{"record":{"id":"0b8d1449339ca022","repo":"netbirdio/netbird","slug":"could-not-create-a-code-verifier-v","errorCode":null,"errorMessage":"could not create a code verifier: %v","messagePattern":"could not create a code verifier: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"client/internal/auth/pkce_flow.go","lineNumber":145,"sourceCode":"\t}, nil\n}\n\n// GetClientID returns the provider client id\nfunc (p *PKCEAuthorizationFlow) GetClientID(_ context.Context) string {\n\treturn p.providerConfig.ClientID\n}\n\n// RequestAuthInfo requests a authorization code login flow information.\nfunc (p *PKCEAuthorizationFlow) RequestAuthInfo(ctx context.Context) (AuthFlowInfo, error) {\n\tstate, err := randomBytesInHex(24)\n\tif err != nil {\n\t\treturn AuthFlowInfo{}, fmt.Errorf(\"could not generate random state: %v\", err)\n\t}\n\tp.state = state\n\n\tcodeVerifier, err := randomBytesInHex(64)\n\tif err != nil {\n\t\treturn AuthFlowInfo{}, fmt.Errorf(\"could not create a code verifier: %v\", err)\n\t}\n\tp.codeVerifier = codeVerifier\n\n\tcodeChallenge := createCodeChallenge(codeVerifier)\n\n\tparams := []oauth2.AuthCodeOption{\n\t\toauth2.SetAuthURLParam(\"code_challenge_method\", \"S256\"),\n\t\toauth2.SetAuthURLParam(\"code_challenge\", codeChallenge),\n\t\toauth2.SetAuthURLParam(\"audience\", p.providerConfig.Audience),\n\t}\n\tif !p.providerConfig.DisablePromptLogin {\n\t\tswitch p.providerConfig.LoginFlag {\n\t\tcase common.LoginFlagPromptLogin:\n\t\t\tparams = append(params, oauth2.SetAuthURLParam(\"prompt\", \"login\"))\n\t\tcase common.LoginFlagMaxAge0:\n\t\t\tparams = append(params, oauth2.SetAuthURLParam(\"max_age\", \"0\"))\n\t\t}\n\t}","sourceCodeStart":127,"sourceCodeEnd":163,"githubUrl":"https://github.com/netbirdio/netbird/blob/93e97f4bf1ad715072dcb3fb6cdb1763431b5a9c/client/internal/auth/pkce_flow.go#L127-L163","documentation":"Returned by PKCEAuthorizationFlow.RequestAuthInfo when randomBytesInHex(64) fails while generating the PKCE code verifier (client/internal/auth/pkce_flow.go:143-146). Same mechanism as error 937: io.ReadFull on crypto/rand.Reader returned an error, so the 64-byte verifier could not be produced and the flow cannot proceed (S256 code challenge is derived from this verifier).","triggerScenarios":"Identical to 937 but at the verifier step, immediately after the state was generated successfully: crypto/rand exhaustion or blocking occurs between the two reads, or the entropy source fails outright at this call.","commonSituations":"Same rare host environments as 937: entropy-starved VMs/containers, sandboxed runtimes blocking getrandom. Seeing 937 and 938 together confirms a host entropy problem rather than transient noise.","solutions":["Verify host entropy availability and retry after the system warms up","Provide hardware/virtio RNG to guests; upgrade the kernel","Check that the security policy permits random-number syscalls for the agent process"],"exampleFix":null,"handlingStrategy":"retry","validationCode":null,"typeGuard":null,"tryCatchPattern":"if err != nil && strings.Contains(err.Error(), \"could not create a code verifier\") {\n\t// same class as 937: crypto/rand failed; fix host entropy and retry the flow\n}","preventionTips":["Treat repeated random-generation failures as an environment defect, not an app bug","Monitor entropy on embedded/VM hosts running the agent","Retry the login flow once the host CRNG is initialized"],"tags":["crypto","entropy","pkce","sandbox","vm"],"backgroundTag":null,"analyzedSha":"93e97f4bf1ad715072dcb3fb6cdb1763431b5a9c","analyzedAt":"2026-08-16T03:09:19.136Z","schemaVersion":2},"datasetVersion":"2026-08-16T08:17:34.114Z"}