comandi - Come generare una chiave privata RSA usando OpenSSL?



key private (3)

Voglio sapere come generare la chiave privata RSA usando la libreria OpenSSL nel mio file sorgente C. So come generarlo usando il comando del terminale.

In realtà il mio file server.c genererà una chiave privata e invierà al client.c Per favore aiutatemi con qualche codice sorgente, se possibile, altrimenti ogni aiuto sarà apprezzato.

Sto lavorando su una macchina Linux.


Answer #1

Voglio sapere come generare la chiave privata RSA usando la libreria openssl nel mio file sorgente c?

Generare la chiave è facile. Basta usare RSA_generate_key_ex . Il programma qui sotto ti mostra come farlo.

Salvare la chiave pubblica e privata è una questione diversa perché è necessario conoscere il formato. Il programma qui sotto ti mostra come farlo in una serie di formati.

Ecco le varie funzioni e formati.

Correlato, vedi Quali sono le differenze tra "BEGIN RSA PRIVATE KEY" e "BEGIN PRIVATE KEY" . Deterge la differenza tra SubjectPublicKeyInfo , PrivateKeyInfo e le chiavi pubbliche e private.

PEM_write_bio_RSAPublicKey (formato PEM PKCS). Avviso BEGIN RSA PUBLIC KEY :

$ cat rsa-public-1.pem
-----BEGIN RSA PUBLIC KEY-----
MIIBCgKCAQEAmkD+kwlbsmvyUYOBuVkyWDyBNxGQNJrKUZu97Z+hBG3OA85fY6oV
CdyoT+KDmtAFgTgY76KRkHVYQH3HYFpec5vNptLJNd6OVJCXR6NFUR2b7aHLkres
qyPMrAHNU16wp85qdHALNd72EoUPkVItHqaBOldx7J9vyUF3bpAWq4XxRlbiK9iv
Yuci4/jr4ppRoso6LZm9Inzm53zYt2AqHUZQ+3WgK+czZyk8tLGEN7rtLZ7opvVA
aAiRGWiUWACtRwmpAq2L5PuWZkYdQ7WQigkx5c3x8iBkeEh022zqYkGOTh2Ue4Uf
rIYuSqjLb2d+jkfZQ1S4LQLQPtMxNV/FqwIDAQAB
-----END RSA PUBLIC KEY-----

PEM_write_bio_PUBKEY (formato PEM tradizionale). Avviso BEGIN PUBLIC KEY :

$ cat rsa-public-2.pem
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAmkD+kwlbsmvyUYOBuVky
WDyBNxGQNJrKUZu97Z+hBG3OA85fY6oVCdyoT+KDmtAFgTgY76KRkHVYQH3HYFpe
c5vNptLJNd6OVJCXR6NFUR2b7aHLkresqyPMrAHNU16wp85qdHALNd72EoUPkVIt
HqaBOldx7J9vyUF3bpAWq4XxRlbiK9ivYuci4/jr4ppRoso6LZm9Inzm53zYt2Aq
HUZQ+3WgK+czZyk8tLGEN7rtLZ7opvVAaAiRGWiUWACtRwmpAq2L5PuWZkYdQ7WQ
igkx5c3x8iBkeEh022zqYkGOTh2Ue4UfrIYuSqjLb2d+jkfZQ1S4LQLQPtMxNV/F
qwIDAQAB
-----END PUBLIC KEY-----

PEM_write_bio_PrivateKey (PEM). Avviso BEGIN PRIVATE KEY :

$ cat rsa-private-1.pem
-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----

PEM_write_bio_PKCS8PrivateKey (PEM). Avviso BEGIN PRIVATE KEY :

$ cat rsa-private-2.pem
-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----

PEM_write_bio_RSAPrivateKey (PEM). Avviso BEGIN RSA PRIVATE KEY :

$ cat rsa-private-3.pem 
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----

i2d_RSAPublicKey_bio (ASN.1 / DER):

$ dumpasn1 rsa-public.der 
  0 266: SEQUENCE {
  4 257:   INTEGER
       :     00 9A 40 FE 93 09 5B B2 6B F2 51 83 81 B9 59 32
       :     58 3C 81 37 11 90 34 9A CA 51 9B BD ED 9F A1 04
       :     6D CE 03 CE 5F 63 AA 15 09 DC A8 4F E2 83 9A D0
       :     05 81 38 18 EF A2 91 90 75 58 40 7D C7 60 5A 5E
       :     73 9B CD A6 D2 C9 35 DE 8E 54 90 97 47 A3 45 51
       :     1D 9B ED A1 CB 92 B7 AC AB 23 CC AC 01 CD 53 5E
       :     B0 A7 CE 6A 74 70 0B 35 DE F6 12 85 0F 91 52 2D
       :     1E A6 81 3A 57 71 EC 9F 6F C9 41 77 6E 90 16 AB
       :             [ Another 129 bytes skipped ]
265   3:   INTEGER 65537
       :   }

0 warnings, 0 errors.

i2d_RSAPrivateKey_bio (ASN.1 / DER):

