d2i_ACCESS_DESCRIPTION, d2i_ADMISSIONS, d2i_ADMISSION_SYNTAX, d2i_ASIdOrRange,
d2i_ASIdentifierChoice, d2i_ASIdentifiers, d2i_ASN1_BIT_STRING,
d2i_ASN1_BMPSTRING, d2i_ASN1_ENUMERATED, d2i_ASN1_GENERALIZEDTIME,
d2i_ASN1_GENERALSTRING, d2i_ASN1_IA5STRING, d2i_ASN1_INTEGER, d2i_ASN1_NULL,
d2i_ASN1_OBJECT, d2i_ASN1_OCTET_STRING, d2i_ASN1_PRINTABLE,
d2i_ASN1_PRINTABLESTRING, d2i_ASN1_SEQUENCE_ANY, d2i_ASN1_SET_ANY,
d2i_ASN1_T61STRING, d2i_ASN1_TIME, d2i_ASN1_TYPE, d2i_ASN1_UINTEGER,
d2i_ASN1_UNIVERSALSTRING, d2i_ASN1_UTCTIME, d2i_ASN1_UTF8STRING,
d2i_ASN1_VISIBLESTRING, d2i_ASRange, d2i_AUTHORITY_INFO_ACCESS,
d2i_AUTHORITY_KEYID, d2i_BASIC_CONSTRAINTS, d2i_CERTIFICATEPOLICIES,
d2i_CMS_ContentInfo, d2i_CMS_ReceiptRequest, d2i_CMS_bio, d2i_CRL_DIST_POINTS,
d2i_DHxparams, d2i_DIRECTORYSTRING, d2i_DISPLAYTEXT, d2i_DIST_POINT,
d2i_DIST_POINT_NAME, d2i_DSA_SIG, d2i_ECDSA_SIG, d2i_ECPKParameters,
d2i_EDIPARTYNAME, d2i_ESS_CERT_ID, d2i_ESS_CERT_ID_V2, d2i_ESS_ISSUER_SERIAL,
d2i_ESS_SIGNING_CERT, d2i_ESS_SIGNING_CERT_V2, d2i_EXTENDED_KEY_USAGE,
d2i_GENERAL_NAME, d2i_GENERAL_NAMES, d2i_IPAddressChoice, d2i_IPAddressFamily,
d2i_IPAddressOrRange, d2i_IPAddressRange, d2i_ISSUER_SIGN_TOOL,
d2i_ISSUING_DIST_POINT, d2i_NAMING_AUTHORITY, d2i_NETSCAPE_CERT_SEQUENCE,
d2i_NETSCAPE_SPKAC, d2i_NETSCAPE_SPKI, d2i_NOTICEREF, d2i_OCSP_BASICRESP,
d2i_OCSP_CERTID, d2i_OCSP_CERTSTATUS, d2i_OCSP_CRLID, d2i_OCSP_ONEREQ,
d2i_OCSP_REQINFO, d2i_OCSP_REQUEST, d2i_OCSP_RESPBYTES, d2i_OCSP_RESPDATA,
d2i_OCSP_RESPID, d2i_OCSP_RESPONSE, d2i_OCSP_REVOKEDINFO, d2i_OCSP_SERVICELOC,
d2i_OCSP_SIGNATURE, d2i_OCSP_SINGLERESP, d2i_OSSL_CMP_MSG,
d2i_OSSL_CMP_PKIHEADER, d2i_OSSL_CMP_PKISI, d2i_OSSL_CRMF_CERTID,
d2i_OSSL_CRMF_CERTTEMPLATE, d2i_OSSL_CRMF_ENCRYPTEDVALUE, d2i_OSSL_CRMF_MSG,
d2i_OSSL_CRMF_MSGS, d2i_OSSL_CRMF_PBMPARAMETER,
d2i_OSSL_CRMF_PKIPUBLICATIONINFO, d2i_OSSL_CRMF_SINGLEPUBINFO, d2i_OTHERNAME,
d2i_PBE2PARAM, d2i_PBEPARAM, d2i_PBKDF2PARAM, d2i_PKCS12, d2i_PKCS12_BAGS,
d2i_PKCS12_MAC_DATA, d2i_PKCS12_SAFEBAG, d2i_PKCS12_bio, d2i_PKCS12_fp,
d2i_PKCS7, d2i_PKCS7_DIGEST, d2i_PKCS7_ENCRYPT, d2i_PKCS7_ENC_CONTENT,
d2i_PKCS7_ENVELOPE, d2i_PKCS7_ISSUER_AND_SERIAL, d2i_PKCS7_RECIP_INFO,
d2i_PKCS7_SIGNED, d2i_PKCS7_SIGNER_INFO, d2i_PKCS7_SIGN_ENVELOPE,
d2i_PKCS7_bio, d2i_PKCS7_fp, d2i_PKCS8_PRIV_KEY_INFO,
d2i_PKCS8_PRIV_KEY_INFO_bio, d2i_PKCS8_PRIV_KEY_INFO_fp, d2i_PKCS8_bio,
d2i_PKCS8_fp, d2i_PKEY_USAGE_PERIOD, d2i_POLICYINFO, d2i_POLICYQUALINFO,
d2i_PROFESSION_INFO, d2i_PROXY_CERT_INFO_EXTENSION, d2i_PROXY_POLICY,
d2i_RSA_OAEP_PARAMS, d2i_RSA_PSS_PARAMS, d2i_SCRYPT_PARAMS, d2i_SCT_LIST,
