{"record":{"id":"e2b361c8d2f5cfd8","repo":"router-for-me/CLIProxyAPI","slug":"failed-to-generate-code-verifier-w","errorCode":null,"errorMessage":"failed to generate code verifier: %w","messagePattern":"failed to generate code verifier: %w","errorType":"console","errorClass":null,"httpStatus":null,"severity":"critical","filePath":"internal/auth/claude/pkce.go","lineNumber":25,"sourceCode":"\t\"crypto/rand\"\n\t\"crypto/sha256\"\n\t\"encoding/base64\"\n\t\"fmt\"\n)\n\n// GeneratePKCECodes generates a PKCE code verifier and challenge pair\n// following RFC 7636 specifications for OAuth 2.0 PKCE extension.\n// This provides additional security for the OAuth flow by ensuring that\n// only the client that initiated the request can exchange the authorization code.\n//\n// Returns:\n//   - *PKCECodes: A struct containing the code verifier and challenge\n//   - error: An error if the generation fails, nil otherwise\nfunc GeneratePKCECodes() (*PKCECodes, error) {\n\t// Generate code verifier: 43-128 characters, URL-safe\n\tcodeVerifier, err := generateCodeVerifier()\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"failed to generate code verifier: %w\", err)\n\t}\n\n\t// Generate code challenge using S256 method\n\tcodeChallenge := generateCodeChallenge(codeVerifier)\n\n\treturn &PKCECodes{\n\t\tCodeVerifier:  codeVerifier,\n\t\tCodeChallenge: codeChallenge,\n\t}, nil\n}\n\n// generateCodeVerifier creates a cryptographically random string\n// of 128 characters using URL-safe base64 encoding\nfunc generateCodeVerifier() (string, error) {\n\t// Generate 96 random bytes (will result in 128 base64 characters)\n\tbytes := make([]byte, 96)\n\t_, err := rand.Read(bytes)\n\tif err != nil {","sourceCodeStart":7,"sourceCodeEnd":43,"githubUrl":"https://github.com/router-for-me/CLIProxyAPI/blob/78f0c4079e3e6273d65d03b5549cffc898703264/internal/auth/claude/pkce.go#L7-L43","documentation":"GeneratePKCECodes wraps the failure of generateCodeVerifier, which draws 96 bytes from crypto/rand and base64url-encodes them into a 128-char RFC 7636 verifier. The only real failure mode is the wrapped rand.Read error (see error 189); there is no user input involved. If this fires, the host's CSPRNG is unavailable.","triggerScenarios":"Calling GeneratePKCECodes() (i.e. starting any Claude OAuth login) on a system where crypto/rand.Read returns an error — typically a blocked entropy source at early boot or a broken getrandom(2) in constrained sandboxes/gVisor.","commonSituations":"Freshly booted VMs/containers where the kernel CRNG is not yet initialized; very old kernels (pre-3.17) without getrandom; minimal VMs (gVisor, some WASI runtimes) with stubbed crypto syscalls; extremely rare in normal servers.","solutions":["Check the wrapped error: on Linux it is usually getrandom blocking — wait for the CRNG to initialize (cat /proc/sys/kernel/random/entropy_avail) and retry login.","Upgrade the kernel past 3.17 / use a standard runtime instead of a stubbed sandbox.","In containers, ensure the host has booted long enough to seed the CRNG before starting the login flow."],"exampleFix":null,"handlingStrategy":"retry","validationCode":"// probe CSPRNG health before starting login\nif _, err := cryptoRandRead(32); err != nil {\n    return fmt.Errorf(\"host entropy unavailable, retry after boot: %w\", err)\n}","typeGuard":null,"tryCatchPattern":"codes, err := claude.GeneratePKCECodes()\nif err != nil {\n    if strings.Contains(err.Error(), \"random\") { // environment issue: wait and retry once\n        time.Sleep(5 * time.Second)\n        codes, err = claude.GeneratePKCECodes()\n    }\n}","preventionTips":["Delay login automation until the host CRNG is seeded (post-boot settle time).","Don't run login in exotic sandboxes lacking getrandom(2)."],"tags":["claude","oauth","pkce","crypto","entropy"],"backgroundTag":null,"analyzedSha":"78f0c4079e3e6273d65d03b5549cffc898703264","analyzedAt":"2026-08-15T12:26:37.444Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}