{"record":{"id":"ede9938286e90ba0","repo":"getsops/sops","slug":"failed-to-generate-polynomial-w","errorCode":null,"errorMessage":"failed to generate polynomial: %w","messagePattern":"failed to generate polynomial: %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"shamir/shamir.go","lineNumber":234,"sourceCode":"\tfor idx := range out {\n\t\t// Store the x coordinate for each part as its last byte\n\t\t// Add 1 to the xCoordinate because if the x coordinate is 0,\n\t\t// then the result of evaluating the polynomial at that point\n\t\t// will be our secret\n\t\tout[idx] = make([]byte, len(secret)+1)\n\t\tout[idx][len(secret)] = uint8(idx) + 1\n\t}\n\n\t// Construct a random polynomial for each byte of the secret.\n\t// Because we are using a field of size 256, we can only represent\n\t// a single byte as the intercept of the polynomial, so we must\n\t// use a new polynomial for each byte.\n\tfor idx, val := range secret {\n\t\t// Create a random polynomial for each point.\n\t\t// This polynomial crosses the y axis at `val`.\n\t\tp, err := makePolynomial(val, uint8(threshold-1))\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"failed to generate polynomial: %w\", err)\n\t\t}\n\n\t\t// Generate a `parts` number of (x,y) pairs\n\t\t// We cheat by encoding the x value once as the final index,\n\t\t// so that it only needs to be stored once.\n\t\tfor i := 0; i < parts; i++ {\n\t\t\t// Add 1 to the xCoordinate because if it's 0,\n\t\t\t// then the result of p.evaluate(x) will be our secret\n\t\t\tx := uint8(i) + 1\n\t\t\t// Evaluate the polynomial at x\n\t\t\ty := p.evaluate(x)\n\t\t\tout[i][idx] = y\n\t\t}\n\t}\n\n\t// Return the encoded secrets\n\treturn out, nil\n}","sourceCodeStart":216,"sourceCodeEnd":252,"githubUrl":"https://github.com/getsops/sops/blob/13442bb98183887d7a9ac09ec8ab0564673a59d8/shamir/shamir.go#L216-L252","documentation":"For each byte of the secret, Split() creates a random polynomial via makePolynomial; this error wraps a failure from that helper (typically a randomness-source failure such as rand.Read erroring). The library throws it because without a polynomial it cannot produce shares.","triggerScenarios":"Calling Split with valid args but makePolynomial failing because the system CSPRNG (crypto/rand) fails — e.g. exhausted entropy, broken /dev/urandom in a container.","commonSituations":"Running in stripped-down containers/chroots where /dev/urandom is unavailable, sandboxed CI environments with restricted syscalls (getrandom blocked).","solutions":["Fix the underlying entropy source: ensure /dev/urandom is accessible or getrandom(2) works in the runtime environment.","Inspect the wrapped %w cause to confirm the rand failure.","Retry after environment repair; randomness failures are usually environmental.","Check seccomp/AppArmor policies blocking getrandom in containers."],"exampleFix":"// after seeing: failed to generate polynomial: ... /dev/urandom ...\n// in Docker, keep default devices and avoid seccomp rules blocking getrandom:\ndocker run --device /dev/urandom ...","handlingStrategy":"retry","validationCode":null,"typeGuard":null,"tryCatchPattern":"shares, err := shamir.Split(secret, parts, threshold)\nif err != nil && strings.Contains(err.Error(), \"failed to generate polynomial\") {\n    // entropy source issue; brief backoff then retry\n    time.Sleep(100 * time.Millisecond)\n    shares, err = shamir.Split(secret, parts, threshold)\n}","preventionTips":["Ensure /dev/urandom availability in containers","Audit seccomp profiles for getrandom blocks","Monitor entropy-related errors in sandboxed CI"],"tags":["shamir","cryptography","randomness","entropy","go"],"backgroundTag":"csprng-failure","analyzedSha":"13442bb98183887d7a9ac09ec8ab0564673a59d8","analyzedAt":"2026-09-01T03:53:00.447Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}