$ dumpasn1 rsa-private.der 
   0 1187: SEQUENCE {
   4    1:   INTEGER 0
   7  257:   INTEGER
         :     00 9A 40 FE 93 09 5B B2 6B F2 51 83 81 B9 59 32
         :     58 3C 81 37 11 90 34 9A CA 51 9B BD ED 9F A1 04
         :     6D CE 03 CE 5F 63 AA 15 09 DC A8 4F E2 83 9A D0
         :     05 81 38 18 EF A2 91 90 75 58 40 7D C7 60 5A 5E
         :     73 9B CD A6 D2 C9 35 DE 8E 54 90 97 47 A3 45 51
         :     1D 9B ED A1 CB 92 B7 AC AB 23 CC AC 01 CD 53 5E
         :     B0 A7 CE 6A 74 70 0B 35 DE F6 12 85 0F 91 52 2D
         :     1E A6 81 3A 57 71 EC 9F 6F C9 41 77 6E 90 16 AB
         :             [ Another 129 bytes skipped ]
 268    3:   INTEGER 65537
 273  256:   INTEGER
         :     5B 26 C3 08 92 44 1C 68 0B 76 3D B6 BF 97 44 D7
         :     BD 51 42 00 5F ED A5 F6 9E 48 E0 EF F5 1F 4A 25
         :     B4 D2 AC F5 D3 48 23 4C 83 96 F6 35 CD 3D 03 65
         :     ED 58 FF EB 43 6E AF 25 98 73 EB 9F 90 81 76 44
         :     EC B1 96 BE 02 66 91 D0 1B 8A A1 CA 94 61 96 B0
         :     5F 7F 09 D7 E9 28 1E A1 B6 F2 F0 45 D4 56 4A A3
         :     2B 56 1F B4 14 AD 9B 34 D8 C6 52 D8 C3 30 03 37
         :     94 7E D2 C1 EF B1 3A F9 EC BC 81 DD D4 C9 80 AB
         :             [ Another 128 bytes skipped ]
  ...

Il programma è scritto in C ++, anche se hai un tag C. Ci permette di evitare un sacco di controllo degli errori e pulizia in quanto è automatico. Ed è abbastanza facile da riconvertire in C.

#include <memory>
using std::unique_ptr;

#include <openssl/bn.h>
#include <openssl/rsa.h>
#include <openssl/pem.h>
#include <openssl/bio.h>
#include <openssl/x509.h>

#include <cassert>
#define ASSERT assert

using BN_ptr = std::unique_ptr<BIGNUM, decltype(&::BN_free)>;
using RSA_ptr = std::unique_ptr<RSA, decltype(&::RSA_free)>;
using EVP_KEY_ptr = std::unique_ptr<EVP_PKEY, decltype(&::EVP_PKEY_free)>;
using BIO_FILE_ptr = std::unique_ptr<BIO, decltype(&::BIO_free)>;

int main(int argc, char* argv[])
{
    int rc;

    RSA_ptr rsa(RSA_new(), ::RSA_free);
    BN_ptr bn(BN_new(), ::BN_free);

    BIO_FILE_ptr pem1(BIO_new_file("rsa-public-1.pem", "w"), ::BIO_free);
    BIO_FILE_ptr pem2(BIO_new_file("rsa-public-2.pem", "w"), ::BIO_free);
    BIO_FILE_ptr pem3(BIO_new_file("rsa-private-1.pem", "w"), ::BIO_free);
    BIO_FILE_ptr pem4(BIO_new_file("rsa-private-2.pem", "w"), ::BIO_free);
    BIO_FILE_ptr pem5(BIO_new_file("rsa-private-3.pem", "w"), ::BIO_free);
    BIO_FILE_ptr der1(BIO_new_file("rsa-public.der", "w"), ::BIO_free);
    BIO_FILE_ptr der2(BIO_new_file("rsa-private.der", "w"), ::BIO_free);

    rc = BN_set_word(bn.get(), RSA_F4);
    ASSERT(rc == 1);

    // Generate key
    rc = RSA_generate_key_ex(rsa.get(), 2048, bn.get(), NULL);
    ASSERT(rc == 1);

    // Convert RSA to PKEY
    EVP_KEY_ptr pkey(EVP_PKEY_new(), ::EVP_PKEY_free);
    rc = EVP_PKEY_set1_RSA(pkey.get(), rsa.get());
    ASSERT(rc == 1);

    //////////

    // Write public key in ASN.1/DER
    rc = i2d_RSAPublicKey_bio(der1.get(), rsa.get());
    ASSERT(rc == 1);

    // Write public key in PKCS PEM
    rc = PEM_write_bio_RSAPublicKey(pem1.get(), rsa.get());
    ASSERT(rc == 1);       

    // Write public key in Traditional PEM
    rc = PEM_write_bio_PUBKEY(pem2.get(), pkey.get());
    ASSERT(rc == 1);

    //////////

    // Write private key in ASN.1/DER
    rc = i2d_RSAPrivateKey_bio(der2.get(), rsa.get());
    ASSERT(rc == 1);

    // Write private key in PKCS PEM.
    rc = PEM_write_bio_PrivateKey(pem3.get(), pkey.get(), NULL, NULL, 0, NULL, NULL);
    ASSERT(rc == 1);

    // Write private key in PKCS PEM
    rc = PEM_write_bio_PKCS8PrivateKey(pem4.get(), pkey.get(), NULL, NULL, 0, NULL, NULL);
    ASSERT(rc == 1);

    // Write private key in Traditional PEM
    rc = PEM_write_bio_RSAPrivateKey(pem5.get(), rsa.get(), NULL, NULL, 0, NULL, NULL);
    ASSERT(rc == 1);

    return 0;
}


Answer #3
#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);




private