cryptos | Pure Python from-scratch zero-dependency implementation of Bitcoin for educational purposes | Cryptography library
kandi X-RAY | cryptos Summary
kandi X-RAY | cryptos Summary
Just me developing a pure Python from-scratch zero-dependency implementation of Bitcoin for educational purposes, including all of the under the hood crypto primitives such as SHA-256 and elliptic curves over finite fields math.
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Top functions reviewed by kandi - BETA
- Generate a base58check address
- Generate a set of prime numbers
- Encode the QR code
- Calculate the Jacobian of a function
- Calculates the RMD160 of b
- Transforms the RMD160 to the RMD160
- Compute SHA256 hash of a message
- Perform RMD160 update
- Calculate the MD160
- Encode a base58 string
- Compute the SHA256 hash of a message
- Pad bytes with zeros
- Calculate the fractional part of a fractional
- Generate a list of prime numbers
- Generate a bitcoin curve
- Generate a secret key
- Read the envelope from the stream
cryptos Key Features
cryptos Examples and Code Snippets
Community Discussions
Trending Discussions on cryptos
QUESTION
I am working on a rails 5 api only. I can get all the data that i want, but i would like to customize the output.I tried some solutions, but couldn't find it yet.
This is my portfolio controller:
...ANSWER
Answered 2021-Jun-12 at 22:13It's not possible to include a collection of objects as a value to a key without wrapping them in an array in JSON. (source (W3Schools))
It is possible, on the other hand, to have a collection of objects, but each one would have to have its own unique key. So the response could be shaped as such:
QUESTION
I have built a model that analyses crypto currency performance, based on raw data downloaded from a web portal. To automate this process, I developed some VBA code that recognizes the downloaded file by going to my "Downloads" directory and selecting the most recent file that has the word "BITFINEX" in its name. My challenge is that some of the cryptos I am interested in do not have that particular keyword included in the filename. Some, for example, use "COINBASE" instead and others may use something else. Bottom line is that I need my macro to choose the most recent of multiple file that include BITFINEX, COINBASE and, say, 5 other names that are not yet defined (for these, there could just be place markers saying, AAA, BBB, CCC, DDD, EEE). I am guessing that there is some version of the "Or" function that is required, but that is unfortunately beyond my coding skills at this point. The code I have attached is for my existing model and works perfectly. Any assistance would be most appreciated.
...ANSWER
Answered 2021-May-29 at 20:42Something like this should work:
QUESTION
I am creating a C# app that authenticates via a node.js server. I am using RSA for this purpose. I generated a public and private key for the server using crypto. Every time the client connects to the server, it generates a key pair for itself. The client gets the server public key from an endpoint. I have used XML strings as well as PEM strings, but neither of them worked. (using RSACryptoServiceProvider) When the server attempted to decrypt it, it threw an OAEP decoding error. I am trying to decrypt the message with the paired private key.
I have viewed other threads but they were not very helpful.
Here's the code for the server. It encrypts/decrypts with the built-in crypto module. (I have tested this with a node.js client and a node.js server, and it works.)
...ANSWER
Answered 2021-Jan-26 at 14:44There are multiple types of padding, and apparently the encryption is trying to use PKCS1 (I guess), and the decryption defaults to OAEP.
In crypto.privateDecrypt
you can set the padding to eg. padding: crypto.constants.RSA_PKCS1_PADDING
and it should work.
You should go for OAEP on both ends if possible (and it should be), in which case your Node code is already ok as the default is OAEP, and C# should be set to OAEP too.
Edit: I mixed it up first, but the point is, you can set the padding type on either end, and they must match. :)
QUESTION
For secure communication between client and server, I want to encrypt and decrypt data from both the client and the server, but I cannot get the same results, the data that comes from the client to the server is not decrypted, also when encrypting the same the same data from the server, I get a distinctive result from encryption on the client.
The client is written in C ++ using Crypto ++. The code:
...ANSWER
Answered 2021-May-18 at 12:34The posted C++ code is fine. It returns the posted ciphertext STpu...0lWJ
on my machine and the ciphertext can be decrypted with the decrypt()
method.
