diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3c60196..6b6d0d6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -140,11 +140,6 @@ jobs:
             if brew list | grep -q ${s3fs_brew_pkg}; then if brew outdated | grep -q ${s3fs_brew_pkg}; then HOMEBREW_NO_AUTO_UPDATE=1 brew upgrade ${s3fs_brew_pkg}; fi; else HOMEBREW_NO_AUTO_UPDATE=1 brew install ${s3fs_brew_pkg}; fi
           done
 
-      - name: Install awscli2
-        run: |
-          curl "https://awscli.amazonaws.com/AWSCLIV2.pkg" -o /tmp/AWSCLIV2.pkg
-          sudo installer -pkg /tmp/AWSCLIV2.pkg -target /
-
       - name: Build
         run: |
           ./autogen.sh
diff --git a/.github/workflows/linux-ci-helper.sh b/.github/workflows/linux-ci-helper.sh
index 852b191..8d6a05e 100755
--- a/.github/workflows/linux-ci-helper.sh
+++ b/.github/workflows/linux-ci-helper.sh
@@ -57,11 +57,7 @@ CONTAINER_OSNAME=$(echo "${CONTAINER_FULLNAME}" | cut -d: -f1)
 # shellcheck disable=SC2034
 CONTAINER_OSVERSION=$(echo "${CONTAINER_FULLNAME}" | cut -d: -f2)
 
-#-----------------------------------------------------------
-# Common variables for awscli2
-#-----------------------------------------------------------
-AWSCLI_URI="https://awscli.amazonaws.com/awscli-exe-linux-$(uname -m).zip"
-AWSCLI_ZIP_FILE="awscliv2.zip"
+CURL_DIRECT_URL="https://github.com/moparisthebest/static-curl/releases/latest/download/curl-$(uname -m | sed -e s/x86_64/amd64/)"
 
 #-----------------------------------------------------------
 # Parameters for configure(set environments)
@@ -79,7 +75,7 @@ CONFIGURE_OPTIONS="--prefix=/usr --with-openssl"
 #
 PACKAGE_ENABLE_REPO_OPTIONS=""
 PACKAGE_INSTALL_ADDITIONAL_OPTIONS=""
-AWSCLI_DIRECT_INSTALL=1
+CURL_DIRECT_INSTALL=0
 
 if [ "${CONTAINER_FULLNAME}" = "ubuntu:25.04" ] ||
    [ "${CONTAINER_FULLNAME}" = "ubuntu:24.04" ]; then
@@ -107,7 +103,6 @@ if [ "${CONTAINER_FULLNAME}" = "ubuntu:25.04" ] ||
         openjdk-21-jre-headless
         pkg-config
         python3
-        unzip
     )
 
 elif [ "${CONTAINER_FULLNAME}" = "ubuntu:22.04" ]; then
@@ -135,9 +130,10 @@ elif [ "${CONTAINER_FULLNAME}" = "ubuntu:22.04" ]; then
         openjdk-21-jre-headless
         pkg-config
         python3
-        unzip
     )
 
+    CURL_DIRECT_INSTALL=1
+
 elif [ "${CONTAINER_FULLNAME}" = "debian:trixie" ]; then
     PACKAGE_MANAGER_BIN="apt-get"
     PACKAGE_UPDATE_OPTIONS="update -y -qq"
@@ -164,7 +160,6 @@ elif [ "${CONTAINER_FULLNAME}" = "debian:trixie" ]; then
         pkg-config
         procps
         python3
-        unzip
     )
 
 elif [ "${CONTAINER_FULLNAME}" = "debian:bookworm" ] ||
@@ -194,9 +189,10 @@ elif [ "${CONTAINER_FULLNAME}" = "debian:bookworm" ] ||
         pkg-config
         procps
         python3
-        unzip
     )
 
