diff --git a/_drafts/TLS_Writeup.txt b/_drafts/TLS_Writeup.txt deleted file mode 100644 index 9297f77..0000000 --- a/_drafts/TLS_Writeup.txt +++ /dev/null @@ -1,130 +0,0 @@ -TLS: An examination into the Security of the Internet, Part 1 - -TLS, more often referred to as SSL, is the means by which a secure connection is -established over a computer network. Most often these connections are -established over the Internet, between a client (ex., web browser) and a server -(ex., a web site). In the specific case of web sites, HTTP is layered on TLS/SSL -to ensure a secure and private connection; HTTPS is not a separate protocol, -rather a combination or protocols. Establishing a secure connection thus -requires a few steps: - -Step 1: Establish an TCP connection - TCP is a transport-layer protocol that establishes a connection which is - reliable and fault-tolerant. As opposed to UDP, TCP will seek to verify that - information is transferred successfully and as intended. This is important - for the next step. The connection is established as follows: - - 1. A client will contact a server and announce it wishes to establish - a connection. (Called a SYN, short for synchronize). This SYN is a - number, stored as part of the TCP header; we'll call it A. - - 2. The server will respond to the client announcing it has received - the client's wish, and also state that it wishes to establish a - connection. (Called a SYN-ACK, short for synchronize-acknowledge). - Ths SYN-ACK is actually two values: One is the ACK value, A+1. The - second is the server's SYN value, which we'll call B. - - 3. The client then acknowledged the server's wish, thus establishing a - connection (Called simply an ACK). Because it was expecting an ACK - value in step 2, and expecting that value to be A+1, it can verify - that this connection is the same as the one it started. Additionally - and similarly, the ACK which gets returned to the server as B+1. - - 4. At this point, the connection is established. Both client and - server have assured themselves of a proper connection thanks to the - three-way handshake described above. From this point forward, the - server has bound a specific port to listen for any further - communications with the client. - -Step 2: Establish an SSL/TLS Connection - TLS, Transport Layer Security, is appropriately on the same layer as TCP, - the transport layer. TLS relies on public key authentication to establish a - secure connection between the aforementioned client and server. The - connection is established as follows: - - 1. A client will announce to the server it wishes to establish a - TLS/SSL connection. It will include information such as it's TLS/SSL - version, the ciphersuites it wishes to use, and which compression - methods it wishes to use. - - 2. The server then uses the highest possible TLS/SSL version, chooses - one of the ciphersuites available to the client, chooses one of the - compression methods available to the client, and sends it's - certificate. A certificate is basically a container for a server's - public key, but with many additional details, and often signed by a - certificate authority, to further verify the certificate contains the - proper key. More on certificates in part 2. - - 3. The client then uses the server's public key to encrypt a secret. - This secret is then sent back to the server. - - 4. The server decrypts the secret with it's private key. This secret - is now shared by only the client and the server, and from this point - on is used for symmetric encryption. - - From this point forward, the connection is encrypted and secure from - external threats. Of course, this all depends on a trusted certificate and - proper encryption algorithms. - -Step 3: Establish an HTTP connection - HTTP is an application-layer protocol, and is responsible for translating - the information from the transport layer into information used by an - application. Your web browser, for example, will utilize HTTP to translate - a bunch of hexidecimal information into alpha-numeric information, which is - then formatted and presented to you as a web page. Security is previously - established thanks to TLS/SSL, and reliability is previously established - thanks to TCP. - -Of course this is an over-simplification of the whole stream. TCP itself is -worthy of many research papers. However, many sources on TCP already do an apt -job of explaining it in understandable ways. I felt that SSL was less-so -explained, so I wanted to dive a bit more into that. In Part 2, I'll dive more -into the TLS handshake, what certificates are and how they play a role, and the -importance of secure ciphersuites for keys. - - -============================ -Sources - [1] https://en.wikipedia.org/wiki/Public-key_cryptography - [2] - https://security.stackexchange.com/questions/6290/how-is-it-possible-that-people-observing-an-https-connection-being-established-w - [3] - https://security.stackexchange.com/questions/20803/how-does-ssl-tls-work - -============================ -Notes -Asymmetric Key Authentication: - - Relies on two keys: Public key, Private key - - Both keys are related, but impossible (computationally infeasable) to - identify the private key based on the public key [1][2] - - The public key can be distributed publicly - - Used to encrypt message to the owner of the private paired key - - Used to verify signatures from the private key - - The private key is kept secret - - Used to decrypt message from the public paired key - - Used to as a digital signature - -Basics of an Asymmetric Key handshake: - 1. Client reaches out to server, requesting a secure connection - 2. Server acknowledges request, sends back it's public key - - This is commonly known as a certificate. Often signed by a - third-party to ensure it is what it's supposed to be. - 3. Client uses this public key to encrypt a secret, and sends the package - back to the server. - 4. The server then uses it's private key to decrypt the public-key - encrypted secret, and uses that secret hence forth to encrypt all traffic. - 5. A private connection is now established. - -Basics of Certificates - 1. A certificate is a vessel for a server to provide authentication - information. - 2. Typically a certificate will contain the following information: - - A UUID of the certificate itself - - The subject of the certificate - - The signature, and signature algorithm used - - The issuer of the certificate, as well as dates when it is valid - - The purpose of the key - - The thumbprint, and algorithm, used to hash the key - - The public key itself - 3. Certificate Authorities act as a third part to verify the integrity of - public keys. diff --git a/_drafts/TLS_Writeup2.html b/_drafts/TLS_Writeup2.html new file mode 100644 index 0000000..8629a9b --- /dev/null +++ b/_drafts/TLS_Writeup2.html @@ -0,0 +1,88 @@ +--- + layout: default + tabtitle: An Examination of TLS, Part 2 + title: An Examination of TLS, Part 2 + tags: tech +--- + +
+

