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putty-source/crypto/CMakeLists.txt
Simon Tatham e98615f0ba New post-quantum kex: ML-KEM, and three hybrids of it.
As standardised by NIST in FIPS 203, this is a lattice-based
post-quantum KEM.

Very vaguely, the idea of it is that your public key is a matrix A and
vector t, and the private key is the knowledge of how to decompose t
into two vectors with all their coefficients small, one transformed by
A relative to the other. Encryption of a binary secret starts by
turning each bit into one of two maximally separated residues mod a
prime q, and then adding 'noise' based on the public key in the form
of small increments and decrements mod q, again with some of the noise
transformed by A relative to the rest. Decryption uses the knowledge
of t's decomposition to align the two sets of noise so that the
_large_ changes (which masked the secret from an eavesdropper) cancel
out, leaving only a collection of small changes to the original secret
vector. Then the vector of input bits can be recovered by assuming
that those accumulated small pieces of noise haven't concentrated in
any particular residue enough to push it more than half way to the
other of its possible starting values.

A weird feature of it is that decryption is not a true mathematical
inverse of encryption. The assumption that the noise doesn't get large
enough to flip any bit of the secret is only probabilistically valid,
not a hard guarantee. In other words, key agreement can fail, simply
by getting particularly unlucky with the distribution of your random
noise! However, the probability of a failure is very low - less than
2^-138 even for ML-KEM-512, and gets even smaller with the larger
variants.

An awkward feature for our purposes is that the matrix A, containing a
large number of residues mod the prime q=3329, is required to be
constructed by a process of rejection sampling, i.e. generating random
12-bit values and throwing away the out-of-range ones. That would be a
real pain for our side-channel testing system, which generally handles
rejection sampling badly (since it necessarily involves data-dependent
control flow and timing variation). Fortunately, the matrix and the
random seed it was made from are both public: the matrix seed is
transmitted as part of the public key, so it's not necessary to try to
hide it. Accordingly, I was able to get the implementation to pass
testsc by means of not varying the matrix seed between runs, which is
justified by the principle of testsc that you vary the _secrets_ to
ensure timing is independent of them - and the matrix seed isn't a
secret, so you're allowed to keep it the same.

The three hybrid algorithms, defined by the current Internet-Draft
draft-kampanakis-curdle-ssh-pq-ke, include one hybrid of ML-KEM-768
with Curve25519 in exactly the same way we were already hybridising
NTRU Prime with Curve25519, and two more hybrids of ML-KEM with ECDH
over a NIST curve. The former hybrid interoperates with the
implementation in OpenSSH 9.9; all three interoperate with the fork
'openssh-oqs' at github.com/open-quantum-safe/openssh, and also with
the Python library AsyncSSH.
2024-12-08 10:41:08 +00:00

