Merge pull request #20915 from bluca/libsystemd_openssl

libsystemd/sd-id128: use only internal hmac, remove khash/OpenSSL support

22 files changed, 301 insertions, 577 deletions

diff --git a/LICENSES/README.md b/LICENSES/README.md
index f01049c13f..3c28de51b1 100644
--- a/LICENSES/README.md
+++ b/LICENSES/README.md
@@ -58,3 +58,8 @@ The following exceptions apply:
    **BSD-3-Clause** license.
  * any files under test/ without an explicit license we assume non-copyrightable
    (eg: computer-generated fuzzer data)
+
+## OpenSSL Notes
+
+Note that building the systemd project with OpenSSL does not affect the libsystemd.so
+shared library, which is not linked with the OpenSSL library.
diff --git a/TODO b/TODO
index d8975158b9..776c90f12e 100644
--- a/TODO
+++ b/TODO
@@ -352,11 +352,9 @@ Features:
 
 * unify on openssl (as soon as OpenSSL 3.0 is out, and the Debian license
   confusion is gone)
-  - port sd_id128_get_machine_app_specific() over from khash
   - port resolved over from libgcrypt (DNSSEC code)
   - port journald + fsprg over from libgcrypt
   - port importd over from libgcrypt
-  - when that's done: kill khash.c
   - when that's done: kill gnutls support in resolved
 