TLS: An examination into the Security of the Internet, Part 2

+ +

TLS, more often referred to as SSL, is the means by which a secure + connection is established over a computer network. Part 1 examines how to + establish a secure connection using TLS. This article examines further the + techniques and technology that makes TLS secure. Specifically, a brief + examination of certificates, cipher suites, and public-key + authentication.

+ +

Certificates

+

A certificate is a vessel for a server to provide authentication + information.

+ +

Cipher Suites

+

A cipher is the algorithm used to encrypt the information + to be transmitted.

+ +

Public-Key Authentication

+

Big topic, very important!

+ +

Sources

+
    +
  1. + Wikipedia: Public-key Cryptography
    2. +
  2. Stack + Exchange: How is it possible that people observing an HTTPS + connection being established wouldn't know how to decrypt + it?
    3. +
  3. + Stack Exchange: How Does SSL/TLS work?
    4. +
+ +

[Bill Niblock][2015-05-][Technology]

+
+ + + + + + + + diff --git a/_drafts/TLS_Writeup2.txt b/_drafts/TLS_Writeup2.txt index bca1e4d..dd01591 100644 --- a/_drafts/TLS_Writeup2.txt +++ b/_drafts/TLS_Writeup2.txt @@ -1,30 +1,31 @@ -TLS: An examination into the Security of the Internet, Part 2 +--- + layout: default + tabtitle: An Examination of TLS, Part 2 + title: An Examination of TLS, Part 2 + tags: tech +--- -In Part 1, I went over how a connection is established with TLS. In this part, I -want to examine the more involved details of TLS itself. Namely, I want to -examine certificates, cipher suites, and public key authentication. +
-Certificates +

TLS: An examination into the Security of the Internet, Part 2

+ + +

Certificates

A certificate is a vessel for a server to provide authentication informat -Cipher Suites +

Cipher Suites

A cipher is the algorithm used to encrypt the information to be transmitted. -Public-Key Authentication +

Public-Key Authentication

Big topic, very important +
-============================ -Sources - [1] https://en.wikipedia.org/wiki/Public-key_cryptography - [2] - https://security.stackexchange.com/questions/6290/how-is-it-possible-that-people-observing-an-https-connection-being-established-w - [3] - https://security.stackexchange.com/questions/20803/how-does-ssl-tls-work + + -============================ -Notes + + + + diff --git a/_posts/2015-04-28-Farewell-to-Windows-Tour.html b/_posts/2015-04-28-Farewell-to-Windows-Tour.html index 8e2dfcb..43f0c8a 100644 --- a/_posts/2015-04-28-Farewell-to-Windows-Tour.html +++ b/_posts/2015-04-28-Farewell-to-Windows-Tour.html @@ -45,7 +45,7 @@ "tour" is for; the last few games I want to play on Windows, before I go Linux only.

-

Featuring

+

Featuring

The list isn't huge, but there are some definite strong players: