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ASN1_generate_nconf(3)                             OpenSSL                            ASN1_generate_nconf(3)



NAME
       ASN1_generate_nconf, ASN1_generate_v3 - ASN1 generation functions

SYNOPSIS
        ASN1_TYPE *ASN1_generate_nconf(char *str, CONF *nconf);
        ASN1_TYPE *ASN1_generate_v3(char *str, X509V3_CTX *cnf);

DESCRIPTION
       These functions generate the ASN1 encoding of a string in an ASN1_TYPE structure.

       str contains the string to encode nconf or cnf contains the optional configuration information where
       additional strings will be read from. nconf will typically come from a config file wherease cnf is
       obtained from an X509V3_CTX structure which will typically be used by X509 v3 certificate extension
       functions. cnf or nconf can be set to NULL if no additional configuration will be used.

GENERATION STRING FORMAT
       The actual data encoded is determined by the string str and the configuration information. The
       general format of the string is:

       [modifier,]type[:value]

       That is zero or more comma separated modifiers followed by a type followed by an optional colon and a
       value. The formats of type, value and modifier are explained below.

       SUPPORTED TYPES

       The supported types are listed below. Unless otherwise specified only the ASCII format is
       permissible.

       BOOLEAN, BOOL
         This encodes a boolean type. The value string is mandatory and should be TRUE or FALSE.
         Additionally TRUE, true, Y, y, YES, yes, FALSE, false, N, n, NO and no are acceptable.

       NULL
         Encode the NULL type, the value string must not be present.

       INTEGER, INT
         Encodes an ASN1 INTEGER type. The value string represents the value of the integer, it can be
         preceeded by a minus sign and is normally interpreted as a decimal value unless the prefix 0x is
         included.

       ENUMERATED, ENUM
         Encodes the ASN1 ENUMERATED type, it is otherwise identical to INTEGER.

       OBJECT, OID
         Encodes an ASN1 OBJECT IDENTIFIER, the value string can be a short name, a long name or numerical
         format.

       UTCTIME, UTC
         Encodes an ASN1 UTCTime structure, the value should be in the format YYMMDDHHMMSSZ.

       GENERALIZEDTIME, GENTIME
         Encodes an ASN1 GeneralizedTime structure, the value should be in the format YYYYMMDDHHMMSSZ.

       OCTETSTRING, OCT
         Encodes an ASN1 OCTET STRING. value represents the contents of this structure, the format strings
         ASCII and HEX can be used to specify the format of value.

       BITSTRING, BITSTR
         Encodes an ASN1 BIT STRING. value represents the contents of this structure, the format strings
         ASCII, HEX and BITLIST can be used to specify the format of value.

         If the format is anything other than BITLIST the number of unused bits is set to zero.

       UNIVERSALSTRING, UNIV, IA5, IA5STRING, UTF8, UTF8String, BMP, BMPSTRING, VISIBLESTRING, VISIBLE,
       PRINTABLESTRING, PRINTABLE, T61, T61STRING, TELETEXSTRING, GeneralString
         These encode the corresponding string types. value represents the contents of this structure. The
         format can be ASCII or UTF8.

       SEQUENCE, SEQ, SET
         Formats the result as an ASN1 SEQUENCE or SET type. value should be a section name which will
         contain the contents. The field names in the section are ignored and the values are in the
         generated string format. If value is absent then an empty SEQUENCE will be encoded.

       MODIFIERS

       Modifiers affect the following structure, they can be used to add EXPLICIT or IMPLICIT tagging, add
       wrappers or to change the string format of the final type and value. The supported formats are
       documented below.

       EXPLICIT, EXP
         Add an explicit tag to the following structure. This string should be followed by a colon and the
         tag value to use as a decimal value.

         By following the number with U, A, P or C UNIVERSAL, APPLICATION, PRIVATE or CONTEXT SPECIFIC
         tagging can be used, the default is CONTEXT SPECIFIC.

       IMPLICIT, IMP
         This is the same as EXPLICIT except IMPLICIT tagging is used instead.

       OCTWRAP, SEQWRAP, SETWRAP, BITWRAP
         The following structure is surrounded by an OCTET STRING, a SEQUENCE, a SET or a BIT STRING
         respectively. For a BIT STRING the number of unused bits is set to zero.

