Polarssl - SHA1 gives different results when input with special characters

Question

I'm trying to hash some data includes Turkish characters inside. For example; when I hashed "aaç" string with Polarssl, sha-1 result comes like that :

10 bf 94 7f 94 65 9f b0 66 76 97 b d4 25 de 9d e4 85 8e ca

but I looked from internet same string's(aaç) hash result comes like :

97 dd 7a 00 e8 ff 49 09 47 60 03 50 83 db 7c ba 87 07 0f d9

why could these two sha1 results be different?

Answer 1

Text encoding differences. The character ç is encoded differently in the ISO 8859-1 and UTF-8 encodings, and this difference causes the SHA-1 hashes of the resulting byte sequences to be different:

SHA1("aa\xe7")     = 10bf947f94659fb06676970bd425de9de4858eca (ISO 8859-1)
SHA1("aa\xc3\xa7") = 97dd7a00e8ff49094760035083db7cba87070fd9 (UTF-8)