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Author's profile photo Isuru Fernando

Base64 Function Modules in SAP ABAP

The base64 algorithm is an efficient way to transfer data via the Internet. In SAP, you can use Base64 when you are implementing file-based interfaces between your SAP system and third-party applications via SAP Process Orchestration. Instead of sending the file as an attachment in a message you can send file data as a Base64 string. For example, for outbound interfaces, you first need to encode the file in Base64 format and transmit it to the target system as a Base64 string. In the target system, you need to decode the Base64 string back to actual data.

This method comes in handy if you want to implement file-based interfaces via the Application Integration Framework (AIF) as AIF is not able to handle file attachments.

 

This article goes into detail on Function Modules (FM) in SAP that we can use to encode and decode Base64 string. Use encoding FMs for outbound interface messages and decoding FMs for inbound interface messages.

Function Modules for Base64 Encoding:

 

There are two function modules to encode a string to Base64 format. First, convert string to Xstring using ‘SCMS_STRING_TO_XSTRING‘. Then use ‘SCMS_BASE64_ENCODE_STR‘ to convert Xstring to Base64.

Function Modules for Base64 Decoding:

 

Decoding is a three-step procedure. Convert Base64 string to Xstring using ‘SCMS_BASE64_DECODE_STR‘. Next, transform the Xstring to Binary using function module ‘SCMS_XSTRING_TO_BINARY‘. Finally, turn the Binary format to String via ‘SCMS_BINARY_TO_STRING‘.

How to Decode and Encode Base64 in SAP PI/PO:

 

In most instances, you will use SAP Process Orchestration (PO) to interface between SAP and third-party applications. In these instances, we can use mapping techniques such as User Defined Functions (UDFs), Java Mappings or Adapter Modules to decode and encode Base64.

I have also developed a sample program to decode/encode base64 in ABAP.

To summarize, you can use Base64 string to transfer data such as files, PDFs, images, etc. between SAP and external APIs. Using this method you can avoid sending files as attachments in the message payload. Use the FMs listed above to Encode and Decode Base64 in your SAP application or interface program.

Thank you for reading, hope this information will help you design interfaces.

 

Cheers!

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      Author's profile photo Tomas Buryanek
      Tomas Buryanek

      Hello,
      i would like to add that there are also BASE64 methods in CL_HTTP_UTILITY class:

      DECODE_BASE64
      ENCODE_BASE64
      DECODE_X_BASE64
      ENCODE_X_BASE64

      And I personally prefer to use this class instead of (unreleased) functions.

      Author's profile photo Isuru Fernando
      Isuru Fernando
      Blog Post Author

      Hello Thomas,

      Certainly, CL_HTTP_UTILITY class methods you have given can be used to encode and decode base64. I have included these methods in my original post.

      Thank you!

       

      Author's profile photo Marco SILVA
      Marco SILVA

      Hello,

      Thank you for this blog!

      I'm getting a corrupted PDF with this code:

        DATA: lv_base64_pdf        TYPE string,
              lv_decodedx          TYPE xstring,
              lv_fullpath          TYPE string,
              lv_bin_filesize      TYPE i,
              lt_data              TYPE solix_tab.
      
          CLEAR: lv_decodedx.
      
          CALL METHOD cl_http_utility=>if_http_utility~decode_x_base64
            EXPORTING
              encoded = lv_base64_pdf
            RECEIVING
              decoded = lv_decodedx.
      
          CALL METHOD cl_bcs_convert=>xstring_to_solix
            EXPORTING
              iv_xstring = lv_decodedx
            RECEIVING
              et_solix   = lt_data.
      
          lv_bin_filesize = xstrlen( lv_decodedx ).
      	
          CALL METHOD cl_gui_frontend_services=>gui_download
            EXPORTING
              bin_filesize            = lv_bin_filesize
              filename                = lv_fullpath
              filetype                = 'BIN'
              show_transfer_status    = ' '
            CHANGING
              data_tab                = lt_data.

      Any clue about what can be wrong?

      Thank you!

       

      Best regards,

      Marco Silva

      Author's profile photo Sandra Rossi
      Sandra Rossi

      Your code looks completely correct. Are you sure the PDF base64 is correct at the beginning?

      Author's profile photo Marco SILVA
      Marco SILVA

      Hello,

      Yes, I'm sure! If I perform this I get my base64 file.

