Actualización a version 4.3.1 - Error composer install

Buen día estamos actualizando a la versión 4.3.1 desde una versión 4.2.1

Al ejecutar composer install nos da lo siguiente:

Installing dependencies from lock file (including require-dev)
Verifying lock file contents can be installed on current platform.
Your lock file does not contain a compatible set of packages. Please run composer update.

Problem 1
- onelogin/php-saml is locked to version 2.16.0 and an update of this package was not requested.
- onelogin/php-saml 2.16.0 requires ext-mcrypt * → it is missing from your system. Install or enable PHP’s mcrypt extension.
Problem 2
- onelogin/php-saml 2.16.0 requires ext-mcrypt * → it is missing from your system. Install or enable PHP’s mcrypt extension.
- siu-toba/framework v3.1.16 requires onelogin/php-saml ~2.16.0 → satisfiable by onelogin/php-saml[2.16.0].
- siu-toba/framework is locked to version v3.1.16 and an update of this package was not requested.

To enable extensions, verify that they are enabled in your .ini files:
- /etc/php/7.2/cli/php.ini
- /etc/php/7.2/cli/conf.d/10-opcache.ini
- /etc/php/7.2/cli/conf.d/10-pdo.ini
- /etc/php/7.2/cli/conf.d/15-xml.ini
- /etc/php/7.2/cli/conf.d/20-calendar.ini
- /etc/php/7.2/cli/conf.d/20-ctype.ini
- /etc/php/7.2/cli/conf.d/20-curl.ini
- /etc/php/7.2/cli/conf.d/20-dom.ini
- /etc/php/7.2/cli/conf.d/20-exif.ini
- /etc/php/7.2/cli/conf.d/20-fileinfo.ini
- /etc/php/7.2/cli/conf.d/20-ftp.ini
- /etc/php/7.2/cli/conf.d/20-gd.ini
- /etc/php/7.2/cli/conf.d/20-gettext.ini
- /etc/php/7.2/cli/conf.d/20-iconv.ini
- /etc/php/7.2/cli/conf.d/20-json.ini
- /etc/php/7.2/cli/conf.d/20-mbstring.ini
- /etc/php/7.2/cli/conf.d/20-pdo_pgsql.ini
- /etc/php/7.2/cli/conf.d/20-pgsql.ini
- /etc/php/7.2/cli/conf.d/20-phar.ini
- /etc/php/7.2/cli/conf.d/20-posix.ini
- /etc/php/7.2/cli/conf.d/20-readline.ini
- /etc/php/7.2/cli/conf.d/20-shmop.ini
- /etc/php/7.2/cli/conf.d/20-simplexml.ini
- /etc/php/7.2/cli/conf.d/20-sockets.ini
- /etc/php/7.2/cli/conf.d/20-sysvmsg.ini
- /etc/php/7.2/cli/conf.d/20-sysvsem.ini
- /etc/php/7.2/cli/conf.d/20-sysvshm.ini
- /etc/php/7.2/cli/conf.d/20-tokenizer.ini
- /etc/php/7.2/cli/conf.d/20-wddx.ini
- /etc/php/7.2/cli/conf.d/20-xmlreader.ini
- /etc/php/7.2/cli/conf.d/20-xmlwriter.ini
- /etc/php/7.2/cli/conf.d/20-xsl.ini
- /etc/php/7.2/cli/conf.d/20-zip.ini
You can also run php --ini inside terminal to see which files are used by PHP in CLI mode.

Ejecutamos composer update

Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.

Problem 1
- Root composer.json requires siu-toba/framework 3.1.*, it is satisfiable by siu-toba/framework[v3.1.0, …, v3.1.17] from composer repo (https://repo.packagist.org) but siu-toba/framework[dev-trunk, 2.7.0, …, 2.7.x-dev] from composer repo (https://satis.siu.edu.ar) has higher repository priority. The packages with higher priority do not match your constraint and are therefore not installable. See https://getcomposer.org/repoprio for details and assistance.

La versión de composer es la 2.0.8. Cual puede ser el problema??

Gracias. Saludos
María José