我使用lib PHPASN1来解码ASN.1字符串,该字符串是pdf文档中的签名值(它位于/ Contents字段中)。我有:
SEQUENCE : [2 children]
|-OBJECT IDENTIFIER : Signed data (1.2.840.113549.1.7.2)
|-[0] CONTEXT-SPECIFIC (0XA0) : [1 child]
|--SEQUENCE : [5 children]
|---INTEGER : 1
|---SET : [1 child]
|----SEQUENCE : [2 children]
....
....
....
....
|-----SEQUENCE : [2 children]
|------OBJECT IDENTIFIER : RSA Encryption
|------NULL : NULL
|-----OCTET STRING : 7D63AB9BBF07C60E581FDEA971AF6BAF87D0CB757E99F307C7A4313210F53E62FA51290B52009E7F3B02424A4B630C7E097477E019E69DE6B2B8A6269B0EED0BBFDF207BF8965859FF13BEBF97918B9CA82AC22CF11C1BEE9579DBC84C9A0D6194C4FFB0759852BECABB3737123176A11017A56554B2CB01861E82B0C0D3B196
现在我想获取加密的消息摘要,但我不知道它在哪里?