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Resolved convert image file into base64 string

  1. How-to
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  1. PRASHANT NIRGUN
    PRASHANT NIRGUN
  2. PowerBuilder
  3. Saturday, 27 August 2022 18:06 PM UTC

I want to convert the image file into base64 Image. used following steps. But wen I check that using any online tool it fails String to image tool

01 I open file in stream Mode and stored into byte variable

02 Convert it to string using AnsiEncode

03 Convert string into base 64 using gcc_system.of_encrypt_base_64('Encrypt Base 64')

 

Code is as follows

//click event of cb_file_open
Blob lblob_data

Integer li_rc, li_fnum
Long ll_length
String ls_title, ls_pathname, ls_filename, ls_filter

ls_title = "Select a File"
ls_filter = "*.jpg,*.jpeg,*.bmp,*.png"

li_rc = GetFileOpenName(ls_title, ls_pathname, ls_filename, "", ls_filter)
If li_rc < 1 Then
Return
End If

li_fnum = FileOpen(ls_pathname, StreamMode!, Read!)
ll_length = FileReadEx(li_fnum, lblob_data)
FileClose(li_fnum)
mle_response.text = String(lblob_data, EncodingAnsi!)
mle_output.txt = gcc_system.of_encrypt_base_64('Encrypt Base 64')

 

I also tried using Topwiz bcrypt tool using following steps attaching image 

01 Button Hash a file

02 copy sle_result.text to mle_message (convert sle_message to mle_message)

03 click button cb_base64

04 copy sle_result.text and test in online tool

Attachments (1)
base64.png base64.png
  1. Encoding
  2. PowerBuilder
Faulting module name: PBSHR.dll, version: 21.0.0.1...
PB 2019 r2 - License Transfer
Accepted Answer
René Ullrich
René Ullrich Accepted Answer Pending Moderation
  1. Tuesday, 30 August 2022 03:04 AM UTC
  2. PowerBuilder
  3. # Permalink
Function Boolean CryptBinaryToString ( & blob pbBinary, & ulong cbBinary, & ulong dwFlags, & Ref string pszString, & Ref ulong pcchString) Library "Crypt32.dll" Alias For "CryptBinaryToStringW"
Comment
PRASHANT NIRGUN
  1. PRASHANT NIRGUN
  2. Tuesday, 30 August 2022 03:06 AM UTC
Thanks to René Ullrich final code is as follows



Blob lblob_data

Int li_fnum

Long ll_length

String ls_pathname, ls_encoded

ULong lul_len, lul_buflen

Boolean lb_rtn



ls_pathname = "D:\tss\images\png\128x128\msgioin.png"

li_fnum = FileOpen(ls_pathname, StreamMode!, Read!)

ll_length = FileReadEx(li_fnum, lblob_data)

FileClose(li_fnum)



lul_len = Len(lblob_data)

lul_buflen = 2 + 1.5 * (lul_len + 2)



lb_rtn = CryptBinaryToString(lblob_data, &

lul_len, CRYPT_STRING_BASE64, &

ls_encoded, lul_buflen)

mle_response.text = ls_encoded
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Responses (4)
John Fauss
John Fauss Accepted Answer Pending Moderation
  1. Saturday, 27 August 2022 18:27 PM UTC
  2. PowerBuilder
  3. # 1

Hi, Prashant - 

You didn't state what version of PB you are using.

If you are using PB 2017 or newer, I suggest you use the Base64Encode function of the CoderObject object to perform Base64 encoding of a Blob.

Look at the PB Help topic for Base64Encode.

Read the image file into a blob variable in a single step using FileReadEx instead of using FileRead and reading it in 64K chunks. The PB Help topic for FileReadEx contains a code sample showing how to read a .BMP file into a Blob variable.

Best regards, John

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mike S
mike S Accepted Answer Pending Moderation
  1. Saturday, 27 August 2022 18:36 PM UTC
  2. PowerBuilder
  3. # 2

this is wrong -->> mle_output.txt = gcc_system.of_encrypt_base_64('Encrypt Base 64')

 

you need to encrypt the blob to base64

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PRASHANT NIRGUN
PRASHANT NIRGUN Accepted Answer Pending Moderation
  1. Saturday, 27 August 2022 19:29 PM UTC
  2. PowerBuilder
  3. # 3

I am very sorry I am using PB 12.5 and my function is as follows and I am returning base64 string only. 

//gcc_system.of_encrypt_base_64('Encrypt Base 64')

String ls_encoded
ULong lul_len, lul_buflen
Boolean lb_rtn

Blob value

// the value to be encoded, needs to be 3 char or more (but not 4?)
value = blob(as_value)
//value = blob(sle_1.text, EncodingUTF16BE!)

lul_len = Len(value)
lul_buflen = lul_len * 2
ls_encoded = Space(lul_buflen)

lb_rtn = CryptBinaryToString(value, &
lul_len, CRYPT_STRING_BASE64, &
ls_encoded, lul_buflen)

IF NOT lb_rtn THEN
ls_encoded = ""
ELSE
// remove the last two chr(0)!
ls_encoded = left(ls_encoded, len(ls_encoded) - 2 )
END IF

Return ls_encoded

Comment
René Ullrich
  1. René Ullrich
  2. Monday, 29 August 2022 05:47 AM UTC
To calculate the buffer length (lul_buflen) I use

lul_buflen = 2 + 1.5 * (lul_len + 2)



To remove the CRLF from BASE64 you can combine (add values) CRYPT_STRING_BASE64 with CRYPT_STRING_NOCRLF (= 1073741824).



To get a BASE64 from a image file you should directly convert the blob to BASE64 as Mike already wrote. Do not convert the blob to string first.

Maybe you have to change your of_encrypt_base_64 function to accept a blob value instead of string or add an extra function for that.



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PRASHANT NIRGUN
  1. PRASHANT NIRGUN
  2. Monday, 29 August 2022 08:06 AM UTC
is it working at your end please share the code external function declaration. I not worked with local external functions. I am using PB 12.5 classical
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