我正在尝试将公钥从我的 iPhone 传递给其他方，但是我无法使用 iOS 的输出。
let parameters: [String: Any] = [
kSecAttrKeySizeInBits as String: 384,
kSecAttrKeyType as String: kSecAttrKeyTypeEC,
kSecPrivateKeyAttrs as String: [
kSecAttrIsPermanent as String: false
]
]
var error: Unmanaged<CFError>?
let privateKey = SecKeyCreateRandomKey(parameters as CFDictionary, &error)
let publicKey = SecKeyCopyPublicKey(privateKey!)
let pub = SecKeyCopyExternalRepresentation(publicKey!, &error)
let pubData = pub as Data?
print(pubData!.base64EncodedString())
输出示例：
BJSCZtBatd2BYEHtyLB0qTZNlphKf3ZTGI6Nke3dSxIDpyP9FWMZbG0zcdIXWEyndskfxV0No/yz369ngL2EHZYw6ggNysOnZ5IQSPOLFFl44m1aAk0o0NdaRXTVAz4jQ==
在Python（我的第二方所在的地方）中，我有以下内容：
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import serialization
pub_key = serialisation.load_pem_public_key(
data=xcode_data.encode(),
backend=default_backend()
)
我得到的错误是
ValueError: Could not deserialize key data.那么文档中描述的
SecKeyCopyExternalRepresentation该方法返回 RSA 密钥的 PCKS #1 格式的数据。对于椭圆曲线公钥，格式遵循 ANSI X9.63 标准，使用字节字符串 04 || X|| Y. 对于椭圆曲线私钥，输出格式为与秘密标量的大端编码连接的公钥，或 04 || X||是|| K. 所有这些表示都使用恒定大小的整数，包括根据需要的前导零。
如何描述
X6.93附注我尝试将
-----BEGIN PUBLIC KEY-----我还没有找到问题的答案，因为我仍然不知道Apple提供的输出到底是什么，但是，我在这个关键导入导出管理器中找到了一个解决方案。
let parameters: [String: Any] = [
kSecAttrKeySizeInBits as String: 384,
kSecAttrKeyType as String: kSecAttrKeyTypeEC,
kSecPrivateKeyAttrs as String: [
kSecAttrIsPermanent as String: false
]
]
var pubKey: SecKey?
var priKey: SecKey?
var error: Unmanaged<CFError>?
let keyPair = SecKeyGeneratePair(parameters as CFDictionary, &pubKey, &priKey)
let publicKeyData = SecKeyCopyExternalRepresentation(pubKey!, &error)
// Code from the library
let ieManager = CryptoExportImportManager()
if let exportPEM = ieManager.exportPublicKeyToPEM(publicKeyData as Data!, keyType: kSecAttrKeyTypeEC as String, keySize: 384) {
print(exportPEM)
} else {
print("Error exporting to PEM")
}
输出示例：
Exporting EC raw key: 97 bytes -----BEGIN PUBLIC KEY----- MHYwEAYHKoZIzj0CAQYFK4EEACIDYgAEFpCnTrJFQq0mZBvy+vzl9noKLZ4/s1cf I6hygug6s8dvBreMhabAcAbbhSa1losjCxV450nq92W9ZymonYasaAuhshDWjmvx 2qTXHEpVEVb9GawqX6XqpWtIBf+meHKS -----END PUBLIC KEY-----Python 实现 使用密码学
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import serialization
xcode = '-----BEGIN PUBLIC KEY-----\nMHYwEAYHKoZIzj0CAQYFK4EEACIDYgAEFpCnTrJFQq0mZBvy+vzl9noKLZ4/s1cf\nI6hygug6s8dvBreMhabAcAbbhSa1losjCxV450nq92W9ZymonYasaAuhshDWjmvx2\nqTXHEpVEVb9GawqX6XqpWtIBf+meHKS\n-----END PUBLIC KEY-----'
pub_key = serialization.load_pem_public_key(xcode.encode(), default_backend())
xcode
输出以下内容：
<cryptography.hazmat.backends.openssl.ec._EllipticCurvePublicKey object at 0x7fb4f6f50e10>请注意，您必须自己在 python 中添加新行才能使这一切正常工作。
更新
ECC 密钥的
SecKeyCopyExternalRepresentation公钥的编码为
04 || X || Y04 || X || Y || K04XYK我将为那些无法使用第三方的人提供答案。
输出格式为04 || X||是[ || K] 没有许多外部系统期望的 EC 标头标识符。将其导出到其他平台时，您需要添加该标头。这是一个例子：