 * add growvol and makevol options for /etc/crypttab, similar to
diff --git a/src/basic/hmac.c b/src/basic/hmac.c
new file mode 100644
index 0000000000..1e4e380aaa
--- /dev/null
+++ b/src/basic/hmac.c
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <assert.h>
+#include <string.h>
+
+#include "hmac.h"
+#include "sha256.h"
+
+#define HMAC_BLOCK_SIZE 64
+#define INNER_PADDING_BYTE 0x36
+#define OUTER_PADDING_BYTE 0x5c
+
+void hmac_sha256(const void *key,
+                 size_t key_size,
+                 const void *input,
+                 size_t input_size,
+                 uint8_t res[static SHA256_DIGEST_SIZE]) {
+
+        uint8_t inner_padding[HMAC_BLOCK_SIZE] = { };
+        uint8_t outer_padding[HMAC_BLOCK_SIZE] = { };
+        uint8_t replacement_key[SHA256_DIGEST_SIZE];
+        struct sha256_ctx hash;
+
+        assert(key);
+        assert(key_size > 0);
+        assert(res);
+
+        /* Implement algorithm as described by FIPS 198. */
+
+        /* The key needs to be block size length or less, hash it if it's longer. */
+        if (key_size > HMAC_BLOCK_SIZE) {
+                sha256_init_ctx(&hash);
+                sha256_process_bytes(key, key_size, &hash);
+                sha256_finish_ctx(&hash, replacement_key);
+                key = replacement_key;
+                key_size = SHA256_DIGEST_SIZE;
+        }
+
+        /* First, copy the key into the padding arrays. If it's shorter than
+         * the block size, the arrays are already initialized to 0. */
+        memcpy(inner_padding, key, key_size);
+        memcpy(outer_padding, key, key_size);
+
+        /* Then, XOR the provided key and any padding leftovers with the fixed
+         * padding bytes as defined in FIPS 198. */
+        for (size_t i = 0; i < HMAC_BLOCK_SIZE; i++) {
+                inner_padding[i] ^= INNER_PADDING_BYTE;
+                outer_padding[i] ^= OUTER_PADDING_BYTE;
+        }
+
+        /* First pass: hash the inner padding array and the input. */
+        sha256_init_ctx(&hash);
+        sha256_process_bytes(inner_padding, HMAC_BLOCK_SIZE, &hash);
+        sha256_process_bytes(input, input_size, &hash);
+        sha256_finish_ctx(&hash, res);
+
+        /* Second pass: hash the outer padding array and the result of the first pass. */
+        sha256_init_ctx(&hash);
+        sha256_process_bytes(outer_padding, HMAC_BLOCK_SIZE, &hash);
+        sha256_process_bytes(res, SHA256_DIGEST_SIZE, &hash);
+        sha256_finish_ctx(&hash, res);
+}
diff --git a/src/basic/hmac.h b/src/basic/hmac.h
new file mode 100644
index 0000000000..12b594c09b
--- /dev/null
+++ b/src/basic/hmac.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include <stdint.h>
+#include <stdlib.h>
+
+#define SHA256_DIGEST_SIZE 32
+
+/* Unoptimized implementation based on FIPS 198. 'res' has to be allocated by
+ * the caller. Prefer external OpenSSL functions, and use this only when
+ * linking to OpenSSL is not desireable (eg: libsystemd.so). */
+void hmac_sha256(const void *key, size_t key_size, const void *input, size_t input_size, uint8_t res[static SHA256_DIGEST_SIZE]);
diff --git a/src/basic/khash.c b/src/basic/khash.c
deleted file mode 100644
index 6a4d1dd594..0000000000
--- a/src/basic/khash.c
+++ /dev/null
@@ -1,321 +0,0 @@
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-
-#include <linux/if_alg.h>
-#include <stdbool.h>
-#include <sys/socket.h>
-
-#include "alloc-util.h"
-#include "fd-util.h"
-#include "hexdecoct.h"
-#include "khash.h"
-#include "macro.h"
-#include "missing_socket.h"
-#include "string-util.h"
-#include "util.h"
-
-/* On current kernels the maximum digest (according to "grep digestsize /proc/crypto | sort -u") is actually 32, but
- * let's add some extra room, the few wasted bytes don't really matter... */
-#define LONGEST_DIGEST 128
-
-struct khash {
-        int fd;
-        char *algorithm;
-        uint8_t digest[LONGEST_DIGEST+1];
-        size_t digest_size;
-        bool digest_valid;
-};
-
-int khash_supported(void) {
-        static const union {
-                struct sockaddr sa;
-                struct sockaddr_alg alg;
-        } sa = {
-                .alg.salg_family = AF_ALG,
-                .alg.salg_type = "hash",
-                .alg.salg_name = "sha256", /* a very common algorithm */
-        };
-
-        static int cached = -1;
-
-        if (cached < 0) {
-                _cleanup_close_ int fd1 = -1, fd2 = -1;
-                uint8_t buf[LONGEST_DIGEST+1];
-
-                fd1 = socket(AF_ALG, SOCK_SEQPACKET|SOCK_CLOEXEC, 0);
-                if (fd1 < 0) {
-                        /* The kernel returns EAFNOSUPPORT if AF_ALG is not supported at all */
-                        if (IN_SET(errno, EAFNOSUPPORT, EOPNOTSUPP))
-                                return (cached = false);
-
-                        return -errno;
-                }
-
-                if (bind(fd1, &sa.sa, sizeof(sa)) < 0) {
-                        /* The kernel returns ENOENT if the selected algorithm is not supported at all. We use a check
-                         * for SHA256 as a proxy for whether the whole API is supported at all. After all it's one of
-                         * the most common hash functions, and if it isn't supported, that's ample indication that
-                         * something is really off. */
-
-                        if (IN_SET(errno, ENOENT, EOPNOTSUPP))
-                                return (cached = false);
-
-                        return -errno;
-                }
-
-                fd2 = accept4(fd1, NULL, 0, SOCK_CLOEXEC);
-                if (fd2 < 0) {
-                        if (errno == EOPNOTSUPP)
-                                return (cached = false);
-
-                        return -errno;
-                }
-
-                if (recv(fd2, buf, sizeof(buf), 0) < 0) {
-                        /* On some kernels we get ENOKEY for non-keyed hash functions (such as sha256), let's refuse
-                         * using the API in those cases, since the kernel is
-                         * broken. https://github.com/systemd/systemd/issues/8278 */
-
-                        if (IN_SET(errno, ENOKEY, EOPNOTSUPP))
-                                return (cached = false);
-                }
-
-                cached = true;
-        }
-
-        return cached;
-}
-
-int khash_new_with_key(khash **ret, const char *algorithm, const void *key, size_t key_size) {
-        union {
-                struct sockaddr sa;
-                struct sockaddr_alg alg;
-        } sa = {
-                .alg.salg_family = AF_ALG,
-                .alg.salg_type = "hash",
-        };
-
-        _cleanup_(khash_unrefp) khash *h = NULL;
-        _cleanup_close_ int fd = -1;
-        int supported;
-        ssize_t n;
-
-        assert(ret);
-        assert(key || key_size == 0);
-
-        /* Filter out an empty algorithm early, as we do not support an algorithm by that name. */
-        if (isempty(algorithm))
-                return -EINVAL;
-
-        /* Overly long hash algorithm names we definitely do not support */
-        if (strlen(algorithm) >= sizeof(sa.alg.salg_name))
-                return -EOPNOTSUPP;
-
-        supported = khash_supported();
-        if (supported < 0)
-                return supported;
-        if (supported == 0)
-                return -EOPNOTSUPP;
-
-        fd = socket(AF_ALG, SOCK_SEQPACKET|SOCK_CLOEXEC, 0);
-        if (fd < 0)
-                return -errno;
-
-        strcpy((char*) sa.alg.salg_name, algorithm);
-        if (bind(fd, &sa.sa, sizeof(sa)) < 0) {
-                if (errno == ENOENT)
-                        return -EOPNOTSUPP;
-                return -errno;
-        }
-
-        if (key) {
-                if (setsockopt(fd, SOL_ALG, ALG_SET_KEY, key, key_size) < 0)
-                        return -errno;
-        }
-
-        h = new0(khash, 1);
-        if (!h)
-                return -ENOMEM;
-
-        h->fd = accept4(fd, NULL, 0, SOCK_CLOEXEC);
-        if (h->fd < 0)
-                return -errno;
-
-        h->algorithm = strdup(algorithm);
-        if (!h->algorithm)
-                return -ENOMEM;
-
-        /* Temporary fix for rc kernel bug: https://bugzilla.redhat.com/show_bug.cgi?id=1395896 */
-        (void) send(h->fd, NULL, 0, 0);
-
-        /* Figure out the digest size */
-        n = recv(h->fd, h->digest, sizeof(h->digest), 0);
-        if (n < 0)
-                return -errno;
-        if (n >= LONGEST_DIGEST) /* longer than what we expected? If so, we don't support this */
-                return -EOPNOTSUPP;
-
-        h->digest_size = (size_t) n;
-        h->digest_valid = true;
-
-        /* Temporary fix for rc kernel bug: https://bugzilla.redhat.com/show_bug.cgi?id=1395896 */
-        (void) send(h->fd, NULL, 0, 0);
-
-        *ret = TAKE_PTR(h);
-
-        return 0;
-}
-
-int khash_new(khash **ret, const char *algorithm) {
-        return khash_new_with_key(ret, algorithm, NULL, 0);
-}
-
-khash* khash_unref(khash *h) {
-        if (!h)
-                return NULL;
-
-        safe_close(h->fd);
-        free(h->algorithm);
-        return mfree(h);
-}
-
-int khash_dup(khash *h, khash **ret) {
-        _cleanup_(khash_unrefp) khash *copy = NULL;
-
-        assert(h);
-        assert(ret);
-
-        copy = newdup(khash, h, 1);
-        if (!copy)
-                return -ENOMEM;
-
-        copy->fd = -1;
-        copy->algorithm = strdup(h->algorithm);
-        if (!copy->algorithm)
-                return -ENOMEM;
-
-        copy->fd = accept4(h->fd, NULL, 0, SOCK_CLOEXEC);
-        if (copy->fd < 0)
-                return -errno;
-
-        *ret = TAKE_PTR(copy);
-
-        return 0;
-}
-
-const char *khash_get_algorithm(khash *h) {
-        assert(h);
-
-        return h->algorithm;
-}
-
-size_t khash_get_size(khash *h) {
-        assert(h);
-
-        return h->digest_size;
-}
-
-int khash_reset(khash *h) {
-        ssize_t n;
-
-        assert(h);
-
-        n = send(h->fd, NULL, 0, 0);
-        if (n < 0)
-                return -errno;
-
-        h->digest_valid = false;
-
-        return 0;
-}
-
-int khash_put(khash *h, const void *buffer, size_t size) {
-        ssize_t n;
-
-        assert(h);
-        assert(buffer || size == 0);
-
-        if (size <= 0)
-                return 0;
-
-        n = send(h->fd, buffer, size, MSG_MORE);
-        if (n < 0)
-                return -errno;
-
-        h->digest_valid = false;
-
-        return 0;
-}
-
-int khash_put_iovec(khash *h, const struct iovec *iovec, size_t n) {
-        struct msghdr mh = {
-                .msg_iov = (struct iovec*) iovec,
-                .msg_iovlen = n,
-        };
-        ssize_t k;
-
-        assert(h);
-        assert(iovec || n == 0);
-
-        if (n <= 0)
-                return 0;
-
-        k = sendmsg(h->fd, &mh, MSG_MORE);
-        if (k < 0)
-                return -errno;
-
-        h->digest_valid = false;
-
-        return 0;
-}
-
-static int retrieve_digest(khash *h) {
-        ssize_t n;
-
-        assert(h);
-
-        if (h->digest_valid)
-                return 0;
-
-        n = recv(h->fd, h->digest, h->digest_size, 0);
-        if (n < 0)
-                return n;
-        if ((size_t) n != h->digest_size) /* digest size changed? */
-                return -EIO;
-
-        h->digest_valid = true;
-
-        return 0;
-}
-
-int khash_digest_data(khash *h, const void **ret) {
-        int r;
-
-        assert(h);
-        assert(ret);
-
-        r = retrieve_digest(h);
-        if (r < 0)
-                return r;
-
-        *ret = h->digest;
-        return 0;
-}
-
-int khash_digest_string(khash *h, char **ret) {
-        int r;
-        char *p;
-
-        assert(h);
-        assert(ret);
-
-        r = retrieve_digest(h);
-        if (r < 0)
-                return r;
-
-        p = hexmem(h->digest, h->digest_size);
-        if (!p)
-                return -ENOMEM;
-
-        *ret = p;
-        return 0;
-}
diff --git a/src/basic/khash.h b/src/basic/khash.h
deleted file mode 100644
index a343d306e9..0000000000
--- a/src/basic/khash.h
+++ /dev/null
@@ -1,37 +0,0 @@
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-#pragma once
-
-#include <inttypes.h>
-#include <sys/types.h>
-#include <sys/uio.h>
-
-#include "macro.h"
-
-typedef struct khash khash;
-
-int khash_supported(void);
-
-/* For plain hash functions. Hash functions commonly supported on today's kernels are: crc32c, crct10dif, crc32,
- * sha224, sha256, sha512, sha384, sha1, md5, md4, sha3-224, sha3-256, sha3-384, sha3-512, and more. */
-int khash_new(khash **ret, const char *algorithm);
-
-/* For keyed hash functions. Hash functions commonly supported on today's kernels are: hmac(sha256), cmac(aes),
- * cmac(des3_ede), hmac(sha3-512), hmac(sha3-384), hmac(sha3-256), hmac(sha3-224), hmac(rmd160), hmac(rmd128),
- * hmac(sha224), hmac(sha512), hmac(sha384), hmac(sha1), hmac(md5), and more. */
-int khash_new_with_key(khash **ret, const char *algorithm, const void *key, size_t key_size);
-
-int khash_dup(khash *h, khash **ret);
-khash* khash_unref(khash *h);
-
-const char *khash_get_algorithm(khash *h);
-size_t khash_get_size(khash *h);
-
-int khash_reset(khash *h);
-
-int khash_put(khash *h, const void *buffer, size_t size);
-int khash_put_iovec(khash *h, const struct iovec *iovec, size_t n);
-
-int khash_digest_data(khash *h, const void **ret);
-int khash_digest_string(khash *h, char **ret);
-
-DEFINE_TRIVIAL_CLEANUP_FUNC(khash*, khash_unref);
diff --git a/src/basic/meson.build b/src/basic/meson.build
index adb7b666c6..cf97f6de1d 100644
--- a/src/basic/meson.build
+++ b/src/basic/meson.build
@@ -72,6 +72,8 @@ basic_sources = files('''
         hashmap.h
         hexdecoct.c
         hexdecoct.h
+        hmac.c
+        hmac.h
         hostname-util.c
         hostname-util.h
         in-addr-util.c
@@ -80,8 +82,6 @@ basic_sources = files('''
         inotify-util.h
         io-util.c
         io-util.h
-        khash.c
-        khash.h
         limits-util.c
         limits-util.h
         linux/btrfs.h
diff --git a/src/boot/efi/meson.build b/src/boot/efi/meson.build
index fef8572c6a..81b750d5d3 100644
--- a/src/boot/efi/meson.build
+++ b/src/boot/efi/meson.build
@@ -12,7 +12,6 @@ efi_headers = files('''
         missing_efi.h
         pe.h
         random-seed.h
-        sha256.h
         shim.h
         splash.h
         util.h
@@ -34,7 +33,6 @@ systemd_boot_sources = '''
         devicetree.c
         drivers.c
         random-seed.c
-        sha256.c
         shim.c
 '''.split()
 
