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Services/KeyExchange: Difference between revisions
→Overview
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<li>The encryption and HMAC keys are derived from that 256 bit key using HMAC-SHA256.</li> | <li>The encryption and HMAC keys are derived from that 256 bit key using HMAC-SHA256.</li> | ||
<li>In third round trip: | <li>In third round trip: | ||
<ul><li>Mobile hashes the | <ul><li>Mobile encrypts the known message "0123456789ABCDEF" with the key, hashes the resulting ciphertext with HMAC-SHA256, and uploads it.</li> | ||
<li>Desktop verifies | <li>Desktop verifies that against the known message encrypted with its key, encrypts the credentials with the encryption key and uploads the encrypted credentials in turn, adding a HMAC-SHA256 hash of the ciphertext (using the HMAC key).</li> | ||
<li>Mobile verifies whether Desktop had the right key by checking the ciphertext against the HMAC-SHA256 hash.</li> | <li>Mobile verifies whether Desktop had the right key by checking the ciphertext against the HMAC-SHA256 hash.</li> | ||
<li>If that verification is successful, Mobile decrypts ciphertext and applies credentials</li> | <li>If that verification is successful, Mobile decrypts ciphertext and applies credentials</li> | ||