diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/obscuren/ecies/params.go')
| -rw-r--r-- | Godeps/_workspace/src/github.com/obscuren/ecies/params.go | 187 |
1 files changed, 0 insertions, 187 deletions
diff --git a/Godeps/_workspace/src/github.com/obscuren/ecies/params.go b/Godeps/_workspace/src/github.com/obscuren/ecies/params.go deleted file mode 100644 index b968c7c17..000000000 --- a/Godeps/_workspace/src/github.com/obscuren/ecies/params.go +++ /dev/null @@ -1,187 +0,0 @@ -package ecies - -// This file contains parameters for ECIES encryption, specifying the -// symmetric encryption and HMAC parameters. - -import ( - "crypto" - "crypto/aes" - "crypto/cipher" - "crypto/elliptic" - "crypto/sha256" - "crypto/sha512" - "fmt" - "hash" -) - -// The default curve for this package is the NIST P256 curve, which -// provides security equivalent to AES-128. -var DefaultCurve = elliptic.P256() - -var ( - ErrUnsupportedECDHAlgorithm = fmt.Errorf("ecies: unsupported ECDH algorithm") - ErrUnsupportedECIESParameters = fmt.Errorf("ecies: unsupported ECIES parameters") -) - -type ECIESParams struct { - Hash func() hash.Hash // hash function - hashAlgo crypto.Hash - Cipher func([]byte) (cipher.Block, error) // symmetric cipher - BlockSize int // block size of symmetric cipher - KeyLen int // length of symmetric key -} - -// Standard ECIES parameters: -// * ECIES using AES128 and HMAC-SHA-256-16 -// * ECIES using AES256 and HMAC-SHA-256-32 -// * ECIES using AES256 and HMAC-SHA-384-48 -// * ECIES using AES256 and HMAC-SHA-512-64 -var ( - ECIES_AES128_SHA256 *ECIESParams - ECIES_AES256_SHA256 *ECIESParams - ECIES_AES256_SHA384 *ECIESParams - ECIES_AES256_SHA512 *ECIESParams -) - -func init() { - ECIES_AES128_SHA256 = &ECIESParams{ - Hash: sha256.New, - hashAlgo: crypto.SHA256, - Cipher: aes.NewCipher, - BlockSize: aes.BlockSize, - KeyLen: 16, - } - - ECIES_AES256_SHA256 = &ECIESParams{ - Hash: sha256.New, - hashAlgo: crypto.SHA256, - Cipher: aes.NewCipher, - BlockSize: aes.BlockSize, - KeyLen: 32, - } - - ECIES_AES256_SHA384 = &ECIESParams{ - Hash: sha512.New384, - hashAlgo: crypto.SHA384, - Cipher: aes.NewCipher, - BlockSize: aes.BlockSize, - KeyLen: 32, - } - - ECIES_AES256_SHA512 = &ECIESParams{ - Hash: sha512.New, - hashAlgo: crypto.SHA512, - Cipher: aes.NewCipher, - BlockSize: aes.BlockSize, - KeyLen: 32, - } -} - -var paramsFromCurve = map[elliptic.Curve]*ECIESParams{ - elliptic.P256(): ECIES_AES128_SHA256, - elliptic.P384(): ECIES_AES256_SHA384, - elliptic.P521(): ECIES_AES256_SHA512, -} - -func AddParamsForCurve(curve elliptic.Curve, params *ECIESParams) { - paramsFromCurve[curve] = params -} - -// ParamsFromCurve selects parameters optimal for the selected elliptic curve. -// Only the curves P256, P384, and P512 are supported. -func ParamsFromCurve(curve elliptic.Curve) (params *ECIESParams) { - return paramsFromCurve[curve] - - /* - switch curve { - case elliptic.P256(): - return ECIES_AES128_SHA256 - case elliptic.P384(): - return ECIES_AES256_SHA384 - case elliptic.P521(): - return ECIES_AES256_SHA512 - default: - return nil - } - */ -} - -// ASN.1 encode the ECIES parameters relevant to the encryption operations. -func paramsToASNECIES(params *ECIESParams) (asnParams asnECIESParameters) { - if nil == params { - return - } - asnParams.KDF = asnNISTConcatenationKDF - asnParams.MAC = hmacFull - switch params.KeyLen { - case 16: - asnParams.Sym = aes128CTRinECIES - case 24: - asnParams.Sym = aes192CTRinECIES - case 32: - asnParams.Sym = aes256CTRinECIES - } - return -} - -// ASN.1 encode the ECIES parameters relevant to ECDH. -func paramsToASNECDH(params *ECIESParams) (algo asnECDHAlgorithm) { - switch params.hashAlgo { - case crypto.SHA224: - algo = dhSinglePass_stdDH_sha224kdf - case crypto.SHA256: - algo = dhSinglePass_stdDH_sha256kdf - case crypto.SHA384: - algo = dhSinglePass_stdDH_sha384kdf - case crypto.SHA512: - algo = dhSinglePass_stdDH_sha512kdf - } - return -} - -// ASN.1 decode the ECIES parameters relevant to the encryption stage. -func asnECIEStoParams(asnParams asnECIESParameters, params *ECIESParams) { - if !asnParams.KDF.Cmp(asnNISTConcatenationKDF) { - params = nil - return - } else if !asnParams.MAC.Cmp(hmacFull) { - params = nil - return - } - - switch { - case asnParams.Sym.Cmp(aes128CTRinECIES): - params.KeyLen = 16 - params.BlockSize = 16 - params.Cipher = aes.NewCipher - case asnParams.Sym.Cmp(aes192CTRinECIES): - params.KeyLen = 24 - params.BlockSize = 16 - params.Cipher = aes.NewCipher - case asnParams.Sym.Cmp(aes256CTRinECIES): - params.KeyLen = 32 - params.BlockSize = 16 - params.Cipher = aes.NewCipher - default: - params = nil - } -} - -// ASN.1 decode the ECIES parameters relevant to ECDH. -func asnECDHtoParams(asnParams asnECDHAlgorithm, params *ECIESParams) { - if asnParams.Cmp(dhSinglePass_stdDH_sha224kdf) { - params.hashAlgo = crypto.SHA224 - params.Hash = sha256.New224 - } else if asnParams.Cmp(dhSinglePass_stdDH_sha256kdf) { - params.hashAlgo = crypto.SHA256 - params.Hash = sha256.New - } else if asnParams.Cmp(dhSinglePass_stdDH_sha384kdf) { - params.hashAlgo = crypto.SHA384 - params.Hash = sha512.New384 - } else if asnParams.Cmp(dhSinglePass_stdDH_sha512kdf) { - params.hashAlgo = crypto.SHA512 - params.Hash = sha512.New - } else { - params = nil - } -} |