d2i_SXNET, d2i_SXNETID, d2i_TS_ACCURACY, d2i_TS_MSG_IMPRINT,
d2i_TS_MSG_IMPRINT_bio, d2i_TS_MSG_IMPRINT_fp, d2i_TS_REQ, d2i_TS_REQ_bio,
d2i_TS_REQ_fp, d2i_TS_RESP, d2i_TS_RESP_bio, d2i_TS_RESP_fp,
d2i_TS_STATUS_INFO, d2i_TS_TST_INFO, d2i_TS_TST_INFO_bio, d2i_TS_TST_INFO_fp,
d2i_USERNOTICE, d2i_X509, d2i_X509_bio, d2i_X509_fp, d2i_X509_ALGOR,
d2i_X509_ALGORS, d2i_X509_ATTRIBUTE, d2i_X509_CERT_AUX, d2i_X509_CINF,
d2i_X509_CRL, d2i_X509_CRL_INFO, d2i_X509_CRL_bio, d2i_X509_CRL_fp,
d2i_X509_EXTENSION, d2i_X509_EXTENSIONS, d2i_X509_NAME, d2i_X509_NAME_ENTRY,
d2i_X509_PUBKEY, d2i_X509_PUBKEY_bio, d2i_X509_PUBKEY_fp, d2i_X509_REQ,
d2i_X509_REQ_INFO, d2i_X509_REQ_bio, d2i_X509_REQ_fp, d2i_X509_REVOKED,
d2i_X509_SIG, d2i_X509_VAL, i2d_ACCESS_DESCRIPTION, i2d_ADMISSIONS,
i2d_ADMISSION_SYNTAX, i2d_ASIdOrRange, i2d_ASIdentifierChoice,
i2d_ASIdentifiers, i2d_ASN1_BIT_STRING, i2d_ASN1_BMPSTRING,
i2d_ASN1_ENUMERATED, i2d_ASN1_GENERALIZEDTIME, i2d_ASN1_GENERALSTRING,
i2d_ASN1_IA5STRING, i2d_ASN1_INTEGER, i2d_ASN1_NULL, i2d_ASN1_OBJECT,
i2d_ASN1_OCTET_STRING, i2d_ASN1_PRINTABLE, i2d_ASN1_PRINTABLESTRING,
i2d_ASN1_SEQUENCE_ANY, i2d_ASN1_SET_ANY, i2d_ASN1_T61STRING, i2d_ASN1_TIME,
i2d_ASN1_TYPE, i2d_ASN1_UNIVERSALSTRING, i2d_ASN1_UTCTIME,
i2d_ASN1_UTF8STRING, i2d_ASN1_VISIBLESTRING, i2d_ASN1_bio_stream, i2d_ASRange,
i2d_AUTHORITY_INFO_ACCESS, i2d_AUTHORITY_KEYID, i2d_BASIC_CONSTRAINTS,
i2d_CERTIFICATEPOLICIES, i2d_CMS_ContentInfo, i2d_CMS_ReceiptRequest,
i2d_CMS_bio, i2d_CRL_DIST_POINTS, i2d_DHxparams, i2d_DIRECTORYSTRING,
i2d_DISPLAYTEXT, i2d_DIST_POINT, i2d_DIST_POINT_NAME, i2d_DSA_SIG,
i2d_ECDSA_SIG, i2d_ECPKParameters, i2d_EDIPARTYNAME, i2d_ESS_CERT_ID,
i2d_ESS_CERT_ID_V2, i2d_ESS_ISSUER_SERIAL, i2d_ESS_SIGNING_CERT,
i2d_ESS_SIGNING_CERT_V2, i2d_EXTENDED_KEY_USAGE, i2d_GENERAL_NAME,
i2d_GENERAL_NAMES, i2d_IPAddressChoice, i2d_IPAddressFamily,
i2d_IPAddressOrRange, i2d_IPAddressRange, i2d_ISSUER_SIGN_TOOL,
i2d_ISSUING_DIST_POINT, i2d_NAMING_AUTHORITY, i2d_NETSCAPE_CERT_SEQUENCE,
i2d_NETSCAPE_SPKAC, i2d_NETSCAPE_SPKI, i2d_NOTICEREF, i2d_OCSP_BASICRESP,
i2d_OCSP_CERTID, i2d_OCSP_CERTSTATUS, i2d_OCSP_CRLID, i2d_OCSP_ONEREQ,
i2d_OCSP_REQINFO, i2d_OCSP_REQUEST, i2d_OCSP_RESPBYTES, i2d_OCSP_RESPDATA,
i2d_OCSP_RESPID, i2d_OCSP_RESPONSE, i2d_OCSP_REVOKEDINFO, i2d_OCSP_SERVICELOC,
i2d_OCSP_SIGNATURE, i2d_OCSP_SINGLERESP, i2d_OSSL_CMP_MSG,
i2d_OSSL_CMP_PKIHEADER, i2d_OSSL_CMP_PKISI, i2d_OSSL_CRMF_CERTID,
i2d_OSSL_CRMF_CERTTEMPLATE, i2d_OSSL_CRMF_ENCRYPTEDVALUE, i2d_OSSL_CRMF_MSG,
i2d_OSSL_CRMF_MSGS, i2d_OSSL_CRMF_PBMPARAMETER,
i2d_OSSL_CRMF_PKIPUBLICATIONINFO, i2d_OSSL_CRMF_SINGLEPUBINFO, i2d_OTHERNAME,
