build: drop crypto.c umbrella source

Instead build all crypto backend sources always, and exclude inactive
ones with guards.

To play better with code checkers and compilers that are blind to
included C sources, e.g. clang with certain compiler warnings and
clang-tidy.

We continue to include `blowfish.c`.

Follow-up to 4f0f4bff5a #941
Cherry-picked from #1561

docs/HACKING-CRYPTO

@@ -33,16 +33,14 @@ LTLIBNEWNAME variable on success.
 
 0.3) Add new header to src/Makefile.inc
 
-0.4) Include new source in src/crypto.c
-
-0.5) Add a new block in configure.ac
+0.4) Add a new block in configure.ac
 
 ```
 elif test "$found_crypto" = "newname"; then
   LIBS="${LIBS} ${LTLIBNEWNAME}"
 ```
 
-0.6) Add CMake detection logic to CMakeLists.txt
+0.5) Add CMake detection logic to CMakeLists.txt
 
 1) Crypto library initialization/termination.
 

src/Makefile.inc

@@ -3,19 +3,22 @@
 CSOURCES =              \
   agent.c               \
   bcrypt_pbkdf.c        \
-  channel.c             \
-  comp.c                \
   chacha.c              \
+  channel.c             \
   cipher-chachapoly.c   \
+  comp.c                \
   crypt.c               \
-  crypto.c              \
   global.c              \
   hostkey.c             \
   keepalive.c           \
   kex.c                 \
   knownhost.c           \
+  libgcrypt.c           \
   mac.c                 \
+  mbedtls.c             \
   misc.c                \
+  openssl.c             \
+  os400qc3.c            \
   packet.c              \
   pem.c                 \
   poly1305.c            \
@@ -26,7 +29,8 @@ CSOURCES =              \
   transport.c           \
   userauth.c            \
   userauth_kbd_packet.c \
-  version.c
+  version.c             \
+  wincng.c
 
 HHEADERS =              \
   chacha.h              \
@@ -53,9 +57,4 @@ HHEADERS =              \
   wincng.h
 
 EXTRA_DIST =            \
-  blowfish.c            \
-  libgcrypt.c           \
-  mbedtls.c             \
-  openssl.c             \
-  os400qc3.c            \
-  wincng.c
+  blowfish.c

src/crypto.c

@@ -1,19 +0,0 @@
-/* Copyright (C) Viktor Szakats
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#define LIBSSH2_CRYPTO_C
-#include "libssh2_priv.h"
-
-#if defined(LIBSSH2_OPENSSL) || defined(LIBSSH2_WOLFSSL)
-#include "openssl.c"
-#elif defined(LIBSSH2_LIBGCRYPT)
-#include "libgcrypt.c"
-#elif defined(LIBSSH2_MBEDTLS)
-#include "mbedtls.c"
-#elif defined(LIBSSH2_OS400QC3)
-#include "os400qc3.c"
-#elif defined(LIBSSH2_WINCNG)
-#include "wincng.c"
-#endif

src/libgcrypt.c

@@ -38,7 +38,9 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifdef LIBSSH2_CRYPTO_C /* Compile this via crypto.c */
+#include "libssh2_priv.h"
+
+#ifdef LIBSSH2_LIBGCRYPT
 
 int _libssh2_hmac_ctx_init(libssh2_hmac_ctx *ctx)
 {
@@ -860,4 +862,4 @@ _libssh2_supported_key_sign_algorithms(LIBSSH2_SESSION *session,
     return NULL;
 }
 
-#endif /* LIBSSH2_CRYPTO_C */
+#endif /* LIBSSH2_LIBGCRYPT */

src/mbedtls.c

@@ -37,7 +37,9 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifdef LIBSSH2_CRYPTO_C /* Compile this via crypto.c */
+#include "libssh2_priv.h"
+
+#ifdef LIBSSH2_MBEDTLS
 
 #include <stdlib.h>
 
@@ -1532,4 +1534,4 @@ _libssh2_supported_key_sign_algorithms(LIBSSH2_SESSION *session,
     return NULL;
 }
 
-#endif /* LIBSSH2_CRYPTO_C */
+#endif /* LIBSSH2_MBEDTLS */

src/openssl.c

@@ -39,7 +39,9 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifdef LIBSSH2_CRYPTO_C /* Compile this via crypto.c */
+#include "libssh2_priv.h"
+
+#if defined(LIBSSH2_OPENSSL) || defined(LIBSSH2_WOLFSSL)
 
 #include <stdlib.h>
 #include <assert.h>
@@ -5237,4 +5239,4 @@ _libssh2_supported_key_sign_algorithms(LIBSSH2_SESSION *session,
     return NULL;
 }
 
-#endif /* LIBSSH2_CRYPTO_C */
+#endif /* LIBSSH2_OPENSSL || LIBSSH2_WOLFSSL */

src/os400qc3.c

@@ -38,7 +38,9 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifdef LIBSSH2_CRYPTO_C /* Compile this via crypto.c */
+#include "libssh2_priv.h"
+
+#ifdef LIBSSH2_OS400QC3
 
 #include <stdlib.h>
 
@@ -2530,6 +2532,6 @@ _libssh2_supported_key_sign_algorithms(LIBSSH2_SESSION *session,
     return NULL;
 }
 
-#endif /* LIBSSH2_CRYPTO_C */
+#endif /* LIBSSH2_OS400QC3 */
 
 /* vim: set expandtab ts=4 sw=4: */

src/wincng.c

@@ -38,7 +38,9 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifdef LIBSSH2_CRYPTO_C /* Compile this via crypto.c */
+#include "libssh2_priv.h"
+
+#ifdef LIBSSH2_WINCNG
 
 /* required for cross-compilation against the w64 mingw-runtime package */
 #if defined(_WIN32_WINNT) && (_WIN32_WINNT < 0x0600)
@@ -4201,4 +4203,4 @@ _libssh2_supported_key_sign_algorithms(LIBSSH2_SESSION *session,
     return NULL;
 }
 
-#endif /* LIBSSH2_CRYPTO_C */
+#endif /* LIBSSH2_WINCNG */