Hi ,
I am currently trying to implement base64 encoding and decoding
scheme in C . Python has a module , base64 , that will do the
encoding and decoding with ease . I am aware of OpenSSL having support
for base64 encoding and decoding , but i will have to now implement
both in C without using the openssl libraries .
I was able to download a code w.r.t. base 64 encoding and
decoding . I am attaching the code below .
void encodeblock( unsigned char cin[3], unsigned char cout[4], int
nlen )
{
cout[0] = cb64[ cin[0] >2 ];
cout[1] = cb64[ ((cin[0] & 0x03) << 4) | ((cin[1] & 0xf0) >4) ];
cout[2] = (unsigned char) (nlen 1 ? cb64[ ((cin[1] & 0x0f) << 2)
| ((cin[2] & 0xc0) >6) ] : '=');
cout[3] = (unsigned char) (nlen 2 ? cb64[ cin[2] & 0x3f ] :
'=');
}
void decodeblock( unsigned char cin[4], unsigned char cout[3] )
{
cout[ 0 ] = (unsigned char ) (cin[0] << 2 | cin[1] >4);
cout[ 1 ] = (unsigned char ) (cin[1] << 4 | cin[2] >2);
cout[ 2 ] = (unsigned char ) (((cin[2] << 6) & 0xc0) | cin[3]);
}
int base641_decodestring(char* pcstr,int size,char** ppcdest)
{
unsigned char cin[4] = {""};
unsigned char cout[3] = {""};
unsigned char cv = 0;
int ni = 0;
int nlen = 0;
char* cptr = pcstr;
*ppcdest = malloc(sizeof(char)*160);
if (!*ppcdest)
{
return 1;
}
memset(*ppcdest,0,sizeof(char)*160);
char* pcstring = malloc( sizeof(char) * SIZE);
if (!pcstring)
{
aps_log("APS_log.txt","\nbae64.c:base64encode:mall oc failed
\n");
return 1;
}
memset(pcstring,'\0',SIZE);
for( nlen = 0, ni = 0; ni < 4; ni++ )
{
cv = 0;
while( cv == 0 )
{
cv = (unsigned char) *cptr;
cv = (unsigned char) ((cv < 43 || cv 122) ? 0 :
cd64[ cv - 43 ]);
if( cv )
{
cv = (unsigned char) ((cv == '$') ? 0 : cv - 61);
}
}
if( cptr++ )
{
nlen++;
if( cv )
{
cin[ ni ] = (unsigned char) (cv - 1);
}
}
else
{
cin[ni] = 0;
}
}
if( nlen )
{
decodeblock( cin, cout );
}
memcpy(*ppcdest,cout,160);
return 0;
}/*end of base64_decode */
char* base64_encode(char* pcstr)
{
unsigned char cin[3] = {""};
unsigned char cout[4] = {""};
int ni = 0;
int nlen = 0;
int flag = 1;
char* cptr = pcstr;
char* pcstring = malloc( sizeof(char) * SIZE);
if (!pcstring)
{
aps_log("APS_log.txt","\nbae64.c:base64encode:mall oc failed
\n");
return (void*)0;
}
memset(pcstring,'\0',SIZE);
while( flag )
{
for( ni = 0; ni < 3; ni++ )
{
cin[ni] = (unsigned char)*cptr;
if( *++cptr != '\0' )
nlen++;
else
{
cin[ni] = 0;
flag = 0;
break;
}
}
encodeblock(cin, cout,nlen);
strcat(pcstring,cout);
}
return pcstring;
}/* end of base64_encode */
But this code gives different hex values as compared to the
python base64.encodestring and base64.decodestring respectively .
I need some help on this matter . I need some pointers on
where is the mistake for the above file . 10 3987
On Mon, 23 Jul 2007 05:37:40 -0700, pycraze wrote:
But this code gives different hex values as compared to the python base64.encodestring and base64.decodestring respectively .
I need some help on this matter . I need some pointers on where is the mistake for the above file .
It's usually easier to re-use existing code than to implement (and
debug) something from scratch. Several Base64 implementations are
available, e.g. http://www.synesis.com.au/software/b64.html
--
Roland Pibinger
"The best software is simple, elegant, and full of drama" - Grady Booch
pycraze wrote:
Hi ,
I am currently trying to implement base64 encoding and decoding
scheme in C . Python has a module , base64 , that will do the
encoding and decoding with ease . I am aware of OpenSSL having support
for base64 encoding and decoding , but i will have to now implement
both in C without using the openssl libraries .
I was able to download a code w.r.t. base 64 encoding and
decoding . I am attaching the code below .
[Snip]
But this code gives different hex values as compared to the
python base64.encodestring and base64.decodestring respectively .
I need some help on this matter . I need some pointers on
where is the mistake for the above file .
On a brief test your code seemed compatible with that bundled into the
MIME support in a Java environment I had to hand. Perhaps the Python
support is based on a different standard/RFC? You might wish to enquire
somewhere where Python is on topic.