In contrast, although the posted C# code returns the posted ciphertext tIDl...RoEM=
, the ciphertext cannot be decrypted using the Decrypt()
method. This has two reasons:
- In the
Encrypt()
and in theDecrypt()
method different keys are used. The key of theDecrypt()
method matches the key applied in the C++ code. With regard to a comparison of the ciphertexts of both codes, the key in theEncrypt()
method should be replaced. - The ciphertext is Base64 encoded in the
Encrypt()
method, but not Base64 decoded in theDecrypt()
method (but ASCII encoded instead). Here a Base64 decoding must be done in theDecrypt()
method (note that an ASCII decoding in theEncrypt()
method is not an alternative, since this would corrupt the ciphertext).
If these two bugs are fixed, the ciphertexts of C++ and C# code match except for the end. This last mismatch is caused by different paddings. In the C++ code PKCS7 padding is used, in the C# code Zero padding. If the padding in the C# code (in the Encrypt()
and Decrypt()
methods) is changed to PaddingMode.PKCS7
, the ciphertexts match.
Other problems in the C# code are:
- In the
Encrypt()
methodEncoding.Default
is used, in theDecrypt()
methodEncoding.ASCII
. Here a consistent encoding, e.g.Encoding.UTF8
should be applied. - The specified 128-bit key size is not consistent with the 256-bit key used. This has no effect because the explicit key specification automatically corrects the key size (nevertheless, the key size should be specified correctly or completely omitted).
Also, it should be noted that a static IV is insecure (for testing purposes, of course, that's OK).
QUESTION
On MSDN about using
, there's the new syntax presented. I like it and started to apply it.
Instead of
...ANSWER
Answered 2021-May-17 at 16:34Under your old code, all your resources, including the StreamWriter
and CryptoStream
, get disposed implicitly at the end of their using
block. Upon being disposed, any pending content would get flushed to the MemoryStream
. Thus, when you inspect the MemoryStream
after the end of these using
blocks, it would be correctly populated.
In your new code, the new using
syntax means that the resources only get disposed at the end of the enclosing block – in this case, the parent method. Thus, when you inspect the MemoryStream
within the same method, you are doing so before StreamWriter
and CryptoStream
have been disposed, and hence before their contents have been flushed to the MemoryStream
.
For the sake of demonstration, calling Dispose
on the StreamWriter
just before reading the MemoryStream
would restore the correct behavior:
QUESTION
I'm trying to make a Linux kernel driver using crypto API.
So first I have my own skcipher algorithm that I developed successfully registered on the crypto API and I can see it in the list of cryptos that is well registered.
...ANSWER
Answered 2021-May-11 at 10:09I managed to resolve the problem, it was stupid mistake because of the Init algorithm function that I confused with Init function module.
QUESTION
I'm trying to write an operator that will download some API data and place it into a table using a dataframe. I've got the following operator code written up:
...ANSWER
Answered 2021-May-09 at 07:40When using MySQL you are given a choice of which python wrapper you want to use. You can use mysql-connector-python
or mysqlclient
. It is mentioned in the docs that you need to specify the client to connect in the Extra
field.
So just add {"client": "mysql-connector-python"}
or {"client": "mysqlclient"}
to the extra field.
Note that a good source for information is the tests. For example check this
QUESTION
I was analysing crypto data using a library called ccxt. With ccxt, I can easily get candlestick for crypto datafeed into dataframe:
...ANSWER
Answered 2021-May-05 at 12:13You can try retaining your code of aggregating a list of dataframes and then concat them after the loop, like below:
QUESTION
I have a data frame data
, which contains information about crypto currencies. I need to find a way to create a vector with symbols of cryptos, which absolute value of market capitalization change in 24h in percentage is at least 10. I have the following function:
ANSWER
Answered 2021-May-04 at 11:03I think you can use subset
+ abs
to make it
QUESTION
I have a data frame named data
, which contains names of cryptos and their values. I also have the following function:
ANSWER
Answered 2021-Apr-29 at 19:54A simple solution with some toy data:
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