Hi, I'm scratching my head over this one. I suspect it's a cccsid and I've
thrown a variety of conversions at it and lost out. Does anyone have any
experience with AES decoding in RPG please?
Thanks in advance !
If I go to a website such as
https://www.devglan.com/online-tools/aes-encryption-decryption and enter a
simple test to encrypt a string, I want to decrypt it in RPG on the
iSeries.
My Test is as follows:
On the website:
Text to encrypt = TEST
mode ECB
No Padding
Key size 256
Secret Key 11111111111111111111111111111111
The Base64 result is 496QM9dt3+pzckI4U5oKAQ==
Now if I use these values in my program, Base64-decode the input, then pass
the result into Qc3DecryptData the result is not 'TEST' :
Result:
[image: image.png]
Here's the program listing:
* CRTRPGMOD TESTDC
* CRTPGM PGM(lib/TESTDC) BNDSRVPGM(QC3DTAEN QC3PRNG)
*
H DEBUG OPTION(*SRCSTMT:*NODEBUGIO)
H DFTACTGRP(*NO) ACTGRP(*NEW) BNDDIR('HTTPAPI':'BASE64')
/copy BASE64_H
/copy httpapi_h
/******************************************************************
/* Interface:
D TESTDC PR ExtPgm('TESTDC')
D input 100A
D textdec 100A
D msg 256A
D TESTDC PI
D input 100A
D textdec 100A
D Msg 256A
D
//****************************************************************
// Procedure def:
// Decrypt Data (OPM, QC3DECDT; ILE, Qc3DecryptData) API
// Restores encrypted data to a clear (intelligible) form.
// ---------------------------------------------------------------
D Qc3DecryptData Pr ExtPgm('QC3DECDT')
D encryptedData 100a
D encryptedDtaL 10I 0
D algorithm like(QC3D0200)
D algorithmFmt 8
D key like(keyC)
D keyFmt 8
D srvProvider 1
D deviceName 10
D clrDta 100a
D clrDtaBufL 10I 0
D clrDtaRtnL 10I 0
D errcde like(APIERR)
//****************************************************************
// Data Structures:
//ALGD0200 algorithm description structure
//Qc3 Format ALGD0200
// -----------------------------------------
DQC3D0200 DS
// Block Cipher Alg:
D QC3BCA 1 4B 0
// Block Length:
D QC3BL 5 8B 0
// Mode:
D QC3MODE 9 9
// Pad Option:
D QC3PO 10 10
// Pad Character:
D QC3PC 11 11
// Reserved:
D QC3ERVED 12 12
// MAC Length:
D QC3MACL 13 16B 0
// Eff Key Size:
D QC3EKS 17 20B 0
// Init Vector:
D QC3IV 21 52
//****************************************************************
// KEYD0200 key description format structure
// Qc3 Format KEYD0200
// -----------------------------------------
DQC3D020000 DS
// Key Type:
D QC3KT 1 4B 0
// Key String Len:
D QC3KSL 5 8B 0
// Key Format:
D QC3KF 9 9
// Reserved:
D QC3ERVED02 10 12 inz(x'000000')
//****************************************************************
// API error structure
// -------------------
D APIERR DS
D ERRPRV 10I 0 INZ(272)
D ERRLEN 10I 0
D EXCPID 7A
D RSRVD2 1A
D EXCPDT 256A
D
//****************************************************************
// Working Vars:
D B64Outlen S 10I 0
D encryptedData S 100a
D encryptedDtaL S 10I 0
D algorithm S like(QC3D0200)
D algorithmFmt S 8 inz('ALGD0200')
D key S like(KeyC)
D keyFmt S 8 inz('KEYD0200')
D srvProvider S 1 inz('1')
D deviceName S 10 inz(*blanks)
D clrDta S 100a
D clrDtaBufL S 10I 0
D clrDtaRtnL S 10I 0
D KeyString S 256
D KeyC S 256
dcl-s txtOut char(50) ccsid(37);
//****************************************************************
// Main:
/free
// Base64 Decode the input string:
// ------------------------------
input='496QM9dt3+pzckI4U5oKAQ==';
B64Outlen = base64_decode( %addr(input)
: %size(%trimr(input))
: %addr(encryptedData)
: %size(encryptedData));
// AES-Decrypt the Base-64 decoded output:
// Set up QC3D0200 algorithm
// -------------------------
// ------- B E G I N -------
// Block cipher algorithm (22 is AES)
QC3BCA = 22;
// Block length (16 is AES)
QC3BL = 16;
// Mode (ECB=0,CBC=1)
QC3MODE = '0';
// Pad Option 1 - Use the char specified in the pad character field
QC3PO = '0';
// Pad Character
QC3PC = X'00';
// Reserved
QC3ERVED = X'00';
// MAC Length - not used - set to null(binary 0s)
QC3MACL = X'00000000';
// Effective key size - must be set to 0.
QC3EKS = 0;
// Initialization vector
// The initialization vector (IV). An IV is not used for mode ECB,
// and must be set to NULL (binary 0s).
QC3IV = *AllX'00';
algorithm = QC3D0200;
// --------- E N D ---------
// Set up QC3D0200 algorithm
// -------------------------
// Set up QC3D0200 Key
// -------------------
// ---- B E G I N ----
// Key Type (KeyFormat 0, KeyLength =32)
// 22 AES
QC3KT = 22;
// Key Format
QC3KF = '0';
// Key String
KeyString ='11111111111111111111111111111111';
// Key Length (AES type 22 has length 32)
QC3KSL = %len(%trimr(KeyString));
KeyC = QC3D020000 + %trimr(KeyString);
Key = KeyC;
// ------ E N D ------
// Set up QC3D0200 Key
// -------------------
// encrypted data= base64-decrypted result
encryptedDtaL = %len(%trimr(encryptedData));
clrDtaBufL= %size(ClrDta);
callP Qc3DecryptData( encryptedData :
encryptedDtaL :
algorithm :
algorithmFmt :
key :
keyFmt :
srvProvider :
deviceName :
clrDta :
clrDtaBufL :
clrDtaRtnL :
APIERR
);
If ERRLEN > 0;
msg = EXCPID;
EndIf;
txtOut = clrDta;
*InLr = *On;
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