How to build mcrypt library in armv7 architecture?

Don't use mcrypt. The MCrypt library has not been updated since 2007. It is highly recommended you switch to OpenSSL or another maintained encryption project.

The PJSIP documentation has instructions on how to use OpenSSL for both IOS and Android devices:

• https://trac.pjsip.org/repos/wiki/Getting-Started/iPhone#OpenSSLSupport
• https://trac.pjsip.org/repos/wiki/Getting-Started/Android#OpenSSLSupport

Instead of using libmcrypt library, we can use below openssl(Github) projects for creating libraries on all architectures as Suggested by above answer. Thank you @Tim.

Use this project build-libssl.sh file for compiling for all architectures both on Android and IOS.

For Android,

https://github.com/ruslansalikhov/openssl-for-android

For IOS,

https://github.com/x2on/OpenSSL-for-iPhone

Just download and compile the project using build-libssl.sh file. It will creates all library for your platform. Either in Android or IOS.

Download the Project and go to the project directory using cmd/terminal.

cd OpenSSL-for-iPhone/

Compile the Project using following command,

./build-libssl.sh

NOTE: Machine must have gcc compiler and SDK installed(Android ndk and IOS).

After Successfull Compilation, go to you PROJECT_DIR(OpenSSL-for-iPhone)/lib folder. Check there is four libraries created for all architectures.

Use following command to check supported Architectures by the library file. Go to the lib path on cmd/terminal interface and check,

lipo -info libcrypto.a

It will show which architectures are supported by the library file.

Architectures in the fat file: libcrypto.a are: i386 armv7s armv7 x86_64 arm64