1# Signing and Signature Verification with an RSA Key Pair (PSS Mode) (ArkTS) 2 3 4For details about the algorithm specifications, see [RSA](crypto-sign-sig-verify-overview.md#rsa). 5 6 7**Signing** 8 9 101. Call [cryptoFramework.createAsyKeyGeneratorBySpec](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#cryptoframeworkcreateasykeygeneratorbyspec10) and [AsyKeyGeneratorBySpec.generateKeyPair](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#generatekeypair-3) to generate an RSA asymmetric key pair (**KeyPair**) based on the specified key parameters. 11 In addition to the example in this topic, [RSA](crypto-asym-key-generation-conversion-spec.md#rsa) and [Generating an Asymmetric Key Pair Based on Key Parameters](crypto-generate-asym-key-pair-from-key-spec.md) may help you better understand how to generate an RSA asymmetric key pair. Note that the input parameters in the reference documents may be different from those in the example below. 12 132. Call [cryptoFramework.createSign](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#cryptoframeworkcreatesign) with the string parameter **'RSA|PSS|SHA256|MGF1_SHA256'** to create a **Sign** instance. As indicated by the string parameter, the key type is RSA without length, the padding mode is **PSS**, the MD algorithm is **SHA256**, and the mask algorithm is **MGF1_SHA256**. 14 153. Call [Sign.init](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#init-3) to initialize the **Sign** instance with the private key (**PriKey**). 16 174. Call [Sign.setSignSpec](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#setsignspec10) to set parameters for signing. In this example, the salt length (**SignSpecItem.PSS_SALT_LEN_NUM**) is set to 32 bytes. The data will be verified in signature verification. 18 195. Call [Sign.getSignSpec](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#getsignspec10) to obtain other parameters for signing. 20 216. Call [Sign.update](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#update-3) to pass in the data to be signed. 22 Currently, the amount of data to be passed in by a single **Sign.update()** is not limited. You can determine how to pass in data based on the data volume. 23 247. Call [Sign.sign](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#sign-1) to generate a signature. 25 26 27**Signature Verification** 28 29 301. Call [cryptoFramework.createVerify](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#cryptoframeworkcreateverify) with the string parameter **'RSA2048|PSS|SHA256|MGF1_SHA256'** to create a **Verify** instance. As indicated by the string parameter, the asymmetric key type is **RSA2048**, the padding mode is **PSS**, the MD algorithm is **SHA256**, and mask algorithm is **MGF1_SHA256**. 31 322. Call [Verify.setVerifySpec](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#setverifyspec10) to set the parameters for signature verification. The parameter value must be the same as that set for signing. 33 343. Call [Verify.init](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#init-5) to initialize the **Verify** instance using the public key (**PubKey**). 35 364. Call [Verify.update](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#update-5) to pass in the data to be verified. 37 Currently, the amount of data to be passed in by a single **Verify.update()** is not limited. You can determine how to pass in data based on the data volume. 38 395. Call [Verify.verify](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#verify-1) to verify the data signature. 40 41- Example (using asynchronous APIs): 42 43 ```ts 44 import { cryptoFramework } from '@kit.CryptoArchitectureKit'; 45 import { buffer } from '@kit.ArkTS'; 46 // Construct the RSA key pair parameter based on the key pair specifications. 