+    CURL_DIRECT_INSTALL=1
+
 elif [ "${CONTAINER_FULLNAME}" = "rockylinux/rockylinux:10" ]; then
     PACKAGE_MANAGER_BIN="dnf"
     PACKAGE_UPDATE_OPTIONS="update -y -qq"
@@ -233,7 +229,6 @@ elif [ "${CONTAINER_FULLNAME}" = "rockylinux/rockylinux:10" ]; then
         perl-Test-Harness
         procps
         python3
-        unzip
         xz
         https://dl.fedoraproject.org/pub/epel/epel-release-latest-10.noarch.rpm
     )
@@ -274,11 +269,12 @@ elif [ "${CONTAINER_FULLNAME}" = "rockylinux:9" ]; then
         perl-Test-Harness
         procps
         python3
-        unzip
         xz
         https://dl.fedoraproject.org/pub/epel/epel-release-latest-9.noarch.rpm
     )
 
+    CURL_DIRECT_INSTALL=1
+
 elif [ "${CONTAINER_FULLNAME}" = "rockylinux:8" ]; then
     PACKAGE_MANAGER_BIN="dnf"
     PACKAGE_UPDATE_OPTIONS="update -y -qq"
@@ -307,9 +303,10 @@ elif [ "${CONTAINER_FULLNAME}" = "rockylinux:8" ]; then
         openssl-devel
         perl-Test-Harness
         python3
-        unzip
     )
 
+    CURL_DIRECT_INSTALL=1
+
 elif [ "${CONTAINER_FULLNAME}" = "fedora:42" ] ||
      [ "${CONTAINER_FULLNAME}" = "fedora:41" ]; then
     PACKAGE_MANAGER_BIN="dnf"
@@ -345,7 +342,6 @@ elif [ "${CONTAINER_FULLNAME}" = "fedora:42" ] ||
         perl-Test-Harness
         procps
         ShellCheck
-        unzip
     )
 
 elif [ "${CONTAINER_FULLNAME}" = "opensuse/leap:15" ]; then
@@ -369,7 +365,6 @@ elif [ "${CONTAINER_FULLNAME}" = "opensuse/leap:15" ]; then
         openssl
         openssl-devel
         procps
-        unzip
     )
 
 elif [ "${CONTAINER_FULLNAME}" = "alpine:3.22" ]; then
@@ -402,8 +397,6 @@ elif [ "${CONTAINER_FULLNAME}" = "alpine:3.22" ]; then
         sed
     )
 
-    AWSCLI_DIRECT_INSTALL=0
-
 else
     echo "No container configured for: ${CONTAINER_FULLNAME}"
     exit 1
@@ -427,17 +420,22 @@ echo "${PRGNAME} [INFO] Install packages."
 # Check Java version
 java -version
 
-#
-# Install awscli
-#
-if [ "${AWSCLI_DIRECT_INSTALL}" -eq 1 ]; then
-    echo "${PRGNAME} [INFO] Install awscli2 package."
+# Install newer curl for older distributions
+if [ "${CURL_DIRECT_INSTALL}" -eq 1 ]; then
+    echo "${PRGNAME} [INFO] Install newer curl package."
 
-    curl "${AWSCLI_URI}" -o "/tmp/${AWSCLI_ZIP_FILE}"
-    unzip "/tmp/${AWSCLI_ZIP_FILE}" -d /tmp
-    /tmp/aws/install
+    curl --fail --location --silent --output "/usr/local/bin/curl" "${CURL_DIRECT_URL}"
+    chmod +x "/usr/local/bin/curl"
+
+    # Rocky Linux 8 and 9 have a different certificate path
+    if [ ! -f /etc/ssl/certs/ca-certificates.crt ]; then
+        ln -s /etc/pki/tls/certs/ca-bundle.crt /etc/ssl/certs/ca-certificates.crt
+    fi
 fi
 
+# Check curl version
+curl --version
+
 #-----------------------------------------------------------
 # Set environment for configure
 #-----------------------------------------------------------
diff --git a/test/integration-test-common.sh b/test/integration-test-common.sh
index 4688060..8435100 100644
--- a/test/integration-test-common.sh
+++ b/test/integration-test-common.sh
@@ -84,6 +84,7 @@ fi
 export TEST_BUCKET_1
 export S3_URL
 export S3_ENDPOINT
+export S3PROXY_CACERT_FILE
 TEST_SCRIPT_DIR=$(pwd)
 export TEST_SCRIPT_DIR
 export TEST_BUCKET_MOUNT_POINT_1=${TEST_BUCKET_1}
diff --git a/test/integration-test-main.sh b/test/integration-test-main.sh
index 6325ffa..3635fd5 100755
--- a/test/integration-test-main.sh
+++ b/test/integration-test-main.sh
@@ -33,7 +33,7 @@ function test_create_empty_file {
 
