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Diffstat (limited to 'node_modules/evp_bytestokey/index.js')
-rw-r--r-- | node_modules/evp_bytestokey/index.js | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/node_modules/evp_bytestokey/index.js b/node_modules/evp_bytestokey/index.js new file mode 100644 index 0000000..f9d4757 --- /dev/null +++ b/node_modules/evp_bytestokey/index.js @@ -0,0 +1,45 @@ +var Buffer = require('safe-buffer').Buffer +var MD5 = require('md5.js') + +/* eslint-disable camelcase */ +function EVP_BytesToKey (password, salt, keyBits, ivLen) { + if (!Buffer.isBuffer(password)) password = Buffer.from(password, 'binary') + if (salt) { + if (!Buffer.isBuffer(salt)) salt = Buffer.from(salt, 'binary') + if (salt.length !== 8) throw new RangeError('salt should be Buffer with 8 byte length') + } + + var keyLen = keyBits / 8 + var key = Buffer.alloc(keyLen) + var iv = Buffer.alloc(ivLen || 0) + var tmp = Buffer.alloc(0) + + while (keyLen > 0 || ivLen > 0) { + var hash = new MD5() + hash.update(tmp) + hash.update(password) + if (salt) hash.update(salt) + tmp = hash.digest() + + var used = 0 + + if (keyLen > 0) { + var keyStart = key.length - keyLen + used = Math.min(keyLen, tmp.length) + tmp.copy(key, keyStart, 0, used) + keyLen -= used + } + + if (used < tmp.length && ivLen > 0) { + var ivStart = iv.length - ivLen + var length = Math.min(ivLen, tmp.length - used) + tmp.copy(iv, ivStart, used, used + length) + ivLen -= length + } + } + + tmp.fill(0) + return { key: key, iv: iv } +} + +module.exports = EVP_BytesToKey |