Provided by: openssl_3.0.13-0ubuntu3.5_amd64 
NAME
migration_guide - OpenSSL migration guide
SYNOPSIS
See the individual manual pages for details.
DESCRIPTION
This guide details the changes required to migrate to new versions of OpenSSL. Currently this covers
OpenSSL 3.0. For earlier versions refer to <https://github.com/openssl/openssl/blob/master/CHANGES.md>.
For an overview of some of the key concepts introduced in OpenSSL 3.0 see crypto(7).
OPENSSL 3.0
Main Changes from OpenSSL 1.1.1
Major Release
OpenSSL 3.0 is a major release and consequently any application that currently uses an older version of
OpenSSL will at the very least need to be recompiled in order to work with the new version. It is the
intention that the large majority of applications will work unchanged with OpenSSL 3.0 if those
applications previously worked with OpenSSL 1.1.1. However this is not guaranteed and some changes may be
required in some cases. Changes may also be required if applications need to take advantage of some of
the new features available in OpenSSL 3.0 such as the availability of the FIPS module.
License Change
In previous versions, OpenSSL was licensed under the dual OpenSSL and SSLeay licenses
<https://www.openssl.org/source/license-openssl-ssleay.txt> (both licenses apply). From OpenSSL 3.0 this
is replaced by the Apache License v2 <https://www.openssl.org/source/apache-license-2.0.txt>.
Providers and FIPS support
One of the key changes from OpenSSL 1.1.1 is the introduction of the Provider concept. Providers collect
together and make available algorithm implementations. With OpenSSL 3.0 it is possible to specify,
either programmatically or via a config file, which providers you want to use for any given application.
OpenSSL 3.0 comes with 5 different providers as standard. Over time third parties may distribute
additional providers that can be plugged into OpenSSL. All algorithm implementations available via
providers are accessed through the "high level" APIs (for example those functions prefixed with "EVP").
They cannot be accessed using the "Low Level APIs".
One of the standard providers available is the FIPS provider. This makes available FIPS validated
cryptographic algorithms. The FIPS provider is disabled by default and needs to be enabled explicitly at
configuration time using the "enable-fips" option. If it is enabled, the FIPS provider gets built and
installed in addition to the other standard providers. No separate installation procedure is necessary.
There is however a dedicated "install_fips" make target, which serves the special purpose of installing
only the FIPS provider into an existing OpenSSL installation.
Not all algorithms may be available for the application at a particular moment. If the application code
uses any digest or cipher algorithm via the EVP interface, the application should verify the result of
the EVP_EncryptInit(3), EVP_EncryptInit_ex(3), and EVP_DigestInit(3) functions. In case when the
requested algorithm is not available, these functions will fail.
See also "Legacy Algorithms" for information on the legacy provider.
See also "Completing the installation of the FIPS Module" and "Using the FIPS Module in applications".
Low Level APIs
OpenSSL has historically provided two sets of APIs for invoking cryptographic algorithms: the "high
level" APIs (such as the "EVP" APIs) and the "low level" APIs. The high level APIs are typically designed
to work across all algorithm types. The "low level" APIs are targeted at a specific algorithm
implementation. For example, the EVP APIs provide the functions EVP_EncryptInit_ex(3),
EVP_EncryptUpdate(3) and EVP_EncryptFinal(3) to perform symmetric encryption. Those functions can be used
with the algorithms AES, CHACHA, 3DES etc. On the other hand, to do AES encryption using the low level
APIs you would have to call AES specific functions such as AES_set_encrypt_key(3), AES_encrypt(3), and so
on. The functions for 3DES are different. Use of the low level APIs has been informally discouraged by
the OpenSSL development team for a long time. However in OpenSSL 3.0 this is made more formal. All such
low level APIs have been deprecated. You may still use them in your applications, but you may start to
see deprecation warnings during compilation (dependent on compiler support for this). Deprecated APIs may
be removed from future versions of OpenSSL so you are strongly encouraged to update your code to use the
high level APIs instead.
This is described in more detail in "Deprecation of Low Level Functions"
Legacy Algorithms
Some cryptographic algorithms such as MD2 and DES that were available via the EVP APIs are now considered
legacy and their use is strongly discouraged. These legacy EVP algorithms are still available in OpenSSL
3.0 but not by default. If you want to use them then you must load the legacy provider. This can be as
simple as a config file change, or can be done programmatically. See OSSL_PROVIDER-legacy(7) for a
complete list of algorithms. Applications using the EVP APIs to access these algorithms should instead
use more modern algorithms. If that is not possible then these applications should ensure that the legacy
provider has been loaded. This can be achieved either programmatically or via configuration. See
crypto(7) man page for more information about providers.
Engines and "METHOD" APIs
The refactoring to support Providers conflicts internally with the APIs used to support engines,
including the ENGINE API and any function that creates or modifies custom "METHODS" (for example
EVP_MD_meth_new(3), EVP_CIPHER_meth_new(3), EVP_PKEY_meth_new(3), RSA_meth_new(3), EC_KEY_METHOD_new(3),
etc.). These functions are being deprecated in OpenSSL 3.0, and users of these APIs should know that
their use can likely bypass provider selection and configuration, with unintended consequences. This is
particularly relevant for applications written to use the OpenSSL 3.0 FIPS module, as detailed below.
Authors and maintainers of external engines are strongly encouraged to refactor their code transforming
engines into providers using the new Provider API and avoiding deprecated methods.
Support of legacy engines
If openssl is not built without engine support or deprecated API support, engines will still work.
However, their applicability will be limited.
New algorithms provided via engines will still work.
Engine-backed keys can be loaded via custom OSSL_STORE implementation. In this case the EVP_PKEY objects
created via ENGINE_load_private_key(3) will be considered legacy and will continue to work.
To ensure the future compatibility, the engines should be turned to providers. To prefer the provider-
based hardware offload, you can specify the default properties to prefer your provider.
Versioning Scheme
The OpenSSL versioning scheme has changed with the OpenSSL 3.0 release. The new versioning scheme has
this format:
MAJOR.MINOR.PATCH
For OpenSSL 1.1.1 and below, different patch levels were indicated by a letter at the end of the release
version number. This will no longer be used and instead the patch level is indicated by the final number
in the version. A change in the second (MINOR) number indicates that new features may have been added.
OpenSSL versions with the same major number are API and ABI compatible. If the major number changes then
API and ABI compatibility is not guaranteed.
For more information, see OpenSSL_version(3).
Other major new features
Certificate Management Protocol (CMP, RFC 4210)
This also covers CRMF (RFC 4211) and HTTP transfer (RFC 6712) See openssl-cmp(1) and
OSSL_CMP_exec_certreq(3) as starting points.
HTTP(S) client
A proper HTTP(S) client that supports GET and POST, redirection, plain and ASN.1-encoded contents,
proxies, and timeouts.
Key Derivation Function API (EVP_KDF)
This simplifies the process of adding new KDF and PRF implementations.
Previously KDF algorithms had been shoe-horned into using the EVP_PKEY object which was not a logical
mapping. Existing applications that use KDF algorithms using EVP_PKEY (scrypt, TLS1 PRF and HKDF) may be
slower as they use an EVP_KDF bridge internally. All new applications should use the new EVP_KDF(3)
interface. See also "Key Derivation Function (KDF)" in OSSL_PROVIDER-default(7) and "Key Derivation
Function (KDF)" in OSSL_PROVIDER-FIPS(7).
Message Authentication Code API (EVP_MAC)
This simplifies the process of adding MAC implementations.
This includes a generic EVP_PKEY to EVP_MAC bridge, to facilitate the continued use of MACs through raw
private keys in functionality such as EVP_DigestSign(3) and EVP_DigestVerify(3).
All new applications should use the new EVP_MAC(3) interface. See also "Message Authentication Code
(MAC)" in OSSL_PROVIDER-default(7) and "Message Authentication Code (MAC)" in OSSL_PROVIDER-FIPS(7).
Algorithm Fetching
Using calls to convenience functions such as EVP_sha256() and EVP_aes_256_gcm() may incur a performance
penalty when using providers. Retrieving algorithms from providers involves searching for an algorithm
by name. This is much slower than directly accessing a method table. It is recommended to prefetch
algorithms if an algorithm is used many times. See "Performance" in crypto(7), "Explicit fetching" in
crypto(7) and "Implicit fetching" in crypto(7).
Support for Linux Kernel TLS
In order to use KTLS, support for it must be compiled in using the "enable-ktls" configuration option. It
must also be enabled at run time using the SSL_OP_ENABLE_KTLS option.
New Algorithms
• KDF algorithms "SINGLE STEP" and "SSH"
See EVP_KDF-SS(7) and EVP_KDF-SSHKDF(7)
• MAC Algorithms "GMAC" and "KMAC"
See EVP_MAC-GMAC(7) and EVP_MAC-KMAC(7).
• KEM Algorithm "RSASVE"
See EVP_KEM-RSA(7).
• Cipher Algorithm "AES-SIV"
See "SIV Mode" in EVP_EncryptInit(3).
• AES Key Wrap inverse ciphers supported by EVP layer.
The inverse ciphers use AES decryption for wrapping, and AES encryption for unwrapping. The
algorithms are: "AES-128-WRAP-INV", "AES-192-WRAP-INV", "AES-256-WRAP-INV", "AES-128-WRAP-PAD-INV",
"AES-192-WRAP-PAD-INV" and "AES-256-WRAP-PAD-INV".
• CTS ciphers added to EVP layer.
The algorithms are "AES-128-CBC-CTS", "AES-192-CBC-CTS", "AES-256-CBC-CTS", "CAMELLIA-128-CBC-CTS",
"CAMELLIA-192-CBC-CTS" and "CAMELLIA-256-CBC-CTS". CS1, CS2 and CS3 variants are supported.
CMS and PKCS#7 updates
• Added CAdES-BES signature verification support.
• Added CAdES-BES signature scheme and attributes support (RFC 5126) to CMS API.
• Added AuthEnvelopedData content type structure (RFC 5083) using AES_GCM
This uses the AES-GCM parameter (RFC 5084) for the Cryptographic Message Syntax. Its purpose is to
support encryption and decryption of a digital envelope that is both authenticated and encrypted
using AES GCM mode.
• PKCS7_get_octet_string(3) and PKCS7_type_is_other(3) were made public.
PKCS#12 API updates
The default algorithms for pkcs12 creation with the PKCS12_create() function were changed to more modern
PBKDF2 and AES based algorithms. The default MAC iteration count was changed to PKCS12_DEFAULT_ITER to
make it equal with the password-based encryption iteration count. The default digest algorithm for the
MAC computation was changed to SHA-256. The pkcs12 application now supports -legacy option that restores
the previous default algorithms to support interoperability with legacy systems.
