https:\/\/linuxconfig.org\/using-openssl-to-encrypt-messages-and-files-on-linux<\/a>\n<\/p>\n\nPublic key encrypt \/ private key decrypt – RSA (small files)
\n<\/h4>\n
\nNote RSA (rsault) is only suitable for very small files and is typically used to encrypt a randomly chosen private key that a larger file gets encrypted with. The reason it won't allow use with large files (say over around 512 bytes) is performance.\n<\/p>\n
\nGenerating a key pair
\n<\/h5>\n
\nGenerate private key\n<\/p>\n
\r\n\r\nopenssl genrsa -out private_key.pem 1024\r\n<\/code><\/pre>\n\nThen use it to generate the public key\n<\/p>\n
\r\n\r\nopenssl rsa -in private_key.pem -out public_key.pem -outform PEM -pubout\r\n<\/code><\/pre>\n\nEncrypt file
\n<\/h5>\n
\nThis will encrypt using RSA and your 1024 bit key.\n<\/p>\n
\r\n\r\nopenssl rsautl -encrypt -inkey public_key.pem -pubin -in encrypt.txt -out encrypt.dat\r\n<\/code><\/pre>\n\nDecrypt File
\n<\/h5>\n\r\n\r\nopenssl rsautl -decrypt -inkey private_key.pem -in encrypt.dat -out new_encrypt.txt\r\n<\/code><\/pre>\n\nPublic key encrypt \/ private key decrypt – SMIME AES (Large files)
\n<\/h4>\n
\n(Good up to around 500MB, dependant on platform and resources)\n<\/p>\n
\nGenerating a key pair
\n<\/h5>\n\r\n\r\nopenssl req -x509 -nodes -days 100000 -newkey rsa:2048 -keyout privatekey.pem -out publickey.pem -subj '\/'\r\n<\/code><\/pre>\n\nEncrypt file
\n<\/h5>\n
\nThis will encrypt using RSA and your 1024 bit key.\n<\/p>\n
\r\n\r\nopenssl smime -encrypt -aes256 -in my_large_file.bin -binary -outform DEM -out my_large_file_encrypted.bin publickey.pem\r\n<\/code><\/pre>\n\nDecrypt File
\n<\/h5>\n\r\n\r\nopenssl smime -decrypt -in my_large_file.bin -binary -inform DEM -inkey privatekey.pem -out my_large_file.bin \r\n<\/code><\/pre>\n\n \n<\/p>\n
\n <\/p>\n","protected":false},"excerpt":{"rendered":"
Good resources https:\/\/linuxconfig.org\/using-openssl-to-encrypt-messages-and-files-on-linux Public key encrypt \/ private key decrypt – RSA (small files) Note RSA (rsault) is only suitable for very small files and is typically used to encrypt a randomly chosen private key that a larger file gets encrypted with. The reason it won't allow use with large files (say over around 512 bytes) […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[134],"tags":[],"class_list":["post-2679","post","type-post","status-publish","format-standard","hentry","category-security"],"_links":{"self":[{"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/posts\/2679","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/comments?post=2679"}],"version-history":[{"count":8,"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/posts\/2679\/revisions"}],"predecessor-version":[{"id":2687,"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/posts\/2679\/revisions\/2687"}],"wp:attachment":[{"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/media?parent=2679"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/categories?post=2679"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/tags?post=2679"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}