How to store a private key in string literal in C?

Question

e.g.

Can I remove newlines in each line?
What is the best method to define multiple lines string literal in C?

Possible duplicate of [How to split a string literal across multiple lines in C / Objective-C?](https://stackoverflow.com/questions/797318/how-to-split-a-string-literal-across-multiple-lines-in-c-objective-c) — kiran Biradar, Oct 11 '18 at 06:54
Just quote each line, e.g. `char *myliteral = "..." "..." "...";` (where the spaces represent newlines) — David C. Rankin, Oct 11 '18 at 06:54
@ShiDoiSi I will compute the digest and signature from a plaintext with the private key. — da_miao_zi, Oct 11 '18 at 06:56
Try `const char *key = "MIIB...bIjD" "6fP......6Oe" ... "Inl...0rI";` — chux - Reinstate Monica, Oct 11 '18 at 06:59
It's a bad idea to embed sensitive information such as passwords or private keys in an executable file. — n. m. could be an AI, Oct 11 '18 at 07:00

score 6 · Accepted Answer · answered Oct 11 '18 at 07:24

Disregarding the security concerns associated with such a "solution", you could do this:

const char* key =
    "MIIBOgIBAAJBANuwDJCXuv/FszouyCcDNIn6++/8EtdVpzvLKpqLdK/fq6Y3bIjD"
    "6fPVCNwANeJsSHKexi4qPkBpZ8/C0Ssnp48CAwEAAQJAHtDmIk42W/R2fJ3dU6Oe"
    "dhBv0K0SU4RfTgLkugL/3j+GIQCiFXBkfO/eG6J8vQlOQaGbK7Zu6bSnCoCdiDmR"
    "sQIhAPysf1AIbRoQGO6HYtAoTUOMlih7dyh4O3jKCqQUa60XAiEA3pRju0/0g2JK"
    "bdSct/kqii1o+RydH79WCnKVgVvulEkCIFdbRADliOLT4erFv/H7nQrXliqU1ROW"
    "zejq4VbtAHUtAiBRP5OkRYx5BUEsFGdc1MyNggQGo0ZL13ld+PPQM7HEWQIhAIU1"
    "InlMgmqV1GzEXsAwRH5RH2zEqAe9mKkU7SZWT0rI";

The pointer key now points to the private key which is embedded in the executable. It doesn't include the newlines because those string literals are automatically concatenated at compile time, no matter what whitespace is between them.

It has been said already, but I'd like to reiterate that something like that shouldn't be done with any keys and data that matters.

How to store a private key in string literal in C?

1 Answers1