diff options
| -rw-r--r-- | internal/utils/x509.go | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/internal/utils/x509.go b/internal/utils/x509.go new file mode 100644 index 0000000..bf99334 --- /dev/null +++ b/internal/utils/x509.go @@ -0,0 +1,487 @@ +package utils + +import ( + "fmt" + + ct "github.com/google/certificate-transparency-go" + "github.com/google/certificate-transparency-go/asn1" + "github.com/google/certificate-transparency-go/x509/pkix" +) + +// Mozilla Public License Version 2.0 +// ================================== +// +// 1. Definitions +// -------------- +// +// 1.1. "Contributor" +// +// means each individual or legal entity that creates, contributes to +// the creation of, or owns Covered Software. +// +// 1.2. "Contributor Version" +// +// means the combination of the Contributions of others (if any) used +// by a Contributor and that particular Contributor's Contribution. +// +// 1.3. "Contribution" +// +// means Covered Software of a particular Contributor. +// +// 1.4. "Covered Software" +// +// means Source Code Form to which the initial Contributor has attached +// the notice in Exhibit A, the Executable Form of such Source Code +// Form, and Modifications of such Source Code Form, in each case +// including portions thereof. +// +// 1.5. "Incompatible With Secondary Licenses" +// +// means +// +// (a) that the initial Contributor has attached the notice described +// in Exhibit B to the Covered Software; or +// +// (b) that the Covered Software was made available under the terms of +// version 1.1 or earlier of the License, but not also under the +// terms of a Secondary License. +// +// 1.6. "Executable Form" +// +// means any form of the work other than Source Code Form. +// +// 1.7. "Larger Work" +// +// means a work that combines Covered Software with other material, in +// a separate file or files, that is not Covered Software. +// +// 1.8. "License" +// +// means this document. +// +// 1.9. "Licensable" +// +// means having the right to grant, to the maximum extent possible, +// whether at the time of the initial grant or subsequently, any and +// all of the rights conveyed by this License. +// +// 1.10. "Modifications" +// +// means any of the following: +// +// (a) any file in Source Code Form that results from an addition to, +// deletion from, or modification of the contents of Covered +// Software; or +// +// (b) any new file in Source Code Form that contains any Covered +// Software. +// +// 1.11. "Patent Claims" of a Contributor +// +// means any patent claim(s), including without limitation, method, +// process, and apparatus claims, in any patent Licensable by such +// Contributor that would be infringed, but for the grant of the +// License, by the making, using, selling, offering for sale, having +// made, import, or transfer of either its Contributions or its +// Contributor Version. +// +// 1.12. "Secondary License" +// +// means either the GNU General Public License, Version 2.0, the GNU +// Lesser General Public License, Version 2.1, the GNU Affero General +// Public License, Version 3.0, or any later versions of those +// licenses. +// +// 1.13. "Source Code Form" +// +// means the form of the work preferred for making modifications. +// +// 1.14. "You" (or "Your") +// +// means an individual or a legal entity exercising rights under this +// License. For legal entities, "You" includes any entity that +// controls, is controlled by, or is under common control with You. For +// purposes of this definition, "control" means (a) the power, direct +// or indirect, to cause the direction or management of such entity, +// whether by contract or otherwise, or (b) ownership of more than +// fifty percent (50%) of the outstanding shares or beneficial +// ownership of such entity. +// +// 2. License Grants and Conditions +// -------------------------------- +// +// 2.1. Grants +// +// Each Contributor hereby grants You a world-wide, royalty-free, +// non-exclusive license: +// +// (a) under intellectual property rights (other than patent or trademark) +// +// Licensable by such Contributor to use, reproduce, make available, +// modify, display, perform, distribute, and otherwise exploit its +// Contributions, either on an unmodified basis, with Modifications, or +// as part of a Larger Work; and +// +// (b) under Patent Claims of such Contributor to make, use, sell, offer +// +// for sale, have made, import, and otherwise transfer either its +// Contributions or its Contributor Version. +// +// 2.2. Effective Date +// +// The licenses granted in Section 2.1 with respect to any Contribution +// become effective for each Contribution on the date the Contributor first +// distributes such Contribution. +// +// 2.3. Limitations on Grant Scope +// +// The licenses granted in this Section 2 are the only rights granted under +// this License. No additional rights or licenses will be implied from the +// distribution or licensing of Covered Software under this License. +// Notwithstanding Section 