Remove the embedded sha1 code, and use one of botan or gcrypt

This adds a hard dependency on one of Botan or gcrypt. Botan is already a
recommended dependency, and gcrypt is probably packaged almost everywhere,
so this should not be a big deal.

ref #3241

louloulibs/CMakeLists.txt

@@ -33,6 +33,10 @@ elseif(NOT WITHOUT_BOTAN)
   find_package(BOTAN)
 endif()
 
+if(NOT BOTAN_FOUND)
+  find_package(GCRYPT REQUIRED)
+endif()
+
 if(WITH_UDNS)
   find_package(UDNS REQUIRED)
 elseif(NOT WITHOUT_UDNS)
@@ -67,6 +71,11 @@ if(BOTAN_FOUND)
   set(BOTAN_FOUND ${BOTAN_FOUND} PARENT_SCOPE)
   set(BOTAN_INCLUDE_DIRS ${BOTAN_INCLUDE_DIRS} PARENT_SCOPE)
 endif()
+if(GCRYPT_FOUND)
+  include_directories(SYSTEM ${GCRYPT_INCLUDE_DIRS})
+  set(GCRYPT_FOUND ${GCRYPT_FOUND} PARENT_SCOPE)
+  set(GCRYPT_INCLUDE_DIRS ${GCRYPT_INCLUDE_DIRS} PARENT_SCOPE)
+endif()
 
 if(UDNS_FOUND)
   include_directories(${UDNS_INCLUDE_DIRS})
@@ -117,6 +126,8 @@ add_library(network STATIC ${source_network})
 target_link_libraries(network logger)
 if(BOTAN_FOUND)
   target_link_libraries(network ${BOTAN_LIBRARIES})
+elseif(GCRYPT_FOUND)
+  target_link_libraries(network ${GCRYPT_LIBRARIES})
 endif()
 if(UDNS_FOUND)
   target_link_libraries(network ${UDNS_LIBRARIES})