httpsig/httpsig.go at master · go-fed/httpsig · GitHub

History

361 lines (332 loc) · 14.1 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

// Implements HTTP request and response signing and verification. Supports the

// major MAC and asymmetric key signature algorithms. It has several safety

// restrictions: One, none of the widely known non-cryptographically safe

// algorithms are permitted; Two, the RSA SHA256 algorithms must be available in

// the binary (and it should, barring export restrictions); Finally, the library

// assumes either the 'Authorizationn' or 'Signature' headers are to be set (but

// not both).

package httpsig

import (

"crypto"

"fmt"

"net/http"

"strings"

"time"

"golang.org/x/crypto/ssh"

)

// Algorithm specifies a cryptography secure algorithm for signing HTTP requests

// and responses.

type Algorithm string

const (

// MAC-based algoirthms.

HMAC_SHA224 Algorithm = hmacPrefix + "-" + sha224String

HMAC_SHA256 Algorithm = hmacPrefix + "-" + sha256String

HMAC_SHA384 Algorithm = hmacPrefix + "-" + sha384String

HMAC_SHA512 Algorithm = hmacPrefix + "-" + sha512String

HMAC_RIPEMD160 Algorithm = hmacPrefix + "-" + ripemd160String

HMAC_SHA3_224 Algorithm = hmacPrefix + "-" + sha3_224String

HMAC_SHA3_256 Algorithm = hmacPrefix + "-" + sha3_256String

HMAC_SHA3_384 Algorithm = hmacPrefix + "-" + sha3_384String

HMAC_SHA3_512 Algorithm = hmacPrefix + "-" + sha3_512String

HMAC_SHA512_224 Algorithm = hmacPrefix + "-" + sha512_224String

HMAC_SHA512_256 Algorithm = hmacPrefix + "-" + sha512_256String

HMAC_BLAKE2S_256 Algorithm = hmacPrefix + "-" + blake2s_256String

HMAC_BLAKE2B_256 Algorithm = hmacPrefix + "-" + blake2b_256String

HMAC_BLAKE2B_384 Algorithm = hmacPrefix + "-" + blake2b_384String

HMAC_BLAKE2B_512 Algorithm = hmacPrefix + "-" + blake2b_512String

BLAKE2S_256 Algorithm = blake2s_256String

BLAKE2B_256 Algorithm = blake2b_256String

BLAKE2B_384 Algorithm = blake2b_384String

BLAKE2B_512 Algorithm = blake2b_512String

// RSA-based algorithms.

RSA_SHA1 Algorithm = rsaPrefix + "-" + sha1String

RSA_SHA224 Algorithm = rsaPrefix + "-" + sha224String

// RSA_SHA256 is the default algorithm.

RSA_SHA256 Algorithm = rsaPrefix + "-" + sha256String

RSA_SHA384 Algorithm = rsaPrefix + "-" + sha384String

RSA_SHA512 Algorithm = rsaPrefix + "-" + sha512String

RSA_RIPEMD160 Algorithm = rsaPrefix + "-" + ripemd160String

// ECDSA algorithms

ECDSA_SHA224 Algorithm = ecdsaPrefix + "-" + sha224String

ECDSA_SHA256 Algorithm = ecdsaPrefix + "-" + sha256String

ECDSA_SHA384 Algorithm = ecdsaPrefix + "-" + sha384String

ECDSA_SHA512 Algorithm = ecdsaPrefix + "-" + sha512String

ECDSA_RIPEMD160 Algorithm = ecdsaPrefix + "-" + ripemd160String

// ED25519 algorithms

// can only be SHA512

ED25519 Algorithm = ed25519Prefix

// Just because you can glue things together, doesn't mean they will

// work. The following options are not supported.

rsa_SHA3_224 Algorithm = rsaPrefix + "-" + sha3_224String

rsa_SHA3_256 Algorithm = rsaPrefix + "-" + sha3_256String

rsa_SHA3_384 Algorithm = rsaPrefix + "-" + sha3_384String

rsa_SHA3_512 Algorithm = rsaPrefix + "-" + sha3_512String

rsa_SHA512_224 Algorithm = rsaPrefix + "-" + sha512_224String

rsa_SHA512_256 Algorithm = rsaPrefix + "-" + sha512_256String

rsa_BLAKE2S_256 Algorithm = rsaPrefix + "-" + blake2s_256String

rsa_BLAKE2B_256 Algorithm = rsaPrefix + "-" + blake2b_256String

rsa_BLAKE2B_384 Algorithm = rsaPrefix + "-" + blake2b_384String

rsa_BLAKE2B_512 Algorithm = rsaPrefix + "-" + blake2b_512String

)

// HTTP Signatures can be applied to different HTTP headers, depending on the

// expected application behavior.

type SignatureScheme string

const (

// Signature will place the HTTP Signature into the 'Signature' HTTP

// header.

Signature SignatureScheme = "Signature"

// Authorization will place the HTTP Signature into the 'Authorization'

// HTTP header.

