1PKCS7_SIGN(3ossl) OpenSSL PKCS7_SIGN(3ossl)
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6 PKCS7_sign_ex, PKCS7_sign - create a PKCS#7 signedData structure
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9 #include <openssl/pkcs7.h>
10 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
18 PKCS7_sign_ex() creates and returns a PKCS#7 signedData structure.
19 signcert is the certificate to sign with, pkey is the corresponding
20 private key. certs is an optional set of extra certificates to include
21 in the PKCS#7 structure (for example any intermediate CAs in the
22 chain). The library context libctx and property query propq are used
23 when retrieving algorithms from providers.
24 The data to be signed is read from BIO data.
26 flags is an optional set of flags.
28 Any of the following flags (ored together) can be passed in the flags
30 parameter.
31 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
34 "text/plain" are prepended to the data.
35 If PKCS7_NOCERTS is set the signer's certificate and the extra certs
37 will not be included in the PKCS7 structure. The signer's certificate
38 must still be supplied in the signcert parameter though. This can
39 reduce the size of the signatures if the signer's certificates can be
40 obtained by other means: for example a previously signed message.
41 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.
46 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.
51 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.
58 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.
63 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.
69 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.
73 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.
77 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().
82 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.
85 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.
91 If signcert and pkey are NULL then a certificates only PKCS#7 structure
93 is output.
94 In versions of OpenSSL before 1.0.0 the signcert and pkey parameters
96 must not be NULL.
97 PKCS7_sign() is like PKCS7_sign_ex() except that it uses default values
99 of NULL for the library context libctx and the property query propq.
100 This is retained for API backward compatibility.
101
103 Some advanced attributes such as counter signatures are not supported.
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106 PKCS7_sign_ex() and PKCS7_sign() return either a valid PKCS7 structure
107 or NULL if an error occurred. The error can be obtained from
108 ERR_get_error(3).
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111 ERR_get_error(3), PKCS7_verify(3)
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114 The function PKCS7_sign_ex() was added in OpenSSL 3.0.
115 The PKCS7_PARTIAL flag, and the ability for certs, signcert, and pkey
117 parameters to be NULL were added in OpenSSL 1.0.0.
118 The PKCS7_STREAM flag was added in OpenSSL 1.0.0.
120
122 Copyright 2002-2023 The OpenSSL Project Authors. All Rights Reserved.
123 Licensed under the Apache License 2.0 (the "License"). You may not use
125 this file except in compliance with the License. You can obtain a copy
126 in the file LICENSE in the source distribution or at
127 <https://www.openssl.org/source/license.html>.
1283.0.9 2023-07-27 PKCS7_SIGN(3ossl)