.\" $OpenBSD: d2i_PrivateKey.3,v 1.11 2024/10/24 21:42:10 tb Exp $ .\" full merge up to: OpenSSL b0edda11 Mar 20 13:00:17 2018 +0000 .\" .\" This file is a derived work. .\" The changes are covered by the following Copyright and license: .\" .\" Copyright (c) 2016, 2021 Ingo Schwarze .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. 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IN NO EVENT SHALL THE OpenSSL PROJECT OR .\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED .\" OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: October 24 2024 $ .Dt D2I_PRIVATEKEY 3 .Os .Sh NAME .Nm d2i_PrivateKey , .Nm d2i_AutoPrivateKey , .Nm d2i_PrivateKey_bio , .Nm d2i_PrivateKey_fp , .Nm i2d_PrivateKey , .Nm i2d_PrivateKey_bio , .Nm i2d_PrivateKey_fp , .Nm i2d_PKCS8PrivateKeyInfo_bio , .Nm i2d_PKCS8PrivateKeyInfo_fp , .Nm d2i_PublicKey , .Nm i2d_PublicKey .Nd decode and encode EVP_PKEY objects .Sh SYNOPSIS .In openssl/evp.h .Ft EVP_PKEY * .Fo d2i_PrivateKey .Fa "int type" .Fa "EVP_PKEY **val_out" .Fa "const unsigned char **der_in" .Fa "long length" .Fc .Ft EVP_PKEY * .Fo d2i_AutoPrivateKey .Fa "EVP_PKEY **val_out" .Fa "const unsigned char **der_in" .Fa "long length" .Fc .Ft EVP_PKEY * .Fo d2i_PrivateKey_bio .Fa "BIO *in_bio" .Fa "EVP_PKEY **val_out" .Fc .Ft EVP_PKEY * .Fo d2i_PrivateKey_fp .Fa "FILE *in_fp" .Fa "EVP_PKEY **val_out" .Fc .Ft int .Fo i2d_PrivateKey .Fa "EVP_PKEY *val_in" .Fa "unsigned char **der_out" .Fc .Ft int .Fo i2d_PrivateKey_bio .Fa "BIO *out_bio" .Fa "EVP_PKEY *val_in" .Fc .Ft int .Fo i2d_PrivateKey_fp .Fa "FILE *out_fp" .Fa "EVP_PKEY *val_in" .Fc .Ft int .Fo i2d_PKCS8PrivateKeyInfo_bio .Fa "BIO *out_bio" .Fa "EVP_PKEY *val_in" .Fc .Ft int .Fo i2d_PKCS8PrivateKeyInfo_fp .Fa "FILE *out_fp" .Fa "EVP_PKEY *val_in" .Fc .Ft EVP_PKEY * .Fo d2i_PublicKey .Fa "int type" .Fa "EVP_PKEY **val_out" .Fa "const unsigned char **der_in" .Fa "long length" .Fc .Ft int .Fo i2d_PublicKey .Fa "EVP_PKEY *val_in" .Fa "unsigned char **der_out" .Fc .Sh DESCRIPTION These are algorithm-independent interfaces to decode and encode private and public keys. For details about the semantics, examples, caveats, and bugs, see .Xr ASN1_item_d2i 3 . .Pp .Fn d2i_PrivateKey decodes a private key using algorithm .Fa type . It attempts to use any algorithm specific format or the PKCS#8 unencrypted .Vt PrivateKeyInfo format defined in RFC 5208 section 5. The .Fa type parameter should be a public key algorithm constant such as .Dv EVP_PKEY_RSA . An error occurs if the decoded key does not match .Fa type . .Pp .Fn d2i_AutoPrivateKey is similar to .Fn d2i_PrivateKey except that it attempts to automatically detect the algorithm. .Pp .Fn d2i_PrivateKey_bio and .Fn d2i_PrivateKey_fp are similar to .Fn d2i_PrivateKey except that they read from a .Vt BIO or .Vt