Authorization SignatureScheme = "Authorization"

)

const (

// The HTTP Signatures specification uses the "Signature" auth-scheme

// for the Authorization header. This is coincidentally named, but not

// semantically the same, as the "Signature" HTTP header value.

signatureAuthScheme = "Signature"

)

// There are subtle differences to the values in the header. The Authorization

// header has an 'auth-scheme' value that must be prefixed to the rest of the

// key and values.

func (s SignatureScheme) authScheme() string {

switch s {

case Authorization:

return signatureAuthScheme

default:

return ""

}

// Signers will sign HTTP requests or responses based on the algorithms and

// headers selected at creation time.

// Signers are not safe to use between multiple goroutines.

// Note that signatures do set the deprecated 'algorithm' parameter for

// backwards compatibility.

type Signer interface {

// SignRequest signs the request using a private key. The public key id

// is used by the HTTP server to identify which key to use to verify the

// signature.

// If the Signer was created using a MAC based algorithm, then the key

// is expected to be of type []byte. If the Signer was created using an

// RSA based algorithm, then the private key is expected to be of type

// *rsa.PrivateKey.

// A Digest (RFC 3230) will be added to the request. The body provided

// must match the body used in the request, and is allowed to be nil.

// The Digest ensures the request body is not tampered with in flight,

// and if the signer is created to also sign the "Digest" header, the

// HTTP Signature will then ensure both the Digest and body are not both

// modified to maliciously represent different content.

SignRequest(pKey crypto.PrivateKey, pubKeyId string, r *http.Request, body []byte) error

// SignResponse signs the response using a private key. The public key

// id is used by the HTTP client to identify which key to use to verify

// the signature.

// If the Signer was created using a MAC based algorithm, then the key

// is expected to be of type []byte. If the Signer was created using an

// RSA based algorithm, then the private key is expected to be of type

// *rsa.PrivateKey.

// A Digest (RFC 3230) will be added to the response. The body provided

// must match the body written in the response, and is allowed to be

// nil. The Digest ensures the response body is not tampered with in

// flight, and if the signer is created to also sign the "Digest"

// header, the HTTP Signature will then ensure both the Digest and body

// are not both modified to maliciously represent different content.

SignResponse(pKey crypto.PrivateKey, pubKeyId string, r http.ResponseWriter, body []byte) error

}

// NewSigner creates a new Signer with the provided algorithm preferences to

// make HTTP signatures. Only the first available algorithm will be used, which

// is returned by this function along with the Signer. If none of the preferred

// algorithms were available, then the default algorithm is used. The headers

// specified will be included into the HTTP signatures.

// The Digest will also be calculated on a request's body using the provided

// digest algorithm, if "Digest" is one of the headers listed.

// The provided scheme determines which header is populated with the HTTP

// Signature.

// An error is returned if an unknown or a known cryptographically insecure

// Algorithm is provided.

func NewSigner(prefs []Algorithm, dAlgo DigestAlgorithm, headers []string, scheme SignatureScheme, expiresIn int64) (Signer, Algorithm, error) {

for _, pref := range prefs {

s, err := newSigner(pref, dAlgo, headers, scheme, expiresIn)

if err != nil {

continue

}

return s, pref, err

}

s, err := newSigner(defaultAlgorithm, dAlgo, headers, scheme, expiresIn)

return s, defaultAlgorithm, err

}

// Signers will sign HTTP requests or responses based on the algorithms and

// headers selected at creation time.

// Signers are not safe to use between multiple goroutines.

// Note that signatures do set the deprecated 'algorithm' parameter for

// backwards compatibility.

type SSHSigner interface {

// SignRequest signs the request using ssh.Signer.

// The public key id is used by the HTTP server to identify which key to use

// to verify the signature.

// A Digest (RFC 3230) will be added to the request. The body provided

// must match the body used in the request, and is allowed to be nil.

// The Digest ensures the request body is not tampered with in flight,

// and if the signer is created to also sign the "Digest" header, the

// HTTP Signature will then ensure both the Digest and body are not both

// modified to maliciously represent different content.

SignRequest(pubKeyId string, r *http.Request, body []byte) error

// SignResponse signs the response using ssh.Signer. The public key

// id is used by the HTTP client to identify which key to use to verify

// the signature.

// A Digest (RFC 3230) will be added to the response. The body provided

// must match the body written in the response, and is allowed to be

// nil. The Digest ensures the response body is not tampered with in

// flight, and if the signer is created to also sign the "Digest"

// header, the HTTP Signature will then ensure both the Digest and body

// are not both modified to maliciously represent different content.

SignResponse(pubKeyId string, r http.ResponseWriter, body []byte) error

}

// NewwSSHSigner creates a new Signer using the specified ssh.Signer

// At the moment only ed25519 ssh keys are supported.

// The headers specified will be included into the HTTP signatures.

// The Digest will also be calculated on a request's body using the provided

// digest algorithm, if "Digest" is one of the headers listed.

