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-rw-r--r--src/lib/libcrypto/doc/PKCS7_encrypt.pod61
1 files changed, 38 insertions, 23 deletions
diff --git a/src/lib/libcrypto/doc/PKCS7_encrypt.pod b/src/lib/libcrypto/doc/PKCS7_encrypt.pod
index 1a507b22a2..2cd925a7e0 100644
--- a/src/lib/libcrypto/doc/PKCS7_encrypt.pod
+++ b/src/lib/libcrypto/doc/PKCS7_encrypt.pod
@@ -6,7 +6,9 @@ PKCS7_encrypt - create a PKCS#7 envelopedData structure
6 6
7=head1 SYNOPSIS 7=head1 SYNOPSIS
8 8
9PKCS7 *PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher, int flags); 9 #include <openssl/pkcs7.h>
10
11 PKCS7 *PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher, int flags);
10 12
11=head1 DESCRIPTION 13=head1 DESCRIPTION
12 14
@@ -16,43 +18,55 @@ B<cipher> is the symmetric cipher to use. B<flags> is an optional set of flags.
16 18
17=head1 NOTES 19=head1 NOTES
18 20
19Only RSA keys are supported in PKCS#7 and envelopedData so the recipient certificates 21Only RSA keys are supported in PKCS#7 and envelopedData so the recipient
20supplied to this function must all contain RSA public keys, though they do not have to 22certificates supplied to this function must all contain RSA public keys, though
21be signed using the RSA algorithm. 23they do not have to be signed using the RSA algorithm.
22 24
23EVP_des_ede3_cbc() (triple DES) is the algorithm of choice for S/MIME use because 25EVP_des_ede3_cbc() (triple DES) is the algorithm of choice for S/MIME use
24most clients will support it. 26because most clients will support it.
25 27
26Some old "export grade" clients may only support weak encryption using 40 or 64 bit 28Some old "export grade" clients may only support weak encryption using 40 or 64
27RC2. These can be used by passing EVP_rc2_40_cbc() and EVP_rc2_64_cbc() respectively. 29bit RC2. These can be used by passing EVP_rc2_40_cbc() and EVP_rc2_64_cbc()
30respectively.
28 31
29The algorithm passed in the B<cipher> parameter must support ASN1 encoding of its 32The algorithm passed in the B<cipher> parameter must support ASN1 encoding of
30parameters. 33its parameters.
31 34
32Many browsers implement a "sign and encrypt" option which is simply an S/MIME 35Many browsers implement a "sign and encrypt" option which is simply an S/MIME
33envelopedData containing an S/MIME signed message. This can be readily produced 36envelopedData containing an S/MIME signed message. This can be readily produced
34by storing the S/MIME signed message in a memory BIO and passing it to 37by storing the S/MIME signed message in a memory BIO and passing it to
35PKCS7_encrypt(). 38PKCS7_encrypt().
36 39
37The following flags can be passed in the B<flags> parameter. 40The following flags can be passed in the B<flags> parameter.
38 41
39If the B<PKCS7_TEXT> flag is set MIME headers for type B<text/plain> are prepended 42If the B<PKCS7_TEXT> flag is set MIME headers for type B<text/plain> are
40to the data. 43prepended to the data.
41 44
42Normally the supplied content is translated into MIME canonical format (as required 45Normally the supplied content is translated into MIME canonical format (as
43by the S/MIME specifications) if B<PKCS7_BINARY> is set no translation occurs. This 46required by the S/MIME specifications) if B<PKCS7_BINARY> is set no translation
44option should be used if the supplied data is in binary format otherwise the translation 47occurs. This option should be used if the supplied data is in binary format
45will corrupt it. If B<PKCS7_BINARY> is set then B<PKCS7_TEXT> is ignored. 48otherwise the translation will corrupt it. If B<PKCS7_BINARY> is set then
49B<PKCS7_TEXT> is ignored.
46 50
47=head1 RETURN VALUES 51If the B<PKCS7_STREAM> flag is set a partial B<PKCS7> structure is output
52suitable for streaming I/O: no data is read from the BIO B<in>.
48 53
49PKCS7_encrypt() returns either a valid PKCS7 structure or NULL if an error occurred. 54=head1 NOTES
50The error can be obtained from ERR_get_error(3).
51 55
52=head1 BUGS 56If the flag B<PKCS7_STREAM> is set the returned B<PKCS7> structure is B<not>
57complete and outputting its contents via a function that does not
58properly finalize the B<PKCS7> structure will give unpredictable
59results.
53 60
54The lack of single pass processing and need to hold all data in memory as 61Several functions including SMIME_write_PKCS7(), i2d_PKCS7_bio_stream(),
55mentioned in PKCS7_sign() also applies to PKCS7_verify(). 62PEM_write_bio_PKCS7_stream() finalize the structure. Alternatively finalization
63can be performed by obtaining the streaming ASN1 B<BIO> directly using
64BIO_new_PKCS7().
65
66=head1 RETURN VALUES
67
68PKCS7_encrypt() returns either a PKCS7 structure or NULL if an error occurred.
69The error can be obtained from ERR_get_error(3).
56 70
57=head1 SEE ALSO 71=head1 SEE ALSO
58 72
@@ -61,5 +75,6 @@ L<ERR_get_error(3)|ERR_get_error(3)>, L<PKCS7_decrypt(3)|PKCS7_decrypt(3)>
61=head1 HISTORY 75=head1 HISTORY
62 76
63PKCS7_decrypt() was added to OpenSSL 0.9.5 77PKCS7_decrypt() was added to OpenSSL 0.9.5
78The B<PKCS7_STREAM> flag was first supported in OpenSSL 1.0.0.
64 79
65=cut 80=cut