fb cryptograher asn1
https://cryptologie.net/
https://cryptologie.net/article/262/what-are-x509-certificates-rfc-asn1-der/
https://cryptologie.net/article/497/eddsa-ed25519-ed25519-ietf-ed25519ph-ed25519ctx-hasheddsa-pureeddsa-wtf/#:~:text=RFC%208032%3A%20Edwards-Curve%20Digital%20Signature%20Algorithm%20%28EdDSA%29%20RFC,valid%20signature%20from%20an%20existing%20signature%20of%20yours.
http://www.gmbz.org.cn/main/bzlb.html
type A struct {
X *big.Int
Y *big.Int
}
func main() {
a := &A{
new(big.Int).SetInt64(255 << 8),
new(big.Int).SetInt64(127),
}
b := new(A)
data ,err := asn1.Marshal(*a);
if err != nil{
panic(err)
}
rest, rerr := asn1.Unmarshal(data, b);
if rerr != nil{
panic(rerr)
}
fmt.Println(rest)
}
https://docs.w3cub.com/go/encoding/asn1/
const (
TagBoolean = 1
TagInteger = 2
TagBitString = 3
TagOctetString = 4
TagNull = 5
TagOID = 6
TagEnum = 10
TagUTF8String = 12
TagSequence = 16
TagSet = 17
TagNumericString = 18
TagPrintableString = 19
TagT61String = 20
TagIA5String = 22
TagUTCTime = 23
TagGeneralizedTime = 24
TagGeneralString = 27
)
ASN.1 class types represent the namespace of the tag.
const (
ClassUniversal = 0
ClassApplication = 1
ClassContextSpecific = 2
ClassPrivate = 3
)
struct ASN1_TEMPLATE_st {
unsigned long flags; /* Various flags */
long tag; /* tag, not used if no tagging */
unsigned long offset; /* Offset of this field in structure */
const char *field_name; /* Field name */
ASN1_ITEM_EXP *item; /* Relevant ASN1_ITEM or ASN1_ADB */
};
/* This is the actual ASN1 item itself */
struct ASN1_ITEM_st { //ASN1_ITEM
char itype; /* The item type, primitive, SEQUENCE, CHOICE
* or extern */
long utype; /* underlying type */
const ASN1_TEMPLATE *templates; /* If SEQUENCE or CHOICE this contains
* the contents */
long tcount; /* Number of templates if SEQUENCE or CHOICE */
const void *funcs; /* functions that handle this type */
long size; /* Structure size (usually) */
const char *sname; /* Structure name */
};
{
ASN1_ITYPE_SEQUENCE,\
V_ASN1_SEQUENCE,\
tname##_seq_tt,\
sizeof(tname##_seq_tt) / sizeof(ASN1_TEMPLATE),\
NULL,\
sizeof(stname),\
#stname
}
struct asn1_string_st {
int length;
int type;
unsigned char *data;
/*
* The value of the following field depends on the type being held. It
* is mostly being used for BIT_STRING so if the input data has a
* non-zero 'unused bits' value, it will be handled correctly
*/
long flags;
};
typedef struct asn1_string_st ASN1_INTEGER;
typedef struct asn1_string_st ASN1_ENUMERATED;
typedef struct asn1_string_st ASN1_BIT_STRING;
typedef struct asn1_string_st ASN1_OFCTET_STRING;
typedef struct asn1_string_st ASN1_PRINTABLESTRING;
typedef struct asn1_string_st ASN1_T61STRING;
typedef struct asn1_string_st ASN1_IA5STRING;
typedef struct asn1_string_st ASN1_GENERALSTRING;
typedef struct asn1_string_st ASN1_UNIVERSALSTRING;
typedef struct asn1_string_st ASN1_BMPSTRING;
typedef struct asn1_string_st ASN1_UTCTIME;
typedef struct asn1_string_st ASN1_TIME;
typedef struct asn1_string_st ASN1_GENERALIZEDTIME;
typedef struct asn1_string_st ASN1_VISIBLESTRING;
typedef struct asn1_string_st ASN1_UTF8STRING;
typedef struct asn1_string_st ASN1_STRING;
typedef int ASN1_BOOLEAN;
typedef int ASN1_NULL;
struct ASN1_ADB_st {
unsigned long flags; /* Various flags */
unsigned long offset; /* Offset of selector field */
int (*adb_cb)(long *psel); /* Application callback */
const ASN1_ADB_TABLE *tbl; /* Table of possible types */
long tblcount; /* Number of entries in tbl */
const ASN1_TEMPLATE *default_tt; /* Type to use if no match */
const ASN1_TEMPLATE *null_tt; /* Type to use if selector is NULL */
};
struct ASN1_ADB_TABLE_st {
long value; /* NID for an object or value for an int */
const ASN1_TEMPLATE tt; /* item for this value */
};
