minor changes for amalgamation

* de-duplicate `struct oid_to_pbes`
* add makefile target
* add amalgamation to release
* fix `small` demo
* add header guards for `tomcrypt_private.h`
* update docs
* add CI job with amalgamated library

Signed-off-by: Steffen Jaeckel <s@jaeckel.eu>

.github/workflows/main.yml

@@ -98,3 +98,24 @@ jobs:
           name: build-${{ github.run_id }}.tar.xz
           path: build-${{ github.run_id }}.tar.xz
           retention-days: 1
+
+  Amalgam:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        cc: [ gcc, clang ]
+        os: [ ubuntu-22.04, ubuntu-24.04 ]
+    steps:
+      - uses: actions/checkout@v4
+      - name: install dependencies
+        run: |
+          sudo apt-get update -qq
+          sudo apt-get remove -y libtommath1
+          curl -s https://packagecloud.io/install/repositories/libtom/packages/script.deb.sh | sudo bash
+          sudo apt-get install libtommath-git-dev
+      - name: run tests
+        env:
+          CC: "${{ matrix.cc }}"
+        run: |
+          make pre_gen
+          make CFLAGS="-DLTM_DESC -DUSE_LTM" EXTRALIBS="-ltommath" AMALGAM=1 -j$(nproc) check

.gitignore

@@ -10,6 +10,7 @@
 # release files
 /libtomcrypt-*
 /crypt-*
+pre_gen/
 
 # suppress output of build process
 gcc_[12].txt

doc/crypt.tex

@@ -8896,6 +8896,28 @@ else()
 endif()
 \end{verbatim}
 
+
+\mysection{Amalgamated library}
+
+LibTomCrypt can also be built as an amalgamated library, i.e. as a single C source file + the header files.
+
+A release of the library contains the amalgamation in the path \texttt{pre\_gen/tomcrypt\_amalgam.c}.
+
+To create the amalgamation one can run:
+
+\begin{verbatim}
+make pre_gen
+\end{verbatim}
+
+The makefiles also support building the amalgamated library via:
+
+\begin{verbatim}
+make CFLAGS="-DLTM_DESC" EXTRALIBS=-ltommath AMALGAM=1
+\end{verbatim}
+
+This will build the library and link against LibTomMath (which must be installed on your system).
+
+
 \mysection{Header Configuration}
 The file \textit{tomcrypt\_cfg.h} is what lets you control various high level macros which control the behaviour of the library.  Build options are also
 stored in \textit{tomcrypt\_custom.h} which allow the enabling and disabling of various algorithms.

makefile

@@ -143,3 +143,16 @@ coverage: $(call print-help,coverage,Create code-coverage of the library - but b
 
 # cleans everything - coverage output and standard 'clean'
 cleancov: cleancov-clean clean
+ifndef AMALGAM
+AMALGAM_FILTER_OUT = src/ciphers/aes/aes_tab.c src/ciphers/aes/aes_enc.c src/ciphers/aes/aes_enc_desc.c
+SOURCES = $(filter-out $(AMALGAM_FILTER_OUT),$(OBJECTS:.o=.c))
+pre_gen/tomcrypt_amalgam.c: $(SOURCES)
+	mkdir -p pre_gen
+	printf "/*\n * This file has been auto-generated, do not edit!\n */\n\n" > $@
+	cat $(SOURCES) >> $@
+
+pre_gen: pre_gen/tomcrypt_amalgam.c
+
+.PHONY: pre_gen
+endif
+

makefile_include.mk

@@ -210,6 +210,7 @@ library: $(call print-help,library,Builds the library) $(LIBNAME)
 