diff --git a/src/boot/efi/sha256.h b/src/boot/efi/sha256.h
deleted file mode 100644
index 464be59c25..0000000000
--- a/src/boot/efi/sha256.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-#pragma once
-
-#include <efi.h>
-#include <efilib.h>
-
-struct sha256_ctx {
-        UINT32 H[8];
-
-        union {
-                UINT64 total64;
-#define TOTAL64_low (1 - (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
-#define TOTAL64_high (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
-                UINT32 total[2];
-        };
-
-        UINT32 buflen;
-
-        union {
-                UINT8 buffer[128]; /* NB: always correctly aligned for UINT32.  */
-                UINT32 buffer32[32];
-                UINT64 buffer64[16];
-        };
-};
-
-void sha256_init_ctx(struct sha256_ctx *ctx);
-void *sha256_finish_ctx(struct sha256_ctx *ctx, VOID *resbuf);
-void sha256_process_bytes(const void *buffer, UINTN len, struct sha256_ctx *ctx);
diff --git a/src/fundamental/macro-fundamental.h b/src/fundamental/macro-fundamental.h
index 20d8dabf29..7fa4b85be7 100644
--- a/src/fundamental/macro-fundamental.h
+++ b/src/fundamental/macro-fundamental.h
@@ -59,6 +59,8 @@
                 #define assert(expr) ({ _likely_(expr) ? VOID_0 : efi_assert(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); })
                 #define assert_not_reached() efi_assert("Code should not be reached", __FILE__, __LINE__, __PRETTY_FUNCTION__)
         #endif
+
+        #define memcpy(a, b, c) CopyMem((a), (b), (c))
 #endif
 