          DATA: lt_soli TYPE soli_tab.
      
          CALL FUNCTION 'CONVERT_STRING_TO_TABLE'
            EXPORTING
              i_string         = lv_base64_pdf
              i_tabline_length = 255
            TABLES
              et_table         = lt_soli.
      
          CALL METHOD cl_gui_frontend_services=>gui_download
            EXPORTING
              filename             = lv_fullpath
              filetype             = 'ASC'
              show_transfer_status = ' '
            CHANGING
              data_tab             = lt_soli
            EXCEPTIONS
              OTHERS               = 1.

      Using an online base64 decoder like https://www.freeformatter.com/base64-encoder.html I'm able to get a working PDF...

      I don't know if it can be an issue of my SAP server... Something about encoding... I'm on a ECC6 EHP8 SP8 (BASIS 750 SP9).

      Regards,

      Marco

      Author's profile photo Marco SILVA
      Marco SILVA

      I guess I have a good hint. If I perform this:

          CALL METHOD cl_http_utility=>if_http_utility~decode_x_base64
            EXPORTING
              encoded = lv_base64_pdf
            RECEIVING
              decoded = lv_decodedx.
      
          CALL METHOD cl_http_utility=>if_http_utility~encode_x_base64
            EXPORTING
              unencoded = lv_decodedx
            RECEIVING
              encoded   = lv_base64_pdf.

      My base64 PDF gets corrupted.

      The good one is the one that has ">>". I get more differences with this "ÿ" strange character in the files...

      I've tried all the base64 decode function modules and class methods that I could find in my system and I always get the same result...

      Any clue?

      Regards,

      Marco

      Author's profile photo Sandra Rossi
      Sandra Rossi

      As I said, no issue at my side with your code, the base64 decoding works and I can open the downloaded file correctly:

      PARAMETERS fullpath TYPE string LOWER CASE DEFAULT 'C:\Users\yourname\Downloads\test.pdf'.
      
      DATA(lv_base64_pdf) = VALUE string( ).
      PERFORM get_very_small_pdf_base64 CHANGING lv_base64_pdf.
      DATA(pdf_reloaded) = VALUE xstring( ).
      PERFORM download_pdf USING lv_base64_pdf fullpath CHANGING pdf_reloaded.
      
      FORM download_pdf
          USING
              lv_base64_pdf TYPE string
              lv_fullpath   TYPE string
          CHANGING
              lv_decodedx   TYPE xstring.
      
        DATA: lv_bin_filesize TYPE i,
              lt_data         TYPE solix_tab.
      
        CLEAR: lv_decodedx.
      
        CALL METHOD cl_http_utility=>if_http_utility~decode_x_base64
          EXPORTING
            encoded = lv_base64_pdf
          RECEIVING
            decoded = lv_decodedx.
      
        CALL METHOD cl_bcs_convert=>xstring_to_solix
          EXPORTING
            iv_xstring = lv_decodedx
          RECEIVING
            et_solix   = lt_data.
      
        lv_bin_filesize = xstrlen( lv_decodedx ).
      
        CALL METHOD cl_gui_frontend_services=>gui_download
          EXPORTING
            bin_filesize         = lv_bin_filesize
            filename             = lv_fullpath
            filetype             = 'BIN'
            show_transfer_status = ' '
          CHANGING
            data_tab             = lt_data.
      
      ENDFORM.
      
