Commit 1b66fc87 authored by Bernd Edlinger's avatar Bernd Edlinger
Browse files

Fix a crash in reuse of i2d_X509_PUBKEY 



If the second PUBKEY is malformed there is use after free.

Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8122)

(cherry picked from commit 5dc40a83c74be579575a512b30d9c1e0364e6a7b)
parent df3b7b99

crypto/x509/x_pubkey.c

+1 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ static int pubkey_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it, 
        /* Attempt to decode public key and cache in pubkey structure. */

        X509_PUBKEY *pubkey = (X509_PUBKEY *)*pval;

        EVP_PKEY_free(pubkey->pkey);

        pubkey->pkey = NULL;

        /*

         * Opportunistically decode the key but remove any non fatal errors

         * from the queue. Subsequent explicit attempts to decode/use the key

test/evp_extra_test.c

+49 −0
Original line number Diff line number Diff line
@@ -299,6 +299,21 @@ static const unsigned char kExampleECPubKeyDER[] = { 
    0x56, 0x6a, 0xc6, 0xc8, 0xa5, 0x0b, 0xe5

};



/*

 * kExampleBadECKeyDER is a sample EC public key with a wrong OID

 * 1.2.840.10045.2.2 instead of 1.2.840.10045.2.1 - EC Public Key

 */

static const unsigned char kExampleBadECPubKeyDER[] = {

    0x30, 0x59, 0x30, 0x13, 0x06, 0x07, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02,

    0x02, 0x06, 0x08, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07, 0x03,

    0x42, 0x00, 0x04, 0xba, 0xeb, 0x83, 0xfb, 0x3b, 0xb2, 0xff, 0x30, 0x53,

    0xdb, 0xce, 0x32, 0xf2, 0xac, 0xae, 0x44, 0x0d, 0x3d, 0x13, 0x53, 0xb8,

    0xd1, 0x68, 0x55, 0xde, 0x44, 0x46, 0x05, 0xa6, 0xc9, 0xd2, 0x04, 0xb7,

    0xe3, 0xa2, 0x96, 0xc8, 0xb2, 0x5e, 0x22, 0x03, 0xd7, 0x03, 0x7a, 0x8b,

    0x13, 0x5c, 0x42, 0x49, 0xc2, 0xab, 0x86, 0xd6, 0xac, 0x6b, 0x93, 0x20,

    0x56, 0x6a, 0xc6, 0xc8, 0xa5, 0x0b, 0xe5

};



static const unsigned char pExampleECParamDER[] = {

    0x06, 0x08, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07

};
@@ -963,6 +978,37 @@ static int test_HKDF(void) 
    return ret;

}



#ifndef OPENSSL_NO_EC

static int test_X509_PUBKEY_inplace(void)

{

  int ret = 0;

  X509_PUBKEY *xp = NULL;

  const unsigned char *p = kExampleECPubKeyDER;

  size_t input_len = sizeof(kExampleECPubKeyDER);



  if (!TEST_ptr(xp = d2i_X509_PUBKEY(NULL, &p, input_len)))

    goto done;



  if (!TEST_ptr(X509_PUBKEY_get0(xp)))

    goto done;



  p = kExampleBadECPubKeyDER;

  input_len = sizeof(kExampleBadECPubKeyDER);



  if (!TEST_ptr(xp = d2i_X509_PUBKEY(&xp, &p, input_len)))

    goto done;



  if (!TEST_true(X509_PUBKEY_get0(xp) == NULL))

    goto done;



  ret = 1;



done:

  X509_PUBKEY_free(xp);

  return ret;

}

#endif



int setup_tests(void)

{

    ADD_TEST(test_EVP_DigestSignInit);
@@ -987,5 +1033,8 @@ int setup_tests(void) 
        return 0;

    ADD_ALL_TESTS(test_EVP_PKEY_check, OSSL_NELEM(keycheckdata));

    ADD_TEST(test_HKDF);

#ifndef OPENSSL_NO_EC

    ADD_TEST(test_X509_PUBKEY_inplace);

#endif

    return 1;

}