Signatures

Collaboration diagram for Signatures:

Data Structures
struct	mcci_tweetnacl_sign_privatekey_t
	Private Key for TweetNaCl sign operations. More...
struct	mcci_tweetnacl_sign_publickey_t
	Public Key for TweetNaCl sign operations. More...
struct	mcci_tweetnacl_sign_signature_t
	Signature block for TweetNaCl sign operations. More...

Macros
#define	mcci_tweetnacl_sign_signature_size()   sizeof(((mcci_tweetnacl_sign_signature_t *)NULL)->bytes)
	Return size of signature, in bytes. More...

Functions
mcci_tweetnacl_result_t	mcci_tweetnacl_sign (unsigned char *pSignedMessage, size_t *pSignedMessageSize, const unsigned char *pMessage, size_t messageSize, const mcci_tweetnacl_sign_privatekey_t *pPrivateKey)
	sign a message (typically a hash of the real message) More...
mcci_tweetnacl_randombytes_error_t	mcci_tweetnacl_sign_keypair (mcci_tweetnacl_sign_publickey_t *pPublicKey, mcci_tweetnacl_sign_privatekey_t *pPrivateKey)
	generate a private key and a corresponding public key More...
static mcci_tweetnacl_result_t	mcci_tweetnacl_sign_open (unsigned char *pMessage, size_t *pMessageSize, const unsigned char *pSignedMessage, size_t messageSize, const mcci_tweetnacl_sign_publickey_t *pPublicKey)
	given a signed message, verify and output signed contents More...

Detailed Description

Macro Definition Documentation

mcci_tweetnacl_sign_signature_size

#define mcci_tweetnacl_sign_signature_size

(

)

sizeof(((mcci_tweetnacl_sign_signature_t *)NULL)->bytes)

Return size of signature, in bytes.

Definition at line 103 of file mcci_tweetnacl_sign.h.

Function Documentation

mcci_tweetnacl_sign()

mcci_tweetnacl_result_t mcci_tweetnacl_sign	(	unsigned char *	pSignedMessage,
		size_t *	pSignedMessageSize,
		const unsigned char *	pMessage,
		size_t	messageSize,
		const mcci_tweetnacl_sign_privatekey_t *	pPrivateKey
	)

sign a message (typically a hash of the real message)

Parameters

[out]	pSignedMessage	points to buffer to received signed message.
[out]	pSignedMessageSize	points to cell to receive size of signed message.
[in]	pMessage	input message
[in]	messageSize	size of input message, in bytes
[in]	pPrivateKey	private key to be used to sign message.

Returns

zero if successfully signed; in which case *pSignedMessageSize is set to the size. Otherwise non-zero, in which case *pSignedMessageSize is zero.

This is a wrapper for TweetNaCl's crypto_sign(), enforcing a few adjustments. Size is a size_t rather than unsigned long long; if the input size is so large that it would wrap around, we refuse to sign, and return a failure. Because crypto_sign() productes an unsigned long long by reference, we have to stage the result and narrow it when copying back to the client. We are careful to avoid overflow, although overflow arguably is impossible.

Note

The buffer at pSignedMessage must be at least messageSize + mcci_tweetnacl_sign_signature_size() bytes long.

mcci_tweetnacl_sign_keypair()

mcci_tweetnacl_randombytes_error_t mcci_tweetnacl_sign_keypair	(	mcci_tweetnacl_sign_publickey_t *	pPublicKey,
		mcci_tweetnacl_sign_privatekey_t *	pPrivateKey
	)

generate a private key and a corresponding public key

Parameters

[out]	pPublicKey	is set to the generated public key.
[in]	pPrivateKey	is set to the generated private key.

Returns

0 for success, non-zero error code for failure.

Note

this function requires that randombytes() be implemented and successful. Further, it requires a cryptographically secure string of bytes when randombytes() succeeds.

See also

https://nacl.cr.yp.to/sign.html

mcci_tweetnacl_sign_open()

static mcci_tweetnacl_result_t mcci_tweetnacl_sign_open ( unsigned char *  pMessage, size_t *  pMessageSize, const unsigned char *  pSignedMessage, size_t  messageSize, const mcci_tweetnacl_sign_publickey_t *  pPublicKey  )

inlinestatic

given a signed message, verify and output signed contents

Parameters

[out]	pMessage	points to buffer to received verified message.
[out]	pMessageSize	points to cell to receive size of verified message.
[in]	pSignedMessage	input signed (opaque) message
[in]	messageSize	size of signed message, in bytes
[in]	pPublicKey	public key to be used to verify message.

Returns

zero if successfully verified; in which case pMessage[] is set to the validated contents, and *pMessageSize is set to the size. Otherwise non-zero, in which case pMessage[] may be changed but should be ignored.

This is a wrapper for TweetNaCl's crypto_sign_open(), enforcing a few adjustments. Size is a size_t rather than unsigned long long. Because crypto_sign_out() productes an unsigned long long by reference, we have to stage the result and narrow it when copying back to the client.

Note

messageSize must be at least 64. The buffer at pMessage must be at least messageSize - 64 bytes long.

Definition at line 162 of file mcci_tweetnacl_sign.h.

References mcci_tweetnacl_sign_publickey_t::bytes.