Zach Zach - 1 month ago 7
iOS Question

Convert NSData to String?

I am storing a openssl private Key EVP_PKEY as nsdata. For this I am serializing into a byte stream using the code below

unsigned char *buf, *p;
int len;
len = i2d_PrivateKey(pkey, NULL);
buf = OPENSSL_malloc(len);
p = buf;
i2d_PrivateKey(pkey, &p);


where pkey is of type EVP_PKEY.
Then I am storing the bytes from buffer 'p' as an NSData using the line given below

NSData *keydata = [NSData dataWithBytes:P length:len];


Now I am converting it to a NSString using the code given below but when i print it into console its giving some other characters.

NSString *content =[ NSString stringWithCString:[keydata bytes] encoding:NSUTF8StringEncoding];


Could someone help?


Basically I want to store the EVP_PKEY
into a sqlite database


am I on the right track?
Thanks.

Answer

you can use ( see NSString Class Reference )

- (id)initWithData:(NSData *)data encoding:(NSStringEncoding)encoding

Example :

NSString *myString = [[NSString alloc] initWithData:myData encoding:NSUTF8StringEncoding];

Remark: Please notice the NSData value must be valid for the encoding specified (UTF-8 in the example above), otherwise nil will be returned:

Returns nil if the initialization fails for some reason (for example if data does not represent valid data for encoding).

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