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@@ -31,8 +31,9 @@ TODO: (very soon)
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Unless otherwise specified, all symmetric ciphers are AES in counter
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mode, with an IV of all 0 bytes. Asymmetric ciphers are either RSA
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- with 1024-bit keys and exponents of 65537, or DH with the safe prime
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- from rfc2409, section 6.2, whose hex representation is:
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+ with 1024-bit keys and exponents of 65537, or DH where the generator
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+ is 2 and the modulus is the safe prime from rfc2409, section 6.2,
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+ whose hex representation is:
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"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E08"
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"8A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B"
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@@ -43,7 +44,7 @@ TODO: (very soon)
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All "hashes" are 20-byte SHA1 cryptographic digests.
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When we refer to "the hash of a public key", we mean the SHA1 hash of the
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- ASN.1 encoding of an RSA public key (as specified in PKCS.1).
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+ DER encoding of an ASN.1 RSA public key (as specified in PKCS.1).
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1. System overview
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@@ -71,9 +72,9 @@ TODO: (very soon)
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least 128 bits, and digests of at least 160 bits.
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An OP or OR always sends a two-certificate chain, consisting of a
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- self-signed certificate containing the OR's identity key, and a second
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- certificate using a short-term connection key. The commonName of the
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- second certificate is the OR's nickname, and the commonName of the first
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+ certificate using a short-term connection key and a second, self-
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+ signed certificate containing the OR's identity key. The commonName of the
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+ first certificate is the OR's nickname, and the commonName of the second
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certificate is the OR's nickname, followed by a space and the string
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"<identity>".
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@@ -164,13 +165,14 @@ TODO: (very soon)
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The payload for a CREATE cell is an 'onion skin', which consists
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of the first step of the DH handshake data (also known as g^x).
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- The data is encrypted to Bob's PK as follows: Suppose Bob's PK is
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- L octets long. If the data to be encrypted is shorter than L-42,
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- then it is encrypted directly (with OAEP padding). If the data is at
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- least as long as L-42, then a randomly generated 16-byte symmetric
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- key is prepended to the data, after which the first L-16-42 bytes
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- of the data are encrypted with Bob's PK; and the rest of the data is
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- encrypted with the symmetric key.
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+ The data is encrypted to Bob's PK as follows: Suppose Bob's PK
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+ modulus is L octets long. If the data to be encrypted is shorter
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+ than L-42, then it is encrypted directly (with OAEP padding: see
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+ ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-1/pkcs-1v2-1.pdf). If the
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+ data is at least as long as L-42, then a randomly generated 16-byte
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+ symmetric key is prepended to the data, after which the first L-16-42
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+ bytes of the data are encrypted with Bob's PK; and the rest of the
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+ data is encrypted with the symmetric key.
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So in this case, the onion skin on the wire looks like:
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RSA-encrypted:
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@@ -265,7 +267,7 @@ TODO: (very soon)
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router's exit policy does not exclude all pending streams
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that need a circuit.
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- 2. Choose a chain of (N-1) chain of N onion routers
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+ 2. Choose a chain of (N-1) onion routers
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(R_1...R_N-1) to constitute the path, such that no router
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appears in the path twice.
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