Added enhanced PKCS#12 APIs which accept a library context OSSL_LIB_CTX and (where relevant) a property
query. Other APIs which handle PKCS#7 and PKCS#8 objects have also been enhanced where required. This
includes:
PKCS12_add_key_ex(3), PKCS12_add_safe_ex(3), PKCS12_add_safes_ex(3), PKCS12_create_ex(3),
PKCS12_decrypt_skey_ex(3), PKCS12_init_ex(3), PKCS12_item_decrypt_d2i_ex(3),
PKCS12_item_i2d_encrypt_ex(3), PKCS12_key_gen_asc_ex(3), PKCS12_key_gen_uni_ex(3),
PKCS12_key_gen_utf8_ex(3), PKCS12_pack_p7encdata_ex(3), PKCS12_pbe_crypt_ex(3),
PKCS12_PBE_keyivgen_ex(3), PKCS12_SAFEBAG_create_pkcs8_encrypt_ex(3), PKCS5_pbe2_set_iv_ex(3),
PKCS5_pbe_set0_algor_ex(3), PKCS5_pbe_set_ex(3), PKCS5_pbkdf2_set_ex(3), PKCS5_v2_PBE_keyivgen_ex(3),
PKCS5_v2_scrypt_keyivgen_ex(3), PKCS8_decrypt_ex(3), PKCS8_encrypt_ex(3), PKCS8_set0_pbe_ex(3).
As part of this change the EVP_PBE_xxx APIs can also accept a library context and property query and will
call an extended version of the key/IV derivation function which supports these parameters. This includes
EVP_PBE_CipherInit_ex(3), EVP_PBE_find_ex(3) and EVP_PBE_scrypt_ex(3).
PKCS#12 KDF versus FIPS
Unlike in 1.x.y, the PKCS12KDF algorithm used when a PKCS#12 structure is created with a MAC that does
not work with the FIPS provider as the PKCS12KDF is not a FIPS approvable mechanism.
See EVP_KDF-PKCS12KDF(7), PKCS12_create(3), openssl-pkcs12(1), OSSL_PROVIDER-FIPS(7).
Windows thread synchronization changes
Windows thread synchronization uses read/write primitives (SRWLock) when supported by the OS, otherwise
CriticalSection continues to be used.
Trace API
A new generic trace API has been added which provides support for enabling instrumentation through trace
output. This feature is mainly intended as an aid for developers and is disabled by default. To utilize
it, OpenSSL needs to be configured with the "enable-trace" option.
If the tracing API is enabled, the application can activate trace output by registering BIOs as trace
channels for a number of tracing and debugging categories. See OSSL_trace_enabled(3).
Key validation updates
EVP_PKEY_public_check(3) and EVP_PKEY_param_check(3) now work for more key types. This includes RSA, DSA,
ED25519, X25519, ED448 and X448. Previously (in 1.1.1) they would return -2. For key types that do not
have parameters then EVP_PKEY_param_check(3) will always return 1.
Other notable deprecations and changes
The function code part of an OpenSSL error code is no longer relevant
This code is now always set to zero. Related functions are deprecated.
STACK and HASH macros have been cleaned up
The type-safe wrappers are declared everywhere and implemented once. See DEFINE_STACK_OF(3) and
DECLARE_LHASH_OF(3).
The RAND_DRBG subsystem has been removed
The new EVP_RAND(3) is a partial replacement: the DRBG callback framework is absent. The RAND_DRBG API
did not fit well into the new provider concept as implemented by EVP_RAND and EVP_RAND_CTX.
Removed FIPS_mode() and FIPS_mode_set()
These functions are legacy APIs that are not applicable to the new provider model. Applications should
instead use EVP_default_properties_is_fips_enabled(3) and EVP_default_properties_enable_fips(3).
Key generation is slower
The Miller-Rabin test now uses 64 rounds, which is used for all prime generation, including RSA key
generation. This affects the time for larger keys sizes.
The default key generation method for the regular 2-prime RSA keys was changed to the FIPS186-4 B.3.6
method (Generation of Probable Primes with Conditions Based on Auxiliary Probable Primes). This method is
slower than the original method.
Change PBKDF2 to conform to SP800-132 instead of the older PKCS5 RFC2898
This checks that the salt length is at least 128 bits, the derived key length is at least 112 bits, and
that the iteration count is at least 1000. For backwards compatibility these checks are disabled by
default in the default provider, but are enabled by default in the FIPS provider.
To enable or disable the checks see OSSL_KDF_PARAM_PKCS5 in EVP_KDF-PBKDF2(7). The parameter can be set
using EVP_KDF_derive(3).
Enforce a minimum DH modulus size of 512 bits
Smaller sizes now result in an error.
SM2 key changes
EC EVP_PKEYs with the SM2 curve have been reworked to automatically become EVP_PKEY_SM2 rather than
EVP_PKEY_EC.
Unlike in previous OpenSSL versions, this means that applications cannot call
"EVP_PKEY_set_alias_type(pkey, EVP_PKEY_SM2)" to get SM2 computations.
Parameter and key generation is also reworked to make it possible to generate EVP_PKEY_SM2 parameters and
keys. Applications must now generate SM2 keys directly and must not create an EVP_PKEY_EC key first. It
is no longer possible to import an SM2 key with domain parameters other than the SM2 elliptic curve ones.
Validation of SM2 keys has been separated from the validation of regular EC keys, allowing to improve the
SM2 validation process to reject loaded private keys that are not conforming to the SM2 ISO standard. In
particular, a private scalar k outside the range 1 <= k < n-1 is now correctly rejected.
EVP_PKEY_set_alias_type() method has been removed
This function made a EVP_PKEY object mutable after it had been set up. In OpenSSL 3.0 it was decided that
a provided key should not be able to change its type, so this function has been removed.
Functions that return an internal key should be treated as read only
Functions such as EVP_PKEY_get0_RSA(3) behave slightly differently in OpenSSL 3.0. Previously they
returned a pointer to the low-level key used internally by libcrypto. From OpenSSL 3.0 this key may now
be held in a provider. Calling these functions will only return a handle on the internal key where the
EVP_PKEY was constructed using this key in the first place, for example using a function or macro such as
EVP_PKEY_assign_RSA(3), EVP_PKEY_set1_RSA(3), etc. Where the EVP_PKEY holds a provider managed key, then
these functions now return a cached copy of the key. Changes to the internal provider key that take place
after the first time the cached key is accessed will not be reflected back in the cached copy. Similarly
any changes made to the cached copy by application code will not be reflected back in the internal
provider key.
For the above reasons the keys returned from these functions should typically be treated as read-only. To
emphasise this the value returned from EVP_PKEY_get0_RSA(3), EVP_PKEY_get0_DSA(3),
EVP_PKEY_get0_EC_KEY(3) and EVP_PKEY_get0_DH(3) have been made const. This may break some existing code.
Applications broken by this change should be modified. The preferred solution is to refactor the code to
avoid the use of these deprecated functions. Failing this the code should be modified to use a const
pointer instead. The EVP_PKEY_get1_RSA(3), EVP_PKEY_get1_DSA(3), EVP_PKEY_get1_EC_KEY(3) and
EVP_PKEY_get1_DH(3) functions continue to return a non-const pointer to enable them to be "freed".
However they should also be treated as read-only.
The public key check has moved from EVP_PKEY_derive() to EVP_PKEY_derive_set_peer()
This may mean result in an error in EVP_PKEY_derive_set_peer(3) rather than during EVP_PKEY_derive(3).
To disable this check use EVP_PKEY_derive_set_peer_ex(dh, peer, 0).
The print format has cosmetic changes for some functions
The output from numerous "printing" functions such as X509_signature_print(3), X509_print_ex(3),
X509_CRL_print_ex(3), and other similar functions has been amended such that there may be cosmetic
differences between the output observed in 1.1.1 and 3.0. This also applies to the -text output from the
openssl x509 and openssl crl applications.
Interactive mode from the openssl program has been removed
From now on, running it without arguments is equivalent to openssl help.
The error return values from some control calls (ctrl) have changed
One significant change is that controls which used to return -2 for invalid inputs, now return -1
indicating a generic error condition instead.
DH and DHX key types have different settable parameters
Previously (in 1.1.1) these conflicting parameters were allowed, but will now result in errors. See
EVP_PKEY-DH(7) for further details. This affects the behaviour of openssl-genpkey(1) for DH parameter
generation.
EVP_CIPHER_CTX_set_flags() ordering change
If using a cipher from a provider the EVP_CIPH_FLAG_LENGTH_BITS flag can only be set after the cipher has
been assigned to the cipher context. See "FLAGS" in EVP_EncryptInit(3) for more information.
Validation of operation context parameters
Due to move of the implementation of cryptographic operations to the providers, validation of various
operation parameters can be postponed until the actual operation is executed where previously it happened
immediately when an operation parameter was set.
For example when setting an unsupported curve with EVP_PKEY_CTX_set_ec_paramgen_curve_nid() this function
call will not fail but later keygen operations with the EVP_PKEY_CTX will fail.
Removal of function code from the error codes
The function code part of the error code is now always set to 0. For that reason the ERR_GET_FUNC() macro
was removed. Applications must resolve the error codes only using the library number and the reason code.
ChaCha20-Poly1305 cipher does not allow a truncated IV length to be used
In OpenSSL 3.0 setting the IV length to any value other than 12 will result in an error. Prior to
OpenSSL 3.0 the ivlen could be smaller that the required 12 byte length, using EVP_CIPHER_CTX_ctrl(ctx,
EVP_CRTL_AEAD_SET_IVLEN, ivlen, NULL). This resulted in an IV that had leading zero padding.
Installation and Compilation
Please refer to the INSTALL.md file in the top of the distribution for instructions on how to build and
install OpenSSL 3.0. Please also refer to the various platform specific NOTES files for your specific
platform.
Upgrading from OpenSSL 1.1.1
Upgrading to OpenSSL 3.0 from OpenSSL 1.1.1 should be relatively straight forward in most cases. The most
likely area where you will encounter problems is if you have used low level APIs in your code (as
discussed above). In that case you are likely to start seeing deprecation warnings when compiling your
application. If this happens you have 3 options:
1. Ignore the warnings. They are just warnings. The deprecated functions are still present and you may
still use them. However be aware that they may be removed from a future version of OpenSSL.
2. Suppress the warnings. Refer to your compiler documentation on how to do this.
3. Remove your usage of the low level APIs. In this case you will need to rewrite your code to use the
high level APIs instead
Error code changes
As OpenSSL 3.0 provides a brand new Encoder/Decoder mechanism for working with widely used file formats,
application code that checks for particular error reason codes on key loading failures might need an
update.
Password-protected keys may deserve special attention. If only some errors are treated as an indicator
that the user should be asked about the password again, it's worth testing these scenarios and processing
the newly relevant codes.
