I could not find a "dev" package for openssl in my system. It is standard Raspbian, /etc/debian_version has "10.2" in it and all updates installed as of today.
Below is what I have available:
pi@raspberrypi:~/ $ apt list|grep openssl
WARNING: apt does not have a stable CLI interface. Use with caution in scripts.
aolserver4-nsopenssl/stable 3.0beta26-6 armhf
bruteforce-salted-openssl/stable 1.4.1-1 armhf
dlang-openssl/stable 2.0.0+1.1.0h-0.1 all
gambas3-gb-openssl/stable 3.12.2-1+b1 armhf
jruby-openssl/stable 0.9.21-2 all
lcmaps-openssl-interface/stable 1.6.6-2 all
libcrypt-openssl-bignum-perl/stable 0.09-1+b1 armhf
libcrypt-openssl-dsa-perl/stable 0.19-1+b2 armhf
libcrypt-openssl-ec-perl/stable 1.31-1+b1 armhf
libcrypt-openssl-pkcs10-perl/stable 0.16-3+b1 armhf
libcrypt-openssl-pkcs12-perl/stable 1.2-1 armhf
libcrypt-openssl-random-perl/stable 0.15-1+b1 armhf
libcrypt-openssl-rsa-perl/stable 0.31-1+b1 armhf
libcrypt-openssl-x509-perl/stable 1.8.12-1 armhf
libcurl4-openssl-dev/stable 7.64.0-4 armhf
libengine-gost-openssl1.1/stable 1.1.0.3-1 armhf
libengine-pkcs11-openssl1.1/stable 0.4.9-4 armhf
libengine-pkcs11-openssl/stable 0.4.9-4 armhf
libevent-openssl-2.1-6/stable 2.1.8-stable-4 armhf
libghc-hsopenssl-dev/stable 0.11.4.15-2+b2 armhf
libghc-hsopenssl-doc/stable 0.11.4.15-2 all
libghc-hsopenssl-prof/stable 0.11.4.15-2+b2 armhf
libghc-hsopenssl-x509-system-dev/stable 0.1.0.3-4+b2 armhf
libghc-hsopenssl-x509-system-doc/stable 0.1.0.3-4 all
libghc-hsopenssl-x509-system-prof/stable 0.1.0.3-4+b2 armhf
libghc-openssl-streams-dev/stable 1.2.1.3-3+b2 armhf
libghc-openssl-streams-doc/stable 1.2.1.3-3 all
libghc-openssl-streams-prof/stable 1.2.1.3-3+b2 armhf
libglobus-gsi-openssl-error-dev/stable 4.1-1 armhf
libglobus-gsi-openssl-error-doc/stable 4.1-1 all
libglobus-gsi-openssl-error0/stable 4.1-1 armhf
libglobus-openssl-module-dev/stable 5.1-1 armhf
libglobus-openssl-module-doc/stable 5.1-1 all
libglobus-openssl-module0/stable 5.1-1 armhf
libgnutls-openssl27/stable 3.6.7-4 armhf
librust-cargo+openssl-dev/stable 0.32.0-2 armhf
librust-cargo+vendored-openssl-dev/stable 0.32.0-2 armhf
librust-git2+openssl-probe-dev/stable 0.7.5-1 armhf
librust-git2+openssl-sys-dev/stable 0.7.5-1 armhf
librust-libgit2-sys+openssl-sys-dev/stable 0.7.10-1 armhf
librust-openssl-dev/stable 0.10.16-1 armhf
librust-openssl-probe-dev/stable 0.1.2-1 armhf
librust-openssl-sys-dev/stable 0.9.40-1 armhf
libxmlsec1-openssl/stable 1.2.27-2 armhf
lua-openssl-dev/stable 20161208-1 armhf
lua-openssl/stable 20161208-1 armhf
openssl-blacklist-extra/stable 0.5-3 all
openssl-blacklist/stable 0.5-3 all
openssl/stable,now 1.1.1d-0+deb10u2 armhf [kurulu,otomatik]
perl-openssl-defaults/stable 3 armhf
puppet-module-camptocamp-openssl/stable 1.5.0-1 all
python-openssl-doc/stable 19.0.0-1 all
python-openssl/stable,now 19.0.0-1 all [kurulu,otomatik]
python3-aioopenssl/stable 0.4.1-2 all
python3-openssl/stable,now 19.0.0-1 all [kurulu,otomatik]
r-cran-openssl/stable 1.2.2+dfsg-1 armhf
ruby-openssl/stable 2.0.5-1+b1 armhf
pi@raspberrypi:~/ $
I do appreciate directions as to how I can use TFPHTTPClient for "https" addresses, please.
Thanks & regards,
Ertan