OPENSSL-ENV(7ossl)

📦 version 3.5.0, in opensuse-leap 16.0

💖 OPENSSL-ENV — OpenSSL environment variables 💖

okay so bestie, welcome to the openssl-env(7ossl) page!! this is literally the group chat of environment variables that the OpenSSL libraries use to override the compiled-in default paths for all sorts of data. ✨

🫶 lowkey important: to avoid security risks, the environment is usually not consulted when the executable is set-user-ID or set-group-ID. so if you're running setuid/setgid binaries, these vars get ignored, no cap.

🌸 DESCRIPTION 🌸

here's the full roster of env vars, bestie. every single one, i'm not skipping any, periodt.

  • CTLOG_FILE — Specifies the path to a certificate transparency log list. 💅 See CTLOG_STORE_new(3).
  • OPENSSL — Specifies the path to the openssl executable. Used by the rehash script (see "Script Configuration" in openssl-rehash(1)) and by the CA.pl script (see "NOTES" in CA.pl(1)).
  • OPENSSL_CONF, OPENSSL_CONF_INCLUDE — Specifies the path to a configuration file and the directory for included files. 🎀 See config(5).
  • OPENSSL_CONFIG — Specifies a configuration option and filename for the req and ca commands invoked by the CA.pl script. See CA.pl(1).
  • OPENSSL_ENGINES — Specifies the directory from which dynamic engines are loaded. 🔥 See openssl-engine(1).
  • OPENSSL_MALLOC_FD, OPENSSL_MALLOC_FAILURES — If built with debugging, this allows memory allocation to fail. 😭 See OPENSSL_malloc(3).
  • OPENSSL_MODULES — Specifies the directory from which cryptographic providers are loaded. Equivalently, the generic -provider-path command-line option may be used. 🦋
  • OPENSSL_TRACE — By default the OpenSSL trace feature is disabled statically. To enable it, OpenSSL must be built with tracing support, which may be configured like this:
"./config enable-trace"

Unless OpenSSL tracing support is generally disabled, enable trace output of specific parts of OpenSSL libraries, by name. 🌈 This output usually makes sense only if you know OpenSSL internals well.

The value of this environment varialble is a comma-separated list of names, with the following available:

  • TRACE — Traces the OpenSSL trace API itself. 👑
  • INIT — Traces OpenSSL library initialization and cleanup.
  • TLS — Traces the TLS/SSL protocol.
  • TLS_CIPHER — Traces the ciphers used by the TLS/SSL protocol.
  • CONF — Show details about provider and engine configuration.
  • ENGINE_TABLE — The function that is used by RSA, DSA (etc) code to select registered ENGINEs, cache defaults and functional references (etc), will generate debugging summaries.
  • ENGINE_REF_COUNT — Reference counts in the ENGINE structure will be monitored with a line of generated for each change.
  • PKCS5V2 — Traces PKCS#5 v2 key generation.
  • PKCS12_KEYGEN — Traces PKCS#12 key generation.
  • PKCS12_DECRYPT — Traces PKCS#12 decryption.
  • X509V3_POLICY — Generates the complete policy tree at various points during X.509 v3 policy evaluation.
  • BN_CTX — Traces BIGNUM context operations.
  • CMP — Traces CMP client and server activity.
  • STORE — Traces STORE operations.
  • DECODER — Traces decoder operations.
  • ENCODER — Traces encoder operations.
  • REF_COUNT — Traces decrementing certain ASN.1 structure references.
  • HTTP — Traces the HTTP client and server, such as messages being sent and received.
  • OPENSSL_WIN32_UTF8 — If set, then UI_OpenSSL(3) returns UTF-8 encoded strings, rather than ones encoded in the current code page, and the openssl(1) program also transcodes the command-line parameters from the current code page to UTF-8. 🪟 This environment variable is only checked on Microsoft Windows platforms.
  • RANDFILE — The state file for the random number generator. This should not be needed in normal use. See RAND_load_file(3).
  • SSL_CERT_DIR, SSL_CERT_FILE — Specify the default directory or file containing CA certificates. 🔐 See SSL_CTX_load_verify_locations(3).
  • TSGET — Additional arguments for the tsget(1) command.
  • OPENSSL_ia32cap, OPENSSL_sparcv9cap, OPENSSL_ppccap, OPENSSL_armcap, OPENSSL_s390xcap, OPENSSL_riscvcap — OpenSSL supports a number of different algorithm implementations for various machines and, by default, it determines which to use based on the processor capabilities and run time feature enquiry. 🤖 These environment variables can be used to exert more control over this selection process. See OPENSSL_ia32cap(3), OPENSSL_s390xcap(3) and OPENSSL_riscvcap(3).
  • NO_PROXY, HTTPS_PROXY, HTTP_PROXY — Specify a proxy hostname. See OSSL_HTTP_parse_url(3).
  • QLOGDIR — Specifies a QUIC qlog output directory. See openssl-qlog(7).
  • OSSL_QFILTER — Used to set a QUIC qlog filter specification. See openssl-qlog(7).
  • SSLKEYLOGFILE — Used to produce the standard format output file for SSL key logging. 🔑 Optionally set this variable to a filename to log all secrets produced by SSL connections. Note, use of the environment variable is predicated on configuring OpenSSL at build time with the enable-sslkeylog feature. The file format standard can be found at <https://datatracker.ietf.org/doc/draft-ietf-tls-keylogfile/>.
💀 BESTIE, SECURITY WARNING, FR FR: the use of SSLKEYLOGFILE poses an explicit security risk. By recording the exchanged keys during an SSL session, it allows any available party with read access to the file to decrypt application traffic sent over that session. 🚨 Use of this feature should be restricted to test and debug environments only. do not do this in prod, i'm begging you. 🙈

Copyright 2019-2024 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

and that's the whole page, bestie!! ✨ version 3.5.0, dated 2026-09-25, that's OPENSSL-ENV(7ossl) signing off. ily, go configure your environment responsibly 💜🧚‍♀️🌸

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