There may be more cases to treat specially, depending on the calling application code.
Upgrading from OpenSSL 1.0.2
Upgrading to OpenSSL 3.0 from OpenSSL 1.0.2 is likely to be significantly more difficult. In addition to
the issues discussed above in the section about "Upgrading from OpenSSL 1.1.1", the main things to be
aware of are:
1. The build and installation procedure has changed significantly.
Check the file INSTALL.md in the top of the installation for instructions on how to build and install
OpenSSL for your platform. Also read the various NOTES files in the same directory, as applicable for
your platform.
2. Many structures have been made opaque in OpenSSL 3.0.
The structure definitions have been removed from the public header files and moved to internal header
files. In practice this means that you can no longer stack allocate some structures. Instead they
must be heap allocated through some function call (typically those function names have a "_new"
suffix to them). Additionally you must use "setter" or "getter" functions to access the fields
within those structures.
For example code that previously looked like this:
EVP_MD_CTX md_ctx;
/* This line will now generate compiler errors */
EVP_MD_CTX_init(&md_ctx);
The code needs to be amended to look like this:
EVP_MD_CTX *md_ctx;
md_ctx = EVP_MD_CTX_new();
...
...
EVP_MD_CTX_free(md_ctx);
3. Support for TLSv1.3 has been added.
This has a number of implications for SSL/TLS applications. See the TLS1.3 page
<https://wiki.openssl.org/index.php/TLS1.3> for further details.
More details about the breaking changes between OpenSSL versions 1.0.2 and 1.1.0 can be found on the
OpenSSL 1.1.0 Changes page <https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes>.
Upgrading from the OpenSSL 2.0 FIPS Object Module
The OpenSSL 2.0 FIPS Object Module was a separate download that had to be built separately and then
integrated into your main OpenSSL 1.0.2 build. In OpenSSL 3.0 the FIPS support is fully integrated into
the mainline version of OpenSSL and is no longer a separate download. For further information see
"Completing the installation of the FIPS Module".
The function calls FIPS_mode() and FIPS_mode_set() have been removed from OpenSSL 3.0. You should rewrite
your application to not use them. See fips_module(7) and OSSL_PROVIDER-FIPS(7) for details.
Completing the installation of the FIPS Module
The FIPS Module will be built and installed automatically if FIPS support has been configured. The
current documentation can be found in the README-FIPS
<https://github.com/openssl/openssl/blob/master/README-FIPS.md> file.
Programming
Applications written to work with OpenSSL 1.1.1 will mostly just work with OpenSSL 3.0. However changes
will be required if you want to take advantage of some of the new features that OpenSSL 3.0 makes
available. In order to do that you need to understand some new concepts introduced in OpenSSL 3.0. Read
"Library contexts" in crypto(7) for further information.
Library Context
A library context allows different components of a complex application to each use a different library
context and have different providers loaded with different configuration settings. See "Library
contexts" in crypto(7) for further info.
If the user creates an OSSL_LIB_CTX via OSSL_LIB_CTX_new(3) then many functions may need to be changed to
pass additional parameters to handle the library context.
Using a Library Context - Old functions that should be changed
If a library context is needed then all EVP_* digest functions that return a const EVP_MD * such as
EVP_sha256() should be replaced with a call to EVP_MD_fetch(3). See "ALGORITHM FETCHING" in crypto(7).
If a library context is needed then all EVP_* cipher functions that return a const EVP_CIPHER * such as
EVP_aes_128_cbc() should be replaced vith a call to EVP_CIPHER_fetch(3). See "ALGORITHM FETCHING" in
crypto(7).
Some functions can be passed an object that has already been set up with a library context such as
d2i_X509(3), d2i_X509_CRL(3), d2i_X509_REQ(3) and d2i_X509_PUBKEY(3). If NULL is passed instead then the
created object will be set up with the default library context. Use X509_new_ex(3), X509_CRL_new_ex(3),
X509_REQ_new_ex(3) and X509_PUBKEY_new_ex(3) if a library context is required.
All functions listed below with a NAME have a replacement function NAME_ex that takes OSSL_LIB_CTX as an
additional argument. Functions that have other mappings are listed along with the respective name.
• ASN1_item_new(3), ASN1_item_d2i(3), ASN1_item_d2i_fp(3), ASN1_item_d2i_bio(3), ASN1_item_sign(3) and
ASN1_item_verify(3)
• BIO_new(3)
• b2i_RSA_PVK_bio() and i2b_PVK_bio()
• BN_CTX_new(3) and BN_CTX_secure_new(3)
• CMS_AuthEnvelopedData_create(3), CMS_ContentInfo_new(3), CMS_data_create(3), CMS_digest_create(3),
CMS_EncryptedData_encrypt(3), CMS_encrypt(3), CMS_EnvelopedData_create(3),
CMS_ReceiptRequest_create0(3) and CMS_sign(3)
• CONF_modules_load_file(3)
• CTLOG_new(3), CTLOG_new_from_base64(3) and CTLOG_STORE_new(3)
• CT_POLICY_EVAL_CTX_new(3)
• d2i_AutoPrivateKey(3), d2i_PrivateKey(3) and d2i_PUBKEY(3)
• d2i_PrivateKey_bio(3) and d2i_PrivateKey_fp(3)
Use d2i_PrivateKey_ex_bio(3) and d2i_PrivateKey_ex_fp(3)
• EC_GROUP_new(3)
Use EC_GROUP_new_by_curve_name_ex(3) or EC_GROUP_new_from_params(3).
• EVP_DigestSignInit(3) and EVP_DigestVerifyInit(3)
• EVP_PBE_CipherInit(3), EVP_PBE_find(3) and EVP_PBE_scrypt(3)
• PKCS5_PBE_keyivgen(3)
• EVP_PKCS82PKEY(3)
• EVP_PKEY_CTX_new_id(3)
Use EVP_PKEY_CTX_new_from_name(3)
• EVP_PKEY_derive_set_peer(3), EVP_PKEY_new_raw_private_key(3) and EVP_PKEY_new_raw_public_key(3)
• EVP_SignFinal(3) and EVP_VerifyFinal(3)
• NCONF_new(3)
• OCSP_RESPID_match(3) and OCSP_RESPID_set_by_key(3)
• OPENSSL_thread_stop(3)
• OSSL_STORE_open(3)
• PEM_read_bio_Parameters(3), PEM_read_bio_PrivateKey(3), PEM_read_bio_PUBKEY(3),
PEM_read_PrivateKey(3) and PEM_read_PUBKEY(3)
• PEM_write_bio_PrivateKey(3), PEM_write_bio_PUBKEY(3), PEM_write_PrivateKey(3) and PEM_write_PUBKEY(3)
• PEM_X509_INFO_read_bio(3) and PEM_X509_INFO_read(3)
• PKCS12_add_key(3), PKCS12_add_safe(3), PKCS12_add_safes(3), PKCS12_create(3), PKCS12_decrypt_skey(3),
PKCS12_init(3), PKCS12_item_decrypt_d2i(3), PKCS12_item_i2d_encrypt(3), PKCS12_key_gen_asc(3),
PKCS12_key_gen_uni(3), PKCS12_key_gen_utf8(3), PKCS12_pack_p7encdata(3), PKCS12_pbe_crypt(3),
PKCS12_PBE_keyivgen(3), PKCS12_SAFEBAG_create_pkcs8_encrypt(3)
• PKCS5_pbe_set0_algor(3), PKCS5_pbe_set(3), PKCS5_pbe2_set_iv(3), PKCS5_pbkdf2_set(3) and
PKCS5_v2_scrypt_keyivgen(3)
• PKCS7_encrypt(3), PKCS7_new(3) and PKCS7_sign(3)
• PKCS8_decrypt(3), PKCS8_encrypt(3) and PKCS8_set0_pbe(3)
• RAND_bytes(3) and RAND_priv_bytes(3)
• SMIME_write_ASN1(3)
• SSL_load_client_CA_file(3)
• SSL_CTX_new(3)
• TS_RESP_CTX_new(3)
• X509_CRL_new(3)
• X509_load_cert_crl_file(3) and X509_load_cert_file(3)
• X509_LOOKUP_by_subject(3) and X509_LOOKUP_ctrl(3)
• X509_NAME_hash(3)
• X509_new(3)
• X509_REQ_new(3) and X509_REQ_verify(3)
• X509_STORE_CTX_new(3), X509_STORE_set_default_paths(3), X509_STORE_load_file(3),
X509_STORE_load_locations(3) and X509_STORE_load_store(3)
New functions that use a Library context
The following functions can be passed a library context if required. Passing NULL will use the default
library context.
• BIO_new_from_core_bio(3)
• EVP_ASYM_CIPHER_fetch(3) and EVP_ASYM_CIPHER_do_all_provided(3)
• EVP_CIPHER_fetch(3) and EVP_CIPHER_do_all_provided(3)
• EVP_default_properties_enable_fips(3) and EVP_default_properties_is_fips_enabled(3)
• EVP_KDF_fetch(3) and EVP_KDF_do_all_provided(3)
• EVP_KEM_fetch(3) and EVP_KEM_do_all_provided(3)
• EVP_KEYEXCH_fetch(3) and EVP_KEYEXCH_do_all_provided(3)
• EVP_KEYMGMT_fetch(3) and EVP_KEYMGMT_do_all_provided(3)
• EVP_MAC_fetch(3) and EVP_MAC_do_all_provided(3)
• EVP_MD_fetch(3) and EVP_MD_do_all_provided(3)
• EVP_PKEY_CTX_new_from_pkey(3)
• EVP_PKEY_Q_keygen(3)
• EVP_Q_mac(3) and EVP_Q_digest(3)
• EVP_RAND(3) and EVP_RAND_do_all_provided(3)
• EVP_set_default_properties(3)
• EVP_SIGNATURE_fetch(3) and EVP_SIGNATURE_do_all_provided(3)
• OSSL_CMP_CTX_new(3) and OSSL_CMP_SRV_CTX_new(3)
• OSSL_CRMF_ENCRYPTEDVALUE_get1_encCert(3)
• OSSL_CRMF_MSG_create_popo(3) and OSSL_CRMF_MSGS_verify_popo(3)
• OSSL_CRMF_pbm_new(3) and OSSL_CRMF_pbmp_new(3)
• OSSL_DECODER_CTX_add_extra(3) and OSSL_DECODER_CTX_new_for_pkey(3)
• OSSL_DECODER_fetch(3) and OSSL_DECODER_do_all_provided(3)
• OSSL_ENCODER_CTX_add_extra(3)
• OSSL_ENCODER_fetch(3) and OSSL_ENCODER_do_all_provided(3)
• OSSL_LIB_CTX_free(3), OSSL_LIB_CTX_load_config(3) and OSSL_LIB_CTX_set0_default(3)
• OSSL_PROVIDER_add_builtin(3), OSSL_PROVIDER_available(3), OSSL_PROVIDER_do_all(3),
OSSL_PROVIDER_load(3), OSSL_PROVIDER_set_default_search_path(3) and OSSL_PROVIDER_try_load(3)
• OSSL_SELF_TEST_get_callback(3) and OSSL_SELF_TEST_set_callback(3)
• OSSL_STORE_attach(3)
• OSSL_STORE_LOADER_fetch(3) and OSSL_STORE_LOADER_do_all_provided(3)
• RAND_get0_primary(3), RAND_get0_private(3), RAND_get0_public(3), RAND_set_DRBG_type(3) and
RAND_set_seed_source_type(3)
Providers
Providers are described in detail here "Providers" in crypto(7). See also "OPENSSL PROVIDERS" in
crypto(7).
Fetching algorithms and property queries
Implicit and Explicit Fetching is described in detail here "ALGORITHM FETCHING" in crypto(7).
Mapping EVP controls and flags to provider OSSL_PARAM(3) parameters
The existing functions for controls (such as EVP_CIPHER_CTX_ctrl(3)) and manipulating flags (such as
EVP_MD_CTX_set_flags(3))internally use OSSL_PARAMS to pass information to/from provider objects. See
OSSL_PARAM(3) for additional information related to parameters.
For ciphers see "CONTROLS" in EVP_EncryptInit(3), "FLAGS" in EVP_EncryptInit(3) and "PARAMETERS" in
EVP_EncryptInit(3).
For digests see "CONTROLS" in EVP_DigestInit(3), "FLAGS" in EVP_DigestInit(3) and "PARAMETERS" in
EVP_DigestInit(3).
Deprecation of Low Level Functions
A significant number of APIs have been deprecated in OpenSSL 3.0. This section describes some common
categories of deprecations. See "Deprecated function mappings" for the list of deprecated functions that
refer to these categories.
Providers are a replacement for engines and low-level method overrides
Any accessor that uses an ENGINE is deprecated (such as EVP_PKEY_set1_engine()). Applications using
engines should instead use providers.
Before providers were added algorithms were overridden by changing the methods used by algorithms. All
these methods such as RSA_new_method() and RSA_meth_new() are now deprecated and can be replaced by using
providers instead.
Deprecated i2d and d2i functions for low-level key types
Any i2d and d2i functions such as d2i_DHparams() that take a low-level key type have been deprecated.
Applications should instead use the OSSL_DECODER(3) and OSSL_ENCODER(3) APIs to read and write files.
See "Migration" in d2i_RSAPrivateKey(3) for further details.
Deprecated low-level key object getters and setters
Applications that set or get low-level key objects (such as EVP_PKEY_set1_DH() or EVP_PKEY_get0()) should
instead use the OSSL_ENCODER (See OSSL_ENCODER_to_bio(3)) or OSSL_DECODER (See OSSL_DECODER_from_bio(3))
APIs, or alternatively use EVP_PKEY_fromdata(3) or EVP_PKEY_todata(3).
Deprecated low-level key parameter getters
Functions that access low-level objects directly such as RSA_get0_n(3) are now deprecated. Applications
should use one of EVP_PKEY_get_bn_param(3), EVP_PKEY_get_int_param(3), l<EVP_PKEY_get_size_t_param(3)>,
EVP_PKEY_get_utf8_string_param(3), EVP_PKEY_get_octet_string_param(3) or EVP_PKEY_get_params(3) to access
fields from an EVP_PKEY. Gettable parameters are listed in "Common RSA parameters" in EVP_PKEY-RSA(7),
"DH parameters" in EVP_PKEY-DH(7), "DSA parameters" in EVP_PKEY-DSA(7), "FFC parameters" in
EVP_PKEY-FFC(7), "Common EC parameters" in EVP_PKEY-EC(7) and "Common X25519, X448, ED25519 and ED448
parameters" in EVP_PKEY-X25519(7). Applications may also use EVP_PKEY_todata(3) to return all fields.
Deprecated low-level key parameter setters
Functions that access low-level objects directly such as RSA_set0_crt_params(3) are now deprecated.
Applications should use EVP_PKEY_fromdata(3) to create new keys from user provided key data. Keys should
be immutable once they are created, so if required the user may use EVP_PKEY_todata(3),
OSSL_PARAM_merge(3), and EVP_PKEY_fromdata(3) to create a modified key. See "Examples" in EVP_PKEY-DH(7)
for more information. See "Deprecated low-level key generation functions" for information on generating
a key using parameters.
Deprecated low-level object creation
Low-level objects were created using methods such as RSA_new(3), RSA_up_ref(3) and RSA_free(3).
Applications should instead use the high-level EVP_PKEY APIs, e.g. EVP_PKEY_new(3), EVP_PKEY_up_ref(3)
and EVP_PKEY_free(3). See also EVP_PKEY_CTX_new_from_name(3) and EVP_PKEY_CTX_new_from_pkey(3).
EVP_PKEYs may be created in a variety of ways: See also "Deprecated low-level key generation functions",
"Deprecated low-level key reading and writing functions" and "Deprecated low-level key parameter
setters".
Deprecated low-level encryption functions
Low-level encryption functions such as AES_encrypt(3) and AES_decrypt(3) have been informally discouraged
from use for a long time. Applications should instead use the high level EVP APIs EVP_EncryptInit_ex(3),
EVP_EncryptUpdate(3), and EVP_EncryptFinal_ex(3) or EVP_DecryptInit_ex(3), EVP_DecryptUpdate(3) and
EVP_DecryptFinal_ex(3).
Deprecated low-level digest functions
Use of low-level digest functions such as SHA1_Init(3) have been informally discouraged from use for a
long time. Applications should instead use the the high level EVP APIs EVP_DigestInit_ex(3),
EVP_DigestUpdate(3) and EVP_DigestFinal_ex(3), or the quick one-shot EVP_Q_digest(3).
Note that the functions SHA1(3), SHA224(3), SHA256(3), SHA384(3) and SHA512(3) have changed to macros
that use EVP_Q_digest(3).
Deprecated low-level signing functions
Use of low-level signing functions such as DSA_sign(3) have been informally discouraged for a long time.
Instead applications should use EVP_DigestSign(3) and EVP_DigestVerify(3). See also
EVP_SIGNATURE-RSA(7), EVP_SIGNATURE-DSA(7), EVP_SIGNATURE-ECDSA(7) and EVP_SIGNATURE-ED25519(7).
Deprecated low-level MAC functions
Low-level mac functions such as CMAC_Init(3) are deprecated. Applications should instead use the new
EVP_MAC(3) interface, using EVP_MAC_CTX_new(3), EVP_MAC_CTX_free(3), EVP_MAC_init(3), EVP_MAC_update(3)
and EVP_MAC_final(3) or the single-shot MAC function EVP_Q_mac(3). See EVP_MAC(3), EVP_MAC-HMAC(7),
EVP_MAC-CMAC(7), EVP_MAC-GMAC(7), EVP_MAC-KMAC(7), EVP_MAC-BLAKE2(7), EVP_MAC-Poly1305(7) and
EVP_MAC-Siphash(7) for additional information.
Note that the one-shot method HMAC() is still available for compatibility purposes, but this can also be
replaced by using EVP_Q_MAC if a library context is required.
Deprecated low-level validation functions
Low-level validation functions such as DH_check(3) have been informally discouraged from use for a long
time. Applications should instead use the high-level EVP_PKEY APIs such as EVP_PKEY_check(3),
EVP_PKEY_param_check(3), EVP_PKEY_param_check_quick(3), EVP_PKEY_public_check(3),
EVP_PKEY_public_check_quick(3), EVP_PKEY_private_check(3), and EVP_PKEY_pairwise_check(3).
Deprecated low-level key exchange functions
Many low-level functions have been informally discouraged from use for a long time. Applications should
instead use EVP_PKEY_derive(3). See EVP_KEYEXCH-DH(7), EVP_KEYEXCH-ECDH(7) and EVP_KEYEXCH-X25519(7).
Deprecated low-level key generation functions
Many low-level functions have been informally discouraged from use for a long time. Applications should
instead use EVP_PKEY_keygen_init(3) and EVP_PKEY_generate(3) as described in EVP_PKEY-DSA(7),
EVP_PKEY-DH(7), EVP_PKEY-RSA(7), EVP_PKEY-EC(7) and EVP_PKEY-X25519(7). The 'quick' one-shot function
EVP_PKEY_Q_keygen(3) and macros for the most common cases: <EVP_RSA_gen(3)> and EVP_EC_gen(3) may also be
used.
Deprecated low-level key reading and writing functions
Use of low-level objects (such as DSA) has been informally discouraged from use for a long time.
Functions to read and write these low-level objects (such as PEM_read_DSA_PUBKEY()) should be replaced.
Applications should instead use OSSL_ENCODER_to_bio(3) and OSSL_DECODER_from_bio(3).
Deprecated low-level key printing functions
Use of low-level objects (such as DSA) has been informally discouraged from use for a long time.
Functions to print these low-level objects such as DSA_print() should be replaced with the equivalent
EVP_PKEY functions. Application should use one of EVP_PKEY_print_public(3), EVP_PKEY_print_private(3),
EVP_PKEY_print_params(3), EVP_PKEY_print_public_fp(3), EVP_PKEY_print_private_fp(3) or
EVP_PKEY_print_params_fp(3). Note that internally these use OSSL_ENCODER_to_bio(3) and
OSSL_DECODER_from_bio(3).
Deprecated function mappings
The following functions have been deprecated in 3.0.
• AES_bi_ige_encrypt() and AES_ige_encrypt()
There is no replacement for the IGE functions. New code should not use these modes. These
undocumented functions were never integrated into the EVP layer. They implemented the AES Infinite
Garble Extension (IGE) mode and AES Bi-directional IGE mode. These modes were never formally
standardised and usage of these functions is believed to be very small. In particular
AES_bi_ige_encrypt() has a known bug. It accepts 2 AES keys, but only one is ever used. The security
implications are believed to be minimal, but this issue was never fixed for backwards compatibility
reasons.
• AES_encrypt(), AES_decrypt(), AES_set_encrypt_key(), AES_set_decrypt_key(), AES_cbc_encrypt(),
AES_cfb128_encrypt(), AES_cfb1_encrypt(), AES_cfb8_encrypt(), AES_ecb_encrypt(), AES_ofb128_encrypt()
• AES_unwrap_key(), AES_wrap_key()
See "Deprecated low-level encryption functions"
• AES_options()
There is no replacement. It returned a string indicating if the AES code was unrolled.
• ASN1_digest(), ASN1_sign(), ASN1_verify()
There are no replacements. These old functions are not used, and could be disabled with the macro
NO_ASN1_OLD since OpenSSL 0.9.7.