     check_file_size "${TEST_TEXT_FILE}" 0
 
-    aws_cli s3api head-object --bucket "${TEST_BUCKET_1}" --key "${OBJECT_NAME}"
+    s3_head "${TEST_BUCKET_1}/${OBJECT_NAME}"
 
     rm_test_file
 }
@@ -381,7 +381,7 @@ function test_remove_nonempty_directory {
 function test_external_directory_creation {
     describe "Test external directory creation ..."
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/directory/"${TEST_TEXT_FILE}"
-    echo "data" | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo "data" | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}"
     # shellcheck disable=SC2010
     ls | grep -q directory
     stat directory >/dev/null 2>&1
@@ -406,7 +406,7 @@ function test_external_modification {
     sleep 1
 
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/"${TEST_TEXT_FILE}"
-    echo "new new" | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo "new new" | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}"
 
     cmp "${TEST_TEXT_FILE}" <(echo "new new")
     rm -f "${TEST_TEXT_FILE}"
@@ -425,7 +425,7 @@ function test_external_creation {
     # If noobj_cache is enabled, we cannot be sure that it is registered in that cache.
     # That's because an error will occur if the upload by aws cli takes more than 1 second.
     #
-    echo "data" | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo "data" | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}"
 
     wait_ostype 1
 
@@ -437,7 +437,7 @@ function test_external_creation {
 function test_read_external_object() {
     describe "create objects via aws CLI and read via s3fs ..."
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/"${TEST_TEXT_FILE}"
-    echo "test" | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo "test" | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}"
     cmp "${TEST_TEXT_FILE}" <(echo "test")
     rm -f "${TEST_TEXT_FILE}"
 }
@@ -448,7 +448,7 @@ function test_read_external_dir_object() {
     local SUB_DIR_TEST_FILE; SUB_DIR_TEST_FILE="${SUB_DIR_NAME}/${TEST_TEXT_FILE}"
     local OBJECT_NAME;       OBJECT_NAME=$(basename "${PWD}")/"${SUB_DIR_TEST_FILE}"
 
-    echo "test" | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo "test" | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}"
 
     if stat "${SUB_DIR_NAME}" | grep -q '1969-12-31[[:space:]]23:59:59[.]000000000'; then
         echo "sub directory a/c/m time is underflow(-1)."
@@ -476,7 +476,7 @@ function test_update_metadata_external_small_object() {
     # chmod
     #
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/"${TEST_CHMOD_FILE}"
-    echo "${TEST_INPUT}" | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo "${TEST_INPUT}" | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}"
     chmod +x "${TEST_CHMOD_FILE}"
     cmp "${TEST_CHMOD_FILE}" <(echo "${TEST_INPUT}")
 
@@ -484,7 +484,7 @@ function test_update_metadata_external_small_object() {
     # chown
     #
     OBJECT_NAME=$(basename "${PWD}")/"${TEST_CHOWN_FILE}"
-    echo "${TEST_INPUT}" | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo "${TEST_INPUT}" | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}"
     chown "${UID}" "${TEST_CHOWN_FILE}"
     cmp "${TEST_CHOWN_FILE}" <(echo "${TEST_INPUT}")
 
@@ -492,7 +492,7 @@ function test_update_metadata_external_small_object() {
     # utimens
     #
     OBJECT_NAME=$(basename "${PWD}")/"${TEST_UTIMENS_FILE}"
-    echo "${TEST_INPUT}" | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo "${TEST_INPUT}" | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}"
     touch "${TEST_UTIMENS_FILE}"
     cmp "${TEST_UTIMENS_FILE}" <(echo "${TEST_INPUT}")
 