 #if defined(static_assert)
diff --git a/src/fundamental/meson.build b/src/fundamental/meson.build
index 3c43081cf6..3aa9fab8cb 100644
--- a/src/fundamental/meson.build
+++ b/src/fundamental/meson.build
@@ -6,10 +6,12 @@ fundamental_headers = files(
         'efi-loader-features.h',
         'macro-fundamental.h',
         'string-util-fundamental.h',
+        'sha256.h',
         'type.h')
 
 sources = '''
         string-util-fundamental.c
+        sha256.c
 '''.split()
 
 # for sd-boot
diff --git a/src/boot/efi/sha256.c b/src/fundamental/sha256.c
index d2e267eeff..0577a24920 100644
--- a/src/boot/efi/sha256.c
+++ b/src/fundamental/sha256.c
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
-/* Stolen from glibc and converted to UEFI style. In glibc it comes with the following copyright blurb: */
+/* Stolen from glibc and converted to our style. In glibc it comes with the following copyright blurb: */
 
 /* Functions to compute SHA256 message digest of files or memory blocks.
    according to the definition of SHA256 in FIPS 180-2.
@@ -23,6 +23,10 @@
 
 /* Written by Ulrich Drepper <drepper@redhat.com>, 2007.  */
 
+#ifndef SD_BOOT
+#include <string.h>
+#endif
+
 #include "macro-fundamental.h"
 #include "sha256.h"
 
@@ -45,12 +49,12 @@
 
 /* This array contains the bytes used to pad the buffer to the next
    64-byte boundary.  (FIPS 180-2:5.1.1)  */
-static const UINT8 fillbuf[64] = {
+static const uint8_t fillbuf[64] = {
         0x80, 0 /* , 0, 0, ...  */
 };
 
 /* Constants for SHA256 from FIPS 180-2:4.2.2.  */
-static const UINT32 K[64] = {
+static const uint32_t K[64] = {
         0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
         0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
         0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
@@ -69,7 +73,7 @@ static const UINT32 K[64] = {
         0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
 };
 
-static void sha256_process_block(const void *, UINTN, struct sha256_ctx *);
+static void sha256_process_block(const void *, size_t, struct sha256_ctx *);
 
 /* Initialize structure containing state of computation.
    (FIPS 180-2:5.3.2)  */
@@ -96,8 +100,8 @@ void sha256_init_ctx(struct sha256_ctx *ctx) {
    aligned for a 32 bits value.  */
 void *sha256_finish_ctx(struct sha256_ctx *ctx, void *resbuf) {
         /* Take yet unprocessed bytes into account.  */
-        UINT32 bytes = ctx->buflen;
-        UINTN pad;
+        uint32_t bytes = ctx->buflen;
+        size_t pad;
 
         assert(ctx);
         assert(resbuf);
@@ -106,7 +110,7 @@ void *sha256_finish_ctx(struct sha256_ctx *ctx, void *resbuf) {
         ctx->total64 += bytes;
 
         pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
-        CopyMem(&ctx->buffer[bytes], fillbuf, pad);
+        memcpy(&ctx->buffer[bytes], fillbuf, pad);
 
         /* Put the 64-bit file length in *bits* at the end of the buffer.  */
         ctx->buffer32[(bytes + pad + 4) / 4] = SWAP(ctx->total[TOTAL64_low] << 3);
@@ -117,13 +121,13 @@ void *sha256_finish_ctx(struct sha256_ctx *ctx, void *resbuf) {
         sha256_process_block(ctx->buffer, bytes + pad + 8, ctx);
 
         /* Put result from CTX in first 32 bytes following RESBUF.  */
-        for (UINTN i = 0; i < 8; ++i)
-                ((UINT32 *) resbuf)[i] = SWAP(ctx->H[i]);
+        for (size_t i = 0; i < 8; ++i)
+                ((uint32_t *) resbuf)[i] = SWAP(ctx->H[i]);
 
         return resbuf;
 }
 
-void sha256_process_bytes(const void *buffer, UINTN len, struct sha256_ctx *ctx) {
+void sha256_process_bytes(const void *buffer, size_t len, struct sha256_ctx *ctx) {
         assert(buffer);
         assert(ctx);
 
@@ -131,10 +135,10 @@ void sha256_process_bytes(const void *buffer, UINTN len, struct sha256_ctx *ctx)
            both inputs first.  */
 
         if (ctx->buflen != 0) {
-                UINTN left_over = ctx->buflen;
-                UINTN add = 128 - left_over > len ? len : 128 - left_over;
+                size_t left_over = ctx->buflen;
+                size_t add = 128 - left_over > len ? len : 128 - left_over;
 
-                CopyMem(&ctx->buffer[left_over], buffer, add);
+                memcpy(&ctx->buffer[left_over], buffer, add);
                 ctx->buflen += add;
 
                 if (ctx->buflen > 64) {
@@ -142,7 +146,7 @@ void sha256_process_bytes(const void *buffer, UINTN len, struct sha256_ctx *ctx)
 
                         ctx->buflen &= 63;
                         /* The regions in the following copy operation cannot overlap.  */
-                        CopyMem(ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
+                        memcpy(ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
                                 ctx->buflen);
                 }
 
@@ -159,13 +163,13 @@ void sha256_process_bytes(const void *buffer, UINTN len, struct sha256_ctx *ctx)
 
 /* To check alignment gcc has an appropriate operator. Other compilers don't.  */
 # if __GNUC__ >= 2
-#  define UNALIGNED_P(p) (((UINTN) p) % __alignof__(UINT32) != 0)
+#  define UNALIGNED_P(p) (((size_t) p) % __alignof__(uint32_t) != 0)
 # else
-#  define UNALIGNED_P(p) (((UINTN) p) % sizeof(UINT32) != 0)
+#  define UNALIGNED_P(p) (((size_t) p) % sizeof(uint32_t) != 0)
 # endif
                 if (UNALIGNED_P(buffer))
                         while (len > 64) {
-                                CopyMem(ctx->buffer, buffer, 64);
+                                memcpy(ctx->buffer, buffer, 64);
                                 sha256_process_block(ctx->buffer, 64, ctx);
                                 buffer = (const char *) buffer + 64;
                                 len -= 64;
@@ -181,14 +185,14 @@ void sha256_process_bytes(const void *buffer, UINTN len, struct sha256_ctx *ctx)
 