• ASN1_STRING_length_set()
Use ASN1_STRING_set(3) or ASN1_STRING_set0(3) instead. This was a potentially unsafe function that
could change the bounds of a previously passed in pointer.
• BF_encrypt(), BF_decrypt(), BF_set_key(), BF_cbc_encrypt(), BF_cfb64_encrypt(), BF_ecb_encrypt(),
BF_ofb64_encrypt()
See "Deprecated low-level encryption functions". The Blowfish algorithm has been moved to the Legacy
Provider.
• BF_options()
There is no replacement. This option returned a constant string.
• BIO_get_callback(), BIO_set_callback(), BIO_debug_callback()
Use the respective non-deprecated _ex() functions.
• BN_is_prime_ex(), BN_is_prime_fasttest_ex()
Use BN_check_prime(3) which avoids possible misuse and always uses at least 64 rounds of the Miller-
Rabin primality test.
• BN_pseudo_rand(), BN_pseudo_rand_range()
Use BN_rand(3) and BN_rand_range(3).
• BN_X931_derive_prime_ex(), BN_X931_generate_prime_ex(), BN_X931_generate_Xpq()
There are no replacements for these low-level functions. They were used internally by
RSA_X931_derive_ex() and RSA_X931_generate_key_ex() which are also deprecated. Use
EVP_PKEY_keygen(3) instead.
• Camellia_encrypt(), Camellia_decrypt(), Camellia_set_key(), Camellia_cbc_encrypt(),
Camellia_cfb128_encrypt(), Camellia_cfb1_encrypt(), Camellia_cfb8_encrypt(),
Camellia_ctr128_encrypt(), Camellia_ecb_encrypt(), Camellia_ofb128_encrypt()
See "Deprecated low-level encryption functions".
• CAST_encrypt(), CAST_decrypt(), CAST_set_key(), CAST_cbc_encrypt(), CAST_cfb64_encrypt(),
CAST_ecb_encrypt(), CAST_ofb64_encrypt()
See "Deprecated low-level encryption functions". The CAST algorithm has been moved to the Legacy
Provider.
• CMAC_CTX_new(), CMAC_CTX_cleanup(), CMAC_CTX_copy(), CMAC_CTX_free(), CMAC_CTX_get0_cipher_ctx()
See "Deprecated low-level MAC functions".
• CMAC_Init(), CMAC_Update(), CMAC_Final(), CMAC_resume()
See "Deprecated low-level MAC functions".
• CRYPTO_mem_ctrl(), CRYPTO_mem_debug_free(), CRYPTO_mem_debug_malloc(), CRYPTO_mem_debug_pop(),
CRYPTO_mem_debug_push(), CRYPTO_mem_debug_realloc(), CRYPTO_mem_leaks(), CRYPTO_mem_leaks_cb(),
CRYPTO_mem_leaks_fp(), CRYPTO_set_mem_debug()
Memory-leak checking has been deprecated in favor of more modern development tools, such as compiler
memory and leak sanitizers or Valgrind.
• CRYPTO_cts128_encrypt_block(), CRYPTO_cts128_encrypt(), CRYPTO_cts128_decrypt_block(),
CRYPTO_cts128_decrypt(), CRYPTO_nistcts128_encrypt_block(), CRYPTO_nistcts128_encrypt(),
CRYPTO_nistcts128_decrypt_block(), CRYPTO_nistcts128_decrypt()
Use the higher level functions EVP_CipherInit_ex2(), EVP_CipherUpdate() and EVP_CipherFinal_ex()
instead. See the "cts_mode" parameter in "Gettable and Settable EVP_CIPHER_CTX parameters" in
EVP_EncryptInit(3). See "EXAMPLES" in EVP_EncryptInit(3) for a AES-256-CBC-CTS example.
• d2i_DHparams(), d2i_DHxparams(), d2i_DSAparams(), d2i_DSAPrivateKey(), d2i_DSAPrivateKey_bio(),
d2i_DSAPrivateKey_fp(), d2i_DSA_PUBKEY(), d2i_DSA_PUBKEY_bio(), d2i_DSA_PUBKEY_fp(),
d2i_DSAPublicKey(), d2i_ECParameters(), d2i_ECPrivateKey(), d2i_ECPrivateKey_bio(),
d2i_ECPrivateKey_fp(), d2i_EC_PUBKEY(), d2i_EC_PUBKEY_bio(), d2i_EC_PUBKEY_fp(), o2i_ECPublicKey(),
d2i_RSAPrivateKey(), d2i_RSAPrivateKey_bio(), d2i_RSAPrivateKey_fp(), d2i_RSA_PUBKEY(),
d2i_RSA_PUBKEY_bio(), d2i_RSA_PUBKEY_fp(), d2i_RSAPublicKey(), d2i_RSAPublicKey_bio(),
d2i_RSAPublicKey_fp()
See "Deprecated i2d and d2i functions for low-level key types"
• DES_crypt(), DES_fcrypt(), DES_encrypt1(), DES_encrypt2(), DES_encrypt3(), DES_decrypt3(),
DES_ede3_cbc_encrypt(), DES_ede3_cfb64_encrypt(), DES_ede3_cfb_encrypt(),DES_ede3_ofb64_encrypt(),
DES_ecb_encrypt(), DES_ecb3_encrypt(), DES_ofb64_encrypt(), DES_ofb_encrypt(), DES_cfb64_encrypt
DES_cfb_encrypt(), DES_cbc_encrypt(), DES_ncbc_encrypt(), DES_pcbc_encrypt(), DES_xcbc_encrypt(),
DES_cbc_cksum(), DES_quad_cksum(), DES_check_key_parity(), DES_is_weak_key(), DES_key_sched(),
DES_options(), DES_random_key(), DES_set_key(), DES_set_key_checked(), DES_set_key_unchecked(),
DES_set_odd_parity(), DES_string_to_2keys(), DES_string_to_key()
See "Deprecated low-level encryption functions". Algorithms for "DESX-CBC", "DES-ECB", "DES-CBC",
"DES-OFB", "DES-CFB", "DES-CFB1" and "DES-CFB8" have been moved to the Legacy Provider.
• DH_bits(), DH_security_bits(), DH_size()
Use EVP_PKEY_get_bits(3), EVP_PKEY_get_security_bits(3) and EVP_PKEY_get_size(3).
• DH_check(), DH_check_ex(), DH_check_params(), DH_check_params_ex(), DH_check_pub_key(),
DH_check_pub_key_ex()
See "Deprecated low-level validation functions"
• DH_clear_flags(), DH_test_flags(), DH_set_flags()
The DH_FLAG_CACHE_MONT_P flag has been deprecated without replacement. The DH_FLAG_TYPE_DH and
DH_FLAG_TYPE_DHX have been deprecated. Use EVP_PKEY_is_a() to determine the type of a key. There is
no replacement for setting these flags.
• DH_compute_key() DH_compute_key_padded()
See "Deprecated low-level key exchange functions".
• DH_new(), DH_new_by_nid(), DH_free(), DH_up_ref()
See "Deprecated low-level object creation"
• DH_generate_key(), DH_generate_parameters_ex()
See "Deprecated low-level key generation functions".
• DH_get0_pqg(), DH_get0_p(), DH_get0_q(), DH_get0_g(), DH_get0_key(), DH_get0_priv_key(),
DH_get0_pub_key(), DH_get_length(), DH_get_nid()
See "Deprecated low-level key parameter getters"
• DH_get_1024_160(), DH_get_2048_224(), DH_get_2048_256()
Applications should instead set the OSSL_PKEY_PARAM_GROUP_NAME as specified in "DH parameters" in
EVP_PKEY-DH(7)) to one of "dh_1024_160", "dh_2048_224" or "dh_2048_256" when generating a DH key.
• DH_KDF_X9_42()
Applications should use EVP_PKEY_CTX_set_dh_kdf_type(3) instead.
• DH_get_default_method(), DH_get0_engine(), DH_meth_*(), DH_new_method(), DH_OpenSSL(),
DH_get_ex_data(), DH_set_default_method(), DH_set_method(), DH_set_ex_data()
See "Providers are a replacement for engines and low-level method overrides"
• DHparams_print(), DHparams_print_fp()
See "Deprecated low-level key printing functions"
• DH_set0_key(), DH_set0_pqg(), DH_set_length()
See "Deprecated low-level key parameter setters"
• DSA_bits(), DSA_security_bits(), DSA_size()
Use EVP_PKEY_get_bits(3), EVP_PKEY_get_security_bits(3) and EVP_PKEY_get_size(3).
• DHparams_dup(), DSA_dup_DH()
There is no direct replacement. Applications may use EVP_PKEY_copy_parameters(3) and EVP_PKEY_dup(3)
instead.
• DSA_generate_key(), DSA_generate_parameters_ex()
See "Deprecated low-level key generation functions".
• DSA_get0_engine(), DSA_get_default_method(), DSA_get_ex_data(), DSA_get_method(), DSA_meth_*(),
DSA_new_method(), DSA_OpenSSL(), DSA_set_default_method(), DSA_set_ex_data(), DSA_set_method()
See "Providers are a replacement for engines and low-level method overrides".
• DSA_get0_p(), DSA_get0_q(), DSA_get0_g(), DSA_get0_pqg(), DSA_get0_key(), DSA_get0_priv_key(),
DSA_get0_pub_key()
See "Deprecated low-level key parameter getters".
• DSA_new(), DSA_free(), DSA_up_ref()
See "Deprecated low-level object creation"
• DSAparams_dup()
There is no direct replacement. Applications may use EVP_PKEY_copy_parameters(3) and EVP_PKEY_dup(3)
instead.
• DSAparams_print(), DSAparams_print_fp(), DSA_print(), DSA_print_fp()
See "Deprecated low-level key printing functions"
• DSA_set0_key(), DSA_set0_pqg()
See "Deprecated low-level key parameter setters"
• DSA_set_flags(), DSA_clear_flags(), DSA_test_flags()
The DSA_FLAG_CACHE_MONT_P flag has been deprecated without replacement.
• DSA_sign(), DSA_do_sign(), DSA_sign_setup(), DSA_verify(), DSA_do_verify()
See "Deprecated low-level signing functions".
• ECDH_compute_key()
See "Deprecated low-level key exchange functions".
• ECDH_KDF_X9_62()
Applications may either set this using the helper function EVP_PKEY_CTX_set_ecdh_kdf_type(3) or by
setting an OSSL_PARAM(3) using the "kdf-type" as shown in "EXAMPLES" in EVP_KEYEXCH-ECDH(7)
• ECDSA_sign(), ECDSA_sign_ex(), ECDSA_sign_setup(), ECDSA_do_sign(), ECDSA_do_sign_ex(),
ECDSA_verify(), ECDSA_do_verify()
See "Deprecated low-level signing functions".