@@ -500,7 +500,7 @@ function test_update_metadata_external_small_object() {
     # set xattr
     #
     OBJECT_NAME=$(basename "${PWD}")/"${TEST_SETXATTR_FILE}"
-    echo "${TEST_INPUT}" | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo "${TEST_INPUT}" | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}"
     set_xattr key value "${TEST_SETXATTR_FILE}"
     cmp "${TEST_SETXATTR_FILE}" <(echo "${TEST_INPUT}")
     XATTR_VALUE=$(get_xattr key "${TEST_SETXATTR_FILE}")
@@ -526,7 +526,7 @@ function test_update_metadata_external_small_object() {
     #
     if ! uname | grep -q Darwin; then
         OBJECT_NAME=$(basename "${PWD}")/"${TEST_RMXATTR_FILE}"
-        echo "${TEST_INPUT}" | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}" --metadata xattr=%7B%22key%22%3A%22dmFsdWU%3D%22%7D
+        echo "${TEST_INPUT}" | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" --header "x-amz-meta-xattr: %7B%22key%22%3A%22dmFsdWU%3D%22%7D"
         del_xattr key "${TEST_RMXATTR_FILE}"
         cmp "${TEST_RMXATTR_FILE}" <(echo "${TEST_INPUT}")
         if find_xattr key "${TEST_RMXATTR_FILE}"; then
@@ -561,7 +561,7 @@ function test_update_metadata_external_large_object() {
     # chmod
     #
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/"${TEST_CHMOD_FILE}"
-    aws_cli s3 cp "${TEMP_DIR}/${BIG_FILE}" "s3://${TEST_BUCKET_1}/${OBJECT_NAME}" --no-progress
+    s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" < "${TEMP_DIR}/${BIG_FILE}"
     chmod +x "${TEST_CHMOD_FILE}"
     cmp "${TEST_CHMOD_FILE}" "${TEMP_DIR}/${BIG_FILE}"
 
@@ -569,7 +569,7 @@ function test_update_metadata_external_large_object() {
     # chown
     #
     OBJECT_NAME=$(basename "${PWD}")/"${TEST_CHOWN_FILE}"
-    aws_cli s3 cp "${TEMP_DIR}/${BIG_FILE}" "s3://${TEST_BUCKET_1}/${OBJECT_NAME}" --no-progress
+    s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" < "${TEMP_DIR}/${BIG_FILE}"
     chown "${UID}" "${TEST_CHOWN_FILE}"
     cmp "${TEST_CHOWN_FILE}" "${TEMP_DIR}/${BIG_FILE}"
 
@@ -577,7 +577,7 @@ function test_update_metadata_external_large_object() {
     # utimens
     #
     OBJECT_NAME=$(basename "${PWD}")/"${TEST_UTIMENS_FILE}"
-    aws_cli s3 cp "${TEMP_DIR}/${BIG_FILE}" "s3://${TEST_BUCKET_1}/${OBJECT_NAME}" --no-progress
+    s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" < "${TEMP_DIR}/${BIG_FILE}"
     touch "${TEST_UTIMENS_FILE}"
     cmp "${TEST_UTIMENS_FILE}" "${TEMP_DIR}/${BIG_FILE}"
 
@@ -585,7 +585,7 @@ function test_update_metadata_external_large_object() {
     # set xattr
     #
     OBJECT_NAME=$(basename "${PWD}")/"${TEST_SETXATTR_FILE}"
-    aws_cli s3 cp "${TEMP_DIR}/${BIG_FILE}" "s3://${TEST_BUCKET_1}/${OBJECT_NAME}" --no-progress
+    s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" < "${TEMP_DIR}/${BIG_FILE}"
     set_xattr key value "${TEST_SETXATTR_FILE}"
     cmp "${TEST_SETXATTR_FILE}" "${TEMP_DIR}/${BIG_FILE}"
     XATTR_VALUE=$(get_xattr key "${TEST_SETXATTR_FILE}")
@@ -611,7 +611,7 @@ function test_update_metadata_external_large_object() {
     #
     if ! uname | grep -q Darwin; then
         OBJECT_NAME=$(basename "${PWD}")/"${TEST_RMXATTR_FILE}"
-        aws_cli s3 cp "${TEMP_DIR}/${BIG_FILE}" "s3://${TEST_BUCKET_1}/${OBJECT_NAME}" --no-progress --metadata xattr=%7B%22key%22%3A%22dmFsdWU%3D%22%7D
+        s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" --header "x-amz-meta-xattr: %7B%22key%22%3A%22dmFsdWU%3D%22%7D" < "${TEMP_DIR}/${BIG_FILE}"
         del_xattr key "${TEST_RMXATTR_FILE}"
         cmp "${TEST_RMXATTR_FILE}" "${TEMP_DIR}/${BIG_FILE}"
         if find_xattr key "${TEST_RMXATTR_FILE}"; then
@@ -954,7 +954,7 @@ function test_update_time_chmod() {
 