47 function genRsaKeyPairSpec(nIn: bigint, eIn: bigint, dIn: bigint) { 48 let rsaCommSpec: cryptoFramework.RSACommonParamsSpec = { 49 n: nIn, 50 algName: "RSA", 51 specType: cryptoFramework.AsyKeySpecType.COMMON_PARAMS_SPEC 52 }; 53 let rsaKeyPairSpec: cryptoFramework.RSAKeyPairSpec = { 54 params: rsaCommSpec, 55 sk: dIn, 56 pk: eIn, 57 algName: "RSA", 58 specType: cryptoFramework.AsyKeySpecType.KEY_PAIR_SPEC 59 }; 60 return rsaKeyPairSpec; 61 } 62 // Generate the RSA2048 key pair parameter. 63 function genRsa2048KeyPairSpec(): cryptoFramework.RSAKeyPairSpec { 64 let nIn = BigInt("0x9260d0750ae117eee55c3f3deaba74917521a262ee76007cdf8a56755ad73a1598a1408410a01434c3f5bc54a88b57fa19fc4328daea0750a4c44e88cff3b2382621b80f670464433e4336e6d003e8cd65bff211da144b88291c2259a00a72b711c116ef7686e8fee34e4d933c868187bdc26f7be071493c86f7a5941c3510806ad67b0f94d88f5cf5c02a092821d8626e8932b65c5bd8c92049c210932b7afa7ac59c0e886ae5c1edb00d8ce2c57633db26bd6639bff73cee82be9275c402b4cf2a4388da8cf8c64eefe1c5a0f5ab8057c39fa5c0589c3e253f0960332300f94bea44877b588e1edbde97cf2360727a09b775262d7ee552b3319b9266f05a25"); 65 let eIn = BigInt("0x010001"); 66 let dIn = BigInt("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"); 67 return genRsaKeyPairSpec(nIn, eIn, dIn); 68 } 69 70 async function verifyMessagePSS() { 71 // The plaintext is split into input1 and input2. 72 let plan1 = "This is Sign test plan1"; 73 let plan2 = "This is Sign test plan2"; 74 let input1: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(plan1, 'utf-8').buffer) }; 75 let input2: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(plan2, 'utf-8').buffer) }; 76 // Generate the RSA key pair parameter (Rsa2048KeyPairSpec) object. 77 let rsaKeyPairSpec = genRsa2048KeyPairSpec(); 78 // Create an RSA key pair generator. 79 let rsaGeneratorSpec = cryptoFramework.createAsyKeyGeneratorBySpec(rsaKeyPairSpec); 80 // Both sign() and verify() support the RSA key with or without the length. 81 let signer = cryptoFramework.createSign("RSA|PSS|SHA256|MGF1_SHA256"); 82 let verifyer = cryptoFramework.createVerify("RSA2048|PSS|SHA256|MGF1_SHA256"); 83 let keyPair = await rsaGeneratorSpec.generateKeyPair(); 84 await signer.init(keyPair.priKey); 85 // After the Sign instance is initialized, set and obtain the PSS parameters. 86 let setN = 32; 87 signer.setSignSpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM, setN); 88 let saltLen = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM); 89 console.info("SaltLen == " + saltLen); 90 let tf = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_TRAILER_FIELD_NUM); 91 console.info("trailer field == " + tf); 92 let md = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_MD_NAME_STR); 93 console.info("md == " + md); 94 let mgf = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_MGF_NAME_STR); 95 console.info("mgf == " + mgf); 96 let mgf1Md = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_MGF1_MD_STR); 97 console.info("mgf1Md == " + mgf1Md); 98 await signer.update(input1); 99 let signMessageBlob = await signer.sign(input2); 100 // Before the Verify instance is initialized, set and get PSS parameters. 101 verifyer.setVerifySpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM, setN); 102 saltLen = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM); 103 console.info("SaltLen == " + saltLen); 104 tf = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_TRAILER_FIELD_NUM); 105 console.info("trailer field == " + tf); 106 md = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_MD_NAME_STR); 107 console.info("md == " + md); 108 mgf = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_MGF_NAME_STR); 109 console.info("mgf == " + mgf); 110 mgf1Md = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_MGF1_MD_STR); 111 await verifyer.init(keyPair.pubKey); 112 await verifyer.update(input1); 113 let verifyResult = await verifyer.verify(input2, signMessageBlob); 114 if (verifyResult === true) { 115 console.info('verify success'); 116 } else { 117 console.error('verify failed'); 118 } 119 } 120 ``` 121 122 123- Example (using synchronous APIs): 124 125 ```ts 126 import { cryptoFramework } from '@kit.CryptoArchitectureKit'; 127 import { buffer } from '@kit.ArkTS'; 128 // Construct the RSA key pair parameter based on the key pair specifications. 