Cannot compile, error: cryptlib.h: No such file or directory

I've downloaded Crypto++ 7.0.0 from the official site, build a static library out of it, included cryptlib header with:

#include "cryptlib.h"

and when I try to compile my program with:

gcc main.cpp ./cryptopp700/libcryptopp.a

it throws at me errors like this:

main.cpp:2:10: fatal error: cryptlib.h: No such file or directory
 #include "cryptlib.h"
          ^~~~~~~~~~~~
compilation terminated.

I also tried with:

-L. -llibcryptopp //while moving libcryptopp.a to the same directory main.cpp is
-L./cryptopp700 -llibcryptopp

so I started wondering if I was doing something wrong, but as I was checking out code examples with static libraries, everything seemed to be fine.

Help please.

Based on:

main.cpp:2:10: fatal error: cryptlib.h: No such file or directory

And:

gcc main.cpp ./cryptopp700/libcryptopp.a

Your directory structure looks like:

+- Project Folder
  |
  +- main.cpp
  |
  +- cryptopp700
    |
    +- cryltib.h
    +- ...
    +- libcryptopp.a

You should only need to add cryptopp700/ to your include header search path with -I:

g++ main.cpp -I ./cryptopp700 ./cryptopp700/libcryptopp.a

Note that you should also use g++ (the C++ compiler), not gcc (the C compiler).

---

You can also install the library since it has been built. By default it installs into /usr/local with:

skylake:cryptopp$ sudo make install
[sudo] password for jwalton:
install -m 644 *.h /usr/local/include/cryptopp
install -m 644 libcryptopp.a /usr/local/lib
install cryptest.exe /usr/local/bin
install -m 644 TestData/*.dat /usr/local/share/cryptopp/TestData
install -m 644 TestVectors/*.txt /usr/local/share/cryptopp/TestVectors

You can install into an alternate location using PREFIX:

skylake:cryptopp$ sudo make install PREFIX=/opt/local
install -m 644 *.h /opt/local/include/cryptopp
install -m 644 libcryptopp.a /opt/local/lib
install cryptest.exe /opt/local/bin
install -m 644 TestData/*.dat /opt/local/share/cryptopp/TestData
install -m 644 TestVectors/*.txt /opt/local/share/cryptopp/TestVectors

Then, you would change you compile and link command to something like:

g++ main.cpp -I /usr/local/include/cryptopp -o main.exe /usr/local/lib/libcryptopp.a

---

After an install like shown below, I normally tell folks to run the self tests. Unfortunately, the won't work if all you did was a make -j 4 or similar.

$ make -j 4
...

$ sudo make install
[sudo] password for jwalton:
install -m 644 *.h /usr/local/include/cryptopp
install -m 644 libcryptopp.a /usr/local/lib
install cryptest.exe /usr/local/bin
install -m 644 TestData/*.dat /usr/local/share/cryptopp/TestData
install -m 644 TestVectors/*.txt /usr/local/share/cryptopp/TestVectors

Here's the error you would get:

skylake:cryptopp$ cd /opt/local/bin/
skylake:bin$ ./cryptest.exe v
Using seed: 1544189072

Testing Settings...

passed:  Your machine is little endian.
passed:  Aligned data access.
passed:  sizeof(byte) == 1
passed:  sizeof(word16) == 2
passed:  sizeof(word32) == 4
passed:  sizeof(word64) == 8
passed:  sizeof(word128) == 16
passed:  sizeof(hword) == 4, sizeof(word) == 8, sizeof(dword) == 16
passed:  cacheLineSize == 64
hasSSE2 == 1, hasSSSE3 == 1, hasSSE4.1 == 1, hasSSE4.2 == 1, hasAVX == 1, hasAVX2 == 1, hasAESNI == 1, hasCLMUL == 1, hasRDRAND == 1, hasRDSEED == 1, hasSHA == 0, isP4 == 0
...

SHA validation suite running...

Exception caught: Can not open file TestVectors/sha.txt for reading

My thinking is things should "just work" for you. You should not need to worry about CRYPTOPP_DATA_DIR for a common case. And you certainly should not have to RTFM to make the common case work. That tells me there's a defect in our engineering process.

We are going to fix that now: Issue 760, Make self-tests run after install by a typical user.