Ubuntu
openssl package

  1. Bug #1884265
  2. Comment #5

Comment 5 for bug 1884265

Revision history for this message
Joy Latten (j-latten) wrote : Re: [fips] Not fully initialized digest segfaulting some client applications

It seems 2 things are happening to generate this issue

1.fips-openssl in bionic has md5 and md5_sha1 in fips digest list with explicit purpose of accommodating PRF use only in fips mode. But you must pass the flag, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW to successfully use them.

2. ntpq does not check return codes from EVP_ calls. It has,
    ctx = EVP_MD_CTX_new();
    EVP_DigestInit(ctx, EVP_get_digestbyname(name));
    EVP_DigestFinal(ctx, digest, &digest_len);
    EVP_MD_CTX_free(ctx);
    if (digest_len > (MAX_MAC_LEN - sizeof(keyid_t)))
        return;

EVP_DigestInit() would have returned 0 in this case indicating a failure.

Possible fixes:
1. in fips-libcrypto library remove md5 from fips digest list and keep md5_sha1 for PRF and mark as fips-allowed. Can still use md5 with EVP_MD_CTX_FLAG_NON_FIPS_ALLOW flag, but its just not in fips digest list.

Note: this fix can be put in fips-update ppa for availability. But, it may be a while before it is re-certified.

2. ntpq should check its return codes and do appropriate thing on error.