      FORM get_very_small_pdf_base64 CHANGING e_string type string.
        " PDF from http://www.tagg.org/pdftest.pdf University of Liverpool
        CONCATENATE
              'JVBERi0xLjIgDQol4uPP0w0KIA0KOSAwIG9iag0KPDwNCi9MZW5ndGggMTAgMCBSDQovRmlsdGVyIC9GbGF0ZURlY29kZSANCj4+'
              'DQpzdHJlYW0NCkiJzZDRSsMwFIafIO/we6eyZuckTZPtbtIWBi0UjYKQGxFbJmpliuLb26QM8X6CJBfJyf99ycmFF6xJagWrrMxz'
              'wJeCEMd+gFjWBC1dLPeCJFkbl/fTKfwnTqt1CK0xIZyEwFYZ2T+fwT8KnmIxUmJinNKJyUiyW7mZVEQ6I54m2K3ZzFiupvgPaee7'
              'JHFuZqyDvxuGBbZdu8D1y+7jYf+2e//C2KOJm9dxfEqqTHMRXZlR0hRJuKwZau6EJa+MOdjpYN/gprq8xVW7aRp0ZY162ySbktoW'
              'vxpPZULGxJLSr+G4UuX+QHrcl/rz/2eqvPgGPPWhqg0KZW5kc3RyZWFtDQplbmRvYmoNCjEwIDAgb2JqDQoyNDYNCmVuZG9iag0K'
              'NCAwIG9iag0KPDwNCi9UeXBlIC9QYWdlDQovUGFyZW50IDUgMCBSDQovUmVzb3VyY2VzIDw8DQovRm9udCA8PA0KL0YwIDYgMCBS'
              'IA0KL0YxIDcgMCBSIA0KPj4NCi9Qcm9jU2V0IDIgMCBSDQo+Pg0KL0NvbnRlbnRzIDkgMCBSDQo+Pg0KZW5kb2JqDQo2IDAgb2Jq'
              'DQo8PA0KL1R5cGUgL0ZvbnQNCi9TdWJ0eXBlIC9UcnVlVHlwZQ0KL05hbWUgL0YwDQovQmFzZUZvbnQgL0FyaWFsDQovRW5jb2Rp'
              'bmcgL1dpbkFuc2lFbmNvZGluZw0KPj4NCmVuZG9iag0KNyAwIG9iag0KPDwNCi9UeXBlIC9Gb250DQovU3VidHlwZSAvVHJ1ZVR5'
              'cGUNCi9OYW1lIC9GMQ0KL0Jhc2VGb250IC9Cb29rQW50aXF1YSxCb2xkDQovRmlyc3RDaGFyIDMxDQovTGFzdENoYXIgMjU1DQov'
              'V2lkdGhzIFsgNzUwIDI1MCAyNzggNDAyIDYwNiA1MDAgODg5IDgzMyAyMjcgMzMzIDMzMyA0NDQgNjA2IDI1MCAzMzMgMjUwIA0K'
              'Mjk2IDUwMCA1MDAgNTAwIDUwMCA1MDAgNTAwIDUwMCA1MDAgNTAwIDUwMCAyNTAgMjUwIDYwNiA2MDYgNjA2IA0KNDQ0IDc0NyA3'
              'NzggNjY3IDcyMiA4MzMgNjExIDU1NiA4MzMgODMzIDM4OSAzODkgNzc4IDYxMSAxMDAwIDgzMyANCjgzMyA2MTEgODMzIDcyMiA2'
              'MTEgNjY3IDc3OCA3NzggMTAwMCA2NjcgNjY3IDY2NyAzMzMgNjA2IDMzMyA2MDYgDQo1MDAgMzMzIDUwMCA2MTEgNDQ0IDYxMSA1'
              'MDAgMzg5IDU1NiA2MTEgMzMzIDMzMyA2MTEgMzMzIDg4OSA2MTEgDQo1NTYgNjExIDYxMSAzODkgNDQ0IDMzMyA2MTEgNTU2IDgz'
              'MyA1MDAgNTU2IDUwMCAzMTAgNjA2IDMxMCA2MDYgDQo3NTAgNTAwIDc1MCAzMzMgNTAwIDUwMCAxMDAwIDUwMCA1MDAgMzMzIDEw'
              'MDAgNjExIDM4OSAxMDAwIDc1MCA3NTAgDQo3NTAgNzUwIDI3OCAyNzggNTAwIDUwMCA2MDYgNTAwIDEwMDAgMzMzIDk5OCA0NDQg'
              'Mzg5IDgzMyA3NTAgNzUwIA0KNjY3IDI1MCAyNzggNTAwIDUwMCA2MDYgNTAwIDYwNiA1MDAgMzMzIDc0NyA0MzggNTAwIDYwNiAz'
              'MzMgNzQ3IA0KNTAwIDQwMCA1NDkgMzYxIDM2MSAzMzMgNTc2IDY0MSAyNTAgMzMzIDM2MSA0ODggNTAwIDg4OSA4OTAgODg5IA0K'
              'NDQ0IDc3OCA3NzggNzc4IDc3OCA3NzggNzc4IDEwMDAgNzIyIDYxMSA2MTEgNjExIDYxMSAzODkgMzg5IDM4OSANCjM4OSA4MzMg'
              'ODMzIDgzMyA4MzMgODMzIDgzMyA4MzMgNjA2IDgzMyA3NzggNzc4IDc3OCA3NzggNjY3IDYxMSANCjYxMSA1MDAgNTAwIDUwMCA1'
