2.2.2 FFC DH Parameters
This structure specifies field parameters for use in deriving finite field cryptography (FFC) Diffie-Hellman (DH) ([SP800-56A] section 5.7.1) keys, as specified in section 3.1.4.1.2.
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1 |
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2 |
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3 |
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Length |
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0x44 |
0x48 |
0x50 |
0x4D |
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Key length |
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Field order (variable) |
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... |
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... |
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Generator (variable) |
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... |
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... |
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Length (4 bytes): A 32-bit unsigned integer. This field MUST be the length, in bytes, of the entire structure. This field is encoded using little-endian format.
Key length (4 bytes): A 32-bit unsigned integer. This field MUST be the length, in bytes, of the public key. This field is encoded using little-endian format.
Field order (variable): This is the large prime field order, and is a domain parameter for the FFC DH algorithm ([SP800-56A] section 5.7.1). This field parameter is referred to as p in [SP800-56A] section 3.2. It MUST be encoded in big-endian format. The length of this field, in bytes, MUST be equal to the value of the Key length field.
Generator (variable): The generator of the subgroup, a domain parameter for the FFC DH algorithm ([SP800-56A] section 5.7.1). This field parameter is referred to as g in [SP800-56A] section 3.2. It MUST be encoded in big-endian format. The length of this field, in bytes, MUST be equal to the value of the Key length field.