Decode url base64

[burkulesomesh43]

Hi,
I want to decode "ssid%40sss". this %40 has vale "@". when i am trying to decode "ssid%40sss" using mbedtls_base64_decode() function the processor gets reset again and again.
Here is my code...

unsigned char *decode_pass=NULL;
size_t len=32;
mbedtls_base64_decode(decode_pass, sizeof(decode_pass), &len,(unsigned char *) get_pass, strlen(get_pass));

can u please help me out.

[ESP_Sprite]

Possibly because what you have is not base64 encoded; it's urlencoded.

[burkulesomesh43]

Possibly because what you have is not base64 encoded; it's urlencoded.

ohh. I got it. it's my mistake. mbedtls function decodes base64 values not the url. thanks for reply.

but actually I want to decode url. Is there any function in esp idf which decodes URL??

[kolban]

There appear to be a number of C language routines on Github that claim to be URL decoders ... here is one that was posted 23 hours ago (from this date/time):

https://github.com/swarajsatvaya/UrlDecoder-C

But there appear to be many others.

[burkulesomesh43]

There appear to be a number of C language routines on Github that claim to be URL decoders ... here is one that was posted 23 hours ago (from this date/time):

https://github.com/swarajsatvaya/UrlDecoder-C

But there appear to be many others.

Thank you very much. very helpful for me. code also includes the substring finder function.

[burkulesomesh43]

There appear to be a number of C language routines on Github that claim to be URL decoders ... here is one that was posted 23 hours ago (from this date/time):

https://github.com/swarajsatvaya/UrlDecoder-C

But there appear to be many others.

Thank you very much. very helpful for me. code also includes the substring finder function.

I am using isxdigit() function given in ctype.h librairy.
but when i am calling this function it gives an error.

error: array subscript has type 'char'

char *urlDecode(const char *str) {

char *dStr = (char *) malloc(strlen(str) + 1);
char eStr[] = "00"; /* for a hex code */

strcpy(dStr, str);
int i; /* the counter for the string */

for(i=0;i<strlen(dStr);++i) {

if(dStr == '%') {
if(dStr[i+1] == 0)
return dStr;

if(isxdigit(dStr[i+1]) && isxdigit(dStr[i+2])) {

//d = 0;

/* combine the next to numbers into one */
eStr[0] = dStr[i+1];
eStr[1] = dStr[i+2];

/* convert it to decimal */
long int x = strtol(eStr, NULL, 16);

/* remove the hex */
memmove(&dStr[i+1], &dStr[i+3], strlen(&dStr[i+3])+1);

dStr = x;
}
}
else if(dStr == '+') { dStr = ' '; }
}
return dStr;
}

How to remove this error??

[kolban]

What source line is reporting the error?

[fly135]

Quick search for "percent decoding c source" has lots of hits. This link has several suggested decoders in C.

https://stackoverflow.com/questions/267 ... ry/2766963

John A

[burkulesomesh43]

What source line is reporting the error?

following line:
if(isxdigit(dStr[i+1]) && isxdigit(dStr[i+2]))

[fly135]

What source line is reporting the error?

He needs to cast the parameter in the isxdigit function call to an int.

Code: Select all

if(isxdigit((int)dStr[i+1]) && isxdigit((int)dStr[i+2]))

John A