              'MDAgNTAwIDUwMCA3NzggNDQ0IDUwMCA1MDAgNTAwIDUwMCAzMzMgMzMzIDMzMyANCjMzMyA1NTYgNjExIDU1NiA1NTYgNTU2IDU1'
              'NiA1NTYgNTQ5IDU1NiA2MTEgNjExIDYxMSA2MTEgNTU2IDYxMSANCjU1NiBdDQovRW5jb2RpbmcgL1dpbkFuc2lFbmNvZGluZw0K'
              'L0ZvbnREZXNjcmlwdG9yIDggMCBSDQo+Pg0KZW5kb2JqDQo4IDAgb2JqDQo8PA0KL1R5cGUgL0ZvbnREZXNjcmlwdG9yDQovRm9u'
              'dE5hbWUgL0Jvb2tBbnRpcXVhLEJvbGQNCi9GbGFncyAxNjQxOA0KL0ZvbnRCQm94IFsgLTI1MCAtMjYwIDEyMzYgOTMwIF0NCi9N'
              'aXNzaW5nV2lkdGggNzUwDQovU3RlbVYgMTQ2DQovU3RlbUggMTQ2DQovSXRhbGljQW5nbGUgMA0KL0NhcEhlaWdodCA5MzANCi9Y'
              'SGVpZ2h0IDY1MQ0KL0FzY2VudCA5MzANCi9EZXNjZW50IDI2MA0KL0xlYWRpbmcgMjEwDQovTWF4V2lkdGggMTAzMA0KL0F2Z1dp'
              'ZHRoIDQ2MA0KPj4NCmVuZG9iag0KMiAwIG9iag0KWyAvUERGIC9UZXh0ICBdDQplbmRvYmoNCjUgMCBvYmoNCjw8DQovS2lkcyBb'
              'NCAwIFIgXQ0KL0NvdW50IDENCi9UeXBlIC9QYWdlcw0KL01lZGlhQm94IFsgMCAwIDYxMiA3OTIgXQ0KPj4NCmVuZG9iag0KMSAw'
              'IG9iag0KPDwNCi9DcmVhdG9yICgxNzI1LmZtKQ0KL0NyZWF0aW9uRGF0ZSAoMS1KYW4tMyAxODoxNVBNKQ0KL1RpdGxlICgxNzI1'
              'LlBERikNCi9BdXRob3IgKFVua25vd24pDQovUHJvZHVjZXIgKEFjcm9iYXQgUERGV3JpdGVyIDMuMDIgZm9yIFdpbmRvd3MpDQov'
              'S2V5d29yZHMgKCkNCi9TdWJqZWN0ICgpDQo+Pg0KZW5kb2JqDQozIDAgb2JqDQo8PA0KL1BhZ2VzIDUgMCBSDQovVHlwZSAvQ2F0'
              'YWxvZw0KL0RlZmF1bHRHcmF5IDExIDAgUg0KL0RlZmF1bHRSR0IgIDEyIDAgUg0KPj4NCmVuZG9iag0KMTEgMCBvYmoNClsvQ2Fs'
              'R3JheQ0KPDwNCi9XaGl0ZVBvaW50IFswLjk1MDUgMSAxLjA4OTEgXQ0KL0dhbW1hIDAuMjQ2OCANCj4+DQpdDQplbmRvYmoNCjEy'
              'IDAgb2JqDQpbL0NhbFJHQg0KPDwNCi9XaGl0ZVBvaW50IFswLjk1MDUgMSAxLjA4OTEgXQ0KL0dhbW1hIFswLjI0NjggMC4yNDY4'
              'IDAuMjQ2OCBdDQovTWF0cml4IFswLjQzNjEgMC4yMjI1IDAuMDEzOSAwLjM4NTEgMC43MTY5IDAuMDk3MSAwLjE0MzEgMC4wNjA2'
              'IDAuNzE0MSBdDQo+Pg0KXQ0KZW5kb2JqDQp4cmVmDQowIDEzDQowMDAwMDAwMDAwIDY1NTM1IGYNCjAwMDAwMDIxNzIgMDAwMDAg'
              'bg0KMDAwMDAwMjA0NiAwMDAwMCBuDQowMDAwMDAyMzYzIDAwMDAwIG4NCjAwMDAwMDAzNzUgMDAwMDAgbg0KMDAwMDAwMjA4MCAw'
              'MDAwMCBuDQowMDAwMDAwNTE4IDAwMDAwIG4NCjAwMDAwMDA2MzMgMDAwMDAgbg0KMDAwMDAwMTc2MCAwMDAwMCBuDQowMDAwMDAw'
              'MDIxIDAwMDAwIG4NCjAwMDAwMDAzNTIgMDAwMDAgbg0KMDAwMDAwMjQ2MCAwMDAwMCBuDQowMDAwMDAyNTQ4IDAwMDAwIG4NCnRy'
              'YWlsZXINCjw8DQovU2l6ZSAxMw0KL1Jvb3QgMyAwIFINCi9JbmZvIDEgMCBSDQovSUQgWzw0NzE0OTUxMDQzM2RkNDg4MmYwNWY4'
              'YzEyNDIyMzczND48NDcxNDk1MTA0MzNkZDQ4ODJmMDVmOGMxMjQyMjM3MzQ+XQ0KPj4NCnN0YXJ0eHJlZg0KMjcyNg0KJSVFT0YN'
              'CgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'
              'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'
              'AAAAAAAAAAAAAAAAAAAA'
              INTO e_string.
      ENDFORM.
      