• ECDSA_size()
Applications should use EVP_PKEY_get_size(3).
• EC_GF2m_simple_method(), EC_GFp_mont_method(), EC_GFp_nist_method(), EC_GFp_nistp224_method(),
EC_GFp_nistp256_method(), EC_GFp_nistp521_method(), EC_GFp_simple_method()
There are no replacements for these functions. Applications should rely on the library automatically
assigning a suitable method internally when an EC_GROUP is constructed.
• EC_GROUP_clear_free()
Use EC_GROUP_free(3) instead.
• EC_GROUP_get_curve_GF2m(), EC_GROUP_get_curve_GFp(), EC_GROUP_set_curve_GF2m(),
EC_GROUP_set_curve_GFp()
Applications should use EC_GROUP_get_curve(3) and EC_GROUP_set_curve(3).
• EC_GROUP_have_precompute_mult(), EC_GROUP_precompute_mult(), EC_KEY_precompute_mult()
These functions are not widely used. Applications should instead switch to named curves which OpenSSL
has hardcoded lookup tables for.
• EC_GROUP_new(), EC_GROUP_method_of(), EC_POINT_method_of()
EC_METHOD is now an internal-only concept and a suitable EC_METHOD is assigned internally without
application intervention. Users of EC_GROUP_new() should switch to a different suitable constructor.
• EC_KEY_can_sign()
Applications should use EVP_PKEY_can_sign(3) instead.
• EC_KEY_check_key()
See "Deprecated low-level validation functions"
• EC_KEY_set_flags(), EC_KEY_get_flags(), EC_KEY_clear_flags()
See "Common EC parameters" in EVP_PKEY-EC(7) which handles flags as separate parameters for
OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT, OSSL_PKEY_PARAM_EC_GROUP_CHECK_TYPE,
OSSL_PKEY_PARAM_EC_ENCODING, OSSL_PKEY_PARAM_USE_COFACTOR_ECDH and OSSL_PKEY_PARAM_EC_INCLUDE_PUBLIC.
See also "EXAMPLES" in EVP_PKEY-EC(7)
• EC_KEY_dup(), EC_KEY_copy()
There is no direct replacement. Applications may use EVP_PKEY_copy_parameters(3) and EVP_PKEY_dup(3)
instead.
• EC_KEY_decoded_from_explicit_params()
There is no replacement.
• EC_KEY_generate_key()
See "Deprecated low-level key generation functions".
• EC_KEY_get0_group(), EC_KEY_get0_private_key(), EC_KEY_get0_public_key(), EC_KEY_get_conv_form(),
EC_KEY_get_enc_flags()
See "Deprecated low-level key parameter getters".
• EC_KEY_get0_engine(), EC_KEY_get_default_method(), EC_KEY_get_method(), EC_KEY_new_method(),
EC_KEY_get_ex_data(), EC_KEY_OpenSSL(), EC_KEY_set_ex_data(), EC_KEY_set_default_method(),
EC_KEY_METHOD_*(), EC_KEY_set_method()
See "Providers are a replacement for engines and low-level method overrides"
• EC_METHOD_get_field_type()
Use EC_GROUP_get_field_type(3) instead. See "Providers are a replacement for engines and low-level
method overrides"
• EC_KEY_key2buf(), EC_KEY_oct2key(), EC_KEY_oct2priv(), EC_KEY_priv2buf(), EC_KEY_priv2oct()
There are no replacements for these.
• EC_KEY_new(), EC_KEY_new_by_curve_name(), EC_KEY_free(), EC_KEY_up_ref()
See "Deprecated low-level object creation"
• EC_KEY_print(), EC_KEY_print_fp()
See "Deprecated low-level key printing functions"
• EC_KEY_set_asn1_flag(), EC_KEY_set_conv_form(), EC_KEY_set_enc_flags()
See "Deprecated low-level key parameter setters".
• EC_KEY_set_group(), EC_KEY_set_private_key(), EC_KEY_set_public_key(),
EC_KEY_set_public_key_affine_coordinates()
See "Deprecated low-level key parameter setters".
• ECParameters_print(), ECParameters_print_fp(), ECPKParameters_print(), ECPKParameters_print_fp()
See "Deprecated low-level key printing functions"
• EC_POINT_bn2point(), EC_POINT_point2bn()
These functions were not particularly useful, since EC point serialization formats are not individual
big-endian integers.
• EC_POINT_get_affine_coordinates_GF2m(), EC_POINT_get_affine_coordinates_GFp(),
EC_POINT_set_affine_coordinates_GF2m(), EC_POINT_set_affine_coordinates_GFp()
Applications should use EC_POINT_get_affine_coordinates(3) and EC_POINT_set_affine_coordinates(3)
instead.
• EC_POINT_get_Jprojective_coordinates_GFp(), EC_POINT_set_Jprojective_coordinates_GFp()
These functions are not widely used. Applications should instead use the
EC_POINT_set_affine_coordinates(3) and EC_POINT_get_affine_coordinates(3) functions.
• EC_POINT_make_affine(), EC_POINTs_make_affine()
There is no replacement. These functions were not widely used, and OpenSSL automatically performs
this conversion when needed.
• EC_POINT_set_compressed_coordinates_GF2m(), EC_POINT_set_compressed_coordinates_GFp()
Applications should use EC_POINT_set_compressed_coordinates(3) instead.
• EC_POINTs_mul()
This function is not widely used. Applications should instead use the EC_POINT_mul(3) function.
• ENGINE_*()
All engine functions are deprecated. An engine should be rewritten as a provider. See "Providers are
a replacement for engines and low-level method overrides".
• ERR_load_*(), ERR_func_error_string(), ERR_get_error_line(), ERR_get_error_line_data(),
ERR_get_state()
OpenSSL now loads error strings automatically so these functions are not needed.
• ERR_peek_error_line_data(), ERR_peek_last_error_line_data()
The new functions are ERR_peek_error_func(3), ERR_peek_last_error_func(3), ERR_peek_error_data(3),
ERR_peek_last_error_data(3), ERR_get_error_all(3), ERR_peek_error_all(3) and
ERR_peek_last_error_all(3). Applications should use ERR_get_error_all(3), or pick information with
ERR_peek functions and finish off with getting the error code by using ERR_get_error(3).
• EVP_CIPHER_CTX_iv(), EVP_CIPHER_CTX_iv_noconst(), EVP_CIPHER_CTX_original_iv()
Applications should instead use EVP_CIPHER_CTX_get_updated_iv(3), EVP_CIPHER_CTX_get_updated_iv(3)
and EVP_CIPHER_CTX_get_original_iv(3) respectively. See EVP_CIPHER_CTX_get_original_iv(3) for
further information.
• EVP_CIPHER_meth_*(), EVP_MD_CTX_set_update_fn(), EVP_MD_CTX_update_fn(), EVP_MD_meth_*()
See "Providers are a replacement for engines and low-level method overrides".
• EVP_PKEY_CTRL_PKCS7_ENCRYPT(), EVP_PKEY_CTRL_PKCS7_DECRYPT(), EVP_PKEY_CTRL_PKCS7_SIGN(),
EVP_PKEY_CTRL_CMS_ENCRYPT(), EVP_PKEY_CTRL_CMS_DECRYPT(), and EVP_PKEY_CTRL_CMS_SIGN()
These control operations are not invoked by the OpenSSL library anymore and are replaced by direct
checks of the key operation against the key type when the operation is initialized.
• EVP_PKEY_CTX_get0_dh_kdf_ukm(), EVP_PKEY_CTX_get0_ecdh_kdf_ukm()
See the "kdf-ukm" item in "DH key exchange parameters" in EVP_KEYEXCH-DH(7) and "ECDH Key Exchange
parameters" in EVP_KEYEXCH-ECDH(7). These functions are obsolete and should not be required.
• EVP_PKEY_CTX_set_rsa_keygen_pubexp()
Applications should use EVP_PKEY_CTX_set1_rsa_keygen_pubexp(3) instead.
• EVP_PKEY_cmp(), EVP_PKEY_cmp_parameters()
Applications should use EVP_PKEY_eq(3) and EVP_PKEY_parameters_eq(3) instead. See
EVP_PKEY_copy_parameters(3) for further details.
• EVP_PKEY_encrypt_old(), EVP_PKEY_decrypt_old(),
Applications should use EVP_PKEY_encrypt_init(3) and EVP_PKEY_encrypt(3) or EVP_PKEY_decrypt_init(3)
and EVP_PKEY_decrypt(3) instead.
• EVP_PKEY_get0()
This function returns NULL if the key comes from a provider.
• EVP_PKEY_get0_DH(), EVP_PKEY_get0_DSA(), EVP_PKEY_get0_EC_KEY(), EVP_PKEY_get0_RSA(),
EVP_PKEY_get1_DH(), EVP_PKEY_get1_DSA(), EVP_PKEY_get1_EC_KEY and EVP_PKEY_get1_RSA(),
EVP_PKEY_get0_hmac(), EVP_PKEY_get0_poly1305(), EVP_PKEY_get0_siphash()
See "Functions that return an internal key should be treated as read only".
• EVP_PKEY_meth_*()
See "Providers are a replacement for engines and low-level method overrides".
• EVP_PKEY_new_CMAC_key()
See "Deprecated low-level MAC functions".
• EVP_PKEY_assign(), EVP_PKEY_set1_DH(), EVP_PKEY_set1_DSA(), EVP_PKEY_set1_EC_KEY(),
EVP_PKEY_set1_RSA()
See "Deprecated low-level key object getters and setters"
• EVP_PKEY_set1_tls_encodedpoint() EVP_PKEY_get1_tls_encodedpoint()
These functions were previously used by libssl to set or get an encoded public key into/from an
EVP_PKEY object. With OpenSSL 3.0 these are replaced by the more generic functions
EVP_PKEY_set1_encoded_public_key(3) and EVP_PKEY_get1_encoded_public_key(3). The old versions have
been converted to deprecated macros that just call the new functions.
• EVP_PKEY_set1_engine(), EVP_PKEY_get0_engine()
See "Providers are a replacement for engines and low-level method overrides".
• EVP_PKEY_set_alias_type()
This function has been removed. There is no replacement. See "EVP_PKEY_set_alias_type() method has
been removed"
• HMAC_Init_ex(), HMAC_Update(), HMAC_Final(), HMAC_size()
See "Deprecated low-level MAC functions".
• HMAC_CTX_new(), HMAC_CTX_free(), HMAC_CTX_copy(), HMAC_CTX_reset(), HMAC_CTX_set_flags(),
HMAC_CTX_get_md()
See "Deprecated low-level MAC functions".
