Re: md5 hashing on GNUstep

[Andreas Höschler]

Hi Nikolaus,

>> I have the following NSString category 
>> 
>>  @implementation NSString (NSStringJsonExtension)
>> 
>>  - (NSString *)md5
>>    {
>>     #ifdef __APPLE__
>>     const char *cStr = [self UTF8String];
>>     unsigned char result[CC_MD5_DIGEST_LENGTH];
>>     CC_MD5( cStr, (int)strlen(cStr), result ); // This is the md5 call
>>     return [NSString stringWithFormat:
>>     @"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
>>     result[0], result[1], result[2], result[3], 
>>     result[4], result[5], result[6], result[7],
>>     result[8], result[9], result[10], result[11],
>>     result[12], result[13], result[14], result[15]
>>     ];  
>>     #else
>>     NSLog(@"md5 not yet supported on GNUstep. Please implement");
> 
> https://u10997244.ct.sendgrid.net/ls/click?upn=VVT4Fr0OoZzgz9hrDLZSJzJAAUzBaOKReTGxr-2Fx-2FWq8S8KGFYM7kdQTwqhxshnPa5cfe_tlKK9kH2hVBWbOLd8XAeSMwRALtWbXyaBq-2FNYuoUwQRR7ONi3bYz9ia6xyFyfNbfGhU69Si1801xDwBL5gLvDlSjhmIe2EpVgZRgSu-2Bjb2oNDnA0jfV-2F1YSTyfooUKnYA3nOLXTyorAnt-2FggoCWgkhOboZl-2B5oYqbI3ohAyJ6Xfv0SXaMI2yI3a3qDA3WZzjl-2BgpRcxxS4V6alTPKiv9uaYDw5JfdAc-2BzQ2sIRJZTq7tN73cGjsS3bQPZjOzy-2Fd5
> 
> maybe
>       unsigned char *MD5(cStr, strlen(cStr), result);
> 
> You need to install openssl devel packages.

Thanks a lot! Your hint got me on the road. The following snippet 

  - (NSString *)md5
    {
     // we might have to do the following on Linux to get the code below working
     // apt-get install libssl-dev
     // #include <openssl/md5.h>
     // Link the framework with -lssl -lcrypto
     const char *cStr = [self UTF8String];
     unsigned char result[MD5_DIGEST_LENGTH];     
     MD5((const unsigned char *)cStr, strlen(cStr), result);     
     return [NSString stringWithFormat:
     @"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
     result[0], result[1], result[2], result[3], 
     result[4], result[5], result[6], result[7],
     result[8], result[9], result[10], result[11],
     result[12], result[13], result[14], result[15]
     ];  
    }

works like a charm. :-)

Thanks,

Andreas