Merge pull request #963 from Gustav-Simonsson/fix_keystore_crypto_comments

Update keystore code comments
This commit is contained in:
Jeffrey Wilcke 2015-05-13 11:51:02 -07:00
commit fad21fb4a5
1 changed files with 7 additions and 6 deletions

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@ -28,21 +28,22 @@ the private key is encrypted and on disk uses another JSON encoding.
Cryptography:
1. Encryption key is first 16 bytes of SHA3-256 of first 16 bytes of
scrypt derived key from user passphrase. Scrypt parameters
1. Encryption key is first 16 bytes of scrypt derived key
from user passphrase. Scrypt parameters
(work factors) [1][2] are defined as constants below.
2. Scrypt salt is 32 random bytes from CSPRNG.
It's stored in plain next to ciphertext in key file.
3. MAC is SHA3-256 of concatenation of ciphertext and last 16 bytes of scrypt derived key.
It's stored in plain next in the key file.
3. MAC is SHA3-256 of concatenation of ciphertext and
last 16 bytes of scrypt derived key.
4. Plaintext is the EC private key bytes.
5. Encryption algo is AES 128 CBC [3][4]
6. CBC IV is 16 random bytes from CSPRNG.
It's stored in plain next to ciphertext in key file.
It's stored in plain next in the key file.
7. Plaintext padding is PKCS #7 [5][6]
Encoding:
1. On disk, the ciphertext, MAC, salt and IV are encoded in a nested JSON object.
1. On disk, the ciphertext, MAC, salt and IV are encoded in a JSON object.
cat a key file to see the structure.
2. byte arrays are base64 JSON strings.
3. The EC private key bytes are in uncompressed form [7].