// The provided scheme determines which header is populated with the HTTP

// Signature.

func NewSSHSigner(s ssh.Signer, dAlgo DigestAlgorithm, headers []string, scheme SignatureScheme, expiresIn int64) (SSHSigner, Algorithm, error) {

sshAlgo := getSSHAlgorithm(s.PublicKey().Type())

if sshAlgo == "" {

return nil, "", fmt.Errorf("key type: %s not supported yet.", s.PublicKey().Type())

}

signer, err := newSSHSigner(s, sshAlgo, dAlgo, headers, scheme, expiresIn)

if err != nil {

return nil, "", err

}

return signer, sshAlgo, nil

}

func getSSHAlgorithm(pkType string) Algorithm {

switch {

case strings.HasPrefix(pkType, sshPrefix+"-"+ed25519Prefix):

return ED25519

case strings.HasPrefix(pkType, sshPrefix+"-"+rsaPrefix):

return RSA_SHA1

}

return ""

}

// Verifier verifies HTTP Signatures.

// It will determine which of the supported headers has the parameters

// that define the signature.

// Verifiers are not safe to use between multiple goroutines.

// Note that verification ignores the deprecated 'algorithm' parameter.

type Verifier interface {

// KeyId gets the public key id that the signature is signed with.

// Note that the application is expected to determine the algorithm

// used based on metadata or out-of-band information for this key id.

KeyId() string

// Verify accepts the public key specified by KeyId and returns an

// error if verification fails or if the signature is malformed. The

// algorithm must be the one used to create the signature in order to

// pass verification. The algorithm is determined based on metadata or

// out-of-band information for the key id.

// If the signature was created using a MAC based algorithm, then the

// key is expected to be of type []byte. If the signature was created

// using an RSA based algorithm, then the public key is expected to be

// of type *rsa.PublicKey.

Verify(pKey crypto.PublicKey, algo Algorithm) error

}

const (

// host is treated specially because golang may not include it in the

// request header map on the server side of a request.

hostHeader = "Host"

)

// NewVerifier verifies the given request. It returns an error if the HTTP

// Signature parameters are not present in any headers, are present in more than

// one header, are malformed, or are missing required parameters. It ignores

// unknown HTTP Signature parameters.

func NewVerifier(r *http.Request) (Verifier, error) {

h := r.Header

if _, hasHostHeader := h[hostHeader]; len(r.Host) > 0 && !hasHostHeader {

h[hostHeader] = []string{r.Host}

}

return newVerifier(h, func(h http.Header, toInclude []string, created int64, expires int64) (string, error) {

return signatureString(h, toInclude, addRequestTarget(r), created, expires)

})

}

// NewResponseVerifier verifies the given response. It returns errors under the

// same conditions as NewVerifier.

func NewResponseVerifier(r *http.Response) (Verifier, error) {

return newVerifier(r.Header, func(h http.Header, toInclude []string, created int64, expires int64) (string, error) {

return signatureString(h, toInclude, requestTargetNotPermitted, created, expires)

})

}

func newSSHSigner(sshSigner ssh.Signer, algo Algorithm, dAlgo DigestAlgorithm, headers []string, scheme SignatureScheme, expiresIn int64) (SSHSigner, error) {

var expires, created int64 = 0, 0

if expiresIn != 0 {

created = time.Now().Unix()

expires = created + expiresIn

}

s, err := signerFromSSHSigner(sshSigner, string(algo))

if err != nil {

return nil, fmt.Errorf("no crypto implementation available for ssh algo %q: %s", algo, err)

}

a := &asymmSSHSigner{

asymmSigner: &asymmSigner{

s: s,

dAlgo: dAlgo,

headers: headers,

targetHeader: scheme,

prefix: scheme.authScheme(),

created: created,

expires: expires,

}

return a, nil

}

func newSigner(algo Algorithm, dAlgo DigestAlgorithm, headers []string, scheme SignatureScheme, expiresIn int64) (Signer, error) {

var expires, created int64 = 0, 0

if expiresIn != 0 {

created = time.Now().Unix()

expires = created + expiresIn

}

s, err := signerFromString(string(algo))

if err == nil {

a := &asymmSigner{

s: s,

dAlgo: dAlgo,

headers: headers,

targetHeader: scheme,

prefix: scheme.authScheme(),

created: created,

expires: expires,

}

return a, nil

}

m, err := macerFromString(string(algo))

if err != nil {

return nil, fmt.Errorf("no crypto implementation available for %q: %s", algo, err)

}

c := &macSigner{

m: m,

dAlgo: dAlgo,

headers: headers,

targetHeader: scheme,

prefix: scheme.authScheme(),

created: created,

expires: expires,

}

return c, nil

}

httpsig/httpsig.go at master · go-fed/httpsig · GitHub

Uh oh!

Expand file tree

Breadcrumbs

httpsig.go

Latest commit

History

Breadcrumbs

httpsig.go

File metadata and controls