# define V_ASN1_UNIVERSAL 0x00
# define V_ASN1_APPLICATION 0x40
# define V_ASN1_CONTEXT_SPECIFIC 0x80
# define V_ASN1_PRIVATE 0xc0
# define V_ASN1_CONSTRUCTED 0x20
# define V_ASN1_PRIMITIVE_TAG 0x1f
# define V_ASN1_PRIMATIVE_TAG 0x1f
# define V_ASN1_APP_CHOOSE -2/* let the recipient choose */
# define V_ASN1_OTHER -3/* used in ASN1_TYPE */
# define V_ASN1_ANY -4/* used in ASN1 template code */
# define V_ASN1_UNDEF -1
/* ASN.1 tag values */
# define V_ASN1_EOC 0
# define V_ASN1_BOOLEAN 1 /**/
# define V_ASN1_INTEGER 2
# define V_ASN1_BIT_STRING 3
# define V_ASN1_OCTET_STRING 4
# define V_ASN1_NULL 5
# define V_ASN1_OBJECT 6
# define V_ASN1_OBJECT_DESCRIPTOR 7
# define V_ASN1_EXTERNAL 8
# define V_ASN1_REAL 9
# define V_ASN1_ENUMERATED 10
# define V_ASN1_UTF8STRING 12
# define V_ASN1_SEQUENCE 16
# define V_ASN1_SET 17
# define V_ASN1_NUMERICSTRING 18 /**/
# define V_ASN1_PRINTABLESTRING 19
# define V_ASN1_T61STRING 20
# define V_ASN1_TELETEXSTRING 20/* alias */
# define V_ASN1_VIDEOTEXSTRING 21 /**/
# define V_ASN1_IA5STRING 22
# define V_ASN1_UTCTIME 23
# define V_ASN1_GENERALIZEDTIME 24 /**/
# define V_ASN1_GRAPHICSTRING 25 /**/
# define V_ASN1_ISO64STRING 26 /**/
# define V_ASN1_VISIBLESTRING 26/* alias */
# define V_ASN1_GENERALSTRING 27 /**/
# define V_ASN1_UNIVERSALSTRING 28 /**/
# define V_ASN1_BMPSTRING 30
/*
* NB the constants below are used internally by ASN1_INTEGER
* and ASN1_ENUMERATED to indicate the sign. They are *not* on
* the wire tag values.
*/
# define V_ASN1_NEG 0x100
# define V_ASN1_NEG_INTEGER (2 | V_ASN1_NEG)
# define V_ASN1_NEG_ENUMERATED (10 | V_ASN1_NEG)
//see go
func getUniversalType(t reflect.Type) (matchAny bool, tagNumber int, isCompound, ok bool) {
switch t {
case rawValueType:
return true, -1, false, true
case objectIdentifierType:
return false, TagOID, false, true
case bitStringType:
return false, TagBitString, false, true
case timeType:
return false, TagUTCTime, false, true
case enumeratedType:
return false, TagEnum, false, true
case bigIntType:
return false, TagInteger, false, true
}
switch t.Kind() {
case reflect.Bool:
return false, TagBoolean, false, true
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return false, TagInteger, false, true
case reflect.Struct:
return false, TagSequence, true, true
case reflect.Slice:
if t.Elem().Kind() == reflect.Uint8 {
return false, TagOctetString, false, true
}
if strings.HasSuffix(t.Name(), "SET") {
return false, TagSet, true, true
}
return false, TagSequence, true, true
case reflect.String:
return false, TagPrintableString, false, true
}
return false, 0, false, false
}
// ASN.1 tags represent the type of the following object.
const (
TagBoolean = 1
TagInteger = 2
TagBitString = 3
TagOctetString = 4
TagNull = 5
TagOID = 6
TagEnum = 10
TagUTF8String = 12
TagSequence = 16
TagSet = 17
TagNumericString = 18
TagPrintableString = 19
TagT61String = 20
TagIA5String = 22
TagUTCTime = 23
TagGeneralizedTime = 24
TagGeneralString = 27
TagBMPString = 30
)
type tagAndLength struct {
class, tag, length int
isCompound bool
}
func appendTagAndLength(dst []byte, t tagAndLength) []byte {
b := uint8(t.class) << 6
if t.isCompound {
b |= 0x20
}
if t.tag >= 31 {
b |= 0x1f
dst = append(dst, b)
dst = appendBase128Int(dst, int64(t.tag))
} else {
b |= uint8(t.tag)
dst = append(dst, b)
}
if t.length >= 128 {
l := lengthLength(t.length)
dst = append(dst, 0x80|byte(l))
dst = appendLength(dst, t.length)
} else {
dst = append(dst, byte(t.length))
}
return dst
}
func appendBase128Int(dst []byte, n int64) []byte {
l := base128IntLength(n)
for i := l - 1; i >= 0; i-- {
o := byte(n >> uint(i*7))
o &= 0x7f
if i != 0 {
o |= 0x80
}
dst = append(dst, o)
}
return dst
}
func appendLength(dst []byte, i int) []byte {
n := lengthLength(i)
for ; n > 0; n-- {
dst = append(dst, byte(i>>uint((n-1)*8)))
}
return dst
}
func lengthLength(i int) (numBytes int) {
numBytes = 1
for i > 255 {
numBytes++
i >>= 8
}
return
}
