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Purpose of base64 encoding6/16/2023 ![]() Now in order to get my text back to original text 'ABCD', lets decode it. SQL>SELECT UTL_RAW.CAST_TO_RAW('QUJDRA=') FROM dual If we convert the ASCII value of these text into hex we get the encoded string returned by Base64 encoding. In order to get encoded string as text instead of RAW we can cast it to VARCHAR2. (Adds '=' sign to output text as we added 0s to make it 6bits)ĥ) Decimal representation of 6 bits representation of text.Ġ10000->16 010100->20 001001->9 000011->3 010001->17 000000->0Ħ) Now lets select from base64 characters(A-Z,a-z,0-9,+,/ altogether 64 characters:0-63) according to the decimal values.īut Oracle Base64 encoding returns this text as RAW(Hex Values). Let me explain how we have got this values according the encoding steps that i have mentioned above.ģ) Binary representation of text grouped by bytes.Ĥ1->01000001 42->01000010 43->01000011 44->01000100Ĥ) Bit representation of text grouped by 6 bits. SQL> SELECT UTL_ENCODE.BASE64_ENCODE('41424344') FROM dual In Oracle we have got UTL_ENCODE package to encode it, which takes RAW and returns encoded value as RAW. We have got the hex values of 'ABCD' that is '41424344'.Ģ) Lets encode this hex using Base64. SQL> SELECT UTL_RAW.CAST_TO_RAW('ABCD') FROM dual Lets say we want to encode the text 'ABCD'.ġ) Lets convert this to RAW data which is hexadecimal values. Now i want to show this practically and also want to shows how the Oracle's Base64 encoding returns RAW value. So bit should be represented as 6 bits string.ĥ) Then these 6 bits string will be converted to decimal number.Ħ) Then it selects the ascii characters(A-Z,a-z,0-1,+ and /) according to the decimal number calculated in step 4. That is, it takes 24 bits of data and returns as 32 bit encoded characters. First of all I would like to tell how the Base64 works as general.Ģ) Converts it to Hexadecimal values(Decimal to Hex conversion).ģ) Represents the text in bits(groups as byte).Ĥ) Since the Base64 takes three bytes of data. Message2 varchar(max) collate Latin1_General_100_CI_AI_SC_UTF8ĭECLARE varchar(max) = 'Dit zijn geen diekrieten e, i en u.It order to understand your problem and to simulate it I have generated one scenario. Message varchar(max) collate Latin1_General_100_CI_AI_SC_UTF8, Create a temp table to store strings as utf8 The following example gives the correct results. You have to actually store it in this collation to have the encoding of utf-8 take effect. ![]() Ok, it turns out that declaring a variable with collation is not enough. Who knows how we can adjust for this? We need te have a valida base64 encoded message because otherwise we're not able to process te information to the external servoce. When you run the results for thought a service like then it shows the result is not a utf-8 string. Unfortunatly it only works without diacritical marks. This function was based of a solution found using the powers of google. The way we calculaten the base64 in normally contained in a function. SELECT as message2, as known_correct_base64 BASE64 ENCODE THE MESSAGE WITHOUT DIACRITICAL MARK SELECT as message, as known_correct_base64 SET = convert(varbinary(max), = cast('' as 'varchar(max)') BASE64 ENCODE THE MESSAGE WITH DIACRITICAL MARK KNOW CORRECT BASE64 RESULTS AS CALCULATED WITH THE OPENSSL LIBRARYĭECLARE nvarchar(max) = 'RGl0IHppam4gZGlla3JpZXRlbiDDqywgw64gZW4gw7ou' ĭECLARE nvarchar(max) = 'RGl0IHppam4gZ2VlbiBkaWVrcmlldGVuIGUsIGkgZW4gdS4=' SAMPLE MESSAGES ONE WITH AND ONE WITHOUT DIACRITICAL MARKSĭECLARE varchar(max) = 'Dit zijn diekrieten ë, î en ú.' ĭECLARE varchar(max) = 'Dit zijn geen diekrieten e, i en u.' I contains a sample for a correctly encoded message and an invalid one. I've created a test script to show the exact problem and to provide a starting point to hopefully find a solution to this issue. Then the webservice we're contacting start throwing errors. This worked fine untill we encountered a diacritical mark (ë, î, ú, etc) in the message we want to encode. ![]() For a webservice we need to base64 encode our message before transmitting it. I'm having some trouble getting things to work.
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