       FORMAT
         This specifies the format of the ultimate value. It should be followed by a colon and one of the
         strings ASCII, UTF8, HEX or BITLIST.

         If no format specifier is included then ASCII is used. If UTF8 is specified then the value string
         must be a valid UTF8 string. For HEX the output must be a set of hex digits. BITLIST (which is only
         valid for a BIT STRING) is a comma separated list of the indices of the set bits, all other bits
         are zero.

EXAMPLES
       A simple IA5String:

        IA5STRING:Hello World

       An IA5String explicitly tagged:

        EXPLICIT:0,IA5STRING:Hello World

       An IA5String explicitly tagged using APPLICATION tagging:

        EXPLICIT:0A,IA5STRING:Hello World

       A BITSTRING with bits 1 and 5 set and all others zero:

        FORMAT=BITLIST,BITSTRING:1,5

       A more complex example using a config file to produce a SEQUENCE consiting of a BOOL an OID and a
       UTF8String:

        asn1 = SEQUENCE:seq_section

        [seq_section]

        field1 = BOOLEAN:TRUE
        field2 = OID:commonName
        field3 = UTF8:Third field

       This example produces an RSAPrivateKey structure, this is the key contained in the file client.pem in
       all OpenSSL distributions (note: the field names such as 'coeff' are ignored and are present just for
       clarity):

        asn1=SEQUENCE:private_key
        [private_key]
        version=INTEGER:0

        n=INTEGER:0xBB6FE79432CC6EA2D8F970675A5A87BFBE1AFF0BE63E879F2AFFB93644\
        D4D2C6D000430DEC66ABF47829E74B8C5108623A1C0EE8BE217B3AD8D36D5EB4FCA1D9

        e=INTEGER:0x010001

        d=INTEGER:0x6F05EAD2F27FFAEC84BEC360C4B928FD5F3A9865D0FCAAD291E2A52F4A\
        F810DC6373278C006A0ABBA27DC8C63BF97F7E666E27C5284D7D3B1FFFE16B7A87B51D

        p=INTEGER:0xF3929B9435608F8A22C208D86795271D54EBDFB09DDEF539AB083DA912\
        D4BD57

        q=INTEGER:0xC50016F89DFF2561347ED1186A46E150E28BF2D0F539A1594BBD7FE467\
        46EC4F

        exp1=INTEGER:0x9E7D4326C924AFC1DEA40B45650134966D6F9DFA3A7F9D698CD4ABEA\
        9C0A39B9

        exp2=INTEGER:0xBA84003BB95355AFB7C50DF140C60513D0BA51D637272E355E397779\
        E7B2458F

        coeff=INTEGER:0x30B9E4F2AFA5AC679F920FC83F1F2DF1BAF1779CF989447FABC2F5\
        628657053A

       This example is the corresponding public key in a SubjectPublicKeyInfo structure:

        # Start with a SEQUENCE
        asn1=SEQUENCE:pubkeyinfo

        # pubkeyinfo contains an algorithm identifier and the public key wrapped
        # in a BIT STRING
        [pubkeyinfo]
        algorithm=SEQUENCE:rsa_alg
        pubkey=BITWRAP,SEQUENCE:rsapubkey

        # algorithm ID for RSA is just an OID and a NULL
        [rsa_alg]
        algorithm=OID:rsaEncryption
        parameter=NULL

        # Actual public key: modulus and exponent
        [rsapubkey]
        n=INTEGER:0xBB6FE79432CC6EA2D8F970675A5A87BFBE1AFF0BE63E879F2AFFB93644\
        D4D2C6D000430DEC66ABF47829E74B8C5108623A1C0EE8BE217B3AD8D36D5EB4FCA1D9

        e=INTEGER:0x010001

RETURN VALUES
       ASN1_generate_nconf() and ASN1_generate_v3() return the encoded data as an ASN1_TYPE structure or
       NULL if an error occurred.

       The error codes that can be obtained by ERR_get_error(3).

SEE ALSO
       ERR_get_error(3)

HISTORY
       ASN1_generate_nconf() and ASN1_generate_v3() were added to OpenSSL 0.9.8



0.9.8                                            2009-04-03                           ASN1_generate_nconf(3)