1SC_ASN1_DECODE(3)            OpenSC API reference            SC_ASN1_DECODE(3)
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NAME

6       sc_asn1_decode - Extract entries from an ASN.1 stream
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SYNOPSIS

9           #include <opensc.h>
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11           int sc_asn1_decode(struct sc_context *ctx, struct sc_asn1_entry *asn1,
12                              const unsigned char *inbuf, size_t len,
13                              const unsigned char **newbuf, size_t *len_left);
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DESCRIPTION

18       This function extracts information from the ASN.1 stream pointed to by
19       inbuf (which is len bytes in size) and stores it into the array of
20       struct sc_asn_1 entries pointed to by asn1. The array must be big
21       enough to contain all the entries that will be found, or an error will
22       be flagged. The last entry in the array must be a NULL entry, i.e. the
23       name field must be set to NULL.
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25       The structure of the expected data must be encoded in the entries in
26       asn1 before calling this function; specifically the name, type, tag and
27       flags fields must be filled in.
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29       The function will then scan the stream and fill in the remaining
30       fields.  newbuf will point to the byte immediately following the
31       extracted record, and len_left will contain the number of bytes left in
32       the buffer. Thus, the newbuf and len_left fields may be passed in to
33       sc_asn1_decode() again, as the inbuf and len parameters, until len
34       reaches 0.
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RETURN VALUE

37       Returns 0 if successful, or a negative value in case of error.
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41opensc                            02/16/2010                 SC_ASN1_DECODE(3)