• i2d_DHparams(), i2d_DHxparams()
See "Deprecated low-level key reading and writing functions" and "Migration" in d2i_RSAPrivateKey(3)
• i2d_DSAparams(), i2d_DSAPrivateKey(), i2d_DSAPrivateKey_bio(), i2d_DSAPrivateKey_fp(),
i2d_DSA_PUBKEY(), i2d_DSA_PUBKEY_bio(), i2d_DSA_PUBKEY_fp(), i2d_DSAPublicKey()
See "Deprecated low-level key reading and writing functions" and "Migration" in d2i_RSAPrivateKey(3)
• i2d_ECParameters(), i2d_ECPrivateKey(), i2d_ECPrivateKey_bio(), i2d_ECPrivateKey_fp(),
i2d_EC_PUBKEY(), i2d_EC_PUBKEY_bio(), i2d_EC_PUBKEY_fp(), i2o_ECPublicKey()
See "Deprecated low-level key reading and writing functions" and "Migration" in d2i_RSAPrivateKey(3)
• i2d_RSAPrivateKey(), i2d_RSAPrivateKey_bio(), i2d_RSAPrivateKey_fp(), i2d_RSA_PUBKEY(),
i2d_RSA_PUBKEY_bio(), i2d_RSA_PUBKEY_fp(), i2d_RSAPublicKey(), i2d_RSAPublicKey_bio(),
i2d_RSAPublicKey_fp()
See "Deprecated low-level key reading and writing functions" and "Migration" in d2i_RSAPrivateKey(3)
• IDEA_encrypt(), IDEA_set_decrypt_key(), IDEA_set_encrypt_key(), IDEA_cbc_encrypt(),
IDEA_cfb64_encrypt(), IDEA_ecb_encrypt(), IDEA_ofb64_encrypt()
See "Deprecated low-level encryption functions". IDEA has been moved to the Legacy Provider.
• IDEA_options()
There is no replacement. This function returned a constant string.
• MD2(), MD2_Init(), MD2_Update(), MD2_Final()
See "Deprecated low-level encryption functions". MD2 has been moved to the Legacy Provider.
• MD2_options()
There is no replacement. This function returned a constant string.
• MD4(), MD4_Init(), MD4_Update(), MD4_Final(), MD4_Transform()
See "Deprecated low-level encryption functions". MD4 has been moved to the Legacy Provider.
• MDC2(), MDC2_Init(), MDC2_Update(), MDC2_Final()
See "Deprecated low-level encryption functions". MDC2 has been moved to the Legacy Provider.
• MD5(), MD5_Init(), MD5_Update(), MD5_Final(), MD5_Transform()
See "Deprecated low-level encryption functions".
• NCONF_WIN32()
This undocumented function has no replacement. See "HISTORY" in config(5) for more details.
• OCSP_parse_url()
Use OSSL_HTTP_parse_url(3) instead.
• OCSP_REQ_CTX type and OCSP_REQ_CTX_*() functions
These methods were used to collect all necessary data to form a HTTP request, and to perform the HTTP
transfer with that request. With OpenSSL 3.0, the type is OSSL_HTTP_REQ_CTX, and the deprecated
functions are replaced with OSSL_HTTP_REQ_CTX_*(). See OSSL_HTTP_REQ_CTX(3) for additional details.
• OPENSSL_fork_child(), OPENSSL_fork_parent(), OPENSSL_fork_prepare()
There is no replacement for these functions. These pthread fork support methods were unused by
OpenSSL.
• OSSL_STORE_ctrl(), OSSL_STORE_do_all_loaders(), OSSL_STORE_LOADER_get0_engine(),
OSSL_STORE_LOADER_get0_scheme(), OSSL_STORE_LOADER_new(), OSSL_STORE_LOADER_set_attach(),
OSSL_STORE_LOADER_set_close(), OSSL_STORE_LOADER_set_ctrl(), OSSL_STORE_LOADER_set_eof(),
OSSL_STORE_LOADER_set_error(), OSSL_STORE_LOADER_set_expect(), OSSL_STORE_LOADER_set_find(),
OSSL_STORE_LOADER_set_load(), OSSL_STORE_LOADER_set_open(), OSSL_STORE_LOADER_set_open_ex(),
OSSL_STORE_register_loader(), OSSL_STORE_unregister_loader(), OSSL_STORE_vctrl()
These functions helped applications and engines create loaders for schemes they supported. These are
all deprecated and discouraged in favour of provider implementations, see provider-storemgmt(7).
• PEM_read_DHparams(), PEM_read_bio_DHparams(), PEM_read_DSAparams(), PEM_read_bio_DSAparams(),
PEM_read_DSAPrivateKey(), PEM_read_DSA_PUBKEY(), PEM_read_bio_DSAPrivateKey and
PEM_read_bio_DSA_PUBKEY(), PEM_read_ECPKParameters(), PEM_read_ECPrivateKey(), PEM_read_EC_PUBKEY(),
PEM_read_bio_ECPKParameters(), PEM_read_bio_ECPrivateKey(), PEM_read_bio_EC_PUBKEY(),
PEM_read_RSAPrivateKey(), PEM_read_RSA_PUBKEY(), PEM_read_RSAPublicKey(),
PEM_read_bio_RSAPrivateKey(), PEM_read_bio_RSA_PUBKEY(), PEM_read_bio_RSAPublicKey(),
PEM_write_bio_DHparams(), PEM_write_bio_DHxparams(), PEM_write_DHparams(), PEM_write_DHxparams(),
PEM_write_DSAparams(), PEM_write_DSAPrivateKey(), PEM_write_DSA_PUBKEY(), PEM_write_bio_DSAparams(),
PEM_write_bio_DSAPrivateKey(), PEM_write_bio_DSA_PUBKEY(), PEM_write_ECPKParameters(),
PEM_write_ECPrivateKey(), PEM_write_EC_PUBKEY(), PEM_write_bio_ECPKParameters(),
PEM_write_bio_ECPrivateKey(), PEM_write_bio_EC_PUBKEY(), PEM_write_RSAPrivateKey(),
PEM_write_RSA_PUBKEY(), PEM_write_RSAPublicKey(), PEM_write_bio_RSAPrivateKey(),
PEM_write_bio_RSA_PUBKEY(), PEM_write_bio_RSAPublicKey(),
See "Deprecated low-level key reading and writing functions"
• PKCS1_MGF1()
See "Deprecated low-level encryption functions".
• RAND_get_rand_method(), RAND_set_rand_method(), RAND_OpenSSL(), RAND_set_rand_engine()
Applications should instead use RAND_set_DRBG_type(3), EVP_RAND(3) and EVP_RAND(7). See
RAND_set_rand_method(3) for more details.
• RC2_encrypt(), RC2_decrypt(), RC2_set_key(), RC2_cbc_encrypt(), RC2_cfb64_encrypt(),
RC2_ecb_encrypt(), RC2_ofb64_encrypt(), RC4(), RC4_set_key(), RC4_options(), RC5_32_encrypt(),
RC5_32_set_key(), RC5_32_decrypt(), RC5_32_cbc_encrypt(), RC5_32_cfb64_encrypt(),
RC5_32_ecb_encrypt(), RC5_32_ofb64_encrypt()
See "Deprecated low-level encryption functions". The Algorithms "RC2", "RC4" and "RC5" have been
moved to the Legacy Provider.
• RIPEMD160(), RIPEMD160_Init(), RIPEMD160_Update(), RIPEMD160_Final(), RIPEMD160_Transform()
See "Deprecated low-level digest functions". The RIPE algorithm has been moved to the Legacy
Provider.
• RSA_bits(), RSA_security_bits(), RSA_size()
Use EVP_PKEY_get_bits(3), EVP_PKEY_get_security_bits(3) and EVP_PKEY_get_size(3).
• RSA_check_key(), RSA_check_key_ex()
See "Deprecated low-level validation functions"
• RSA_clear_flags(), RSA_flags(), RSA_set_flags(), RSA_test_flags(), RSA_setup_blinding(),
RSA_blinding_off(), RSA_blinding_on()
All of these RSA flags have been deprecated without replacement:
RSA_FLAG_BLINDING, RSA_FLAG_CACHE_PRIVATE, RSA_FLAG_CACHE_PUBLIC, RSA_FLAG_EXT_PKEY,
RSA_FLAG_NO_BLINDING, RSA_FLAG_THREAD_SAFE RSA_METHOD_FLAG_NO_CHECK
• RSA_generate_key_ex(), RSA_generate_multi_prime_key()
See "Deprecated low-level key generation functions".
• RSA_get0_engine()
See "Providers are a replacement for engines and low-level method overrides"
• RSA_get0_crt_params(), RSA_get0_d(), RSA_get0_dmp1(), RSA_get0_dmq1(), RSA_get0_e(),
RSA_get0_factors(), RSA_get0_iqmp(), RSA_get0_key(), RSA_get0_multi_prime_crt_params(),
RSA_get0_multi_prime_factors(), RSA_get0_n(), RSA_get0_p(), RSA_get0_pss_params(), RSA_get0_q(),
RSA_get_multi_prime_extra_count()
See "Deprecated low-level key parameter getters"
• RSA_new(), RSA_free(), RSA_up_ref()
See "Deprecated low-level object creation".
• RSA_get_default_method(), RSA_get_ex_data and RSA_get_method()
See "Providers are a replacement for engines and low-level method overrides".
• RSA_get_version()
There is no replacement.
• RSA_meth_*(), RSA_new_method(), RSA_null_method and RSA_PKCS1_OpenSSL()
See "Providers are a replacement for engines and low-level method overrides".
• RSA_padding_add_*(), RSA_padding_check_*()
See "Deprecated low-level signing functions" and "Deprecated low-level encryption functions".
• RSA_print(), RSA_print_fp()
See "Deprecated low-level key printing functions"
• RSA_public_encrypt(), RSA_private_decrypt()
See "Deprecated low-level encryption functions"
• RSA_private_encrypt(), RSA_public_decrypt()
This is equivalent to doing sign and verify recover operations (with a padding mode of none). See
"Deprecated low-level signing functions".
• RSAPrivateKey_dup(), RSAPublicKey_dup()
There is no direct replacement. Applications may use EVP_PKEY_dup(3).
• RSAPublicKey_it(), RSAPrivateKey_it()
See "Deprecated low-level key reading and writing functions"
• RSA_set0_crt_params(), RSA_set0_factors(), RSA_set0_key(), RSA_set0_multi_prime_params()
See "Deprecated low-level key parameter setters".
• RSA_set_default_method(), RSA_set_method(), RSA_set_ex_data()
See "Providers are a replacement for engines and low-level method overrides"
• RSA_sign(), RSA_sign_ASN1_OCTET_STRING(), RSA_verify(), RSA_verify_ASN1_OCTET_STRING(),
RSA_verify_PKCS1_PSS(), RSA_verify_PKCS1_PSS_mgf1()
See "Deprecated low-level signing functions".
