Sample code for 30+ languages & platforms
C

Generate RSA SSH Key

See more SSH Key Examples

Generates an RSA SSH key and saves to various public and private key file formats (OpenSSH and PuTTY).

Chilkat C Downloads

C
#include <C_CkSshKey.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkSshKey key;
    int numBits;
    int exponent;
    const char *exportedKey;
    BOOL exportEncrypted;

    success = FALSE;

    key = CkSshKey_Create();

    // numBits may range from 384 to 4096.  Typical values are
    // 1024 or 2048.  (must be a multiple of 64)
    // A good choice for the exponent is 65537.  Chilkat recommends
    // always using this value.
    numBits = 2048;
    exponent = 65537;
    success = CkSshKey_GenerateRsaKey(key,numBits,exponent);
    if (success != TRUE) {
        printf("Bad params passed to RSA key generation method.\n");
        CkSshKey_Dispose(key);
        return;
    }

    // Note: Generating a public/private key pair is CPU intensive
    // and may take a short amount of time (more than few seconds,
    // but less than a minute).

    // Export the RSA private key to OpenSSH, PuTTY, and XML and save. 
    exportEncrypted = FALSE;
    exportedKey = CkSshKey_toOpenSshPrivateKey(key,exportEncrypted);
    // Chilkat provides a SaveText method for convenience...
    success = CkSshKey_SaveText(key,exportedKey,"privkey_openssh_unencrypted.pem");

    // Export with encryption to OpenSSH private key format:
    CkSshKey_putPassword(key,"secret");
    exportEncrypted = TRUE;
    exportedKey = CkSshKey_toOpenSshPrivateKey(key,exportEncrypted);
    success = CkSshKey_SaveText(key,exportedKey,"privkey_openssh_encrypted.pem");

    // Export the RSA private key to unencrypted PuTTY format:
    exportEncrypted = FALSE;
    exportedKey = CkSshKey_toPuttyPrivateKey(key,exportEncrypted);
    success = CkSshKey_SaveText(key,exportedKey,"privkey_putty_unencrypted.ppk");

    // Export the RSA private key to encrypted PuTTY format:
    CkSshKey_putPassword(key,"secret");
    exportEncrypted = TRUE;
    exportedKey = CkSshKey_toPuttyPrivateKey(key,exportEncrypted);
    success = CkSshKey_SaveText(key,exportedKey,"privkey_putty_encrypted.ppk");

    // Export private key to XML:
    exportedKey = CkSshKey_toXml(key);
    success = CkSshKey_SaveText(key,exportedKey,"privkey.xml");

    // ----------------------------------------------------
    // Now for the public key....
    // ----------------------------------------------------

    // The Secure Shell (SSH) Public Key File Format
    // is documented in RFC 4716.
    exportedKey = CkSshKey_toRfc4716PublicKey(key);
    success = CkSshKey_SaveText(key,exportedKey,"pubkey_rfc4716.pub");

    // OpenSSH has a separate public-key file format, which 
    // is also supported by Chilkat SshKey:
    exportedKey = CkSshKey_toOpenSshPublicKey(key);
    success = CkSshKey_SaveText(key,exportedKey,"pubkey_openSsh.pub");

    printf("Finished.\n");


    CkSshKey_Dispose(key);

    }