i2d_PBE2PARAM, i2d_PBEPARAM, i2d_PBKDF2PARAM, i2d_PKCS12, i2d_PKCS12_BAGS,
i2d_PKCS12_MAC_DATA, i2d_PKCS12_SAFEBAG, i2d_PKCS12_bio, i2d_PKCS12_fp,
i2d_PKCS7, i2d_PKCS7_DIGEST, i2d_PKCS7_ENCRYPT, i2d_PKCS7_ENC_CONTENT,
i2d_PKCS7_ENVELOPE, i2d_PKCS7_ISSUER_AND_SERIAL, i2d_PKCS7_NDEF,
i2d_PKCS7_RECIP_INFO, i2d_PKCS7_SIGNED, i2d_PKCS7_SIGNER_INFO,
i2d_PKCS7_SIGN_ENVELOPE, i2d_PKCS7_bio, i2d_PKCS7_fp,
i2d_PKCS8PrivateKeyInfo_bio, i2d_PKCS8PrivateKeyInfo_fp,
i2d_PKCS8_PRIV_KEY_INFO, i2d_PKCS8_PRIV_KEY_INFO_bio,
i2d_PKCS8_PRIV_KEY_INFO_fp, i2d_PKCS8_bio, i2d_PKCS8_fp,
i2d_PKEY_USAGE_PERIOD, i2d_POLICYINFO, i2d_POLICYQUALINFO,
i2d_PROFESSION_INFO, i2d_PROXY_CERT_INFO_EXTENSION, i2d_PROXY_POLICY,
i2d_RSA_OAEP_PARAMS, i2d_RSA_PSS_PARAMS, i2d_SCRYPT_PARAMS, i2d_SCT_LIST,
i2d_SXNET, i2d_SXNETID, i2d_TS_ACCURACY, i2d_TS_MSG_IMPRINT,
i2d_TS_MSG_IMPRINT_bio, i2d_TS_MSG_IMPRINT_fp, i2d_TS_REQ, i2d_TS_REQ_bio,
i2d_TS_REQ_fp, i2d_TS_RESP, i2d_TS_RESP_bio, i2d_TS_RESP_fp,
i2d_TS_STATUS_INFO, i2d_TS_TST_INFO, i2d_TS_TST_INFO_bio, i2d_TS_TST_INFO_fp,
i2d_USERNOTICE, i2d_X509, i2d_X509_bio, i2d_X509_fp, i2d_X509_ALGOR,
i2d_X509_ALGORS, i2d_X509_ATTRIBUTE, i2d_X509_CERT_AUX, i2d_X509_CINF,
i2d_X509_CRL, i2d_X509_CRL_INFO, i2d_X509_CRL_bio, i2d_X509_CRL_fp,
i2d_X509_EXTENSION, i2d_X509_EXTENSIONS, i2d_X509_NAME, i2d_X509_NAME_ENTRY,
i2d_X509_PUBKEY, i2d_X509_PUBKEY_bio, i2d_X509_PUBKEY_fp, i2d_X509_REQ,
i2d_X509_REQ_INFO, i2d_X509_REQ_bio, i2d_X509_REQ_fp, i2d_X509_REVOKED,
i2d_X509_SIG, i2d_X509_VAL, - convert objects from/to ASN.1/DER representation
TYPE *d2i_TYPE(TYPE **a, const unsigned char **ppin, long length);
TYPE *d2i_TYPE_bio(BIO *bp, TYPE **a);
TYPE *d2i_TYPE_fp(FILE *fp, TYPE **a);
int i2d_TYPE(const TYPE *a, unsigned char **ppout);
int i2d_TYPE(TYPE *a, unsigned char **ppout);
int i2d_TYPE_fp(FILE *fp, const TYPE *a);
int i2d_TYPE_fp(FILE *fp, TYPE *a);
int i2d_TYPE_bio(BIO *bp, const TYPE *a);
int i2d_TYPE_bio(BIO *bp, TYPE *a);
In the description here, TYPE is used a placeholder
for any of the OpenSSL datatypes, such as X509_CRL. The function
parameters ppin and ppout are generally either both named
pp in the headers, or in and out.
These functions convert OpenSSL objects to and from their
ASN.1/DER encoding. Unlike the C structures which can have pointers to
sub-objects within, the DER is a serialized encoding, suitable for sending
over the network, writing to a file, and so on.
d2i_TYPE() attempts to decode
len bytes at *ppin. If successful a pointer to the
TYPE structure is returned and *ppin is
incremented to the byte following the parsed data. If a is not NULL
then a pointer to the returned structure is also written to *a. If an
error occurred then NULL is returned.
On a successful return, if *a is not NULL then it is
assumed that *a contains a valid TYPE
structure and an attempt is made to reuse it. For
TYPE structures where it matters it is possible
to set up a library context on the decoded structure this way (see the
EXAMPLES section). However using the "reuse" capability for
other purposes is strongly discouraged (see BUGS below,
and the discussion in the RETURN VALUES section).
d2i_TYPE_bio() is similar to
d2i_ TYPE() except it attempts to parse data
from BIO bp.
d2i_TYPE_fp() is similar to
d2i_ TYPE() except it attempts to parse data
from FILE pointer fp.
i2d_TYPE() encodes the structure
pointed to by a into DER format. If ppout is not NULL, it
writes the DER encoded data to the buffer at *ppout, and increments
it to point after the data just written. If the return value is negative an
error occurred, otherwise it returns the length of the encoded data.
If *ppout is NULL memory will be allocated for a buffer and
the encoded data written to it. In this case *ppout is not
incremented and it points to the start of the data just written.
i2d_TYPE_bio() is similar to
i2d_ TYPE() except it writes the encoding of the
structure a to BIO bp and it returns 1 for success and 0 for
failure.
i2d_TYPE_fp() is similar to
i2d_ TYPE() except it writes the encoding of the
structure a to FILE pointer fp and it returns 1 for success
and 0 for failure.
These routines do not encrypt private keys and therefore offer no
security; use PEM_write_PrivateKey(3) or similar for writing to
files.
The letters i and d in i2d_TYPE()
stand for "internal" (that is, an internal C structure) and
"DER" respectively. So i2d_TYPE()
converts from internal to DER.
The functions can also understand BER forms.
The actual TYPE structure passed to
i2d_TYPE() must be a valid populated
TYPE structure -- it cannot simply be fed
with an empty structure such as that returned by TYPE_new().
The encoded data is in binary form and may contain embedded zeros.
Therefore, any FILE pointers or BIOs should be opened in binary mode.
Functions such as strlen() will not return the correct length
of the encoded structure.
The ways that *ppin and *ppout are incremented after
the operation can trap the unwary. See the WARNINGS section for some
common errors. The reason for this-auto increment behaviour is to reflect a
typical usage of ASN1 functions: after one structure is encoded or decoded
another will be processed after it.
The following points about the data types might be useful:
- ASN1_OBJECT
- Represents an ASN1 OBJECT IDENTIFIER.
- DHparams
- Represents a PKCS#3 DH parameters structure.
- DHxparams
- Represents an ANSI X9.42 DH parameters structure.
- ECDSA_SIG
- Represents an ECDSA signature.
- X509_ALGOR
- Represents an AlgorithmIdentifier structure as used in IETF RFC
6960 and elsewhere.
- X509_NAME
- Represents a Name type as used for subject and issuer names in IETF
RFC 6960 and elsewhere.
- X509_REQ
- Represents a PKCS#10 certificate request.
- X509_SIG
- Represents the DigestInfo structure defined in PKCS#1 and
PKCS#7.
d2i_TYPE(),
d2i_TYPE_bio() and
d2i_TYPE_fp() return a valid
TYPE structure or NULL if an error occurs. If the
"reuse" capability has been used with a valid structure being passed
in via a, then the object is freed in the event of error and *a
is set to NULL.
i2d_TYPE() returns the number of bytes
successfully encoded or a negative value if an error occurs.
i2d_TYPE_bio() and
i2d_TYPE_fp() return 1 for success and 0 if an
error occurs.
Allocate and encode the DER encoding of an X509 structure:
int len;
unsigned char *buf;
buf = NULL;
len = i2d_X509(x, &buf);
if (len < 0)
/* error */
Attempt to decode a buffer:
X509 *x;
unsigned char *buf;
const unsigned char *p;
int len;
/* Set up buf and len to point to the input buffer. */
p = buf;
x = d2i_X509(NULL, &p, len);
if (x == NULL)
/* error */
Alternative technique:
X509 *x;
unsigned char *buf;
const unsigned char *p;
int len;
/* Set up buf and len to point to the input buffer. */
p = buf;
x = NULL;
if (d2i_X509(&x, &p, len) == NULL)
/* error */
Setting up a library context and property query:
X509 *x;
unsigned char *buf;
const unsigned char *p;
int len;
OSSL_LIB_CTX *libctx = ....;
const char *propq = ....;
/* Set up buf and len to point to the input buffer. */
p = buf;
x = X509_new_ex(libctx, propq);
if (d2i_X509(&x, &p, len) == NULL)
/* error, x was freed and NULL assigned to it (see RETURN VALUES) */
Using a temporary variable is mandatory. A common mistake is to attempt to use a
buffer directly as follows:
int len;
unsigned char *buf;
len = i2d_X509(x, NULL);
buf = OPENSSL_malloc(len);
...
i2d_X509(x, &buf);
...
OPENSSL_free(buf);
This code will result in buf apparently containing garbage
because it was incremented after the call to point after the data just
written. Also buf will no longer contain the pointer allocated by
OPENSSL_malloc() and the subsequent call to OPENSSL_free() is
likely to crash.
Another trap to avoid is misuse of the a argument to
d2i_TYPE():
X509 *x;
if (d2i_X509(&x, &p, len) == NULL)
/* error */
This will probably crash somewhere in d2i_X509(). The
reason for this is that the variable x is uninitialized and an
attempt will be made to interpret its (invalid) value as an X509
structure, typically causing a segmentation violation. If x is set to
NULL first then this will not happen.
In some versions of OpenSSL the "reuse" behaviour of
d2i_TYPE() when *a is valid is broken and
some parts of the reused structure may persist if they are not present in the
new one. Additionally, in versions of OpenSSL prior to 1.1.0, when the
"reuse" behaviour is used and an error occurs the behaviour is
inconsistent. Some functions behaved as described here, while some did not
free *a on error and did not set *a to NULL.
As a result of the above issues the "reuse" behaviour is
strongly discouraged.
i2d_TYPE() will not return an error in
many versions of OpenSSL, if mandatory fields are not initialized due to a
programming error then the encoded structure may contain invalid data or
omit the fields entirely and will not be parsed by
d2i_TYPE (). This may be fixed in future so code
should not assume that i2d_TYPE() will always
succeed.
Any function which encodes a structure
(i2d_TYPE (),
i2d_TYPE_bio() or
i2d_TYPE_fp()) may return a stale encoding if
the structure has been modified after deserialization or previous
serialization. This is because some objects cache the encoding for
efficiency reasons.
Copyright 1998-2023 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>.