246 lines
7.3 KiB
CMake

add_sources_from_current_dir(crypto
aes-common.c
aes-select.c
aes-sw.c
aesgcm-common.c
aesgcm-select.c
aesgcm-sw.c
aesgcm-ref-poly.c
arcfour.c
argon2.c
bcrypt.c
blake2.c
blowfish.c
chacha20-poly1305.c
crc32.c
des.c
diffie-hellman.c
dsa.c
ecc-arithmetic.c
ecc-ssh.c
hash_simple.c
hmac.c
kex-hybrid.c
mac.c
mac_simple.c
md5.c
mlkem.c
mpint.c
ntru.c
openssh-certs.c
prng.c
pubkey-pem.c
pubkey-ppk.c
pubkey-ssh1.c
rfc6979.c
rsa.c
sha256-common.c
sha256-select.c
sha256-sw.c
sha512-common.c
sha512-select.c
sha512-sw.c
sha3.c
sha1-common.c
sha1-select.c
sha1-sw.c
xdmauth.c)
include(CheckCSourceCompiles)
function(test_compile_with_flags outvar)
cmake_parse_arguments(OPT "" ""
"GNU_FLAGS;MSVC_FLAGS;ADD_SOURCES_IF_SUCCESSFUL;TEST_SOURCE" "${ARGN}")
# Figure out what flags are applicable to this compiler.
set(flags)
if(CMAKE_C_COMPILER_ID MATCHES "GNU" OR
CMAKE_C_COMPILER_ID MATCHES "Clang")
set(flags ${OPT_GNU_FLAGS})
endif()
if(CMAKE_C_COMPILER_ID MATCHES "MSVC")
set(flags ${OPT_MSVC_FLAGS})
endif()
# See if we can compile the provided test program.
foreach(i ${flags})
set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${i}")
endforeach()
check_c_source_compiles("${OPT_TEST_SOURCE}" "${outvar}")
if(${outvar} AND OPT_ADD_SOURCES_IF_SUCCESSFUL)
# Make an object library that compiles the implementation with the
# necessary flags, and add the resulting objects to the crypto
# library.
set(libname object_lib_${outvar})
add_library(${libname} OBJECT ${OPT_ADD_SOURCES_IF_SUCCESSFUL})
target_compile_options(${libname} PRIVATE ${flags})
target_sources(crypto PRIVATE $<TARGET_OBJECTS:${libname}>)
endif()
# Export the output to the caller's scope, so that further tests can
# be based on it.
set(${outvar} ${${outvar}} PARENT_SCOPE)
endfunction()
# ----------------------------------------------------------------------
# Try to enable x86 intrinsics-based crypto implementations.
test_compile_with_flags(HAVE_WMMINTRIN_H
GNU_FLAGS -msse4.1
TEST_SOURCE "
#include <wmmintrin.h>
#include <smmintrin.h>
volatile __m128i r, a, b;
int main(void) { r = _mm_xor_si128(a, b); }")
if(HAVE_WMMINTRIN_H)
test_compile_with_flags(HAVE_AES_NI
GNU_FLAGS -msse4.1 -maes
TEST_SOURCE "
#include <wmmintrin.h>
#include <smmintrin.h>
volatile __m128i r, a, b;
int main(void) { r = _mm_aesenc_si128(a, b); }"
ADD_SOURCES_IF_SUCCESSFUL aes-ni aes-ni.c)
# shaintrin.h doesn't exist on all compilers; sometimes it's folded
# into the other headers
test_compile_with_flags(HAVE_SHAINTRIN_H
GNU_FLAGS -msse4.1 -msha
TEST_SOURCE "
#include <wmmintrin.h>
#include <smmintrin.h>
#include <immintrin.h>
#include <shaintrin.h>
volatile __m128i r, a, b;
int main(void) { r = _mm_xor_si128(a, b); }")
if(HAVE_SHAINTRIN_H)
set(include_shaintrin "#include <shaintrin.h>")
else()
set(include_shaintrin "")
endif()
test_compile_with_flags(HAVE_SHA_NI
GNU_FLAGS -msse4.1 -msha
TEST_SOURCE "
#include <wmmintrin.h>
#include <smmintrin.h>
#include <immintrin.h>
${include_shaintrin}
volatile __m128i r, a, b, c;
int main(void) { r = _mm_sha256rnds2_epu32(a, b, c); }"
ADD_SOURCES_IF_SUCCESSFUL sha256-ni.c sha1-ni.c)
test_compile_with_flags(HAVE_CLMUL
GNU_FLAGS -msse4.1 -mpclmul
TEST_SOURCE "
#include <wmmintrin.h>
#include <tmmintrin.h>
volatile __m128i r, a, b;
int main(void) { r = _mm_clmulepi64_si128(a, b, 5);
r = _mm_shuffle_epi8(r, a); }"
ADD_SOURCES_IF_SUCCESSFUL aesgcm-clmul.c)
endif()
