1ASN1_generate_nconf(3)              OpenSSL             ASN1_generate_nconf(3)
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NAME

6       ASN1_generate_nconf, ASN1_generate_v3 - ASN1 generation functions
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SYNOPSIS

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

DESCRIPTION

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

GENERATION STRING FORMAT

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

EXAMPLES

127       A simple IA5String:
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129        IA5STRING:Hello World
130
131       An IA5String explicitly tagged:
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133        EXPLICIT:0,IA5STRING:Hello World
134
135       An IA5String explicitly tagged using APPLICATION tagging:
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137        EXPLICIT:0A,IA5STRING:Hello World
138
139       A BITSTRING with bits 1 and 5 set and all others zero:
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141        FORMAT:BITLIST,BITSTRING:1,5
142
143       A more complex example using a config file to produce a SEQUENCE
144       consiting of a BOOL an OID and a UTF8String:
145
146        asn1 = SEQUENCE:seq_section
147
148        [seq_section]
149
150        field1 = BOOLEAN:TRUE
151        field2 = OID:commonName
152        field3 = UTF8:Third field
153
154       This example produces an RSAPrivateKey structure, this is the key
155       contained in the file client.pem in all OpenSSL distributions (note:
156       the field names such as 'coeff' are ignored and are present just for
157       clarity):
158
159        asn1=SEQUENCE:private_key
160        [private_key]
161        version=INTEGER:0
162
163        n=INTEGER:0xBB6FE79432CC6EA2D8F970675A5A87BFBE1AFF0BE63E879F2AFFB93644\
164        D4D2C6D000430DEC66ABF47829E74B8C5108623A1C0EE8BE217B3AD8D36D5EB4FCA1D9
165
166        e=INTEGER:0x010001
167
168        d=INTEGER:0x6F05EAD2F27FFAEC84BEC360C4B928FD5F3A9865D0FCAAD291E2A52F4A\
169        F810DC6373278C006A0ABBA27DC8C63BF97F7E666E27C5284D7D3B1FFFE16B7A87B51D
170
171        p=INTEGER:0xF3929B9435608F8A22C208D86795271D54EBDFB09DDEF539AB083DA912\
172        D4BD57
173
174        q=INTEGER:0xC50016F89DFF2561347ED1186A46E150E28BF2D0F539A1594BBD7FE467\
175        46EC4F
176
177        exp1=INTEGER:0x9E7D4326C924AFC1DEA40B45650134966D6F9DFA3A7F9D698CD4ABEA\
178        9C0A39B9
179
180        exp2=INTEGER:0xBA84003BB95355AFB7C50DF140C60513D0BA51D637272E355E397779\
181        E7B2458F
182
183        coeff=INTEGER:0x30B9E4F2AFA5AC679F920FC83F1F2DF1BAF1779CF989447FABC2F5\
184        628657053A
185
186       This example is the corresponding public key in a SubjectPublicKeyInfo
187       structure:
188
189        # Start with a SEQUENCE
190        asn1=SEQUENCE:pubkeyinfo
191
192        # pubkeyinfo contains an algorithm identifier and the public key wrapped
193        # in a BIT STRING
194        [pubkeyinfo]
195        algorithm=SEQUENCE:rsa_alg
196        pubkey=BITWRAP,SEQUENCE:rsapubkey
197
198        # algorithm ID for RSA is just an OID and a NULL
199        [rsa_alg]
200        algorithm=OID:rsaEncryption
201        parameter=NULL
202
203        # Actual public key: modulus and exponent
204        [rsapubkey]
205        n=INTEGER:0xBB6FE79432CC6EA2D8F970675A5A87BFBE1AFF0BE63E879F2AFFB93644\
206        D4D2C6D000430DEC66ABF47829E74B8C5108623A1C0EE8BE217B3AD8D36D5EB4FCA1D9
207
208        e=INTEGER:0x010001
209

RETURN VALUES

211       ASN1_generate_nconf() and ASN1_generate_v3() return the encoded data as
212       an ASN1_TYPE structure or NULL if an error occurred.
213
214       The error codes that can be obtained by ERR_get_error(3).
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SEE ALSO

217       ERR_get_error(3)
218

HISTORY

220       ASN1_generate_nconf() and ASN1_generate_v3() were added to OpenSSL
221       0.9.8
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2251.0.2o                            2019-09-10            ASN1_generate_nconf(3)
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