      Author's profile photo Marco SILVA
      Marco SILVA

      Sandra,

      Thank you for your time.

      When I validate the base64 here I get the following message:

      • The specified value is not a valid Base64 string. Try to specify a different standard.
      • The following characters are not suitable for the specified standard: -_
      I’m getting this base64 PDF from Google Gmail API, so I guess the format is not the one expected by SAP… Google API send a “base64url”, which is valid but maybe SAP tools aren’t compatible with that.
      Regards,
      Marco
      Author's profile photo Sandra Rossi
      Sandra Rossi

      "This encoding [base64url] is technically identical to the previous one [base64], except for the 62:nd and 63:rd alphabet character, as indicated in Table 2 [- instead of + and _ instead of /]." (https://tools.ietf.org/html/rfc4648#section-5)

      so:

      base64 = translate( val = base64url from = '-_' to = '+/' ).
      or
      base64url = translate( val = base64 from = '+/' to = '-_' ).
      
      Author's profile photo Marco SILVA
      Marco SILVA

      Dear Sandra,

      You are totally right! It works fine now!

      Thank you so much for your time!

      Regards,

      Marco

      Author's profile photo Lars Hvam
      Lars Hvam

      "secure and efficient", can you elaborate on this part? From a security perspective, the data is not encrypted or checksummed, for efficiency, base64 encoded data is typically larger than the original.

      Author's profile photo Isaias Freitas
      Isaias Freitas

      Indeed…

      If you want to add security, transmit the data using HTTPS or SNC 😉

      Author's profile photo Sandra Rossi
      Sandra Rossi

      If you talk about SCMS_STRING_TO_XSTRING then you may complete that it encodes the string in UTF-8 by default. Idem for the decoding, you convert from a xstring text in UTF-8. Note that instead of all those old function modules, you may use CL_ABAP_CODEPAGE (ABAP 7.02 to 7.52), that's much shorter:

      DATA: xstr TYPE xstring,
            str  TYPE string.
      TRY.
      
      str = cl_abap_codepage=>convert_from( source = xstr ). " default is UTF-8
      
      xstr = cl_abap_codepage=>convert_to( source = str ). " default is UTF-8
      
      CATCH cx_root.
        " handle conversion errors
      ENDTRY.
      Author's profile photo Isuru Fernando
      Isuru Fernando
      Blog Post Author

      Thank you for sharing Sandra!

      Author's profile photo genia scott
      genia scott

      Thank you for sharing Sandra!

      Useful Code!!

      Author's profile photo Rafael Chagas
      Rafael Chagas

      Nice work Fernando.

      I used it to check my data sent using CPI.

      Thanks a lot.