[.NET] - 在Create一个RSA密钥的是要注意的长度问题

有时候我们需要自己手动的创建RSA密钥，但是在密钥创建之后，在使用的时候会有类似密钥长度不正确的错误信息被抛出，那可能就是在创建一个RSA密钥的时候，对于的elements长度没设置正确，所以的elements长度要求可以在这里找到:

http://msdn.microsoft.com/en-us/library/cc250013.aspx

　　  Type (1 byte):  Length MUST be 1 byte.

　　  This field MUST be set to 0x07.

Version (1 byte):  Length MUST be 1 byte.

This field MUST be set to 0x02.

Reserved (2 bytes):  Length MUST be 2 bytes.

This field MUST be set to 0 and ignored upon receipt.

Key Alg (4 bytes):  Length MUST be 4 bytes.

This field MUST be present as an unsigned integer in little-endian format.

Value MUST be 0x0000A400 (RSA_KEYX).

Magic (4 bytes):  Length MUST be 4 bytes.

This field MUST be present as an unsigned integer in little-endian format.

Value MUST be 0x32415352 (RSA2).

Bitlen (4 bytes):  Length MUST be 4 bytes.

This field MUST be present as an unsigned integer in little-endian format.

The value of this field MUST indicate the number of bits in the (Rivest-Shamir-Adleman) RSA modules. (This is the RSA key size.)

PubExp (4 bytes):  Length MUST be 4 bytes.

This field MUST be present as an unsigned integer in little-endian format.

The value of this field MUST be the RSA public key exponent for this key. The client SHOULD set this value to 65,537.

Modulus (variable):  This field MUST be of length ceil(bl/8), where bl is the value of the Bitlen field defined in the preceding diagram.

This field MUST be present as a byte string in little-endian format.

The value MUST be the RSA key modulus. The modulus is defined as p*q.

P (variable):  This field MUST be of length ceil(bl/16), where bl is the value of the Bitlen field defined in the preceding diagram.

This field MUST be present as a byte string in little-endian format.

The value contained in this field MUST be one of the prime number factors of the modulus (given in the previous field).

Q (variable):  This field MUST be of length ceil(bl/16), where bl is the value of the Bitlen field defined in the preceding diagram.

This field MUST be present as a byte string in little-endian format.

The value MUST be the other prime number factor of the RSA modulus.

Dp (variable):  This field MUST be of length ceil(bl/16), where bl is the value of the Bitlen field defined in the preceding diagram.

This field MUST be present as a byte string in little-endian format.

The value of this field MUST be d mod (p-1), where d is the private exponent of this RSA private key.

Dq (variable):  This field MUST be of length ceil(bl/16), where bl is the value of the Bitlen field defined in the preceding diagram.

This field MUST be present as a byte string in little-endian format.

The value of this field MUST be d mod (q-1), where d is the private exponent of this RSA private key.

Iq (variable):  This field MUST be of length ceil(bl/16), where bl is the value of the Bitlen field defined in the preceding diagram.

This field MUST be present as a byte string in little-endian format.

This field MUST contain the inverse of q modulus p.

D (variable):  This field MUST be of length ceil(bl/8), where bl is the value of the Bitlen field defined in the preceding diagram.

This field MUST be present as a byte string in little-endian format.

The value in this field is the RSA private exponent.

Note  Ceil(x) is the value of x rounded up to the closest integer. For example, ceil(1.2) = 2 and ceil(3) = 3