let fullKeyData = CFDataCreateMutable(kCFAllocatorDefault, CFIndex(0))
if fullKeyData != nil
{
//Fixed schema header per key size in bits
//var headerBytes256r1: [UInt8] = [0x30, 0x59, 0x30, 0x13, 0x06, 0x07, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01, 0x06, 0x08, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07, 0x03, 0x42, 0x00] //uncomment if you use 256 bit EC keys
var header384r1: [UInt8] = [0x30, 0x76, 0x30, 0x10, 0x06, 0x07, 0x2A, 0x86, 0x48, 0xCE, 0x3D, 0x02, 0x01, 0x06, 0x05, 0x2B, 0x81, 0x04, 0x00, 0x22, 0x03, 0x62, 0x00] //384 bit EC keys
//var header521r1: [UInt8] = [0x30, 0x81, 0x9B, 0x30, 0x10, 0x06, 0x07, 0x2A, 0x86, 0x48, 0xCE, 0x3D, 0x02, 0x01, 0x06, 0x05, 0x2B, 0x81, 0x04, 0x00, 0x23, 0x03, 0x81, 0x86, 0x00] // For 521 bit EC keys
let headerSize = CFIndex(header384r1.count)
CFDataAppendBytes(fullKeyData, &header384r1, headerSize)
CFDataAppendBytes(fullKeyData, CFDataGetBytePtr(pub), CFDataGetLength(pub)) //pub = data you got from SecKeyCopyExternalRepresentation
var pem = ""
//pem.append("-----BEGIN PUBLIC KEY-----\n") //uncomment if needed
pem.append((fullKeyData as Data?)?.base64EncodedString() ?? "")
//pem.append("\n-----END PUBLIC KEY-----\n") //uncomment if needed
//do something with pem
}
BJSCZtBatd2BYEHtyLB0qTZNlphKf3ZTGI6Nke3dSxIDpyP9FWMZbG0zcdIXWEyndskfxV0No/yz369ngL2EHZYw6ggNysOnZ5IQSPOLFFl44m1aAk0o0NdaRXTVAz4jQ==
密钥似乎格式错误。
它似乎是 EC 密钥。我怀疑这是公开的，详细信息为
04 || X || YXY$ cat key.dat
BJSCZtBatd2BYEHtyLB0qTZNlphKf3ZTGI6Nke3dSxIDpyP9FWMZbG0zcdIXWENyndskfxV0No/yz369ngL2EHZYw6ggNysOnZ5IQSPOLFFl44m1aAk0o0NdaRXTVAz4jQ==
$ base64 -d key.dat | hexdump -C
00000000 04 94 82 66 d0 5a b5 dd 81 60 41 ed c8 b0 74 a9 |...f.Z...`A...t.|
00000010 36 4d 96 98 4a 7f 76 53 18 8e 8d 91 ed dd 4b 12 |6M..J.vS......K.|
00000020 03 a7 23 fd 15 63 19 6c 6d 33 71 d2 17 58 43 72 |..#..c.lm3q..XCr|
00000030 9d db 24 7f 15 74 36 8f f2 cf 7e bd 9e 02 f6 10 |..$..t6...~.....|
00000040 76 58 c3 a8 20 37 2b 0e 9d 9e 48 41 23 ce 2c 51 |vX.. 7+...HA#.,Q|
00000050 65 e3 89 b5 68 09 34 a3 43 5d 69 15 d3 54 0c f8 |e...h.4.C]i..T..|
00000060 8d |.|
00000061
对于椭圆曲线密钥，您可以使用 CryptoKit 的
P256.Signing.PublicKey例如：
import CryptoKit
let externalRepresentation = SecKeyCopyExternalRepresentation(...)
let p256PublicKey = try P256.Signing.PublicKey(x963Representation: externalRepresentation ?? Data())
let derData = p256PublicKey.derRepresentation
print(derData.base64EncodedString())
// MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEBstxGDlRch5JplnnBRXSG8X+pxV25WcfGH/+h6sG8XgiCxR+W2x9y0wcqnD5GF7clLbOqnEjPWEv2GXsJ1mfSw==
如果您需要 PEM 而不是 DER 表示形式，则可以使用
p256PublicKey.pemRepresentation-----BEGIN PUBLIC KEY-----
MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEBstxGDlRch5JplnnBRXSG8X+pxV2
5WcfGH/+h6sG8XgiCxR+W2x9y0wcqnD5GF7clLbOqnEjPWEv2GXsJ1mfSw==
-----END PUBLIC KEY-----