30 lines
		
	
	
		
			657 B
		
	
	
	
		
			Go
		
	
	
	
			
		
		
	
	
			30 lines
		
	
	
		
			657 B
		
	
	
	
		
			Go
		
	
	
	
package ber
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import (
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	"errors"
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	"io"
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)
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func readHeader(reader io.Reader) (identifier Identifier, length int, read int, err error) {
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	if i, c, err := readIdentifier(reader); err != nil {
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		return Identifier{}, 0, read, err
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	} else {
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		identifier = i
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		read += c
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	}
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	if l, c, err := readLength(reader); err != nil {
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		return Identifier{}, 0, read, err
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	} else {
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		length = l
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		read += c
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	}
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	// Validate length type with identifier (x.600, 8.1.3.2.a)
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	if length == LengthIndefinite && identifier.TagType == TypePrimitive {
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		return Identifier{}, 0, read, errors.New("indefinite length used with primitive type")
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	}
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	return identifier, length, read, nil
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}
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