# ----------------------------------------------------------------------
# Try to enable Arm Neon intrinsics-based crypto implementations.
# Start by checking which header file we need. ACLE specifies that it
# ought to be <arm_neon.h>, on both 32- and 64-bit Arm, but Visual
# Studio for some reason renamed the header to <arm64_neon.h> in
# 64-bit, and gives an error if you use the standard name. (However,
# clang-cl does let you use the standard name.)
test_compile_with_flags(HAVE_ARM_NEON_H
MSVC_FLAGS -D_ARM_USE_NEW_NEON_INTRINSICS
TEST_SOURCE "
#include <arm_neon.h>
volatile uint8x16_t r, a, b;
int main(void) { r = veorq_u8(a, b); }")
if(HAVE_ARM_NEON_H)
set(neon ON)
set(neon_header "arm_neon.h")
else()
test_compile_with_flags(HAVE_ARM64_NEON_H TEST_SOURCE "
#include <arm64_neon.h>
volatile uint8x16_t r, a, b;
int main(void) { r = veorq_u8(a, b); }")
if(HAVE_ARM64_NEON_H)
set(neon ON)
set(neon_header "arm64_neon.h")
set(USE_ARM64_NEON_H ON)
endif()
endif()
if(neon)
# If we have _some_ NEON header, look for the individual things we
# can enable with it.
# The 'crypto' architecture extension includes support for AES,
# SHA-1, and SHA-256.
test_compile_with_flags(HAVE_NEON_CRYPTO
GNU_FLAGS -march=armv8-a+crypto
MSVC_FLAGS -D_ARM_USE_NEW_NEON_INTRINSICS
TEST_SOURCE "
#include <${neon_header}>
volatile uint8x16_t r, a, b;
volatile uint32x4_t s, x, y, z;
int main(void) { r = vaeseq_u8(a, b); s = vsha256hq_u32(x, y, z); }"
ADD_SOURCES_IF_SUCCESSFUL aes-neon.c sha256-neon.c sha1-neon.c)
test_compile_with_flags(HAVE_NEON_PMULL
GNU_FLAGS -march=armv8-a+crypto
MSVC_FLAGS -D_ARM_USE_NEW_NEON_INTRINSICS
TEST_SOURCE "
#include <${neon_header}>
volatile poly128_t r;
volatile poly64_t a, b;
volatile poly64x2_t u, v;
int main(void) { r = vmull_p64(a, b); r = vmull_high_p64(u, v); }"
ADD_SOURCES_IF_SUCCESSFUL aesgcm-neon.c)
test_compile_with_flags(HAVE_NEON_VADDQ_P128
GNU_FLAGS -march=armv8-a+crypto
MSVC_FLAGS -D_ARM_USE_NEW_NEON_INTRINSICS
TEST_SOURCE "
#include <${neon_header}>
volatile poly128_t r;
int main(void) { r = vaddq_p128(r, r); }")
# The 'sha3' architecture extension, despite the name, includes
# support for SHA-512 (from the SHA-2 standard) as well as SHA-3
# proper.
#
# Versions of clang up to and including clang 12 support this
# extension in assembly language, but not the ACLE intrinsics for
# it. So we check both.
test_compile_with_flags(HAVE_NEON_SHA512_INTRINSICS
GNU_FLAGS -march=armv8.2-a+crypto+sha3
TEST_SOURCE "
#include <${neon_header}>
volatile uint64x2_t r, a, b;
int main(void) { r = vsha512su0q_u64(a, b); }"
ADD_SOURCES_IF_SUCCESSFUL sha512-neon.c)
if(HAVE_NEON_SHA512_INTRINSICS)
set(HAVE_NEON_SHA512 ON)
else()
test_compile_with_flags(HAVE_NEON_SHA512_ASM
GNU_FLAGS -march=armv8.2-a+crypto+sha3
TEST_SOURCE "
#include <${neon_header}>
volatile uint64x2_t r, a;
int main(void) { __asm__(\"sha512su0 %0.2D,%1.2D\" : \"+w\" (r) : \"w\" (a)); }"
ADD_SOURCES_IF_SUCCESSFUL sha512-neon.c)
if(HAVE_NEON_SHA512_ASM)
set(HAVE_NEON_SHA512 ON)
endif()
endif()
endif()
set(HAVE_AES_NI ${HAVE_AES_NI} PARENT_SCOPE)
set(HAVE_SHA_NI ${HAVE_SHA_NI} PARENT_SCOPE)
set(HAVE_SHAINTRIN_H ${HAVE_SHAINTRIN_H} PARENT_SCOPE)
set(HAVE_NEON_CRYPTO ${HAVE_NEON_CRYPTO} PARENT_SCOPE)
set(HAVE_NEON_SHA512 ${HAVE_NEON_SHA512} PARENT_SCOPE)
set(HAVE_NEON_SHA512_INTRINSICS ${HAVE_NEON_SHA512_INTRINSICS} PARENT_SCOPE)
set(USE_ARM64_NEON_H ${USE_ARM64_NEON_H} PARENT_SCOPE)