How to generate RSA private key using OpenSSL?

by 
#include <openssl/rsa.h>
#include <openssl/pem.h>

const int kBits = 1024;
const int kExp = 3;

int keylen;
char *pem_key;

RSA *rsa = RSA_generate_key(kBits, kExp, 0, 0);

/* To get the C-string PEM form: */
BIO *bio = BIO_new(BIO_s_mem());
PEM_write_bio_RSAPrivateKey(bio, rsa, NULL, NULL, 0, NULL, NULL);

keylen = BIO_pending(bio);
pem_key = calloc(keylen+1, 1); /* Null-terminate */
BIO_read(bio, pem_key, keylen);

printf("%s", pem_key);

BIO_free_all(bio);
RSA_free(rsa);
free(pem_key);

More Related Contents:

  1. Use OpenSSL RSA key with .Net
  2. How to implement Server Name Indication (SNI)
  3. Password to key function compatible with OpenSSL commands?
  4. C# RSA Public Key Output Not Correct
  5. AES CTR 256 Encryption Mode of operation on OpenSSL
  6. How to compile .c file with OpenSSL includes?
  7. Directly Read/Write Handshake data with Memory BIO
  8. How to Generate Unique Public and Private Key via RSA
  9. Error: “invalid use of incomplete type ‘RSA {aka struct rsa_st}” in OpenSSL 1.1.0
  10. AES (aes-cbc-128, aes-cbc-192, aes-cbc-256) encryption/decryption with openssl C
  11. How do I build OpenSSL statically linked against Windows runtime?
  12. x509 certificate verification in C
  13. How to do encryption using AES in Openssl
  14. Build OpenVPN with specific OpenSSL version
  15. Serving multiple domains in one box with SNI
  16. Should C compilers immediately free "further unused" memories? [closed]
  17. how many bytes is this struct? – how many bytes is pointer to a struct? [closed]
  18. Using LEA on values that aren’t addresses / pointers?
  19. Display an array of color in C [closed]
  20. Atomicity of `write(2)` to a local filesystem
  21. Cholesky decomposition with OpenMP
  22. Why does stdout need explicit flushing when redirected to file?
  23. Does the size of pointers vary in C? [duplicate]
  24. Does unaligned memory access always cause bus errors?
  25. XML Parser for C [closed]
  26. Need to know when no data appears between two token separators using strtok()
  27. What does a dot before the variable name in struct mean?
  28. How do I reimplement (or wrap) a syscall function on Linux?
  29. Memory map for a 2D array in C
  30. what is the difference between difftime and ‘-‘?

Leave a Comment