 
 # List of objects to compile (all goes to libtomcrypt.a)
+ifndef AMALGAM
 OBJECTS=src/ciphers/aes/aes.o src/ciphers/aes/aes_desc.o src/ciphers/aes/aes_enc.o \
 src/ciphers/aes/aes_enc_desc.o src/ciphers/aes/aesni.o src/ciphers/anubis.o src/ciphers/blowfish.o \
 src/ciphers/camellia.o src/ciphers/cast5.o src/ciphers/des.o src/ciphers/idea.o src/ciphers/kasumi.o \
@@ -401,6 +402,11 @@ src/stream/salsa20/xsalsa20_setup.o src/stream/salsa20/xsalsa20_test.o \
 src/stream/sober128/sober128_stream.o src/stream/sober128/sober128_stream_memory.o \
 src/stream/sober128/sober128_test.o src/stream/sosemanuk/sosemanuk.o \
 src/stream/sosemanuk/sosemanuk_memory.o src/stream/sosemanuk/sosemanuk_test.o
+else
+OBJECTS=pre_gen/tomcrypt_amalgam.o
+
+LTC_CFLAGS := $(LTC_CFLAGS) -Wno-shadow -Isrc/ciphers/aes -Isrc/ciphers/safer -Isrc/ciphers/twofish -Isrc/hashes/whirl -Isrc/stream/sober128
+endif
 
 # List of test objects to compile (all goes to libtomcrypt_prof.a)
 TOBJECTS=tests/base16_test.o tests/base32_test.o tests/base64_test.o tests/bcrypt_test.o \
@@ -537,6 +543,7 @@ zipup: $(call print-help,zipup,Prepare the archives for a release) doc/crypt.pdf
 	-@(find libtomcrypt-$(VERSION)/ -type f | xargs grep 'FIXM[E]') && echo '############## BEWARE: the "fixme" marker was found !!! ##############' || true
 	mkdir -p libtomcrypt-$(VERSION)/doc
 	cp doc/crypt.pdf libtomcrypt-$(VERSION)/doc/crypt.pdf
+	$(MAKE) -C libtomcrypt-$(VERSION)/ pre_gen
 	tar -c libtomcrypt-$(VERSION)/ | xz -6e -c - > crypt-$(VERSION).tar.xz
 	zip -9rq crypt-$(VERSION).zip libtomcrypt-$(VERSION)
 	rm -rf libtomcrypt-$(VERSION)

src/headers/tomcrypt_private.h

@@ -4,6 +4,9 @@
 #include "tomcrypt.h"
 #include <stdarg.h>
 
+#ifndef TOMCRYPT_PRIVATE_H_
+#define TOMCRYPT_PRIVATE_H_
+
 /*
  * Internal Macros
  */
@@ -105,6 +108,11 @@ typedef struct
    unsigned long key_bits;
 } pbes_arg;
 
+typedef struct {
+   const pbes_properties *data;
+   const char *oid;
+} oid_to_pbes;
+
 /*
  * Internal functions
  */
@@ -692,3 +700,5 @@ int which ## _export(unsigned char *out, unsigned long *outlen, prng_state *prng
       #define LTC_WIN32_BCRYPT
    #endif
 #endif
+
+#endif /* TOMCRYPT_PRIVATE_H_ */

src/misc/pbes/pbes1.c

@@ -50,11 +50,6 @@ static const pbes_properties s_pbes1_types[] = {
    { s_pkcs_12_wrap,     "sha1",  "3des", 24, 8 },
 };
 
-typedef struct {
-   const pbes_properties *data;
-   const char *oid;
-} oid_to_pbes;
-
 static const oid_to_pbes s_pbes1_list[] = {
    { &s_pbes1_types[0], "1.2.840.113549.1.5.1"    },  /* http://www.oid-info.com/get/1.2.840.113549.1.5.1    pbeWithMD2AndDES-CBC */
    { &s_pbes1_types[1], "1.2.840.113549.1.5.4"    },  /* http://www.oid-info.com/get/1.2.840.113549.1.5.4    pbeWithMD2AndRC2-CBC */

src/misc/pbes/pbes2.c

@@ -39,11 +39,6 @@ static const pbes_properties s_pbes2_default_types[] = {
    { s_pkcs_5_alg2_wrap, "sha1",   "aes",  32, 0 },
 };
 
-typedef struct {
-   const pbes_properties *data;
-   const char* oid;
-} oid_to_pbes;
-
 static const oid_to_pbes s_pbes2_list[] = {
    { &s_pbes2_default_types[0], "1.3.14.3.2.7"            },  /* http://www.oid-info.com/get/1.3.14.3.2.7            desCBC */
    { &s_pbes2_default_types[1], "1.2.840.113549.3.2"      },  /* http://www.oid-info.com/get/1.2.840.113549.3.2      rc2CBC */