Roland Pibinger wrote:
On Mon, 23 Jul 2007 05:37:40 -0700, pycraze wrote:
> But this code gives different hex values as compared to the python base64.encodestring and base64.decodestring respectively . I need some help on this matter . I need some pointers on where is the mistake for the above file .
It's usually easier to re-use existing code
He did ... He said
>I was able to download a code w.r.t. base 64 encoding and decoding . I am attaching the code below .
I've downloaded and built the same code (it was easily found via Google)
and it seems to be compatible with the implementation in the Java
environment I have lying around, so I think the issue may be with the
way he's trying to use the Python implementation, but what do I know
about that?
On Jul 23, 8:29 pm, rpbg...@yahoo.com (Roland Pibinger) wrote:
On Mon, 23 Jul 2007 05:37:40 -0700, pycraze wrote:
But this code gives different hex values as compared to the
python base64.encodestring and base64.decodestring respectively .
I need some help on this matter . I need some pointers on
where is the mistake for the above file .
It's usually easier to re-use existing code than to implement (and
debug) something from scratch. Several Base64 implementations are
available, e.g.http://www.synesis.com.au/software/b64.html
--
Roland Pibinger
"The best software is simple, elegant, and full of drama" - Grady Booch
Hi Roland ,
Thank you for your assistance . Python uses base64 encode and decode
schemes specified in RFC 3548 . I am looking to implement this in C .
In the link you have sent , the base64 library is according to RFC
1113 .
Mark Bluemel wrote:
pycraze wrote:
>Hi ,
I am currently trying to implement base64 encoding and decoding scheme in C . Python has a module , base64 , that will do the encoding and decoding with ease . I am aware of OpenSSL having support for base64 encoding and decoding , but i will have to now implement both in C without using the openssl libraries .
I was able to download a code w.r.t. base 64 encoding and decoding . I am attaching the code below .
[Snip]
> But this code gives different hex values as compared to the python base64.encodestring and base64.decodestring respectively .
I need some help on this matter . I need some pointers on where is the mistake for the above file .
On a brief test your code seemed compatible with that bundled into the
MIME support in a Java environment I had to hand. Perhaps the Python
support is based on a different standard/RFC? You might wish to enquire
somewhere where Python is on topic.
I also checked with Python to a limited extent and that also seems OK.
What problems are you having?
On Jul 23, 8:46 pm, Mark Bluemel <mark_blue...@pobox.comwrote:
Mark Bluemel wrote:
pycraze wrote:
Hi ,
I am currently trying to implement base64 encoding and decoding
scheme in C . Python has a module , base64 , that will do the
encoding and decoding with ease . I am aware of OpenSSL having support
for base64 encoding and decoding , but i will have to now implement
both in C without using the openssl libraries .
I was able to download a code w.r.t. base 64 encoding and
decoding . I am attaching the code below .
[Snip]
But this code gives different hex values as compared to the
python base64.encodestring and base64.decodestring respectively .
I need some help on this matter . I need some pointers on
where is the mistake for the above file .
On a brief test your code seemed compatible with that bundled into the
MIME support in a Java environment I had to hand. Perhaps the Python
support is based on a different standard/RFC? You might wish to enquire
somewhere where Python is on topic.
I also checked with Python to a limited extent and that also seems OK.
What problems are you having?
Roland ,
The python's base64 module gives me a different string as compared
the above C code . I am currently using OpenSSL library for the base64
encode and decode schemes . The OpenSSL gives similar output as
compared to python base64 when i encode the same input string .
I do not want to use OpenSSL library and would want to implement
now in pure C . So i am stuck with only this code . I get to see
numerous C codes that have implemented base64 encoding and decoding
schemes . I am looking particularly for the RFC 3548 specification of
base64 encoding and decoding .
pycraze wrote:
Thank you for your assistance . Python uses base64 encode and decode
schemes specified in RFC 3548 . I am looking to implement this in C .
In the link you have sent , the base64 library is according to RFC
1113 .
So is the code you downloaded...
A little examination shows that 3548 and 1113 are very similar. See
http://www.faqs.org/rfcs/rfc<number>.html
The encoding alphabet is identical between the two. I have not read the
specs in detail, but suspect the differences are related to things like
line length, line endings, padding rules and the like. With a little
study these small differences should be fairly easy to understand and
adapt your code for.
pycraze wrote:
On Jul 23, 8:46 pm, Mark Bluemel <mark_blue...@pobox.comwrote:
>>Mark Bluemel wrote:
[Snip]
Roland ,
I'm not Roland
The python's base64 module gives me a different string as compared
the above C code .
How different?
I am currently using OpenSSL library for the base64
encode and decode schemes . The OpenSSL gives similar output as
compared to python base64 when i encode the same input string .
I do not want to use OpenSSL library and would want to implement
now in pure C . So i am stuck with only this code . I get to see
numerous C codes that have implemented base64 encoding and decoding
schemes . I am looking particularly for the RFC 3548 specification of
base64 encoding and decoding .