         /* Move remaining bytes into internal buffer.  */
         if (len > 0) {
-                UINTN left_over = ctx->buflen;
+                size_t left_over = ctx->buflen;
 
-                CopyMem(&ctx->buffer[left_over], buffer, len);
+                memcpy(&ctx->buffer[left_over], buffer, len);
                 left_over += len;
                 if (left_over >= 64) {
                         sha256_process_block(ctx->buffer, 64, ctx);
                         left_over -= 64;
-                        CopyMem(ctx->buffer, &ctx->buffer[64], left_over);
+                        memcpy(ctx->buffer, &ctx->buffer[64], left_over);
                 }
                 ctx->buflen = left_over;
         }
@@ -197,21 +201,21 @@ void sha256_process_bytes(const void *buffer, UINTN len, struct sha256_ctx *ctx)
 
 /* Process LEN bytes of BUFFER, accumulating context into CTX.
    It is assumed that LEN % 64 == 0.  */
-static void sha256_process_block(const void *buffer, UINTN len, struct sha256_ctx *ctx) {
-        const UINT32 *words = buffer;
-        UINTN nwords = len / sizeof(UINT32);
+static void sha256_process_block(const void *buffer, size_t len, struct sha256_ctx *ctx) {
+        const uint32_t *words = buffer;
+        size_t nwords = len / sizeof(uint32_t);
 
         assert(buffer);
         assert(ctx);
 
-        UINT32 a = ctx->H[0];
-        UINT32 b = ctx->H[1];
-        UINT32 c = ctx->H[2];
-        UINT32 d = ctx->H[3];
-        UINT32 e = ctx->H[4];
-        UINT32 f = ctx->H[5];
-        UINT32 g = ctx->H[6];
-        UINT32 h = ctx->H[7];
+        uint32_t a = ctx->H[0];
+        uint32_t b = ctx->H[1];
+        uint32_t c = ctx->H[2];
+        uint32_t d = ctx->H[3];
+        uint32_t e = ctx->H[4];
+        uint32_t f = ctx->H[5];
+        uint32_t g = ctx->H[6];
+        uint32_t h = ctx->H[7];
 
         /* First increment the byte count.  FIPS 180-2 specifies the possible
            length of the file up to 2^64 bits.  Here we only compute the
@@ -221,15 +225,15 @@ static void sha256_process_block(const void *buffer, UINTN len, struct sha256_ct
         /* Process all bytes in the buffer with 64 bytes in each round of
            the loop.  */
         while (nwords > 0) {
-                UINT32 W[64];
-                UINT32 a_save = a;
-                UINT32 b_save = b;
-                UINT32 c_save = c;
-                UINT32 d_save = d;
-                UINT32 e_save = e;
-                UINT32 f_save = f;
-                UINT32 g_save = g;
-                UINT32 h_save = h;
+                uint32_t W[64];
+                uint32_t a_save = a;
+                uint32_t b_save = b;
+                uint32_t c_save = c;
+                uint32_t d_save = d;
+                uint32_t e_save = e;
+                uint32_t f_save = f;
+                uint32_t g_save = g;
+                uint32_t h_save = h;
 
                 /* Operators defined in FIPS 180-2:4.1.2.  */
 #define Ch(x, y, z) ((x & y) ^ (~x & z))
@@ -244,17 +248,17 @@ static void sha256_process_block(const void *buffer, UINTN len, struct sha256_ct
 #define CYCLIC(w, s) ((w >> s) | (w << (32 - s)))
 
                 /* Compute the message schedule according to FIPS 180-2:6.2.2 step 2.  */
-                for (UINTN t = 0; t < 16; ++t) {
+                for (size_t t = 0; t < 16; ++t) {
                         W[t] = SWAP (*words);
                         ++words;
                 }
-                for (UINTN t = 16; t < 64; ++t)
+                for (size_t t = 16; t < 64; ++t)
                         W[t] = R1 (W[t - 2]) + W[t - 7] + R0 (W[t - 15]) + W[t - 16];
 
                 /* The actual computation according to FIPS 180-2:6.2.2 step 3.  */
-                for (UINTN t = 0; t < 64; ++t) {
-                        UINT32 T1 = h + S1 (e) + Ch (e, f, g) + K[t] + W[t];
-                        UINT32 T2 = S0 (a) + Maj (a, b, c);
+                for (size_t t = 0; t < 64; ++t) {
+                        uint32_t T1 = h + S1 (e) + Ch (e, f, g) + K[t] + W[t];
+                        uint32_t T2 = S0 (a) + Maj (a, b, c);
                         h = g;
                         g = f;
                         f = e;
diff --git a/src/fundamental/sha256.h b/src/fundamental/sha256.h
new file mode 100644
index 0000000000..9fc090b4e0
--- /dev/null
+++ b/src/fundamental/sha256.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#ifdef SD_BOOT
+#include <efi.h>
+#include <efilib.h>
+#endif
+
+#include "type.h"
+
+struct sha256_ctx {
+        uint32_t H[8];
+
+        union {
+                uint64_t total64;
+#define TOTAL64_low (1 - (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
+#define TOTAL64_high (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+                uint32_t total[2];
+        };
+
+        uint32_t buflen;
+
+        union {
+                uint8_t  buffer[128]; /* NB: always correctly aligned for UINT32.  */
+                uint32_t buffer32[32];
+                uint64_t buffer64[16];
+        };
+};
+
+void sha256_init_ctx(struct sha256_ctx *ctx);
+void *sha256_finish_ctx(struct sha256_ctx *ctx, void *resbuf);
+void sha256_process_bytes(const void *buffer, size_t len, struct sha256_ctx *ctx);
diff --git a/src/fundamental/string-util-fundamental.c b/src/fundamental/string-util-fundamental.c
index 383e390577..101d3f7196 100644
--- a/src/fundamental/string-util-fundamental.c
+++ b/src/fundamental/string-util-fundamental.c
@@ -8,7 +8,7 @@
 #include "string-util-fundamental.h"
 
 sd_char *startswith(const sd_char *s, const sd_char *prefix) {
-        sd_size_t l;
+        size_t l;
 
         assert(s);
         assert(prefix);
@@ -22,7 +22,7 @@ sd_char *startswith(const sd_char *s, const sd_char *prefix) {
 
