libssh2 problem

Hello
i have find on wiki the way to install libssh2

but on config of  libssh2-1.8.0 i have a error

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./configure --with-php-config=/usr/local/bin/php-config

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checking for libssl... no
configure: error: No crypto library found!
Try --with-libssl-prefix=PATH
 or --with-libgcrypt-prefix=PATH
 or --with-libmbedtls-prefix=PATH
 or --with-wincng on Windows
i've search on google but i've not found

anybody can help me

thanks