B4X Requires Chilkat v11.0.0+

Duplicate openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

See more RSA Examples

Demonstrates how to duplicate the creation of an RSA signature produced by this OpenSSL command:

openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

B4X

Dim success As Boolean = False

'  This example assumes the Chilkat API to have been previously unlocked.
'  See Global Unlock Sample for sample code.

Dim pkey As ChilkatPrivateKey
pkey.Initialize("pkey")

'  Load the private key from an RSA PEM file:
success = pkey.LoadPemFile("myKey.pem")

Dim rsa As ChilkatRsa
rsa.Initialize

'  Import the private key into the RSA component:
success = rsa.UsePrivateKey(pkey)
If success = False Then
    Log(rsa.LastErrorText)
    Return
End If


'  OpenSSL uses BigEndian byte ordering:
rsa.LittleEndian = False

'  The resulting signature will be a Base64 string:
rsa.EncodingMode = "base64"

'  For simplicity, we're not loading
'  the data to be signed from a file.  We are instead simply
'  using a literal string value.  
Dim strData As String = "This is the text to be signed."

'  Hash the input using MD5, and then sign the hash:
'  Other valid hash algorithm choices are "md2" and "sha-1".
Dim base64Sig As String = rsa.SignStringENC(strData, "md5")

Log(base64Sig)

Log("Success!")