     local t0=1000000000  # 9 September 2001
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/"${TEST_TEXT_FILE}"
-    echo data | aws_cli s3 cp --metadata="atime=${t0},ctime=${t0},mtime=${t0}" - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo data | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" --header "x-amz-meta-atime: ${t0}" --header "x-amz-meta-ctime: ${t0}" --header "x-amz-meta-mtime: ${t0}"
     local base_atime; base_atime=$(get_atime "${TEST_TEXT_FILE}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_TEXT_FILE}")
     local base_mtime; base_mtime=$(get_mtime "${TEST_TEXT_FILE}")
@@ -981,7 +981,7 @@ function test_update_time_chown() {
     #
     local t0=1000000000  # 9 September 2001
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/"${TEST_TEXT_FILE}"
-    echo data | aws_cli s3 cp --metadata="atime=${t0},ctime=${t0},mtime=${t0}" - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo data | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" --header "x-amz-meta-atime=${t0}" --header "x-amz-meta-ctime=${t0}" --header "x-amz-meta-mtime=${t0}"
     local base_atime; base_atime=$(get_atime "${TEST_TEXT_FILE}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_TEXT_FILE}")
     local base_mtime; base_mtime=$(get_mtime "${TEST_TEXT_FILE}")
@@ -1024,7 +1024,7 @@ function test_update_time_xattr() {
 
     local t0=1000000000  # 9 September 2001
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/"${TEST_TEXT_FILE}"
-    echo data | aws_cli s3 cp --metadata="atime=${t0},ctime=${t0},mtime=${t0}" - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo data | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" --header "x-amz-meta-atime: ${t0}" --header "x-amz-meta-ctime: ${t0}" --header "x-amz-meta-mtime: ${t0}"
     local base_atime; base_atime=$(get_atime "${TEST_TEXT_FILE}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_TEXT_FILE}")
     local base_mtime; base_mtime=$(get_mtime "${TEST_TEXT_FILE}")
@@ -1061,7 +1061,7 @@ function test_update_time_touch() {
 
     local t0=1000000000  # 9 September 2001
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/"${TEST_TEXT_FILE}"
-    echo data | aws_cli s3 cp --metadata="atime=${t0},ctime=${t0},mtime=${t0}" - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo data | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" --header "x-amz-meta-atime: ${t0}" --header "x-amz-meta-ctime: ${t0}" --header "x-amz-meta-mtime: ${t0}"
     local base_atime; base_atime=$(get_atime "${TEST_TEXT_FILE}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_TEXT_FILE}")
     local base_mtime; base_mtime=$(get_mtime "${TEST_TEXT_FILE}")
@@ -1085,7 +1085,7 @@ function test_update_time_touch_a() {
 
     local t0=1000000000  # 9 September 2001
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/"${TEST_TEXT_FILE}"
-    echo data | aws_cli s3 cp --metadata="atime=${t0},ctime=${t0},mtime=${t0}" - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo data | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" --header "x-amz-meta-atime: ${t0}" --header "x-amz-meta-ctime: ${t0}" --header "x-amz-meta-mtime: ${t0}"
     local base_atime; base_atime=$(get_atime "${TEST_TEXT_FILE}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_TEXT_FILE}")
     local base_mtime; base_mtime=$(get_mtime "${TEST_TEXT_FILE}")
@@ -1121,7 +1121,7 @@ function test_update_time_append() {
 
