![Hashes - Native
(MD5 hash: 'Hello') asHexString.
buffer := ByteArray new: 16384.
hash := SHA new.
file := (ObjectMemory imageFilename
withEncoding: #binary) readStream.
[ [ file atEnd ] whileFalse: [ | read |
read :=
file nextAvailable: buffer size
into: buffer
startingAt: 1.
hash updateWith: buffer from: 1 to: read ].
] ensure: [ file close ].
hash digest asHexString.](https://image.slidesharecdn.com/09-esug-nativeorexternal-110901012341-phpapp01/85/Native-or-External-4-320.jpg)
![Hashes - External
buffer := ByteArray new: 16384.
hash := Hash new algorithm: 'SHA1'; yourself.
file := (ObjectMemory imageFilename
withEncoding: #binary) readStream.
[ [ file atEnd ] whileFalse: [ | read |
read :=
file nextAvailable: buffer size
into: buffer
startingAt: 1.
hash update: read from: buffer ].
hash finish asHexString
] ensure: [ file close. hash release ].](https://image.slidesharecdn.com/09-esug-nativeorexternal-110901012341-phpapp01/85/Native-or-External-5-320.jpg)
![Ciphers - Speed
megs := 100.
buffer := ByteArray new: 1000.
time := [
megs * 1000 timesRepeat: [
1 to: buffer size do: [ :i |
buffer at: i put: (buffer at: i) ]]
] timeToRun.
megs asFloat / time asSeconds.
time := [ self readWriteMegs: megs ] timeToRun.
megs asFloat / time asSeconds](https://image.slidesharecdn.com/09-esug-nativeorexternal-110901012341-phpapp01/85/Native-or-External-8-320.jpg)
![Ciphers - External
buffer := ByteArray new: message size + iv size.
cipher := Cipher new.
padding := iv size - (message size iv size).
padding := ByteArray new: padding withAll: padding.
[ | count |
cipher algorithm: 'AES' mode: 'CBC'
key: key iv: iv encrypt: true.
count := cipher update: message size
from: message into: buffer.
result := buffer copyFrom: 1 to: count.
count := cipher update: padding size
from: padding into: buffer.
result := result, (buffer copyFrom: 1 to: count).
count := cipher finishInto: buffer.
result, (buffer copyFrom: 1 to: count)
] ensure: [ cipher release ]](https://image.slidesharecdn.com/09-esug-nativeorexternal-110901012341-phpapp01/85/Native-or-External-9-320.jpg)
![Public Key - External
key := PrivateKey RSALength: 1024.
[ | digest |
digest := (message reading hashing: 'SHA1')
-= 0; close; digest.
key sign: digest
hash: 'SHA1'
padding: 'PKCS1'
] ensure: [ key release ]](https://image.slidesharecdn.com/09-esug-nativeorexternal-110901012341-phpapp01/85/Native-or-External-12-320.jpg)
Native or External?
- 1. Native or External? Lessons learned implementing cryptography for VisualWorks Martin Kobetic Cincom Smalltalk Engineering ESUG 2011
- 2. Let's implement SSL! DES, MD5, SHA, RSA, DSA, RC4, X.509, ASN.1, DER, ... * SSL 3.0, RSA, DES, RC4, basic X.509 (RSA only) * DH, DSA, + SSL integration, AES * X.509 on ASN.1, faster RSA (CRT),... * new ASN.1 (read/write), more X.509 * protocols/S (HTTPS, SMTPS,....)
- 3. What is Cryptography hashes MD5, SHA1, SHA256, ... secret key (symmetric) ciphers AES, DES, RC4,... public key algorithms * signing (RSA, DSA, ECDSA) * encryption (RSA) * key agreement (DH, ECDH)
- 4. Hashes - Native (MD5 hash: 'Hello') asHexString. buffer := ByteArray new: 16384. hash := SHA new. file := (ObjectMemory imageFilename withEncoding: #binary) readStream. [ [ file atEnd ] whileFalse: [ | read | read := file nextAvailable: buffer size into: buffer startingAt: 1. hash updateWith: buffer from: 1 to: read ]. ] ensure: [ file close ]. hash digest asHexString.
- 5. Hashes - External buffer := ByteArray new: 16384. hash := Hash new algorithm: 'SHA1'; yourself. file := (ObjectMemory imageFilename withEncoding: #binary) readStream. [ [ file atEnd ] whileFalse: [ | read | read := file nextAvailable: buffer size into: buffer startingAt: 1. hash update: read from: buffer ]. hash finish asHexString ] ensure: [ file close. hash release ].
- 6. Hashes - Xtreams ((ObjectMemory imageFilename reading hashing: 'SHA1' ) -= 0; close; digest ) asHexString
- 7. Ciphers - Native message := 'Hello World!' asByteArrayEncoding: #ascii. key := 'Open Sesame!!!!!' asByteArrayEncoding: #ascii. ((ARC4 key: key) encrypt: message) asHexString. cipher := AES key: key. cipher := CipherBlockChaining on: cipher. iv := ByteArray new: 16 withAll: 1. cipher setIV: iv. cipher := BlockPadding on: cipher. (cipher encrypt: message) asHexString
- 8. Ciphers - Speed megs := 100. buffer := ByteArray new: 1000. time := [ megs * 1000 timesRepeat: [ 1 to: buffer size do: [ :i | buffer at: i put: (buffer at: i) ]] ] timeToRun. megs asFloat / time asSeconds. time := [ self readWriteMegs: megs ] timeToRun. megs asFloat / time asSeconds
- 9. Ciphers - External buffer := ByteArray new: message size + iv size. cipher := Cipher new. padding := iv size - (message size iv size). padding := ByteArray new: padding withAll: padding. [ | count | cipher algorithm: 'AES' mode: 'CBC' key: key iv: iv encrypt: true. count := cipher update: message size from: message into: buffer. result := buffer copyFrom: 1 to: count. count := cipher update: padding size from: padding into: buffer. result := result, (buffer copyFrom: 1 to: count). count := cipher finishInto: buffer. result, (buffer copyFrom: 1 to: count) ] ensure: [ cipher release ]
- 10. Ciphers - Xtreams ((( ByteArray new writing encrypting: 'AES' mode: 'CBC' key: key iv: iv ) hashing: 'SHA1' ) write: message; write: padding; close; terminal ) asHexString
- 11. Public Key - Native keys := RSAKeyGenerator keySize: 1024. keys publicKey. rsa := RSA new privateKey: keys privateKey. rsa useMD5. sig := rsa sign: message.
- 12. Public Key - External key := PrivateKey RSALength: 1024. [ | digest | digest := (message reading hashing: 'SHA1') -= 0; close; digest. key sign: digest hash: 'SHA1' padding: 'PKCS1' ] ensure: [ key release ]
- 13. Native - Pros * understanding and know-how * ease of use and deployment * automatically cross platform * easy integration * debugging
- 14. Native - Cons * maintenance/evolution * security issues * speed * certification * hardware integration * export restrictions
- 15. External - Pros * development cost (maybe) * evolves for free (hopefully) * speed * certification (possibly) * hardware integration (possibly)
- 16. External - Cons * platform coverage * integration issues * support * FFI issues * brittleness
- 17. Summary * seamless use * seamless deployment * platform coverage * capability coverage * extensibility * other constraints * certification/approved implementations * hardware support * performance