 #ifndef SD_BOOT
 sd_char *startswith_no_case(const sd_char *s, const sd_char *prefix) {
-        sd_size_t l;
+        size_t l;
 
         assert(s);
         assert(prefix);
@@ -36,7 +36,7 @@ sd_char *startswith_no_case(const sd_char *s, const sd_char *prefix) {
 #endif
 
 sd_char* endswith(const sd_char *s, const sd_char *postfix) {
-        sd_size_t sl, pl;
+        size_t sl, pl;
 
         assert(s);
         assert(postfix);
@@ -57,7 +57,7 @@ sd_char* endswith(const sd_char *s, const sd_char *postfix) {
 }
 
 sd_char* endswith_no_case(const sd_char *s, const sd_char *postfix) {
-        sd_size_t sl, pl;
+        size_t sl, pl;
 
         assert(s);
         assert(postfix);
diff --git a/src/fundamental/string-util-fundamental.h b/src/fundamental/string-util-fundamental.h
index 7455c05492..dc0c1202be 100644
--- a/src/fundamental/string-util-fundamental.h
+++ b/src/fundamental/string-util-fundamental.h
@@ -68,10 +68,10 @@ static inline const sd_char *yes_no(sd_bool b) {
 sd_int strverscmp_improved(const sd_char *a, const sd_char *b);
 
 /* Like startswith(), but operates on arbitrary memory blocks */
-static inline void *memory_startswith(const void *p, sd_size_t sz, const sd_char *token) {
+static inline void *memory_startswith(const void *p, size_t sz, const sd_char *token) {
         assert(token);
 
-        sd_size_t n = strlen(token) * sizeof(sd_char);
+        size_t n = strlen(token) * sizeof(sd_char);
         if (sz < n)
                 return NULL;
 
diff --git a/src/fundamental/type.h b/src/fundamental/type.h
index f645d2de7f..2a9a114bbc 100644
--- a/src/fundamental/type.h
+++ b/src/fundamental/type.h
@@ -7,7 +7,7 @@
 typedef BOOLEAN sd_bool;
 typedef CHAR16  sd_char;
 typedef INTN    sd_int;
-typedef UINTN   sd_size_t;
+typedef UINTN   size_t;
 
 #define true    TRUE
 #define false   FALSE
@@ -18,5 +18,4 @@ typedef UINTN   sd_size_t;
 typedef bool    sd_bool;
 typedef char    sd_char;
 typedef int     sd_int;
-typedef size_t  sd_size_t;
 #endif
diff --git a/src/libsystemd/meson.build b/src/libsystemd/meson.build
index 8ec871f6a4..02b2cd64b2 100644
--- a/src/libsystemd/meson.build
+++ b/src/libsystemd/meson.build
@@ -170,8 +170,7 @@ libsystemd_static = static_library(
         include_directories : libsystemd_includes,
         link_with : libbasic,
         dependencies : [threads,
-                        librt,
-                        libopenssl],
+                        librt],
         c_args : libsystemd_c_args)
 
 libsystemd_sym = files('libsystemd.sym')
diff --git a/src/libsystemd/sd-id128/sd-id128.c b/src/libsystemd/sd-id128/sd-id128.c
index 28ae10a198..992b19130e 100644
--- a/src/libsystemd/sd-id128/sd-id128.c
+++ b/src/libsystemd/sd-id128/sd-id128.c
@@ -4,21 +4,14 @@
 #include <fcntl.h>
 #include <unistd.h>
 
-#if HAVE_OPENSSL
-#include <openssl/hmac.h>
-#include <openssl/sha.h>
-#endif
-
 #include "sd-id128.h"
 
 #include "alloc-util.h"
 #include "fd-util.h"
 #include "hexdecoct.h"
+#include "hmac.h"
 #include "id128-util.h"
 #include "io-util.h"
-#if !HAVE_OPENSSL
-#include "khash.h"
-#endif
 #include "macro.h"
 #include "missing_syscall.h"
 #include "random-util.h"
@@ -278,43 +271,15 @@ _public_ int sd_id128_randomize(sd_id128_t *ret) {
 }
 
 static int get_app_specific(sd_id128_t base, sd_id128_t app_id, sd_id128_t *ret) {
+        uint8_t hmac[SHA256_DIGEST_SIZE];
         sd_id128_t result;
 
         assert(ret);
 
-#if HAVE_OPENSSL
-        /* We prefer doing this in-process, since we this means we are not dependent on kernel configuration,
-         * and this also works in locked down container environments. But some distros don't like OpenSSL's
-         * license and its (in-) compatibility with GPL2, hence also support khash */
-        uint8_t md[256/8];
-        if (!HMAC(EVP_sha256(),
-                  &base, sizeof(base),
-                  (const unsigned char*) &app_id, sizeof(app_id),
-                  md, NULL))
-                return -ENOTRECOVERABLE;
+        hmac_sha256(&base, sizeof(base), &app_id, sizeof(app_id), hmac);
 
         /* Take only the first half. */
-        memcpy(&result, md, MIN(sizeof(md), sizeof(result)));
-#else
-        _cleanup_(khash_unrefp) khash *h = NULL;
-        const void *p;
-        int r;
-
-        r = khash_new_with_key(&h, "hmac(sha256)", &base, sizeof(base));
-        if (r < 0)
-                return r;
-
-        r = khash_put(h, &app_id, sizeof(app_id));
-        if (r < 0)
-                return r;
-
-        r = khash_digest_data(h, &p);
-        if (r < 0)
-                return r;
-
-        /* We chop off the trailing 16 bytes */
-        memcpy(&result, p, MIN(khash_get_size(h), sizeof(result)));
-#endif
+        memcpy(&result, hmac, MIN(sizeof(hmac), sizeof(result)));
 
         *ret = id128_make_v4_uuid(result);
         return 0;
diff --git a/src/test/meson.build b/src/test/meson.build
index fea7f107fd..292b6329e4 100644
--- a/src/test/meson.build
+++ b/src/test/meson.build
@@ -592,8 +592,6 @@ tests += [
 
