checksum

问题 I have a requirement to perform checksum (for data integrity) for SFTP. I was hoping this could be done during the SFTP file transfer - I realize this could be product dependent (FYI: using CLEO VLTrader), but was wondering if this is customary? I am also looking for alternative data integrity checking options that are as good (or better) than using a checksum algorithm. Thanks! 回答1: With the SFTP, running over an encrypted SSH session, there's negligible chance the file contents could get

问题 The SHA1 hashes stored in the tree objects (as returned by git ls-tree ) do not match the SHA1 hashes of the file content (as returned by sha1sum ) $ git cat-file blob 4716ca912495c805b94a88ef6dc3fb4aff46bf3c | sha1sum de20247992af0f949ae8df4fa9a37e4a03d7063e - How does git compute file hashes? Does it compress the content before computing the hash? 回答1: Git prefixes the object with "blob ", followed by the length (as a human-readable integer), followed by a NUL character $ echo -e 'blob 14

问题 The SHA1 hashes stored in the tree objects (as returned by git ls-tree ) do not match the SHA1 hashes of the file content (as returned by sha1sum ) $ git cat-file blob 4716ca912495c805b94a88ef6dc3fb4aff46bf3c | sha1sum de20247992af0f949ae8df4fa9a37e4a03d7063e - How does git compute file hashes? Does it compress the content before computing the hash? 回答1: Git prefixes the object with "blob ", followed by the length (as a human-readable integer), followed by a NUL character $ echo -e 'blob 14

问题 The SHA1 hashes stored in the tree objects (as returned by git ls-tree ) do not match the SHA1 hashes of the file content (as returned by sha1sum ) $ git cat-file blob 4716ca912495c805b94a88ef6dc3fb4aff46bf3c | sha1sum de20247992af0f949ae8df4fa9a37e4a03d7063e - How does git compute file hashes? Does it compress the content before computing the hash? 回答1: Git prefixes the object with "blob ", followed by the length (as a human-readable integer), followed by a NUL character $ echo -e 'blob 14

问题 Is there any simple way of generating (and checking) MD5 checksums of a list of files in Python? (I have a small program I'm working on, and I'd like to confirm the checksums of the files). 回答1: You can use hashlib.md5() Note that sometimes you won't be able to fit the whole file in memory. In that case, you'll have to read chunks of 4096 bytes sequentially and feed them to the Md5 function: def md5(fname): hash_md5 = hashlib.md5() with open(fname, "rb") as f: for chunk in iter(lambda: f.read

问题 So I'm trying to figure out how to get my exe to have the same hash code/checksum when it's recompiled. I'm using FastSum to generate the checksum. Currently, no code changes are made, I'm just rebuilding the project in VS and the checksum comes out different. The code is written in c++. I'm not familiar with using hash codes and/or checksums in this manner, but I did some research and read something about needing a consistent GUID. But I have no idea how that would tie into the checksum

问题 It seems that there are a number of conditions that cause CHECKSUM_AGG to return 0 that I wouldn't have expected. I've only been able to find one discussed, which is that duplicate values will cause it. That can be solved via a DISTINCT or GROUP BY . I've also found a couple more scenarios that make less sense to me. One was provided by my boss and one I found MSDN. These I don't know how to explain. Here is some SQL that demonstrates the scenarios: SELECT CHECKSUM_AGG(T.Number) AS

问题 Are there algorithms for putting a digest into the file being digested? In otherwords, are there algorithms or libraries, or is it even possible to have a hash/digest of a file contained in the file being hashed/digested. This would be handy for obvious reasons, such as built in digests of ISOs. I've tried googling things like "MD5 injection" and "digest in a file of a file." No luck (probably for good reason.) Not sure if it is even mathematically possible. Seems you'd be able to roll

问题 What is the best method for getting a SHA2 checksum in windows? I'm looking for something equivalent to md5sums-1.2 utility referenced for putty downloads, with more options than just md5. Edit - after more searching it seems only sha1 sha256 sha512 have working programs for anything outside of hashing text. I want to find the sha2 checksum of a file, is this no dice yet due to sha2 recently becoming popular? 回答1: You can install 7-zip 15.14 or later - one of the new features (optionally)

问题 I want to send a lot of data from c# to my database, together with a calculated checksum as the last value, which should be compared to the one that the SQL Server's stored procedure will compute from those values. To achieve this, I have tried a lot of different ways like the SQL built-in Checksum method and different hashings, but either the C# and SQL compute a different value, or the hashing doesn't work with nvarchars and integers (fx. MD5 hashing) which is required for me. Did anyone