FILE pointer. .Pp .Fn i2d_PrivateKey encodes .Fa val_in . It uses an algorithm specific format or, if none is defined for that key type, the PKCS#8 unencrypted .Vt PrivateKeyInfo format. .Pp .Fn i2d_PrivateKey_bio and .Fn i2d_PrivateKey_fp are similar to .Fn i2d_PrivateKey except that they write to a .Vt BIO or .Vt FILE pointer and use a different convention for their return values. .Pp .Fn i2d_PKCS8PrivateKeyInfo_bio and .Fn i2d_PKCS8PrivateKeyInfo_fp encode .Fa val_in in PKCS#8 unencrypted .Vt PrivateKeyInfo format. They are similar to .Fn i2d_PrivateKey except that they don't use any algorithm-specific formats and that they write to a .Vt BIO or .Vt FILE pointer rather than to a buffer. .Pp All these functions use DER format and unencrypted keys. Applications wishing to encrypt or decrypt private keys should use other functions such as .Xr d2i_PKCS8PrivateKey_bio 3 instead. .Pp If .Pf * Fa val_out is not .Dv NULL when calling .Fn d2i_PrivateKey or .Fn d2i_AutoPrivateKey (i.e. an existing structure is being reused) and the key format is PKCS#8, then .Pf * Fa val_out will be freed and replaced on a successful call. .Pp .Fn d2i_PublicKey calls .Xr d2i_DSAPublicKey 3 , .Xr o2i_ECPublicKey 3 , or .Xr d2i_RSAPublicKey 3 depending on .Fa type and stores the result in the returned .Vt EVP_PKEY object. .Pp .Fn i2d_PublicKey calls .Xr i2d_DSAPublicKey 3 , .Xr i2o_ECPublicKey 3 , or .Xr i2d_RSAPublicKey 3 depending on the algorithm used by .Fa val_in . .Sh RETURN VALUES .Fn d2i_PrivateKey , .Fn d2i_AutoPrivateKey , .Fn d2i_PrivateKey_bio , .Fn d2i_PrivateKey_fp , and .Fn d2i_PublicKey return a valid .Vt EVP_PKEY structure or .Dv NULL if an error occurs. .Pp .Fn i2d_PrivateKey and .Fn i2d_PublicKey return the number of bytes successfully encoded or a negative value if an error occurs. .Pp .Fn i2d_PrivateKey_bio , .Fn i2d_PrivateKey_fp , .Fn i2d_PKCS8PrivateKeyInfo_bio , and .Fn i2d_PKCS8PrivateKeyInfo_fp return 1 for success or 0 if an error occurs. .Pp For all functions, the error code can be obtained by calling .Xr ERR_get_error 3 . .Sh SEE ALSO .Xr d2i_PKCS8_PRIV_KEY_INFO 3 , .Xr d2i_PKCS8PrivateKey_bio 3 , .Xr EVP_PKEY_new 3 , .Xr EVP_PKEY_type 3 , .Xr PEM_write_PrivateKey 3 , .Xr PKCS8_PRIV_KEY_INFO_new 3 .Sh STANDARDS RFC 5208: Public-Key Cryptography Standards (PKCS) #8: Private-Key Information Syntax Specification .Sh HISTORY .Fn d2i_PrivateKey , .Fn i2d_PrivateKey , .Fn d2i_PublicKey , and .Fn i2d_PublicKey first appeared in SSLeay 0.6.0 and have been available since .Ox 2.4 . .Pp .Fn d2i_AutoPrivateKey , .Fn d2i_PrivateKey_bio , .Fn d2i_PrivateKey_fp , .Fn i2d_PrivateKey_bio , .Fn i2d_PrivateKey_fp , .Fn i2d_PKCS8PrivateKeyInfo_bio , and .Fn i2d_PKCS8PrivateKeyInfo_fp first appeared in OpenSSL 0.9.5 and have been available since .Ox 2.7 .