如何使用openssl生成RSA私钥？
我想知道如何在c源文件中使用openssl liberary生成RSA私钥？ 我知道如何使用terminal命令生成它。 其实我的server.c文件将生成一个私钥并发送到client.c请尽可能帮助我一些源代码，否则任何帮助将不胜感激。 我正在使用Linux机器。
#include <openssl/rsa.h> #include <openssl/pem.h> const int kBits = 1024; const int kExp = 3; int keylen; char *pem_key; RSA *rsa = RSA_generate_key(kBits, kExp, 0, 0); /* To get the C-string PEM form: */ BIO *bio = BIO_new(BIO_s_mem()); PEM_write_bio_RSAPrivateKey(bio, rsa, NULL, NULL, 0, NULL, NULL); keylen = BIO_pending(bio); pem_key = calloc(keylen+1, 1); /* Null-terminate */ BIO_read(bio, pem_key, keylen); printf("%s", pem_key); BIO_free_all(bio); RSA_free(rsa); free(pem_key); 我想知道如何在我的c源文件中使用openssl库生成RSA私钥？
生成密钥很容易。 只需使用RSA_generate_key_ex 。 下面的程序显示如何做到这一点。
保存公钥和私钥是另一回事，因为你需要知道格式。 下面的程序向您展示了如何以多种格式进行操作。
以下是各种function和格式。
相关的，请参阅“开始RSA私钥”和“开始私钥”之间的区别是什么 。 它讨论了SubjectPublicKeyInfo ， PrivateKeyInfo和公钥和私钥之间的区别。
PEM_write_bio_RSAPublicKey （PKCS PEM格式）。 通知开始BEGIN RSA PUBLIC KEY ：
$ cat rsa-public-1.pem -----BEGIN RSA PUBLIC KEY----- MIIBCgKCAQEAmkD+kwlbsmvyUYOBuVkyWDyBNxGQNJrKUZu97Z+hBG3OA85fY6oV CdyoT+KDmtAFgTgY76KRkHVYQH3HYFpec5vNptLJNd6OVJCXR6NFUR2b7aHLkres qyPMrAHNU16wp85qdHALNd72EoUPkVItHqaBOldx7J9vyUF3bpAWq4XxRlbiK9iv Yuci4/jr4ppRoso6LZm9Inzm53zYt2AqHUZQ+3WgK+czZyk8tLGEN7rtLZ7opvVA aAiRGWiUWACtRwmpAq2L5PuWZkYdQ7WQigkx5c3x8iBkeEh022zqYkGOTh2Ue4Uf rIYuSqjLb2d+jkfZQ1S4LQLQPtMxNV/FqwIDAQAB -----END RSA PUBLIC KEY-----
PEM_write_bio_PUBKEY （传统的PEM格式）。 通知开始BEGIN PUBLIC KEY ：
$ cat rsa-public-2.pem -----BEGIN PUBLIC KEY----- MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAmkD+kwlbsmvyUYOBuVky WDyBNxGQNJrKUZu97Z+hBG3OA85fY6oVCdyoT+KDmtAFgTgY76KRkHVYQH3HYFpe c5vNptLJNd6OVJCXR6NFUR2b7aHLkresqyPMrAHNU16wp85qdHALNd72EoUPkVIt HqaBOldx7J9vyUF3bpAWq4XxRlbiK9ivYuci4/jr4ppRoso6LZm9Inzm53zYt2Aq HUZQ+3WgK+czZyk8tLGEN7rtLZ7opvVAaAiRGWiUWACtRwmpAq2L5PuWZkYdQ7WQ igkx5c3x8iBkeEh022zqYkGOTh2Ue4UfrIYuSqjLb2d+jkfZQ1S4LQLQPtMxNV/F qwIDAQAB -----END PUBLIC KEY-----
PEM_write_bio_PrivateKey （PEM）。 注意开始BEGIN PRIVATE KEY ：