     local t0=1000000000  # 9 September 2001
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/"${TEST_TEXT_FILE}"
-    echo data | aws_cli s3 cp --metadata="atime=${t0},ctime=${t0},mtime=${t0}" - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo data | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" --header "x-amz-meta-atime: ${t0}" --header "x-amz-meta-ctime: ${t0}" --header "x-amz-meta-mtime: ${t0}"
     local base_atime; base_atime=$(get_atime "${TEST_TEXT_FILE}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_TEXT_FILE}")
     local base_mtime; base_mtime=$(get_mtime "${TEST_TEXT_FILE}")
@@ -1145,7 +1145,7 @@ function test_update_time_cp_p() {
 
     local t0=1000000000  # 9 September 2001
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/"${TEST_TEXT_FILE}"
-    echo data | aws_cli s3 cp --metadata="atime=${t0},ctime=${t0},mtime=${t0}" - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo data | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" --header "x-amz-meta-atime: ${t0}" --header "x-amz-meta-ctime: ${t0}" --header "x-amz-meta-mtime: ${t0}"
     local base_atime; base_atime=$(get_atime "${TEST_TEXT_FILE}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_TEXT_FILE}")
     local base_mtime; base_mtime=$(get_mtime "${TEST_TEXT_FILE}")
@@ -1171,7 +1171,7 @@ function test_update_time_mv() {
 
     local t0=1000000000  # 9 September 2001
     local OBJECT_NAME; OBJECT_NAME=$(basename "${PWD}")/"${TEST_TEXT_FILE}"
-    echo data | aws_cli s3 cp --metadata="atime=${t0},ctime=${t0},mtime=${t0}" - "s3://${TEST_BUCKET_1}/${OBJECT_NAME}"
+    echo data | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME}" --header "x-amz-meta-atime: ${t0}" --header "x-amz-meta-ctime: ${t0}" --header "x-amz-meta-mtime: ${t0}"
     local base_atime; base_atime=$(get_atime "${TEST_TEXT_FILE}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_TEXT_FILE}")
     local base_mtime; base_mtime=$(get_mtime "${TEST_TEXT_FILE}")
@@ -1205,7 +1205,7 @@ function test_update_directory_time_chmod() {
     #
     local t0=1000000000  # 9 September 2001
     local DIRECTORY_NAME; DIRECTORY_NAME=$(basename "${PWD}")/"${TEST_DIR}"
-    aws_cli s3api put-object --content-type="application/x-directory" --metadata="atime=${t0},ctime=${t0},mtime=${t0}" --bucket "${TEST_BUCKET_1}" --key "$DIRECTORY_NAME/"
+    s3_cp "${TEST_BUCKET_1}/${DIRECTORY_NAME}/" --header "Content-Type: application/x-directory" --header "x-amz-meta-atime: ${t0}" --header "x-amz-meta-ctime: ${t0}" --header "x-amz-meta-mtime: ${t0}" < /dev/null
 
     local base_atime; base_atime=$(get_atime "${TEST_DIR}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_DIR}")
@@ -1231,7 +1231,7 @@ function test_update_directory_time_chown {
 
     local t0=1000000000  # 9 September 2001
     local DIRECTORY_NAME; DIRECTORY_NAME=$(basename "${PWD}")/"${TEST_DIR}"
-    aws_cli s3api put-object --content-type="application/x-directory" --metadata="atime=${t0},ctime=${t0},mtime=${t0}" --bucket "${TEST_BUCKET_1}" --key "$DIRECTORY_NAME/"
+    s3_cp "${TEST_BUCKET_1}/${DIRECTORY_NAME}/" --header "Content-Type: application/x-directory" --header "x-amz-meta-atime: ${t0}" --header "x-amz-meta-ctime: ${t0}" --header "x-amz-meta-mtime: ${t0}" < /dev/null
 
     local base_atime; base_atime=$(get_atime "${TEST_DIR}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_DIR}")
@@ -1267,7 +1267,7 @@ function test_update_directory_time_set_xattr {
 
     local t0=1000000000  # 9 September 2001
     local DIRECTORY_NAME; DIRECTORY_NAME=$(basename "${PWD}")/"${TEST_DIR}"
-    aws_cli s3api put-object --content-type="application/x-directory" --metadata="atime=${t0},ctime=${t0},mtime=${t0}" --bucket "${TEST_BUCKET_1}" --key "$DIRECTORY_NAME/"
+    s3_cp "${TEST_BUCKET_1}/${DIRECTORY_NAME}/" --header "Content-Type: application/x-directory" --header "x-amz-meta-atime: ${t0}" --header "x-amz-meta-ctime: ${t0}" --header "x-amz-meta-mtime: ${t0}" < /dev/null
 