2.1(b) above, no patent license is granted by a +// Contributor: +// +// (a) for any code that a Contributor has removed from Covered Software; +// +// or +// +// (b) for infringements caused by: (i) Your and any other third party's +// +// modifications of Covered Software, or (ii) the combination of its +// Contributions with other software (except as part of its Contributor +// Version); or +// +// (c) under Patent Claims infringed by Covered Software in the absence of +// +// its Contributions. +// +// This License does not grant any rights in the trademarks, service marks, +// or logos of any Contributor (except as may be necessary to comply with +// the notice requirements in Section 3.4). +// +// 2.4. Subsequent Licenses +// +// No Contributor makes additional grants as a result of Your choice to +// distribute the Covered Software under a subsequent version of this +// License (see Section 10.2) or under the terms of a Secondary License (if +// permitted under the terms of Section 3.3). +// +// 2.5. Representation +// +// Each Contributor represents that the Contributor believes its +// Contributions are its original creation(s) or it has sufficient rights +// to grant the rights to its Contributions conveyed by this License. +// +// 2.6. Fair Use +// +// This License is not intended to limit any rights You have under +// applicable copyright doctrines of fair use, fair dealing, or other +// equivalents. +// +// 2.7. Conditions +// +// Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted +// in Section 2.1. +// +// 3. Responsibilities +// ------------------- +// +// 3.1. Distribution of Source Form +// +// All distribution of Covered Software in Source Code Form, including any +// Modifications that You create or to which You contribute, must be under +// the terms of this License. You must inform recipients that the Source +// Code Form of the Covered Software is governed by the terms of this +// License, and how they can obtain a copy of this License. You may not +// attempt to alter or restrict the recipients' rights in the Source Code +// Form. +// +// 3.2. Distribution of Executable Form +// +// If You distribute Covered Software in Executable Form then: +// +// (a) such Covered Software must also be made available in Source Code +// +// Form, as described in Section 3.1, and You must inform recipients of +// the Executable Form how they can obtain a copy of such Source Code +// Form by reasonable means in a timely manner, at a charge no more +// than the cost of distribution to the recipient; and +// +// (b) You may distribute such Executable Form under the terms of this +// +// License, or sublicense it under different terms, provided that the +// license for the Executable Form does not attempt to limit or alter +// the recipients' rights in the Source Code Form under this License. +// +// 3.3. Distribution of a Larger Work +// +// You may create and distribute a Larger Work under terms of Your choice, +// provided that You also comply with the requirements of this License for +// the Covered Software. If the Larger Work is a combination of Covered +// Software with a work governed by one or more Secondary Licenses, and the +// Covered Software is not Incompatible With Secondary Licenses, this +// License permits You to additionally distribute such Covered Software +// under the terms of such Secondary License(s), so that the recipient of +// the Larger Work may, at their option, further distribute the Covered +// Software under the terms of either this License or such Secondary +// License(s). +// +// 3.4. Notices +// +// You may not remove or alter the substance of any license notices +// (including copyright notices, patent notices, disclaimers of warranty, +// or limitations of liability) contained within the Source Code Form of +// the Covered Software, except that You may alter any license notices to +// the extent required to remedy known factual inaccuracies. +// +// 3.5. Application of Additional Terms +// +// You may choose to offer, and to charge a fee for, warranty, support, +// indemnity or liability obligations to one or more recipients of Covered +// Software. However, You may do so only on Your own behalf, and not on +// behalf of any Contributor. You must make it absolutely clear that any +// such warranty, support, indemnity, or liability obligation is offered by +// You alone, and You hereby agree to indemnify every Contributor for any +// liability incurred by such Contributor as a result of warranty, support, +// indemnity or liability terms You offer. You may include additional +// disclaimers of warranty and limitations of liability specific to any +// jurisdiction. +// +// 4. Inability to Comply Due to Statute or Regulation +// --------------------------------------------------- +// +// If it is impossible for You to comply with any of the terms of this +// License with respect to some or all of the Covered Software due to +// statute, judicial order, or regulation then You must: (a) comply with +// the terms