/src/lib/libcrypto/rc4/asm/rc4-x86_64.pl
index 8de869489f..2bac7d744d 100755
--- a/src/lib/libcrypto/rc4/asm/rc4-x86_64.pl
+++ b/src/lib/libcrypto/rc4/asm/rc4-x86_64.pl
@@ -127,7 +127,9 @@ $code=<<___;
 .globl  RC4
 .type   RC4,\@function,4
 .align  16
-RC4:    or      $len,$len
+RC4:
+        endbr64
+        or      $len,$len
         jne     .Lentry
         ret
 .Lentry:
@@ -433,6 +435,7 @@ $code.=<<___;
 .type   RC4_set_key,\@function,3
 .align  16
 RC4_set_key:
+        endbr64
         lea     8($dat),$dat
         lea     ($inp,$len),$inp
         neg     $len
@@ -505,6 +508,7 @@ RC4_set_key:
 .type   RC4_options,\@abi-omnipotent
 .align  16
 RC4_options:
+        endbr64
         lea     .Lopts(%rip),%rax
         mov     OPENSSL_ia32cap_P(%rip),%edx
         bt      \$IA32CAP_BIT0_INTELP4,%edx
diff --git a/src/lib/libcrypto/sha/asm/sha1-x86_64.pl b/src/lib/libcrypto/sha/asm/sha1-x86_64.pl
index 43eee73c4a..e15ff47f88 100755
--- a/src/lib/libcrypto/sha/asm/sha1-x86_64.pl
+++ b/src/lib/libcrypto/sha/asm/sha1-x86_64.pl
@@ -222,6 +222,7 @@ $code.=<<___;
 .type   sha1_block_data_order,\@function,3
 .align  16
 sha1_block_data_order:
+        endbr64
         mov     OPENSSL_ia32cap_P+0(%rip),%r9d
         mov     OPENSSL_ia32cap_P+4(%rip),%r8d
         test    \$IA32CAP_MASK1_SSSE3,%r8d              # check SSSE3 bit
@@ -309,6 +310,7 @@ $code.=<<___;
 .align  16
 sha1_block_data_order_ssse3:
 _ssse3_shortcut:
+        endbr64
         push    %rbx
         push    %rbp
         push    %r12
@@ -729,6 +731,7 @@ $code.=<<___;
 .align  16
 sha1_block_data_order_avx:
 _avx_shortcut:
+        endbr64
         push    %rbx
         push    %rbp
         push    %r12
@@ -1099,6 +1102,7 @@ $code.=<<___;
 .type   se_handler,\@abi-omnipotent
 .align  16
 se_handler:
+        endbr64
         push    %rsi
         push    %rdi
         push    %rbx
diff --git a/src/lib/libcrypto/sha/asm/sha512-x86_64.pl b/src/lib/libcrypto/sha/asm/sha512-x86_64.pl
index 0517eab660..120693feeb 100755
--- a/src/lib/libcrypto/sha/asm/sha512-x86_64.pl
+++ b/src/lib/libcrypto/sha/asm/sha512-x86_64.pl
@@ -175,6 +175,7 @@ $code=<<___;
 .type   $func,\@function,4
 .align  16
 $func:
+        endbr64
         push    %rbx
         push    %rbp
         push    %r12
diff --git a/src/lib/libcrypto/whrlpool/asm/wp-x86_64.pl b/src/lib/libcrypto/whrlpool/asm/wp-x86_64.pl
index de5d3acfb4..7958f6d289 100644
--- a/src/lib/libcrypto/whrlpool/asm/wp-x86_64.pl
+++ b/src/lib/libcrypto/whrlpool/asm/wp-x86_64.pl
@@ -57,6 +57,7 @@ $code=<<___;
 .type   $func,\@function,3
 .align  16
 $func:
+        endbr64
         push    %rbx
         push    %rbp
         push    %r12
diff --git a/src/lib/libcrypto/x86_64cpuid.pl b/src/lib/libcrypto/x86_64cpuid.pl
index 1b67d1110f..dc56732a28 100644
--- a/src/lib/libcrypto/x86_64cpuid.pl
+++ b/src/lib/libcrypto/x86_64cpuid.pl
@@ -18,6 +18,7 @@ print<<___;
 .extern         OPENSSL_cpuid_setup
 .hidden         OPENSSL_cpuid_setup
 .section        .init
+        endbr64
         call    OPENSSL_cpuid_setup
 
 .extern OPENSSL_ia32cap_P
@@ -29,6 +30,7 @@ print<<___;
 .type   OPENSSL_ia32_cpuid,\@abi-omnipotent
 .align  16
 OPENSSL_ia32_cpuid:
+        endbr64
         mov     %rbx,%r8                # save %rbx
 
         xor     %eax,%eax