1ASN1_GENERATE_NCONF(3ossl)          OpenSSL         ASN1_GENERATE_NCONF(3ossl)
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NAME

6       ASN1_generate_nconf, ASN1_generate_v3 - ASN1 string generation
7       functions
8

SYNOPSIS

10        #include <openssl/asn1.h>
11
12        ASN1_TYPE *ASN1_generate_nconf(const char *str, CONF *nconf);
13        ASN1_TYPE *ASN1_generate_v3(const char *str, X509V3_CTX *cnf);
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DESCRIPTION

16       These functions generate the ASN1 encoding of a string in an ASN1_TYPE
17       structure.
18
19       str contains the string to encode. nconf or cnf contains the optional
20       configuration information where additional strings will be read from.
21       nconf will typically come from a config file whereas cnf is obtained
22       from an X509V3_CTX structure, which will typically be used by X509 v3
23       certificate extension functions. cnf or nconf can be set to NULL if no
24       additional configuration will be used.
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GENERATION STRING FORMAT

27       The actual data encoded is determined by the string str and the
28       configuration information. The general format of the string is:
29
30       [modifier,]type[:value]
31
32       That is zero or more comma separated modifiers followed by a type
33       followed by an optional colon and a value. The formats of type, value
34       and modifier are explained below.
35
36   Supported Types
37       The supported types are listed below.  Case is not significant in the
38       type names.  Unless otherwise specified only the ASCII format is
39       permissible.
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41       BOOLEAN, BOOL
42           This encodes a boolean type. The value string is mandatory and
43           should be TRUE or FALSE. Additionally TRUE, true, Y, y, YES, yes,
44           FALSE, false, N, n, NO and no are acceptable.
45
46       NULL
47           Encode the NULL type, the value string must not be present.
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49       INTEGER, INT
50           Encodes an ASN1 INTEGER type. The value string represents the value
51           of the integer, it can be prefaced by a minus sign and is normally
52           interpreted as a decimal value unless the prefix 0x is included.
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54       ENUMERATED, ENUM
55           Encodes the ASN1 ENUMERATED type, it is otherwise identical to
56           INTEGER.
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58       OBJECT, OID
59           Encodes an ASN1 OBJECT IDENTIFIER, the value string can be a short
60           name, a long name or numerical format.
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62       UTCTIME, UTC
63           Encodes an ASN1 UTCTime structure, the value should be in the
64           format YYMMDDHHMMSSZ.
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66       GENERALIZEDTIME, GENTIME
67           Encodes an ASN1 GeneralizedTime structure, the value should be in
68           the format YYYYMMDDHHMMSSZ.
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70       OCTETSTRING, OCT
71           Encodes an ASN1 OCTET STRING. value represents the contents of this
72           structure, the format strings ASCII and HEX can be used to specify
73           the format of value.
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75       BITSTRING, BITSTR
76           Encodes an ASN1 BIT STRING. value represents the contents of this
77           structure, the format strings ASCII, HEX and BITLIST can be used to
78           specify the format of value.
79
80           If the format is anything other than BITLIST the number of unused
81           bits is set to zero.
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83       UNIVERSALSTRING, UNIV, IA5, IA5STRING, UTF8, UTF8String, BMP,
84       BMPSTRING, VISIBLESTRING, VISIBLE, PRINTABLESTRING, PRINTABLE, T61,
85       T61STRING, TELETEXSTRING, GeneralString, NUMERICSTRING, NUMERIC
86           These encode the corresponding string types. value represents the
87           contents of this structure. The format can be ASCII or UTF8.
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89       SEQUENCE, SEQ, SET
90           Formats the result as an ASN1 SEQUENCE or SET type. value should be
91           a section name which will contain the contents. The field names in
92           the section are ignored and the values are in the generated string
93           format. If value is absent then an empty SEQUENCE will be encoded.
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95   Modifiers
96       Modifiers affect the following structure, they can be used to add
97       EXPLICIT or IMPLICIT tagging, add wrappers or to change the string
98       format of the final type and value. The supported formats are
99       documented below.
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101       EXPLICIT, EXP
102           Add an explicit tag to the following structure. This string should
103           be followed by a colon and the tag value to use as a decimal value.
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105           By following the number with U, A, P or C UNIVERSAL, APPLICATION,
106           PRIVATE or CONTEXT SPECIFIC tagging can be used, the default is
107           CONTEXT SPECIFIC.
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109       IMPLICIT, IMP
110           This is the same as EXPLICIT except IMPLICIT tagging is used
111           instead.
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113       OCTWRAP, SEQWRAP, SETWRAP, BITWRAP
114           The following structure is surrounded by an OCTET STRING, a
115           SEQUENCE, a SET or a BIT STRING respectively. For a BIT STRING the
116           number of unused bits is set to zero.
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118       FORMAT
119           This specifies the format of the ultimate value. It should be
120           followed by a colon and one of the strings ASCII, UTF8, HEX or
121           BITLIST.
122
123           If no format specifier is included then ASCII is used. If UTF8 is
124           specified then the value string must be a valid UTF8 string. For
125           HEX the output must be a set of hex digits. BITLIST (which is only
126           valid for a BIT STRING) is a comma separated list of the indices of
127           the set bits, all other bits are zero.
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RETURN VALUES

