B4i Library iRSA - RSA encryption / decryption

This is a wrapper of: https://github.com/ideawu/Objective-C-RSA

It is an implementation of RSA asymmetric encryption.

Usage example (based on the library developer blog):

Sub Process_Globals
   'These global variables will be declared once when the application starts.
   'Public variables can be accessed from all modules.
   Public App As Application
   Public NavControl As NavigationController
   Private Page1 As Page
   Private rsa As RSA
   Private PrivateKey As String = $"-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----"$
   Private PublicKey As String = $"-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDEChqe80lJLTTkJD3X3Lyd7Fj+
zuOhDZkjuLNPog3YR20e5JcrdqI9IFzNbACY/GQVhbnbvBqYgyql8DfPCGXpn0+X
NSxELIUw9Vh32QuhGNr3/TBpechrVeVpFPLwyaYNEk1CawgHCeQqf5uaqiaoBDOT
qeox88Lc1ld7MsfggQIDAQAB
-----END PUBLIC KEY-----"$
End Sub

Private Sub Application_Start (Nav As NavigationController)
   'SetDebugAutoFlushLogs(True) 'Uncomment if program crashes before all logs are printed.
   NavControl = Nav
   Page1.Initialize("Page1")
   Page1.Title = "Page 1"
   Page1.RootPanel.Color = Colors.White
   NavControl.ShowPage(Page1)
   Dim enc() As Byte = rsa.EncryptWithPrivateKey("abc".GetBytes("utf8"), PrivateKey)
   Dim bc As ByteConverter 'iRandomAccessFile
   Log(bc.HexFromBytes(enc))
   Dim dec() As Byte = rsa.DecryptWithPublicKey(enc, PublicKey)
   Log(BytesToString(dec, 0, dec.Length, "UTF8"))
End Sub

If you are running it on the simulator then you need to add this line:

#Entitlement: <key>keychain-access-groups</key><array><string>$(AppIdentifierPrefix)</string></array>

 

[Marcus Araujo]

Cool! Thank you very much!

 

[Carlos marin]

Is it possible to change the key size for example to 2048 or 4096?

 

[Erel]

No. The underlying library doesn't support it.

 

[Nestor Castro Jr]

Hello Erel,

I tried to use your sample with a Key pairs that I genareted with 3th part software but it does not work. My keys has 1024 bits. Do you know what I'm doing worng?

This is my Keys:

Private PrivateKey As String = $"-----BEGIN RSA PRIVATE KEY-----
MIICXgIBAAKBgQDWoUvEUYyayg3LfgJjCp1dElri0OloQ0eiT9vp900aHnvcT/Et
N4VPHh8arokkoK252BD7f8Z8SSXJdkZ7YHWNsHyKj5WZW0N3qlvswsR1O9v2I8Zz
MX2PnSfQolTLrPLNNZIfCwuu5FhkTjfi6PK2rjnoFRPy3a0iMGxXRPLQTwIDAQAB
AoGAPGWDNqlkEaLOIvdAoLI5+hjSLoVvSQG1xL0IO1x1++WcITD1wy2ee9cUFaQL
v5zfhi6BCOS56/uBgKGhz9IjAcoamXG7KF3vRJu9F0xqlBQpjTgKDwtJnKuNncRF
BXZiJTc3zKVzMB4EWmSh5owcXuYGE1JA2NWekPCUK9JVByECQQDf+A+q9bSWc+AH
rBbZYu3y8pdu2vAMKyOXksBrJJnZU3X6uNmHVGKpflKOrRZtUtNIMJN5vA453srK
E6n5Jri5AkEA9VNRjL9KueChj4HKZZ7uxiBnfEQr3m9EnD8ekgtwxeKkpCN7sKNs
+SGGXZ53VaHmpC8DesZ8FDm/Yg42Nv29RwJBAKuHP/ie1P+lHx7BHX6/1Z0LTg8I
fm/TWh7rtZJZJbrbwK+UgoSyjB1jMbczuMlhdY8EJO5GqF6J0qWRCcxXa4ECQQCl
Dr/pkLL4SPiqk0rYAIzqZNb7tupFKFvjPFyXKndfzNO1U+JewDYLkNDUoE/uH5YM
lU0kB/NnsErh8Gntqd71AkEAzB6voi3BSxpTdReWeUpVBzLSkyNZr655XCOAAqhV
C6VsLi9PfoHpu9PLa5nl5fHIOJTtulg9lsVOJoH0SxvMjA==
-----END RSA PRIVATE KEY-----"$
Private PublicKey As String = $"-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCwM0kt6D4aeXk/XzjObmCDS5AX
dqKdX4zLQz4a00TdhhBR4JjnF0srXo3M0d6izSoFVsQaYFQDWo9TJZrfC7qKhiaZ
EL18GvnGCTblndYDkFMLdwd/0a0yfu1Ga1HyV2SBivZYwNoF7hcPOpzR7ZTgCnlL
zFLrH+sDdG5fhMLFmQIDAQAB
-----END PUBLIC KEY-----"$

 

[Erel]

Have you seen the library developer post about the usage: http://www.ideawu.com/blog/post/132.html ?

Especially the key configuration:

"digest_alg" => "sha512",
"private_key_bits" => 1024,
"private_key_type" => OPENSSL_KEYTYPE_RSA,

 

[Nestor Castro Jr]

Have you seen the library developer post about the usage: http://www.ideawu.com/blog/post/132.html ?

Especially the key configuration:

"digest_alg" => "sha512",
"private_key_bits" => 1024,
"private_key_type" => OPENSSL_KEYTYPE_RSA,

You're right! I had to add one more parameter: work with PKCs8 format for the private key. Now it is working fine! Thank you!