{"record":{"id":"cffa65497fed94d8","repo":"hyperledger/fabric","slug":"pem-decoding-resulted-in-an-empty-block","errorCode":null,"errorMessage":"PEM decoding resulted in an empty block","messagePattern":"PEM decoding resulted in an empty block","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"msp/mspimpl.go","lineNumber":953,"sourceCode":"\t\tif len(chain) <= 1 {\n\t\t\treturn nil, fmt.Errorf(\"failed to traverse certificate verification chain\"+\n\t\t\t\t\" for leaf or intermediate certificate, with subject %s\", cert.Subject)\n\t\t}\n\t\tparentCert = chain[1]\n\n\t\t// Sanitize\n\t\treturn sanitizeECDSASignedCert(cert, parentCert)\n\t}\n\treturn cert, nil\n}\n\n// IsWellFormed checks if the given identity can be deserialized into its provider-specific form.\n// In this MSP implementation, well formed means that the PEM has a Type which is either\n// the string 'CERTIFICATE' or the Type is missing altogether.\nfunc (msp *bccspmsp) IsWellFormed(identity *m.SerializedIdentity) error {\n\tbl, rest := pem.Decode(identity.IdBytes)\n\tif bl == nil {\n\t\treturn errors.New(\"PEM decoding resulted in an empty block\")\n\t}\n\tif len(rest) > 0 {\n\t\treturn errors.Errorf(\"identity %s for MSP %s has trailing bytes\", string(identity.IdBytes), identity.Mspid)\n\t}\n\n\t// Important: This method looks very similar to getCertFromPem(idBytes []byte) (*x509.Certificate, error)\n\t// But we:\n\t// 1) Must ensure PEM block is of type CERTIFICATE or is empty\n\t// 2) Must not replace getCertFromPem with this method otherwise we will introduce\n\t//    a change in validation logic which will result in a chain fork.\n\tif bl.Type != \"CERTIFICATE\" && bl.Type != \"\" {\n\t\treturn errors.Errorf(\"pem type is %s, should be 'CERTIFICATE' or missing\", bl.Type)\n\t}\n\tcert, err := x509.ParseCertificate(bl.Bytes)\n\tif err != nil {\n\t\treturn err\n\t}\n","sourceCodeStart":935,"sourceCodeEnd":971,"githubUrl":"https://github.com/hyperledger/fabric/blob/2736b63f8fd5932511d56fe68b7039d15977f7f6/msp/mspimpl.go#L935-L971","documentation":"IsWellFormed deserializes a SerializedIdentity and first PEM-decodes IdBytes. If pem.Decode returns nil, the bytes are not PEM at all (no BEGIN/END block), so the identity cannot be a certificate and the library rejects it immediately.","triggerScenarios":"Calling msp.IsWellFormed(&m.SerializedIdentity{IdBytes: ...}) or upstream validation where IdBytes is empty, truncated, or contains raw DER bytes / base64 without PEM headers.","commonSituations":"Storing the certificate without its BEGIN CERTIFICATE lines after JSON round-tripping; passing the DER encoding instead of the PEM; a file read that dropped the header due to encoding issues; empty signcerts directory.","solutions":["Ensure IdBytes contains a full PEM block beginning with -----BEGIN CERTIFICATE-----","Re-export the identity from the MSP signcerts file rather than re-encoding the DER","Check that the cert file was not truncated or stripped of headers during copy/paste","Validate locally: pem.Decode(bytes) returns non-nil before calling IsWellFormed"],"exampleFix":"// before\nidBytes := cert.Raw // raw DER, no PEM\n// after\nidBytes := pem.EncodeToMemory(&pem.Block{Type: \"CERTIFICATE\", Bytes: cert.Raw})","handlingStrategy":"validation","validationCode":"func hasPEM(b []byte) bool { blk, _ := pem.Decode(b); return blk != nil }\nif !hasPEM(idBytes) { return errors.New(\"identity bytes are not PEM\") }","typeGuard":"func isPEMCertificate(b []byte) bool {\n\tblk, _ := pem.Decode(b)\n\treturn blk != nil && blk.Type == \"CERTIFICATE\"\n}","tryCatchPattern":"if err := msp.IsWellFormed(si); err != nil {\n\tif strings.Contains(err.Error(), \"empty block\") {\n\t\t// IdBytes not PEM: re-export cert with PEM encoding\n\t}\n\treturn err\n}","preventionTips":["Never strip PEM headers; store certs as .pem/.crt, not raw DER","Beware JSON/base64 round-trips that mangle PEM content","Check file contents with head -1 (expect -----BEGIN CERTIFICATE-----)"],"tags":["pem","x509","fabric","serialization"],"backgroundTag":"invalid-pem-block","analyzedSha":"2736b63f8fd5932511d56fe68b7039d15977f7f6","analyzedAt":"2026-09-04T08:52:36.465Z","contentChangedAt":"2026-09-04T08:52:36.465Z","schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}