130       ASN1_generate_nconf() and ASN1_generate_v3() return the encoded data as
131       an ASN1_TYPE structure or NULL if an error occurred.
132
133       The error codes that can be obtained by ERR_get_error(3).
134

EXAMPLES

136       A simple IA5String:
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138        IA5STRING:Hello World
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140       An IA5String explicitly tagged:
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142        EXPLICIT:0,IA5STRING:Hello World
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144       An IA5String explicitly tagged using APPLICATION tagging:
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146        EXPLICIT:0A,IA5STRING:Hello World
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148       A BITSTRING with bits 1 and 5 set and all others zero:
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150        FORMAT:BITLIST,BITSTRING:1,5
151
152       A more complex example using a config file to produce a SEQUENCE
153       consisting of a BOOL an OID and a UTF8String:
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155        asn1 = SEQUENCE:seq_section
156
157        [seq_section]
158
159        field1 = BOOLEAN:TRUE
160        field2 = OID:commonName
161        field3 = UTF8:Third field
162
163       This example produces an RSAPrivateKey structure, this is the key
164       contained in the file client.pem in all OpenSSL distributions (note:
165       the field names such as 'coeff' are ignored and are present just for
166       clarity):
167
168        asn1=SEQUENCE:private_key
169        [private_key]
170        version=INTEGER:0
171
172        n=INTEGER:0xBB6FE79432CC6EA2D8F970675A5A87BFBE1AFF0BE63E879F2AFFB93644\
173        D4D2C6D000430DEC66ABF47829E74B8C5108623A1C0EE8BE217B3AD8D36D5EB4FCA1D9
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175        e=INTEGER:0x010001
176
177        d=INTEGER:0x6F05EAD2F27FFAEC84BEC360C4B928FD5F3A9865D0FCAAD291E2A52F4A\
178        F810DC6373278C006A0ABBA27DC8C63BF97F7E666E27C5284D7D3B1FFFE16B7A87B51D
179
180        p=INTEGER:0xF3929B9435608F8A22C208D86795271D54EBDFB09DDEF539AB083DA912\
181        D4BD57
182
183        q=INTEGER:0xC50016F89DFF2561347ED1186A46E150E28BF2D0F539A1594BBD7FE467\
184        46EC4F
185
186        exp1=INTEGER:0x9E7D4326C924AFC1DEA40B45650134966D6F9DFA3A7F9D698CD4ABEA\
187        9C0A39B9
188
189        exp2=INTEGER:0xBA84003BB95355AFB7C50DF140C60513D0BA51D637272E355E397779\
190        E7B2458F
191
192        coeff=INTEGER:0x30B9E4F2AFA5AC679F920FC83F1F2DF1BAF1779CF989447FABC2F5\
193        628657053A
194
195       This example is the corresponding public key in a SubjectPublicKeyInfo
196       structure:
197
198        # Start with a SEQUENCE
199        asn1=SEQUENCE:pubkeyinfo
200
201        # pubkeyinfo contains an algorithm identifier and the public key wrapped
202        # in a BIT STRING
203        [pubkeyinfo]
204        algorithm=SEQUENCE:rsa_alg
205        pubkey=BITWRAP,SEQUENCE:rsapubkey
206
207        # algorithm ID for RSA is just an OID and a NULL
208        [rsa_alg]
209        algorithm=OID:rsaEncryption
210        parameter=NULL
211
212        # Actual public key: modulus and exponent
213        [rsapubkey]
214        n=INTEGER:0xBB6FE79432CC6EA2D8F970675A5A87BFBE1AFF0BE63E879F2AFFB93644\
215        D4D2C6D000430DEC66ABF47829E74B8C5108623A1C0EE8BE217B3AD8D36D5EB4FCA1D9
216
217        e=INTEGER:0x010001
218

SEE ALSO

220       ERR_get_error(3)
221
223       Copyright 2002-2021 The OpenSSL Project Authors. All Rights Reserved.
224
225       Licensed under the Apache License 2.0 (the "License").  You may not use
226       this file except in compliance with the License.  You can obtain a copy
227       in the file LICENSE in the source distribution or at
228       <https://www.openssl.org/source/license.html>.
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2323.0.9                             2023-07-27        ASN1_GENERATE_NCONF(3ossl)
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