of this License to the maximum extent possible; and (b) +// describe the limitations and the code they affect. Such description must +// be placed in a text file included with all distributions of the Covered +// Software under this License. Except to the extent prohibited by statute +// or regulation, such description must be sufficiently detailed for a +// recipient of ordinary skill to be able to understand it. +// +// 5. Termination +// -------------- +// +// 5.1. The rights granted under this License will terminate automatically +// if You fail to comply with any of its terms. However, if You become +// compliant, then the rights granted under this License from a particular +// Contributor are reinstated (a) provisionally, unless and until such +// Contributor explicitly and finally terminates Your grants, and (b) on an +// ongoing basis, if such Contributor fails to notify You of the +// non-compliance by some reasonable means prior to 60 days after You have +// come back into compliance. Moreover, Your grants from a particular +// Contributor are reinstated on an ongoing basis if such Contributor +// notifies You of the non-compliance by some reasonable means, this is the +// first time You have received notice of non-compliance with this License +// from such Contributor, and You become compliant prior to 30 days after +// Your receipt of the notice. +// +// 5.2. If You initiate litigation against any entity by asserting a patent +// infringement claim (excluding declaratory judgment actions, +// counter-claims, and cross-claims) alleging that a Contributor Version +// directly or indirectly infringes any patent, then the rights granted to +// You by any and all Contributors for the Covered Software under Section +// 2.1 of this License shall terminate. +// +// 5.3. In the event of termination under Sections 5.1 or 5.2 above, all +// end user license agreements (excluding distributors and resellers) which +// have been validly granted by You or Your distributors under this License +// prior to termination shall survive termination. +// +// ************************************************************************ +// * * +// * 6. Disclaimer of Warranty * +// * ------------------------- * +// * * +// * Covered Software is provided under this License on an "as is" * +// * basis, without warranty of any kind, either expressed, implied, or * +// * statutory, including, without limitation, warranties that the * +// * Covered Software is free of defects, merchantable, fit for a * +// * particular purpose or non-infringing. The entire risk as to the * +// * quality and performance of the Covered Software is with You. * +// * Should any Covered Software prove defective in any respect, You * +// * (not any Contributor) assume the cost of any necessary servicing, * +// * repair, or correction. This disclaimer of warranty constitutes an * +// * essential part of this License. No use of any Covered Software is * +// * authorized under this License except under this disclaimer. * +// * * +// ************************************************************************ +// +// ************************************************************************ +// * * +// * 7. Limitation of Liability * +// * -------------------------- * +// * * +// * Under no circumstances and under no legal theory, whether tort * +// * (including negligence), contract, or otherwise, shall any * +// * Contributor, or anyone who distributes Covered Software as * +// * permitted above, be liable to You for any direct, indirect, * +// * special, incidental, or consequential damages of any character * +// * including, without limitation, damages for lost profits, loss of * +// * goodwill, work stoppage, computer failure or malfunction, or any * +// * and all other commercial damages or losses, even if such party * +// * shall have been informed of the possibility of such damages. This * +// * limitation of liability shall not apply to liability for death or * +// * personal injury resulting from such party's negligence to the * +// * extent applicable law prohibits such limitation. Some * +// * jurisdictions do not allow the exclusion or limitation of * +// * incidental or consequential damages, so this exclusion and * +// * limitation may not apply to You. * +// * * +// ************************************************************************ +// +// 8. Litigation +// ------------- +// +// Any litigation relating to this License may be brought only in the +// courts of a jurisdiction where the defendant maintains its principal +// place of business and such litigation shall be governed by laws of that +// jurisdiction, without reference to its conflict-of-law provisions. +// Nothing in this Section shall prevent a party's ability to bring +// cross-claims or counter-claims. +// +// 9. Miscellaneous +// ---------------- +// +// This License represents the complete agreement concerning the subject +// matter hereof. If any provision of this License is held to be +// unenforceable, such provision