         [['src/test/test-id128.c']],
 
-        [['src/test/test-hash.c']],
-
         [['src/test/test-gcrypt-util.c'],
          [], [], [], 'HAVE_GCRYPT'],
 
@@ -629,6 +627,8 @@ tests += [
 
         [['src/test/test-nscd-flush.c'],
          [], [], [], 'ENABLE_NSCD', 'manual'],
+
+        [['src/test/test-hmac.c']],
 ]
 
 ############################################################
diff --git a/src/test/test-hash.c b/src/test/test-hash.c
deleted file mode 100644
index 270fcd0df4..0000000000
--- a/src/test/test-hash.c
+++ /dev/null
@@ -1,76 +0,0 @@
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-
-#include <errno.h>
-#include <stdio.h>
-
-#include "alloc-util.h"
-#include "log.h"
-#include "string-util.h"
-#include "khash.h"
-#include "tests.h"
-
-int main(int argc, char *argv[]) {
-        _cleanup_(khash_unrefp) khash *h = NULL, *copy = NULL;
-        _cleanup_free_ char *s = NULL;
-        int r;
-
-        test_setup_logging(LOG_DEBUG);
-
-        assert_se(khash_new(&h, NULL) == -EINVAL);
-        assert_se(khash_new(&h, "") == -EINVAL);
-
-        r = khash_supported();
-        assert_se(r >= 0);
-        if (r == 0)
-                return log_tests_skipped("khash not supported on this kernel");
-
-        assert_se(khash_new(&h, "foobar") == -EOPNOTSUPP); /* undefined hash function */
-
-        assert_se(khash_new(&h, "sha256") >= 0);
-        assert_se(khash_get_size(h) == 32);
-        assert_se(streq(khash_get_algorithm(h), "sha256"));
-
-        assert_se(khash_digest_string(h, &s) >= 0);
-        assert_se(streq(s, "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"));
-        s = mfree(s);
-
-        assert_se(khash_put(h, "foobar", 6) >= 0);
-        assert_se(khash_digest_string(h, &s) >= 0);
-        assert_se(streq(s, "c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2"));
-        s = mfree(s);
-
-        assert_se(khash_put(h, "piep", 4) >= 0);
-        assert_se(khash_digest_string(h, &s) >= 0);
-        assert_se(streq(s, "f114d872b5ea075d3be9040d0b7a429514b3f9324a8e8e3dc3fb24c34ee56bea"));
-        s = mfree(s);
-
-        assert_se(khash_put(h, "foo", 3) >= 0);
-        assert_se(khash_dup(h, &copy) >= 0);
-
-        assert_se(khash_put(h, "bar", 3) >= 0);
-        assert_se(khash_put(copy, "bar", 3) >= 0);
-
-        assert_se(khash_digest_string(h, &s) >= 0);
-        assert_se(streq(s, "c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2"));
-        s = mfree(s);
-
-        assert_se(khash_digest_string(copy, &s) >= 0);
-        assert_se(streq(s, "c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2"));
-        s = mfree(s);
-
-        h = khash_unref(h);
-
-        assert_se(khash_new_with_key(&h, "hmac(sha256)", "quux", 4) >= 0);
-        assert_se(khash_get_size(h) == 32);
-        assert_se(streq(khash_get_algorithm(h), "hmac(sha256)"));
-
-        assert_se(khash_digest_string(h, &s) >= 0);
-        assert_se(streq(s, "abed9f8218ab473f77218a6a7d39abf1d21fa46d0700c4898e330ba88309d5ae"));
-        s = mfree(s);
-
-        assert_se(khash_put(h, "foobar", 6) >= 0);
-        assert_se(khash_digest_string(h, &s) >= 0);
-        assert_se(streq(s, "33f6c70a60db66007d5325d5d1dea37c371354e5b83347a59ad339ce9f4ba3dc"));
-
-        return 0;
-}
diff --git a/src/test/test-hmac.c b/src/test/test-hmac.c
new file mode 100644
index 0000000000..5c73eca110
--- /dev/null
+++ b/src/test/test-hmac.c
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "hexdecoct.h"
+#include "hmac.h"
+#include "string-util.h"
+#include "tests.h"
+
+static void hmac_sha256_by_string(const char *key, const char *value, uint8_t res[static SHA256_DIGEST_SIZE]) {
+        hmac_sha256(key, strlen(key), value, strlen(value), res);
+}
+
+static void test_hmac(void) {
+    uint8_t result[SHA256_DIGEST_SIZE];
+    char *hex_result = NULL;
+
+    log_info("/* %s */", __func__);
+
+    /* Results compared with output of 'echo -n "<input>" | openssl dgst -sha256 -hmac "<key>"' */
+
+    hmac_sha256_by_string("waldo",
+                          "",
+                          result);
+    hex_result = hexmem(result, sizeof(result));
+    assert_se(streq_ptr(hex_result, "cadd5e42114351181f3abff477641d88efb57d2b5641a1e5c6d623363a6d3bad"));
+    hex_result = mfree(hex_result);
+
+    hmac_sha256_by_string("waldo",
+                          "baldohaldo",
+                          result);
+    hex_result = hexmem(result, sizeof(result));
+    assert_se(streq_ptr(hex_result, "c47ad5031ba21605e52c6ca68090d66a2dd5ccf84efa4bace15361a8cba63cda"));
+    hex_result = mfree(hex_result);
+
+    hmac_sha256_by_string("waldo",
+                          "baldo haldo",
+                          result);
+    hex_result = hexmem(result, sizeof(result));
+    assert_se(streq_ptr(hex_result, "4e8974ad6c08b98cc2519cd1e27aa7195769fcf86db1dd7ceaab4d44c490ad69"));
+    hex_result = mfree(hex_result);
+
+    hmac_sha256_by_string("waldo",
+                          "baldo 4e8974ad6c08b98cc2519cd1e27aa7195769fcf86db1dd7ceaab4d44c490ad69 haldo",
+                          result);
+    hex_result = hexmem(result, sizeof(result));
+    assert_se(streq_ptr(hex_result, "039f3df430b19753ffb493e5b90708f75c5210b63c6bcbef3374eb3f0a3f97f7"));
+    hex_result = mfree(hex_result);
+
+    hmac_sha256_by_string("4e8974ad6c08b98cc2519cd1e27aa7195769fcf86db1dd7ceaab4d44c490ad69",
+                          "baldo haldo",
+                          result);
+    hex_result = hexmem(result, sizeof(result));
+    assert_se(streq_ptr(hex_result, "c4cfaf48077cbb0bbd177a09e59ec4c248f4ca771503410f5b54b98d88d2f47b"));
+    hex_result = mfree(hex_result);
+
+    hmac_sha256_by_string("4e8974ad6c08b98cc2519cd1e27aa7195769fcf86db1dd7ceaab4d44c490ad69",
+                          "supercalifragilisticexpialidocious",
+                          result);
+    hex_result = hexmem(result, sizeof(result));
+    assert_se(streq_ptr(hex_result, "2c059e7a63c4c3b23f47966a65fd2f8a2f5d7161e2e90d78ff68866b5c375cb7"));
+    hex_result = mfree(hex_result);
+
+    hmac_sha256_by_string("4e8974ad6c08b98cc2519cd1e27aa7195769fcf86db1dd7ceaab4d44c490ad69c47ad5031ba21605e52c6ca68090d66a2dd5ccf84efa4bace15361a8cba63cda",
+                          "supercalifragilisticexpialidocious",
+                          result);
+    hex_result = hexmem(result, sizeof(result));
+    assert_se(streq_ptr(hex_result, "1dd1d1d45b9d9f9673dc9983c968c46ff3168e03cfeb4156a219eba1af4cff5f"));
+    hex_result = mfree(hex_result);
+}
+
+int main(int argc, char **argv) {
+        test_setup_logging(LOG_INFO);
+
+        test_hmac();
+
+        return 0;
+}
diff --git a/src/test/test-id128.c b/src/test/test-id128.c
index a61b35b9a3..79dc7de159 100644
--- a/src/test/test-id128.c
+++ b/src/test/test-id128.c
@@ -12,19 +12,20 @@
 #include "id128-util.h"
 #include "macro.h"
 #include "string-util.h"
+#include "tests.h"
 #include "tmpfile-util.h"
-#include "util.h"
 
