| =pod |
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| =head1 NAME |
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| SMIME_read_CMS - parse S/MIME message. |
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| =head1 SYNOPSIS |
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| #include <openssl/cms.h> |
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| CMS_ContentInfo *SMIME_read_CMS(BIO *in, BIO **bcont); |
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| =head1 DESCRIPTION |
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| SMIME_read_CMS() parses a message in S/MIME format. |
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| B<in> is a BIO to read the message from. |
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| If cleartext signing is used then the content is saved in a memory bio which is |
| written to B<*bcont>, otherwise B<*bcont> is set to NULL. |
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| The parsed CMS_ContentInfo structure is returned or NULL if an |
| error occurred. |
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| =head1 NOTES |
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| If B<*bcont> is not NULL then the message is clear text signed. B<*bcont> can |
| then be passed to CMS_verify() with the B<CMS_DETACHED> flag set. |
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| Otherwise the type of the returned structure can be determined |
| using CMS_get0_type(). |
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| To support future functionality if B<bcont> is not NULL B<*bcont> should be |
| initialized to NULL. For example: |
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| BIO *cont = NULL; |
| CMS_ContentInfo *cms; |
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| cms = SMIME_read_CMS(in, &cont); |
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| =head1 BUGS |
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| The MIME parser used by SMIME_read_CMS() is somewhat primitive. While it will |
| handle most S/MIME messages more complex compound formats may not work. |
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| The parser assumes that the CMS_ContentInfo structure is always base64 encoded |
| and will not handle the case where it is in binary format or uses quoted |
| printable format. |
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| The use of a memory BIO to hold the signed content limits the size of message |
| which can be processed due to memory restraints: a streaming single pass option |
| should be available. |
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| =head1 RETURN VALUES |
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| SMIME_read_CMS() returns a valid B<CMS_ContentInfo> structure or B<NULL> |
| if an error occurred. The error can be obtained from ERR_get_error(3). |
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| =head1 SEE ALSO |
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| L<ERR_get_error(3)|ERR_get_error(3)>, L<CMS_type(3)|CMS_type(3)> |
| L<SMIME_read_CMS(3)|SMIME_read_CMS(3)>, L<CMS_sign(3)|CMS_sign(3)>, |
| L<CMS_verify(3)|CMS_verify(3)>, L<CMS_encrypt(3)|CMS_encrypt(3)> |
| L<CMS_decrypt(3)|CMS_decrypt(3)> |
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| =head1 HISTORY |
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| SMIME_read_CMS() was added to OpenSSL 0.9.8 |
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| =cut |