吴璨
22 lines
488 B
Go
22 lines
488 B
Go
package app
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import (
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"errors"
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)
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func pkcs7Unpad(src []byte, blockSize int) ([]byte, error) {
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if len(src) == 0 || len(src)%blockSize != 0 {
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return nil, errors.New("invalid pkcs7 length")
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}
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pad := int(src[len(src)-1])
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if pad == 0 || pad > blockSize || pad > len(src) {
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return nil, errors.New("invalid pkcs7 padding")
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}
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for _, v := range src[len(src)-pad:] {
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if int(v) != pad {
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return nil, errors.New("invalid pkcs7 padding bytes")
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}
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}
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return src[:len(src)-pad], nil
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}
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