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Appendix B. Test Vectors

Appendix B. Test Vectors​

All values are in hexadecimal.

B.1. AES-f8 Test Vectors​

SRTP PREFIX LENGTH : 0

RTP packet header : 806e5cba50681de55c621599

RTP packet payload : 70736575646f72616e646f6d6e657373 20697320746865206e65787420626573 74207468696e67

ROC : d462564a key : 234829008467be186c3de14aae72d62c salt key : 32f2870d key-mask (m) : 32f2870d555555555555555555555555 key XOR key-mask : 11baae0dd132eb4d3968b41ffb278379

IV : 006e5cba50681de55c621599d462564a IV' : 595b699bbd3bc0df26062093c1ad8f73

j = 0 IV' xor j : 595b699bbd3bc0df26062093c1ad8f73 S(-1) : 00000000000000000000000000000000 IV' xor S(-1) xor j : 595b699bbd3bc0df26062093c1ad8f73 S(0) : 71ef82d70a172660240709c7fbb19d8e plaintext : 70736575646f72616e646f6d6e657373 ciphertext : 019ce7a26e7854014a6366aa95d4eefd

j = 1 IV' xor j : 595b699bbd3bc0df26062093c1ad8f72 S(0) : 71ef82d70a172660240709c7fbb19d8e IV' xor S(0) xor j : 28b4eb4cb72ce6bf020129543a1c12fc S(1) : 3abd640a60919fd43bd289a09649b5fc plaintext : 20697320746865206e65787420626573 ciphertext : 1ad4172a14f9faf455b7f1d4b62bd08f

j = 2 IV' xor j : 595b699bbd3bc0df26062093c1ad8f71 S(1) : 3abd640a60919fd43bd289a09649b5fc IV' xor S(1) xor j : 63e60d91ddaa5f0b1dd4a93357e43a8d S(2) : 220c7a8715266565b09ecc8a2a62b11b plaintext : 74207468696e67 ciphertext : 562c0eef7c4802

B.2. AES-CM Test Vectors​

   Keystream segment length: 1044512 octets (65282 AES blocks)
   Session Key:      2B7E151628AED2A6ABF7158809CF4F3C
   Rollover Counter: 00000000
   Sequence Number:  0000
   SSRC:             00000000
   Session Salt:     F0F1F2F3F4F5F6F7F8F9FAFBFCFD0000 (already shifted)
   Offset:           F0F1F2F3F4F5F6F7F8F9FAFBFCFD0000

   Counter                            Keystream

   F0F1F2F3F4F5F6F7F8F9FAFBFCFD0000   E03EAD0935C95E80E166B16DD92B4EB4
   F0F1F2F3F4F5F6F7F8F9FAFBFCFD0001   D23513162B02D0F72A43A2FE4A5F97AB
   F0F1F2F3F4F5F6F7F8F9FAFBFCFD0002   41E95B3BB0A2E8DD477901E4FCA894C0
   ...                                ...
   F0F1F2F3F4F5F6F7F8F9FAFBFCFDFEFF   EC8CDF7398607CB0F2D21675EA9EA1E4
   F0F1F2F3F4F5F6F7F8F9FAFBFCFDFF00   362B7C3C6773516318A077D7FC5073AE
   F0F1F2F3F4F5F6F7F8F9FAFBFCFDFF01   6A2CC3787889374FBEB4C81B17BA6C44

Nota Bene: this test case is contrived so that the latter part of the keystream segment coincides with the test case in Section F.5.1 of [CTR].

B.3. Key Derivation Test Vectors​

This section provides test data for the default key derivation function, which uses AES-128 in Counter Mode. In the following, we walk through the initial key derivation for the AES-128 Counter Mode cipher, which requires a 16 octet session encryption key and a 14 octet session salt, and an authentication function which requires a 94-octet session authentication key. These values are called the cipher key, the cipher salt, and the auth key in the following. Since this is the initial key derivation and the key derivation rate is equal to zero, the value of (index DIV key_derivation_rate) is zero (actually, a six-octet string of zeros). In the following, we shorten key_derivation_rate to kdr.

The inputs to the key derivation function are the 16 octet master key and the 14 octet master salt:

     master key:  E1F97A0D3E018BE0D64FA32C06DE4139
     master salt: 0EC675AD498AFEEBB6960B3AABE6

We first show how the cipher key is generated. The input block for AES-CM is generated by exclusive-oring the master salt with the concatenation of the encryption key label 0x00 with (index DIV kdr), then padding on the right with two null octets (which implements the multiply-by-2^16 operation, see Section 4.3.3). The resulting value is then AES-CM- encrypted using the master key to get the cipher key.

     index DIV kdr:                 000000000000
     label:                       00
     master salt:   0EC675AD498AFEEBB6960B3AABE6
     -----------------------------------------------
     xor:           0EC675AD498AFEEBB6960B3AABE6     (x, PRF input)

     x*2^16:        0EC675AD498AFEEBB6960B3AABE60000 (AES-CM input)

     cipher key:    C61E7A93744F39EE10734AFE3FF7A087 (AES-CM output)

Next, we show how the cipher salt is generated. The input block for AES-CM is generated by exclusive-oring the master salt with the concatenation of the encryption salt label. That value is padded and encrypted as above.

     index DIV kdr:                 000000000000
     label:                       02
     master salt:   0EC675AD498AFEEBB6960B3AABE6

     ----------------------------------------------
     xor:           0EC675AD498AFEE9B6960B3AABE6     (x, PRF input)

     x*2^16:        0EC675AD498AFEE9B6960B3AABE60000 (AES-CM input)

                    30CBBC08863D8C85D49DB34A9AE17AC6 (AES-CM ouptut)

     cipher salt:   30CBBC08863D8C85D49DB34A9AE1

We now show how the auth key is generated. The input block for AES-CM is generated as above, but using the authentication key label.

     index DIV kdr:                   000000000000
     label:                         01
     master salt:     0EC675AD498AFEEBB6960B3AABE6
     -----------------------------------------------
     xor:             0EC675AD498AFEEAB6960B3AABE6     (x, PRF input)

     x*2^16:          0EC675AD498AFEEAB6960B3AABE60000 (AES-CM input)

Below, the auth key is shown on the left, while the corresponding AES input blocks are shown on the right.

   auth key                           AES input blocks
   CEBE321F6FF7716B6FD4AB49AF256A15   0EC675AD498AFEEAB6960B3AABE60000
   6D38BAA48F0A0ACF3C34E2359E6CDBCE   0EC675AD498AFEEAB6960B3AABE60001
   E049646C43D9327AD175578EF7227098   0EC675AD498AFEEAB6960B3AABE60002
   6371C10C9A369AC2F94A8C5FBCDDDC25   0EC675AD498AFEEAB6960B3AABE60003
   6D6E919A48B610EF17C2041E47403576   0EC675AD498AFEEAB6960B3AABE60004
   6B68642C59BBFC2F34DB60DBDFB2       0EC675AD498AFEEAB6960B3AABE60005
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