1PKCS7_SIGN(3ossl)                   OpenSSL                  PKCS7_SIGN(3ossl)
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NAME

6       PKCS7_sign_ex, PKCS7_sign - create a PKCS#7 signedData structure
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SYNOPSIS

9        #include <openssl/pkcs7.h>
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11        PKCS7 *PKCS7_sign_ex(X509 *signcert, EVP_PKEY *pkey, STACK_OF(X509) *certs,
12                             BIO *data, int flags, OSSL_LIB_CTX *libctx,
13                             const char *propq);
14        PKCS7 *PKCS7_sign(X509 *signcert, EVP_PKEY *pkey, STACK_OF(X509) *certs,
15                          BIO *data, int flags);
16

DESCRIPTION

18       PKCS7_sign_ex() creates and returns a PKCS#7 signedData structure.
19       igncert is the certificate to sign with, Ipkey> is the corresponding
20       private key. certs is an optional additional set of certificates to
21       include in the PKCS#7 structure (for example any intermediate CAs in
22       the chain). The library context libctx and property query propq are
23       used when retrieving algorithms from providers.
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25       The data to be signed is read from BIO data.
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27       flags is an optional set of flags.
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29       Any of the following flags (ored together) can be passed in the flags
30       parameter.
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32       Many S/MIME clients expect the signed content to include valid MIME
33       headers. If the PKCS7_TEXT flag is set MIME headers for type text/plain
34       are prepended to the data.
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36       If PKCS7_NOCERTS is set the signer's certificate will not be included
37       in the PKCS7 structure, the signer's certificate must still be supplied
38       in the signcert parameter though. This can reduce the size of the
39       signature if the signers certificate can be obtained by other means:
40       for example a previously signed message.
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42       The data being signed is included in the PKCS7 structure, unless
43       PKCS7_DETACHED is set in which case it is omitted. This is used for
44       PKCS7 detached signatures which are used in S/MIME plaintext signed
45       messages for example.
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47       Normally the supplied content is translated into MIME canonical format
48       (as required by the S/MIME specifications) if PKCS7_BINARY is set no
49       translation occurs. This option should be used if the supplied data is
50       in binary format otherwise the translation will corrupt it.
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52       The signedData structure includes several PKCS#7
53       authenticatedAttributes including the signing time, the PKCS#7 content
54       type and the supported list of ciphers in an SMIMECapabilities
55       attribute. If PKCS7_NOATTR is set then no authenticatedAttributes will
56       be used. If PKCS7_NOSMIMECAP is set then just the SMIMECapabilities are
57       omitted.
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59       If present the SMIMECapabilities attribute indicates support for the
60       following algorithms: triple DES, 128 bit RC2, 64 bit RC2, DES and 40
61       bit RC2. If any of these algorithms is disabled then it will not be
62       included.
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64       If the flags PKCS7_STREAM is set then the returned PKCS7 structure is
65       just initialized ready to perform the signing operation. The signing is
66       however not performed and the data to be signed is not read from the
67       data parameter. Signing is deferred until after the data has been
68       written. In this way data can be signed in a single pass.
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70       If the PKCS7_PARTIAL flag is set a partial PKCS7 structure is output to
71       which additional signers and capabilities can be added before
72       finalization.
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74       If the flag PKCS7_STREAM is set the returned PKCS7 structure is not
75       complete and outputting its contents via a function that does not
76       properly finalize the PKCS7 structure will give unpredictable results.
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78       Several functions including SMIME_write_PKCS7(),
79       i2d_PKCS7_bio_stream(), PEM_write_bio_PKCS7_stream() finalize the
80       structure. Alternatively finalization can be performed by obtaining the
81       streaming ASN1 BIO directly using BIO_new_PKCS7().
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83       If a signer is specified it will use the default digest for the signing
84       algorithm. This is SHA1 for both RSA and DSA keys.
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86       The certs, signcert and pkey parameters can all be NULL if the
87       PKCS7_PARTIAL flag is set. One or more signers can be added using the
88       function PKCS7_sign_add_signer(). PKCS7_final() must also be called to
89       finalize the structure if streaming is not enabled. Alternative signing
90       digests can also be specified using this method.
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92       If signcert and pkey are NULL then a certificates only PKCS#7 structure
93       is output.
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95       In versions of OpenSSL before 1.0.0 the signcert and pkey parameters
96       must NOT be NULL.
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98       PKCS7_sign() is similar to PKCS7_sign_ex() but uses default values of
99       NULL for the library context libctx and the property query propq.
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BUGS

102       Some advanced attributes such as counter signatures are not supported.
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RETURN VALUES

105       PKCS7_sign_ex() and PKCS7_sign() return either a valid PKCS7 structure
106       or NULL if an error occurred.  The error can be obtained from
107       ERR_get_error(3).
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SEE ALSO

110       ERR_get_error(3), PKCS7_verify(3)
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HISTORY

113       The function PKCS7_sign_ex() was added in OpenSSL 3.0.
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115       The PKCS7_PARTIAL flag, and the ability for certs, signcert, and pkey
116       parameters to be NULL were added in OpenSSL 1.0.0.
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118       The PKCS7_STREAM flag was added in OpenSSL 1.0.0.
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121       Copyright 2002-2020 The OpenSSL Project Authors. All Rights Reserved.
122
123       Licensed under the Apache License 2.0 (the "License").  You may not use
124       this file except in compliance with the License.  You can obtain a copy
125       in the file LICENSE in the source distribution or at
126       <https://www.openssl.org/source/license.html>.
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1303.0.5                             2022-11-01                 PKCS7_SIGN(3ossl)
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