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| author | Alex Stapleton <alexs@prol.etari.at> | 2014-02-28 19:53:18 +0000 |
|---|---|---|
| committer | Alex Stapleton <alexs@prol.etari.at> | 2014-03-01 10:13:36 +0000 |
| commit | 53ecc9837e39f596bb6b17980aef19c1668c732b (patch) | |
| tree | 5fd07ef370919114d4ae9e0e27fc996e752e3a36 | |
| parent | bf1241307711a2f081d448e5132a435922c05681 (diff) | |
| download | cryptography-53ecc9837e39f596bb6b17980aef19c1668c732b.tar.gz cryptography-53ecc9837e39f596bb6b17980aef19c1668c732b.tar.bz2 cryptography-53ecc9837e39f596bb6b17980aef19c1668c732b.zip | |
Use buffer of EVP_MAX_MD_SIZE bytes for digests
OpenSSL doesn't actually guarantee to only write to digest_size worth of
bytes in the output buffer. The examples and docs claim this constant is
the max.
| -rw-r--r-- | cryptography/hazmat/backends/openssl/backend.py | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py index aa6dc83a..0dc6803e 100644 --- a/cryptography/hazmat/backends/openssl/backend.py +++ b/cryptography/hazmat/backends/openssl/backend.py @@ -534,14 +534,14 @@ class _HashContext(object): def finalize(self): buf = self._backend._ffi.new("unsigned char[]", - self.algorithm.digest_size) + self._backend._lib.EVP_MAX_MD_SIZE) outlen = self._backend._ffi.new("unsigned int *") res = self._backend._lib.EVP_DigestFinal_ex(self._ctx, buf, outlen) assert res != 0 assert outlen[0] == self.algorithm.digest_size res = self._backend._lib.EVP_MD_CTX_cleanup(self._ctx) assert res == 1 - return self._backend._ffi.buffer(buf)[:] + return self._backend._ffi.buffer(buf)[:outlen[0]] @utils.register_interface(interfaces.HashContext) @@ -593,7 +593,7 @@ class _HMACContext(object): def finalize(self): buf = self._backend._ffi.new("unsigned char[]", - self.algorithm.digest_size) + self._backend._lib.EVP_MAX_MD_SIZE) outlen = self._backend._ffi.new("unsigned int *") res = self._backend._lib.Cryptography_HMAC_Final( self._ctx, buf, outlen @@ -601,7 +601,7 @@ class _HMACContext(object): assert res != 0 assert outlen[0] == self.algorithm.digest_size self._backend._lib.HMAC_CTX_cleanup(self._ctx) - return self._backend._ffi.buffer(buf)[:] + return self._backend._ffi.buffer(buf)[:outlen[0]] @utils.register_interface(interfaces.AsymmetricSignatureContext) |