shall be reformed only to the extent +// necessary to make it enforceable. Any law or regulation which provides +// that the language of a contract shall be construed against the drafter +// shall not be used to construe this License against a Contributor. +// +// 10. Versions of the License +// --------------------------- +// +// 10.1. New Versions +// +// Mozilla Foundation is the license steward. Except as provided in Section +// 10.3, no one other than the license steward has the right to modify or +// publish new versions of this License. Each version will be given a +// distinguishing version number. +// +// 10.2. Effect of New Versions +// +// You may distribute the Covered Software under the terms of the version +// of the License under which You originally received the Covered Software, +// or under the terms of any subsequent version published by the license +// steward. +// +// 10.3. Modified Versions +// +// If you create software not governed by this License, and you want to +// create a new license for such software, you may create and use a +// modified version of this License if you rename the license and remove +// any references to the name of the license steward (except to note that +// such modified license differs from this License). +// +// 10.4. Distributing Source Code Form that is Incompatible With Secondary +// Licenses +// +// If You choose to distribute Source Code Form that is Incompatible With +// Secondary Licenses under the terms of this version of the License, the +// notice described in Exhibit B of this License must be attached. +// +// Exhibit A - Source Code Form License Notice +// ------------------------------------------- +// +// This Source Code Form is subject to the terms of the Mozilla Public +// License, v. 2.0. If a copy of the MPL was not distributed with this +// file, You can obtain one at http://mozilla.org/MPL/2.0/. +// +// If it is not possible or desirable to put the notice in a particular +// file, then You may include the notice in a location (such as a LICENSE +// file in a relevant directory) where a recipient would be likely to look +// for such a notice. +// +// You may add additional accurate notices of copyright ownership. +// +// Exhibit B - "Incompatible With Secondary Licenses" Notice +// --------------------------------------------------------- +// +// This Source Code Form is "Incompatible With Secondary Licenses", as +// defined by the Mozilla Public License, v. 2.0. +// +// From: +// https://gitlab.torproject.org/tpo/onion-services/sauteed-onions/monitor/-/blob/main/follow-go/main.go#L115-124 +// https://gitlab.torproject.org/tpo/onion-services/sauteed-onions/monitor/-/blob/main/follow-go/x509.go +// https://github.com/SSLMate/certspotter/blob/54f34077d3bebe8aafce07dcfbffeb928c6e1d04/x509.go#L380 + +func SANsFromLeafEntries(startIndex int64, leafEntries []ct.LeafEntry) (sans []string, errs []error) { + for offset, leafEntry := range leafEntries { + leafIndex := startIndex + int64(offset) + e, err := ct.LogEntryFromLeaf(leafIndex, &leafEntry) + if err != nil { + errs = append(errs, fmt.Errorf("leaf at index %d: %v", leafIndex, err)) + continue + } + s, err := sansFromLogEntry(e) + if err != nil { + errs = append(errs, fmt.Errorf("leaf at index %d: %v", leafIndex, err)) + } + sans = append(sans, s...) + } + return +} + +func sansFromLogEntry(entry *ct.LogEntry) ([]string, error) { + if entry.Precert == nil && entry.X509Cert == nil { + return nil, fmt.Errorf("no (pre)cert in log entry") + } + if entry.Precert != nil && entry.X509Cert != nil { + return nil, fmt.Errorf("both precert and cert in log entry") + } + + var exts []pkix.Extension + if entry.Precert != nil { + exts = entry.Precert.TBSCertificate.Extensions + } + if entry.X509Cert != nil { + exts = entry.X509Cert.Extensions + } + + var sans []string + for _, ext := range exts { + if ext.Id.Equal(asn1.ObjectIdentifier{2, 5, 29, 17}) { + moreSANs, err := extract(ext) + if err != nil { + return nil, fmt.Errorf("parse: %v", err) + } + + sans = append(sans, moreSANs...) + } + } + return sans, nil +} + +func extract(extSAN pkix.Extension) ([]string, error) { + var seq asn1.RawValue + rest, err := asn1.Unmarshal(extSAN.Value, &seq) + if err != nil { + return nil, fmt.Errorf("failed to parse subjectAltName extension: %v", err) + } + if len(rest) != 0 { + // Don't complain if the SAN is followed by exactly one zero byte, which is a common error. + if !(len(rest) == 1 && rest[0] == 0) { + return nil, fmt.Errorf("trailing data in subjectAltName extension: %v", rest) + } + } + if !seq.IsCompound || seq.Tag != 16 || seq.Class != 0 { + return nil, fmt.Errorf("failed to parse subjectAltName extension: bad SAN sequence") + } + + sans := []string{} + buf := seq.Bytes + for len(buf) > 0 { + var val asn1.RawValue + var err error + buf, err = asn1.Unmarshal(buf, &val) + if err != nil { + return nil, fmt.Errorf("failed to parse subjectAltName extension item: %v", err) + } + + sans = append(sans, string(val.Bytes)) + } + return sans, nil +} |