Unable to encrypt private key with encryption algo AES-256-CBC using i2d_PKCS8PrivateKey_nid_bio API

[absrivas-in]

Version: OpenSSL 3.0.13 30

Hi,
When i am trying to decrypt the private key encrypted with Algo NID_pbe_WithSHA1And3_Key_TripleDES_CBC
using i2d_PKCS8PrivateKey_nid_bio API in fips mode i am getting error.

In non fips mode it is working fine.

Hence to allow decryption in fips mode i want to encrypt private key with AES-256-CBC mode using i2d_PKCS8PrivateKey_nid_bio API, but in documentation or openssl sample code i didn't find anything related to my requirement.

Can you please help me on this.

[absrivas-in]

Found i2d_PKCS8PrivateKey_bio api where i can pass evp aes-256-cbc cipher.
May i know is it right approach for encrypting private key ?

const EVP_CIPHER cipher = EVP_CIPHER_fetch(libctx, "AES-256-CBC", NULL);
if(i2d_PKCS8PrivateKey_bio(bp, pkeyobj, cipher, (const char)encpwd, encpwdlen, NULL, NULL) != 1)
{
printf("i2d_PKCS8PrivateKey_bio Failed");
}
if (cipher != NULL)
EVP_CIPHER_free(cipher);

[absrivas-in]

Thanks @t8m for confirming.
I have some query on top that and requiring some clarification:

1. Can you please confirm that NID_pbe_WithSHA1And3_Key_TripleDES_CBC is not supported in fips mode.
2. Why only decryption is failing in fips mode not the encryption with algo NID_pbe_WithSHA1And3_Key_TripleDES_CBC.
3. PKCS12 file decryption in fips mode we are not seeing such error if we pkcs12 is encrypted with
   NID_pbe_WithSHA1And3_Key_TripleDES_CBC. Why ?

[t8m]

You would have to give concrete commands that you're using with the concrete errors you're seeing. Otherwise I am unable to elaborate this further.

[absrivas-in]

Hi @t8m ,
As requested please find following information:

Code snippet:
pvtKeyDecryption.c.zip
Failure is happening in below code snippet.

p8inf = PKCS8_decrypt_ex(p8, passphrase, strlen(passphrase), lib_ctx, NULL);
if (p8inf == NULL) {
    fprintf(stderr, "Enable to decrypt Pvt Key !!!\n");
    oret =  -1;
    goto end;
}

Output:

Loading fips provider...
All Provider has been loaded !!!
Enable to decrypt Pvt Key !!!
- Detailed error: unsupported
Private key decryption failed

private_Key.pem.zip
password: keypwd12

Observation:
openssl version
OpenSSL 3.0.13 30 Jan 2024 (Library: OpenSSL 3.0.13 30 Jan 2024)

openssl pkcs8 -topk8 -in private_key.pem -passin pass:keypwd12 -outform DER -out private_key.der -v1 PBE-SHA1-DES -passout pass:passwd
output:
Error encrypting key 80E2169AEF7F0000:error:0308010C:digital envelope routines:inner_evp_generic_fetch:unsupported:crypto/evp/evp_fetch.c:386:Global default library context, Algorithm (PBKDF1 : 0), Properties (<null>) 80E2169AEF7F0000:error:11800067:PKCS12 routines:PKCS12_item_i2d_encrypt_ex:encrypt error:crypto/pkcs12/p12_decr.c:193: 80E2169AEF7F0000:error:11800067:PKCS12 routines:PKCS8_set0_pbe_ex:encrypt error:crypto/pkcs12/p12_p8e.c:80:

If i am running same command with following version, i am able to generate der file with pbeWithSHA1AndDES-CBC
OpenSSL 1.1.1k FIPS 25 Mar 2021

[t8m]

You need the legacy provider loaded to be able to use -v1 PBE-SHA1-DES algorithm. This is an extremely weak algorithm not providing any real protection. I would not recommend using it at all.

[absrivas-in]

Hi @t8m ,
PBE-SHA1-DES transalates to pbeWithSHA1And3-KeyTripleDES-CBC

1. Why error is not being thrown at the time of encryption in fips mode if it is weak algorithm ?
2. I am seeing different behaviour when trying to load p12 file wallet encrypted with pbeWithSHA1And3-KeyTripleDES-CBC using following API.
   if (PKCS12_get_safe( asafes, i, (char*)passwd, passwdLen, &bags, &count) != 1)

By using same algo pbeWithSHA1And3-KeyTripleDES-CBC
PKCS12_get_safe is able to decrypt p12 file in fips mode. but
PKCS8_decrypt_ex is unable to decrypt the private key in fips mode ?

Is this is a bug in Openssl ?