129 function genRsaKeyPairSpec(nIn: bigint, eIn: bigint, dIn: bigint) { 130 let rsaCommSpec: cryptoFramework.RSACommonParamsSpec = { 131 n: nIn, 132 algName: "RSA", 133 specType: cryptoFramework.AsyKeySpecType.COMMON_PARAMS_SPEC 134 }; 135 let rsaKeyPairSpec: cryptoFramework.RSAKeyPairSpec = { 136 params: rsaCommSpec, 137 sk: dIn, 138 pk: eIn, 139 algName: "RSA", 140 specType: cryptoFramework.AsyKeySpecType.KEY_PAIR_SPEC 141 }; 142 return rsaKeyPairSpec; 143 } 144 // Generate the RSA2048 key pair parameter. 145 function genRsa2048KeyPairSpec(): cryptoFramework.RSAKeyPairSpec { 146 let nIn = BigInt("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"); 147 let eIn = BigInt("0x010001"); 148 let dIn = BigInt("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"); 149 return genRsaKeyPairSpec(nIn, eIn, dIn); 150 } 151 152 function verifyMessagePSS() { 153 // The plaintext is split into input1 and input2. 154 let plan1 = "This is Sign test plan1"; 155 let plan2 = "This is Sign test plan2"; 156 let input1: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(plan1, 'utf-8').buffer) }; 157 let input2: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(plan2, 'utf-8').buffer) }; 158 // Generate the RSA key pair parameter (Rsa2048KeyPairSpec) object. 159 let rsaKeyPairSpec = genRsa2048KeyPairSpec(); 160 // Create an RSA key pair generator. 161 let rsaGeneratorSpec = cryptoFramework.createAsyKeyGeneratorBySpec(rsaKeyPairSpec); 162 // Both sign() and verify() support the RSA key with or without the length. 163 let signer = cryptoFramework.createSign("RSA|PSS|SHA256|MGF1_SHA256"); 164 let verifyer = cryptoFramework.createVerify("RSA2048|PSS|SHA256|MGF1_SHA256"); 165 let keyPair = rsaGeneratorSpec.generateKeyPairSync(); 166 signer.initSync(keyPair.priKey); 167 // After the Sign instance is initialized, set and obtain the PSS parameters. 168 let setN = 32; 169 signer.setSignSpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM, setN); 170 let saltLen = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM); 171 console.info("SaltLen == " + saltLen); 172 let tf = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_TRAILER_FIELD_NUM); 173 console.info("trailer field == " + tf); 174 let md = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_MD_NAME_STR); 175 console.info("md == " + md); 176 let mgf = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_MGF_NAME_STR); 177 console.info("mgf == " + mgf); 178 let mgf1Md = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_MGF1_MD_STR); 179 console.info("mgf1Md == " + mgf1Md); 180 signer.updateSync(input1); 181 let signMessageBlob = signer.signSync(input2); 182 // Before the Verify instance is initialized, set and get PSS parameters. 183 verifyer.setVerifySpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM, setN); 184 saltLen = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM); 185 console.info("SaltLen == " + saltLen); 186 tf = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_TRAILER_FIELD_NUM); 187 console.info("trailer field == " + tf); 188 md = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_MD_NAME_STR); 189 console.info("md == " + md); 190 mgf = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_MGF_NAME_STR); 191 console.info("mgf == " + mgf); 192 mgf1Md = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_MGF1_MD_STR); 193 verifyer.initSync(keyPair.pubKey); 194 verifyer.updateSync(input1); 195 let verifyResult = verifyer.verifySync(input2, signMessageBlob); 196 if (verifyResult === true) { 197 console.info('verify success'); 198 } else { 199 console.error('verify failed'); 200 } 201 } 202 ``` 203