     local base_atime; base_atime=$(get_atime "${TEST_DIR}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_DIR}")
@@ -1303,7 +1303,7 @@ function test_update_directory_time_touch {
 
     local t0=1000000000  # 9 September 2001
     local DIRECTORY_NAME; DIRECTORY_NAME=$(basename "${PWD}")/"${TEST_DIR}"
-    aws_cli s3api put-object --content-type="application/x-directory" --metadata="atime=${t0},ctime=${t0},mtime=${t0}" --bucket "${TEST_BUCKET_1}" --key "$DIRECTORY_NAME/"
+    s3_cp "${TEST_BUCKET_1}/${DIRECTORY_NAME}/" --header "Content-Type: application/x-directory" --header "x-amz-meta-atime: ${t0}" --header "x-amz-meta-ctime: ${t0}" --header "x-amz-meta-mtime: ${t0}" < /dev/null
 
     local base_atime; base_atime=$(get_atime "${TEST_DIR}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_DIR}")
@@ -1328,7 +1328,7 @@ function test_update_directory_time_touch_a {
 
     local t0=1000000000  # 9 September 2001
     local DIRECTORY_NAME; DIRECTORY_NAME=$(basename "${PWD}")/"${TEST_DIR}"
-    aws_cli s3api put-object --content-type="application/x-directory" --metadata="atime=${t0},ctime=${t0},mtime=${t0}" --bucket "${TEST_BUCKET_1}" --key "$DIRECTORY_NAME/"
+    s3_cp "${TEST_BUCKET_1}/${DIRECTORY_NAME}/" --header "Content-Type: application/x-directory" --header "x-amz-meta-atime: ${t0}" --header "x-amz-meta-ctime: ${t0}" --header "x-amz-meta-mtime: ${t0}" < /dev/null
 
     local base_atime; base_atime=$(get_atime "${TEST_DIR}")
     local base_ctime; base_ctime=$(get_ctime "${TEST_DIR}")
@@ -2379,8 +2379,8 @@ function test_not_existed_dir_obj() {
     #
     local OBJECT_NAME_1; OBJECT_NAME_1="${DIR_NAME}/not_existed_dir_single/${TEST_TEXT_FILE}"
     local OBJECT_NAME_2; OBJECT_NAME_2="${DIR_NAME}/not_existed_dir_parent/not_existed_dir_child/${TEST_TEXT_FILE}"
-    echo data1 | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${OBJECT_NAME_1}"
-    echo data2 | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${OBJECT_NAME_2}"
+    echo data1 | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME_1}"
+    echo data2 | s3_cp "${TEST_BUCKET_1}/${OBJECT_NAME_2}"
 
     # Top directory
     # shellcheck disable=SC2010
@@ -2744,7 +2744,7 @@ function test_file_names_longer_than_posix() {
     fi
     rm -f "${a256}"
 
-    echo data | aws_cli s3 cp - "s3://${TEST_BUCKET_1}/${DIR_NAME}/${a256}"
+    echo data | s3_cp "${TEST_BUCKET_1}/${DIR_NAME}/${a256}"
     files=(*)
     if [ "${#files[@]}" = 0 ]; then
         echo "failed to list long file name"
diff --git a/test/small-integration-test.sh b/test/small-integration-test.sh
index 6a1029f..f597eb3 100755
--- a/test/small-integration-test.sh
+++ b/test/small-integration-test.sh
@@ -69,8 +69,8 @@ fi
 
 start_s3proxy
 
-if ! aws_cli s3api head-bucket --bucket "${TEST_BUCKET_1}" --region "${S3_ENDPOINT}"; then
-    aws_cli s3 mb "s3://${TEST_BUCKET_1}" --region "${S3_ENDPOINT}"
+if ! s3_head "${TEST_BUCKET_1}"; then
+    s3_mb "${TEST_BUCKET_1}"
 fi
 
