PKCS7_get_octet_string - return octet string from a PKCS#7 envelopedData structure

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       Licensed under the Apache License 2.0 (the "License").  You may not use this file except in compliance
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3.5.0                                              2025-06-04                       PKCS7_GET_OCTET_STRING(3SSL)

PKCS7_get_octet_string() returns a pointer to an ASN1 octet string from a PKCS#7 envelopedData structure
       or NULL if the structure cannot be parsed.

       PKCS7_get_octet_string - return octet string from a PKCS#7 envelopedData structure

       As the 0 implies, PKCS7_get_octet_string() returns internal pointers which should not be freed by the
       caller.

PKCS7_get_octet_string() returns an ASN1_OCTET_STRING pointer.

PKCS7_type_is_data(3)

        #include <openssl/pkcs7.h>

        ASN1_OCTET_STRING *PKCS7_get_octet_string(PKCS7 *p7);