I've posted a link elsewhere in the thread, but simply doing a Google
search for "RFC 3548" would have found it.
On Mon, 23 Jul 2007 16:58:46 +0100, Mark Bluemel wrote:
>A little examination shows that 3548 and 1113 are very similar. See http://www.faqs.org/rfcs/rfc<number>.html
So, assuming they are different, which is the right one? A format
primarily created for exchange of data can hardly be used in different
variants.
--
Roland Pibinger
"The best software is simple, elegant, and full of drama" - Grady Booch rp*****@yahoo.com (Roland Pibinger) writes:
On Mon, 23 Jul 2007 16:58:46 +0100, Mark Bluemel wrote:
>>A little examination shows that 3548 and 1113 are very similar. See http://www.faqs.org/rfcs/rfc<number>.html
So, assuming they are different, which is the right one? A format
primarily created for exchange of data can hardly be used in different
variants.
That's a good question (assuming that they really are significantly
different), but it's not a C question.
--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister" This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics
by: Karl Pech |
last post by:
Hi all,
I'm trying to write a program which can read in files in the following
format:
sos_encoded.txt:
---
begin-base64 644 sos.txt
UGxlYXNlLCBoZWxwIG1lIQ==
---
|
by: simon |
last post by:
Hi
I am trying to install MIME::Base64 and MIME::QuotedPrint using CPAN on
Suse 9.1. Suse comes with Perl v5.8.3 already installed.
The error message I receive is as follows:
...
|
by: John |
last post by:
Hi all,
I've been going through google and yahoo looking for a certain base64
decoder in C without success. What I'm after is something that you can
pass a base64 encoded string into and get back...
|
by: AHanso |
last post by:
Hey I am new to C# (My background is in Java),
I am writing a C# application (that uses the Compact Framework) that
communicates to a Java server. To login the server is expecting the
password...
|
by: Russell Warren |
last post by:
I've got a case where I want to convert binary blocks of data (various
ctypes objects) to base64 strings.
The conversion calls in the base64 module expect strings as input, so
right now I'm...
|
by: Roland Rickborn |
last post by:
Hallo zusammen,
in meine Anwendung ist ein Bild eingebettet und oben in der Leiste soll
ein Icon erscheinen.
Ausserdem will ich nur _eine_ Datei ausgeben, also ohne zusärtliche
Bild-Dateien...
|
by: mirandacascade |
last post by:
I am attempting to implement a process, and I'm pretty sure that a
major roadblock is that I do not understand the nomenclature. The
specs indicate that the goal is to calculate a message digest...
|
by: pycraze |
last post by:
Hi ,
I am working on Fedora core 5 and my OS version is
2.6.15-1.2054_FC5 . My GCC version is 4.1.1 20070105 (Red Hat
4.1.1-51) .
I am currently using the openssl libraries to write a...
|
by: pycraze |
last post by:
Hi ,
I am currently trying to implement base64 encoding and decoding
scheme in C . Python has a module , base64 , that will do the
encoding and decoding with ease . I am aware of OpenSSL having...
|
by: DJRhino |
last post by:
Was curious if anyone else was having this same issue or not....
I was just Up/Down graded to windows 11 and now my access combo boxes are not acting right. With win 10 I could start typing...
|
by: isladogs |
last post by:
The next Access Europe meeting will be on Wednesday 4 Oct 2023 starting at 18:00 UK time (6PM UTC+1) and finishing at about 19:15 (7.15PM)
The start time is equivalent to 19:00 (7PM) in Central...
|
by: Aliciasmith |
last post by:
In an age dominated by smartphones, having a mobile app for your business is no longer an option; it's a necessity. Whether you're a startup or an established enterprise, finding the right mobile app...
|
by: tracyyun |
last post by:
Hello everyone,
I have a question and would like some advice on network connectivity. I have one computer connected to my router via WiFi, but I have two other computers that I want to be able to...
|
by: NeoPa |
last post by:
Hello everyone.
I find myself stuck trying to find the VBA way to get Access to create a PDF of the currently-selected (and open) object (Form or Report).
I know it can be done by selecting :...
|
by: Teri B |
last post by:
Hi, I have created a sub-form Roles. In my course form the user selects the roles assigned to the course.
0ne-to-many. One course many roles.
Then I created a report based on the Course form and...
|
by: nia12 |
last post by:
Hi there,
I am very new to Access so apologies if any of this is obvious/not clear.
I am creating a data collection tool for health care employees to complete. It consists of a number of...
|
by: NeoPa |
last post by:
Introduction
For this article I'll be focusing on the Report (clsReport) class. This simply handles making the calling Form invisible until all of the Reports opened by it have been closed, when it...
|
by: isladogs |
last post by:
The next online meeting of the Access Europe User Group will be on Wednesday 6 Dec 2023 starting at 18:00 UK time (6PM UTC) and finishing at about 19:15 (7.15PM).
In this month's session, Mike...
| |