• RSA_X931_derive_ex(), RSA_X931_generate_key_ex(), RSA_X931_hash_id()
There are no replacements for these functions. X931 padding can be set using "Signature Parameters"
in EVP_SIGNATURE-RSA(7). See OSSL_SIGNATURE_PARAM_PAD_MODE.
• SEED_encrypt(), SEED_decrypt(), SEED_set_key(), SEED_cbc_encrypt(), SEED_cfb128_encrypt(),
SEED_ecb_encrypt(), SEED_ofb128_encrypt()
See "Deprecated low-level encryption functions". The SEED algorithm has been moved to the Legacy
Provider.
• SHA1_Init(), SHA1_Update(), SHA1_Final(), SHA1_Transform(), SHA224_Init(), SHA224_Update(),
SHA224_Final(), SHA256_Init(), SHA256_Update(), SHA256_Final(), SHA256_Transform(), SHA384_Init(),
SHA384_Update(), SHA384_Final(), SHA512_Init(), SHA512_Update(), SHA512_Final(), SHA512_Transform()
See "Deprecated low-level digest functions".
• SRP_Calc_A(), SRP_Calc_B(), SRP_Calc_client_key(), SRP_Calc_server_key(), SRP_Calc_u(), SRP_Calc_x(),
SRP_check_known_gN_param(), SRP_create_verifier(), SRP_create_verifier_BN(), SRP_get_default_gN(),
SRP_user_pwd_free(), SRP_user_pwd_new(), SRP_user_pwd_set0_sv(), SRP_user_pwd_set1_ids(),
SRP_user_pwd_set_gN(), SRP_VBASE_add0_user(), SRP_VBASE_free(), SRP_VBASE_get1_by_user(),
SRP_VBASE_init(), SRP_VBASE_new(), SRP_Verify_A_mod_N(), SRP_Verify_B_mod_N()
There are no replacements for the SRP functions.
• SSL_CTX_set_tmp_dh_callback(), SSL_set_tmp_dh_callback(), SSL_CTX_set_tmp_dh(), SSL_set_tmp_dh()
These are used to set the Diffie-Hellman (DH) parameters that are to be used by servers requiring
ephemeral DH keys. Instead applications should consider using the built-in DH parameters that are
available by calling SSL_CTX_set_dh_auto(3) or SSL_set_dh_auto(3). If custom parameters are necessary
then applications can use the alternative functions SSL_CTX_set0_tmp_dh_pkey(3) and
SSL_set0_tmp_dh_pkey(3). There is no direct replacement for the "callback" functions. The callback
was originally useful in order to have different parameters for export and non-export ciphersuites.
Export ciphersuites are no longer supported by OpenSSL. Use of the callback functions should be
replaced by one of the other methods described above.
• SSL_CTX_set_tlsext_ticket_key_cb()
Use the new SSL_CTX_set_tlsext_ticket_key_evp_cb(3) function instead.
• WHIRLPOOL(), WHIRLPOOL_Init(), WHIRLPOOL_Update(), WHIRLPOOL_Final(), WHIRLPOOL_BitUpdate()
See "Deprecated low-level digest functions". The Whirlpool algorithm has been moved to the Legacy
Provider.
• X509_certificate_type()
This was an undocumented function. Applications can use X509_get0_pubkey(3) and
X509_get0_signature(3) instead.
• X509_http_nbio(), X509_CRL_http_nbio()
Use X509_load_http(3) and X509_CRL_load_http(3) instead.
NID handling for provided keys and algorithms
The following functions for NID (numeric id) handling have changed semantics.
• EVP_PKEY_id(), EVP_PKEY_get_id()
This function was previously used to reliably return the NID of an EVP_PKEY object, e.g., to look up
the name of the algorithm of such EVP_PKEY by calling OBJ_nid2sn(3). With the introduction of
provider(7)s EVP_PKEY_id() or its new equivalent EVP_PKEY_get_id(3) might now also return the value
-1 (EVP_PKEY_KEYMGMT) indicating the use of a provider to implement the EVP_PKEY object. Therefore,
the use of EVP_PKEY_get0_type_name(3) is recommended for retrieving the name of the EVP_PKEY
algorithm.
Using the FIPS Module in applications
See fips_module(7) and OSSL_PROVIDER-FIPS(7) for details.
OpenSSL command line application changes
New applications
openssl kdf uses the new EVP_KDF(3) API. openssl kdf uses the new EVP_MAC(3) API.
Added options
-provider_path and -provider are available to all apps and can be used multiple times to load any
providers, such as the 'legacy' provider or third party providers. If used then the 'default' provider
would also need to be specified if required. The -provider_path must be specified before the -provider
option.
The list app has many new options. See openssl-list(1) for more information.
-crl_lastupdate and -crl_nextupdate used by openssl ca allows explicit setting of fields in the generated
CRL.
Removed options
Interactive mode is not longer available.
The -crypt option used by openssl passwd. The -c option used by openssl x509, openssl dhparam, openssl
dsaparam, and openssl ecparam.
Other Changes
The output of Command line applications may have minor changes. These are primarily changes in
capitalisation and white space. However, in some cases, there are additional differences. For example,
the DH parameters output from openssl dhparam now lists 'P', 'Q', 'G' and 'pcounter' instead of 'prime',
'generator', 'subgroup order' and 'counter' respectively.
The openssl commands that read keys, certificates, and CRLs now automatically detect the PEM or DER
format of the input files so it is not necessary to explicitly specify the input format anymore. However
if the input format option is used the specified format will be required.
openssl speed no longer uses low-level API calls. This implies some of the performance numbers might not
be comparable with the previous releases due to higher overhead. This applies particularly to measuring
performance on smaller data chunks.
b<openssl dhparam>, openssl dsa, openssl gendsa, openssl dsaparam, openssl genrsa and openssl rsa have
been modified to use PKEY APIs. openssl genrsa and openssl rsa now write PKCS #8 keys by default.
Default settings
"SHA256" is now the default digest for TS query used by openssl ts.
Deprecated apps
openssl rsautl is deprecated, use openssl pkeyutl instead. openssl dhparam, openssl dsa, openssl gendsa,
openssl dsaparam, openssl genrsa, openssl rsa, openssl genrsa and openssl rsa are now in maintenance mode
and no new features will be added to them.
TLS Changes
• TLS 1.3 FFDHE key exchange support added
This uses DH safe prime named groups.
• Support for fully "pluggable" TLSv1.3 groups.
This means that providers may supply their own group implementations (using either the "key exchange"
or the "key encapsulation" methods) which will automatically be detected and used by libssl.
• SSL and SSL_CTX options are now 64 bit instead of 32 bit.
The signatures of the functions to get and set options on SSL and SSL_CTX objects changed from
"unsigned long" to "uint64_t" type.
This may require source code changes. For example it is no longer possible to use the SSL_OP_ macro
values in preprocessor "#if" conditions. However it is still possible to test whether these macros
are defined or not.
See SSL_CTX_get_options(3), SSL_CTX_set_options(3), SSL_get_options(3) and SSL_set_options(3).
• SSL_set1_host() and SSL_add1_host() Changes
These functions now take IP literal addresses as well as actual hostnames.
• Added SSL option SSL_OP_CLEANSE_PLAINTEXT
If the option is set, openssl cleanses (zeroizes) plaintext bytes from internal buffers after
delivering them to the application. Note, the application is still responsible for cleansing other
copies (e.g.: data received by SSL_read(3)).
• Client-initiated renegotiation is disabled by default.
To allow it, use the -client_renegotiation option, the SSL_OP_ALLOW_CLIENT_RENEGOTIATION flag, or the
"ClientRenegotiation" config parameter as appropriate.
• Secure renegotiation is now required by default for TLS connections
Support for RFC 5746 secure renegotiation is now required by default for SSL or TLS connections to
succeed. Applications that require the ability to connect to legacy peers will need to explicitly
set SSL_OP_LEGACY_SERVER_CONNECT. Accordingly, SSL_OP_LEGACY_SERVER_CONNECT is no longer set as part
of SSL_OP_ALL.
• Combining the Configure options no-ec and no-dh no longer disables TLSv1.3
Typically if OpenSSL has no EC or DH algorithms then it cannot support connections with TLSv1.3.
However OpenSSL now supports "pluggable" groups through providers. Therefore third party providers
may supply group implementations even where there are no built-in ones. Attempting to create TLS
connections in such a build without also disabling TLSv1.3 at run time or using third party provider
groups may result in handshake failures. TLSv1.3 can be disabled at compile time using the
"no-tls1_3" Configure option.
• SSL_CTX_set_ciphersuites() and SSL_set_ciphersuites() changes.
The methods now ignore unknown ciphers.
• Security callback change.
The security callback, which can be customised by application code, supports the security operation
SSL_SECOP_TMP_DH. This is defined to take an EVP_PKEY in the "other" parameter. In most places this
is what is passed. All these places occur server side. However there was one client side call of this
security operation and it passed a DH object instead. This is incorrect according to the definition
of SSL_SECOP_TMP_DH, and is inconsistent with all of the other locations. Therefore this client side
call has been changed to pass an EVP_PKEY instead.
• New SSL option SSL_OP_IGNORE_UNEXPECTED_EOF
The SSL option SSL_OP_IGNORE_UNEXPECTED_EOF is introduced. If that option is set, an unexpected EOF
is ignored, it pretends a close notify was received instead and so the returned error becomes
SSL_ERROR_ZERO_RETURN.
• The security strength of SHA1 and MD5 based signatures in TLS has been reduced.
This results in SSL 3, TLS 1.0, TLS 1.1 and DTLS 1.0 no longer working at the default security level
of 1 and instead requires security level 0. The security level can be changed either using the cipher
string with @SECLEVEL, or calling SSL_CTX_set_security_level(3). This also means that where the
signature algorithms extension is missing from a ClientHello then the handshake will fail in TLS 1.2
at security level 1. This is because, although this extension is optional, failing to provide one
means that OpenSSL will fallback to a default set of signature algorithms. This default set requires
the availability of SHA1.
• X509 certificates signed using SHA1 are no longer allowed at security level 1 and above.
In TLS/SSL the default security level is 1. It can be set either using the cipher string with
@SECLEVEL, or calling SSL_CTX_set_security_level(3). If the leaf certificate is signed with SHA-1, a
call to SSL_CTX_use_certificate(3) will fail if the security level is not lowered first. Outside
TLS/SSL, the default security level is -1 (effectively 0). It can be set using
X509_VERIFY_PARAM_set_auth_level(3) or using the -auth_level options of the commands.
SEE ALSO
fips_module(7)
HISTORY
The migration guide was created for OpenSSL 3.0.
COPYRIGHT
Copyright 2021-2023 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>.
3.0.13 2025-02-05 MIGRATION_GUIDE(7SSL)