 #define ID128_WALDI SD_ID128_MAKE(01, 02, 03, 04, 05, 06, 07, 08, 09, 0a, 0b, 0c, 0d, 0e, 0f, 10)
 #define STR_WALDI "0102030405060708090a0b0c0d0e0f10"
 #define UUID_WALDI "01020304-0506-0708-090a-0b0c0d0e0f10"
 
-int main(int argc, char *argv[]) {
+static void test_id128(void) {
         sd_id128_t id, id2;
         char t[SD_ID128_STRING_MAX], q[ID128_UUID_STRING_MAX];
         _cleanup_free_ char *b = NULL;
         _cleanup_close_ int fd = -1;
-        int r;
+
+        log_info("/* %s */", __func__);
 
         assert_se(sd_id128_randomize(&id) == 0);
         printf("random: %s\n", sd_id128_to_string(id, t));
@@ -146,16 +147,18 @@ int main(int argc, char *argv[]) {
         assert_se(id128_read_fd(fd, ID128_UUID, &id2) >= 0);
         assert_se(sd_id128_equal(id, id2));
 
-        r = sd_id128_get_machine_app_specific(SD_ID128_MAKE(f0,3d,aa,eb,1c,33,4b,43,a7,32,17,29,44,bf,77,2e), &id);
-        if (r == -EOPNOTSUPP)
-                log_info("khash not supported on this kernel, skipping sd_id128_get_machine_app_specific() checks");
-        else {
-                assert_se(r >= 0);
-                assert_se(sd_id128_get_machine_app_specific(SD_ID128_MAKE(f0,3d,aa,eb,1c,33,4b,43,a7,32,17,29,44,bf,77,2e), &id2) >= 0);
-                assert_se(sd_id128_equal(id, id2));
-                assert_se(sd_id128_get_machine_app_specific(SD_ID128_MAKE(51,df,0b,4b,c3,b0,4c,97,80,e2,99,b9,8c,a3,73,b8), &id2) >= 0);
-                assert_se(!sd_id128_equal(id, id2));
-        }
+        assert_se(sd_id128_get_machine_app_specific(SD_ID128_MAKE(f0,3d,aa,eb,1c,33,4b,43,a7,32,17,29,44,bf,77,2e), &id) >= 0);
+        assert_se(sd_id128_get_machine_app_specific(SD_ID128_MAKE(f0,3d,aa,eb,1c,33,4b,43,a7,32,17,29,44,bf,77,2e), &id2) >= 0);
+        assert_se(sd_id128_equal(id, id2));
+        assert_se(sd_id128_get_machine_app_specific(SD_ID128_MAKE(51,df,0b,4b,c3,b0,4c,97,80,e2,99,b9,8c,a3,73,b8), &id2) >= 0);
+        assert_se(!sd_id128_equal(id, id2));
+}
+
+static void test_sd_id128_get_invocation(void) {
+        sd_id128_t id;
+        int r;
+
+        log_info("/* %s */", __func__);
 
         /* Query the invocation ID */
         r = sd_id128_get_invocation(&id);
@@ -163,6 +166,35 @@ int main(int argc, char *argv[]) {
                 log_warning_errno(r, "Failed to get invocation ID, ignoring: %m");
         else
                 log_info("Invocation ID: " SD_ID128_FORMAT_STR, SD_ID128_FORMAT_VAL(id));
+}
+
+static void benchmark_sd_id128_get_machine_app_specific(void) {
+        unsigned iterations = slow_tests_enabled() ? 1000000 : 1000;
+        usec_t t, q;
+
+        log_info("/* %s (%u iterations) */", __func__, iterations);
+
+        sd_id128_t id = ID128_WALDI, id2;
+
+        t = now(CLOCK_MONOTONIC);
+
+        for (unsigned i = 0; i < iterations; i++) {
+                id.qwords[1] = i;
+
+                assert_se(sd_id128_get_machine_app_specific(id, &id2) >= 0);
+        }
+
+        q = now(CLOCK_MONOTONIC) - t;
+
+        log_info("%lf µs each\n", (double) q / iterations);
+}
+
+int main(int argc, char *argv[]) {
+        test_setup_logging(LOG_INFO);
+
+        test_id128();
+        test_sd_id128_get_invocation();
+        benchmark_sd_id128_get_machine_app_specific();
 
         return 0;
 }