/usr/man/cat.3/ASN1_generate_nconf.3.Z

NAME

       ASN1_generate_nconf, ASN1_generate_v3 - ASN1 generation functions

SYNOPSIS

        #include <openssl/asn1.h>

        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 config-
       uration information. The general format of the string is:

       [modifier,]type[:value]

       That is zero or more comma separated modifiers followed by a type fol-
       lowed 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 prefaced 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 INTE-
         GER.

       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, BMP-
       STRING, VISIBLESTRING, VISIBLE, PRINTABLESTRING, PRINTABLE, T61,
       T61STRING, TELETEXSTRING, GeneralString, NUMERICSTRING, NUMERIC
         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 for-
         mat. 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 for-
       mat 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 CON-
         TEXT 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 fol-
         lowed 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 con-
       siting 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 con-
       tained in the file client.pem in all OpenSSL distributions (note: the
       field names such as 'coeff' are ignored and are present just for clar-
       ity):

        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

1.0.2t                            2019-09-10            ASN1_generate_nconf(3)
See also ASN1_generate_v3(3)