tree 6c0117c3cb3732c55d081fc9ece532025c711bae
parent f0accf28ea7ad6d2e74b72bcffd925850aa722f8
author Waleed Elmelegy <waleed.elmelegy@arm.com> 1693836682 +0100
committer Waleed Elmelegy <waleed.elmelegy@arm.com> 1694182434 +0100

Improve & test legacy mbedtls_pkcs12_pbe
* Prevent pkcs12_pbe encryption when PKCS7 padding has been
  disabled since this not part of the specs.
* Allow decryption when PKCS7 padding is disabled for legacy
  reasons, However, invalid padding is not checked.
* Document new behaviour, known limitations and possible
  security concerns.
* Add tests to check these scenarios. Test data has been
  generated by the below code using OpenSSL as a reference:

int main()
{
    char pass[] = "\xBB\xBB\xBB\xBB\xBB\xBB\xBB\xBB\xBB";
    unsigned char salt[] = "\xCC\xCC\xCC\xCC\xCC\xCC\xCC\xCC\xCC";
    unsigned char plaintext[] = "\xAA\xAA\xAA\xAA\xAA\xAA\xAA\xAA";
    unsigned char *ciphertext = NULL;
    int iter = 10;
    X509_ALGOR *alg =  X509_ALGOR_new();
    int ciphertext_len = 0;
    int alg_nid = NID_pbe_WithSHA1And3_Key_TripleDES_CBC;
    alg->parameter = ASN1_TYPE_new();
    struct asn1_object_st * aobj;
    PKCS5_pbe_set0_algor(alg, alg_nid, iter,
                         salt, sizeof(salt)-1);

    aobj = alg->algorithm;
    printf("\"30%.2X", 2 + aobj->length + alg->parameter->value.asn1_string->length);
    printf("06%.2X", aobj->length);
    for (int i = 0; i < aobj->length; i++) {
        printf("%.2X", aobj->data[i]);
    }

    for (int i = 0; i < alg->parameter->value.asn1_string->length; i++) {
        printf("%.2X", alg->parameter->value.asn1_string->data[i]);
    }
    printf("\":\"");

    for (int i = 0; i < sizeof(pass)-1; i++) {
        printf("%.2X", pass[i] & 0xFF);
    }
    printf("\":\"");
    for (int i = 0; i < sizeof(plaintext)-1; i++) {
        printf("%.2X", plaintext[i]);
    }
    printf("\":");
    printf("0");
    printf(":\"");

    unsigned char * res = PKCS12_pbe_crypt(alg, pass, sizeof(pass)-1, plaintext, sizeof(plaintext)-1, &ciphertext, &ciphertext_len, 1);

    if (res == NULL)
        printf("Encryption failed!\n");
    for (int i = 0; i < ciphertext_len; i++) {
        printf("%.2X", res[i]);
    }
    printf("\"\n");

    return 0;
}

Signed-off-by: Waleed Elmelegy <waleed.elmelegy@arm.com>