 for flag in "${FLAGS[@]}"; do
diff --git a/test/test-utils.sh b/test/test-utils.sh
index e1b7ed3..cdc02ae 100644
--- a/test/test-utils.sh
+++ b/test/test-utils.sh
@@ -363,7 +363,10 @@ function get_user_and_group() {
 
 function check_content_type() {
     local INFO_STR
-    INFO_STR=$(aws_cli s3api head-object --bucket "${TEST_BUCKET_1}" --key "$1" | jq -r .ContentType)
+    TEMPNAME="$(mktemp)"
+    s3_head "${TEST_BUCKET_1}/$1" --dump-header "$TEMPNAME"
+    INFO_STR=$(sed -n 's/^Content-Type: //pi' "$TEMPNAME" | tr -d '\r\n')
+    rm -f "$TEMPNAME"
     if [ "${INFO_STR}" != "$2" ]
     then
         echo "Expected Content-Type: $2 but got: ${INFO_STR}"
@@ -377,27 +380,34 @@ function get_disk_avail_size() {
     echo "${DISK_AVAIL_SIZE}"
 }
 
-function aws_cli() {
-    local FLAGS=""
-    if [ -n "${S3FS_PROFILE}" ]; then
-        FLAGS="--profile ${S3FS_PROFILE}"
-    fi
+function s3_head() {
+    local S3_PATH=$1
+    shift
+    curl --aws-sigv4 "aws:amz:$S3_ENDPOINT:s3" --user "$AWS_ACCESS_KEY_ID:$AWS_SECRET_ACCESS_KEY" \
+        --cacert "$S3PROXY_CACERT_FILE" --fail --silent \
+        "$@" \
+        --head "$S3_URL/$S3_PATH"
+}
 
-    if [ "$1" = "s3" ] && [ "$2" != "ls" ] && [ "$2" != "mb" ]; then
-        if s3fs_args | grep -q use_sse=custom; then
-            FLAGS="${FLAGS} --sse-c AES256 --sse-c-key fileb:///tmp/ssekey.bin"
-        fi
-    elif [ "$1" = "s3api" ] && [ "$2" != "head-bucket" ]; then
-        if s3fs_args | grep -q use_sse=custom; then
-            FLAGS="${FLAGS} --sse-customer-algorithm AES256 --sse-customer-key $(cat /tmp/ssekey) --sse-customer-key-md5 $(cat /tmp/ssekeymd5)"
-        fi
-    fi
+function s3_mb() {
+    local S3_BUCKET=$1
+    curl --aws-sigv4 "aws:amz:$S3_ENDPOINT:s3" --user "$AWS_ACCESS_KEY_ID:$AWS_SECRET_ACCESS_KEY" \
+        --cacert "$S3PROXY_CACERT_FILE" --fail --silent \
+        --request PUT "$S3_URL/$S3_BUCKET"
+}
 
-    # [NOTE]
-    # AWS_EC2_METADATA_DISABLED for preventing the metadata service(to 169.254.169.254).
-    # shellcheck disable=SC2086,SC2068
-    # TODO: disable checksums to work around https://github.com/gaul/s3proxy/issues/760
-    AWS_EC2_METADATA_DISABLED=true AWS_REQUEST_CHECKSUM_CALCULATION=WHEN_REQUIRED aws $@ --endpoint-url "${S3_URL}" --ca-bundle /tmp/keystore.pem ${FLAGS}
+function s3_cp() {
+    local S3_PATH=$1
+    shift
+    TEMPNAME="$(mktemp)"
+    cat > "$TEMPNAME"
+    # TODO: use filenames instead of stdin?
+    curl --aws-sigv4 "aws:amz:$S3_ENDPOINT:s3" --user "$AWS_ACCESS_KEY_ID:$AWS_SECRET_ACCESS_KEY" \
+        --cacert "$S3PROXY_CACERT_FILE" --fail --silent \
+        --header "Content-Length: $(wc -c < "$TEMPNAME")" \
+        "$@" \
+        --request PUT --data-binary "@$TEMPNAME" "$S3_URL/$S3_PATH"
+    rm -f "$TEMPNAME"
 }
 
 function wait_for_port() {