RSA_MakeKeysXtd

Generate an RSA key pair and save as two key files.

VBA/VB6 Syntax

nRet = RSA_MakeKeysXtd(strPubKeyFile, strPriKeyFile, strPassword, nBits, nExpFermat, strParams, nOptionFlags)

C/C++ Syntax

Parameters

szPubKeyFile

[in] Output filename for public key.

szPriKeyFile

[in] Output filename for (encrypted) private key.

szPassword

[in] Password for encrypted private key (required).

nBits

[in] Required key modulus size in bits (minimum 96).

nExpFermat

[in] exponent e to be used. Select from:
PKI_RSAEXP_EQ_3 for 3
PKI_RSAEXP_EQ_5 for 5
PKI_RSAEXP_EQ_17 for 17 (0x11)
PKI_RSAEXP_EQ_257 for 257 (0x101)
PKI_RSAEXP_EQ_65537 for 65537 (0x10001) (default)

szParams

[in] Optional parameters. Set as the empty string "" for defaults. Otherwise include a set of attribute-value pairs separated by a semi-colon ";" to set options from the following

• count=<nnn> to set the iteration count in the encrypted private key used in the PBKDF method, e.g. "count=5000;" [default=2048]
• prf=<hmac-name> to change the HMAC algorithm used in the PBKDF2 method, e.g. "prf=hmacWithSHA256;" [default=hmacwithSHA1]
• rngseed=<string> to add some extra user-specified additional seed for the random number generator, e.g. "rngseed=pqrrr1234xyz;"

Valid values for hmac-name are {hmacWithSHA1|hmacWithSHA224|hmacWithSHA256|hmacWithSHA384|hmacWithSHA512}.

nOptions

[in] a flag to indicate the password-based encryption scheme to be used to encrypt the private key file. Select from:
PKI_PBE_SHA_3DES (0) for "pbeWithSHAAnd3-KeyTripleDES-CBC" from PKCS12 (default)
PKI_PBE_PBKDF2_DESEDE3 for PBKDF2 using des-EDE3-CBC
PKI_PBE_PBKDF2_AES128 for PBKDF2 using aes128-CBC
PKI_PBE_PBKDF2_AES192 for PBKDF2 using aes192-CBC
PKI_PBE_PBKDF2_AES256 for PBKDF2 using aes256-CBC
(there are more options - see security options for encrypted private keys)
and optionally add
PKI_KEYGEN_INDICATE to indicate progress in a console window (see remarks below),
plus one of
PKI_KEY_FORMAT_PEM to save the key files in PEM form (default is binary DER-encoded format)
or PKI_KEY_FORMAT_SSL to save the key files in PEM form with the public key as an OpenSSL-compatible subjectPublicKeyInfo file.

Returns (VBA/C)

If successful, the return value is zero; otherwise it returns a nonzero error code.

.NET Equivalent

Rsa.MakeKeys Method

Python Equivalent

Remarks

The RSA keys are stored by default as a pair of DER-encoded binary files.

Setting the PKI_KEYGEN_INDICATE flag will show progress in a separate console window (actually two, one for p and one for q). Having a console window show progress will keep a parent application (like MS Access) happy and prevent it hanging due to boredom. The program will close these console windows down automatically (do not use Ctrl-C or Ctrl-Break: it will kill your entire process altogether!). Do not use the PKI_KEYGEN_INDICATE option in a multi-threaded environment. For console-based programs, this option just shows the progress in the standard output.

Example (VBA core function)

Example (VBA wrapper function)

Dim r As Long
' Create a 2048-bit RSA key pair using defaults
r = rsaMakeKeys("myrsa2048.pub", "myrsa2048.p8e", "password", 2048)
' Same but using stronger security and in PEM format
r = rsaMakeKeys("myrsa2048ex.pub", "myrsa2048ex.p8e", "password1", 2048,,"count=6000;prf=hmacWithSHA256", PKI_PBE_PBKDF2_AES128 Or PKI_KEY_FORMAT_PEM)

See Also

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