$ cat rsa-private-1.pem -----BEGIN PRIVATE KEY----- MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQCaQP6TCVuya/JR g4G5WTJYPIE3EZA0mspRm73tn6EEbc4Dzl9jqhUJ3KhP4oOa0AWBOBjvopGQdVhA fcdgWl5zm82m0sk13o5UkJdHo0VRHZvtocuSt6yrI8ysAc1TXrCnzmp0cAs13vYS hQ+RUi0epoE6V3Hsn2/JQXdukBarhfFGVuIr2K9i5yLj+OvimlGiyjotmb0ifObn fNi3YCodRlD7daAr5zNnKTy0sYQ3uu0tnuim9UBoCJEZaJRYAK1HCakCrYvk+5Zm Rh1DtZCKCTHlzfHyIGR4SHTbbOpiQY5OHZR7hR+shi5KqMtvZ36OR9lDVLgtAtA+ 0zE1X8WrAgMBAAECggEAWybDCJJEHGgLdj22v5dE171RQgBf7aX2nkjg7/UfSiW0 0qz100gjTIOW9jXNPQNl7Vj/60NuryWYc+ufkIF2ROyxlr4CZpHQG4qhypRhlrBf fwnX6Sgeobby8EXUVkqjK1YftBStmzTYxlLYwzADN5R+0sHvsTr57LyB3dTJgKsn 4iAuJXfR4EthZ6iEM+D8FrmXt5lJ2d1FoMLKiC09M7nMuY9ARqR6O5Tr/Tq4vqfw La6Mv3mWrD2nIznyTJtxUkAxvCRi1tfHOw2YCl6u2JqqWRjLBeaGNyydhGeVH5PT utPHtDciCxpUgGuQ8wNBEstiGYXklpLJFS48+bWVCQKBgQDLC4DNeZ/Tc9g+WUFU ypVCTKfCYt2YmLcNeKDqIPdt14PmV3odIxZGJ1OWrNK1LA50pet0xxY1HRjcBsN+ XUIc5Xa/0nWazdz7c0nqzZgOpVYfPcApQ1K/dqsoWzRY+rlz2PEOYJwMaKW/kkVV 8EPEg38Ck/qr5iKsBYljTteHhQKBgQDCe+iKtPjlFPJ4WX8vTu5QVpRjYmqj87/j 4JFpSh7Lv2PsxSCGQR/7JoyB8Zaz9dyP+RV8/ySJuwGqSseU+W495h8oHe1DtIxU lTR1GB4YI4BU+txvydzQiaFyEUdEFqJblCxXg+XDAcwCUYESLbR661ljbVV/0Qep HMTeXgfnbwKBgDPMYHSK1ZItGHp3bKpD8CX0xktZy2xVcUV3g52XAWg9NcH6iQWL 4O/Oso1a03oynhF2DoZBD9JG9QOUmiTPh8E1bMDs4OG4KOrg83d6MZNy7HCV4ULl kOOVU369HbKha9Q5AO4JCWZFABvKJfQRkkg8v5cZxzY5RJkb5Hu4LlW9AoGACvxg 2GT8okQapj23934n7BXX7/1BNN2x+zdWP3JWZv/6rwc7nRnUqqU0zqpM7wF2YhOZ 6SOodrc/ktUCjSHB3nE/VU7LdkWen7CF9A9Ws9pdh29cQFxQwt7jZcQgGHKG3VFz Z8Yllmxlj8P23IYEaeUdeYZVjBDMs/rSDBWXsLUCgYEAw4TTKH/4BdnRIKhNLp63 n8oGo7Cc/idSQD8XbUVpPbLmychOs2no3Y0XT+xRTAuXjm0GYdmY3Sk3/polGMu5 NHmi5293eAxJ+9ikSD+bYCaLCXFI2PmgJkm+uS1WucqQOSAKOXS6mfsv2pn9YXKw QCMIqX4p7BmO7OD1CFEu6ho= -----END PRIVATE KEY-----
PEM_write_bio_PKCS8PrivateKey （PEM）。 注意开始BEGIN PRIVATE KEY ：
$ cat rsa-private-2.pem -----BEGIN PRIVATE KEY----- MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQCaQP6TCVuya/JR g4G5WTJYPIE3EZA0mspRm73tn6EEbc4Dzl9jqhUJ3KhP4oOa0AWBOBjvopGQdVhA fcdgWl5zm82m0sk13o5UkJdHo0VRHZvtocuSt6yrI8ysAc1TXrCnzmp0cAs13vYS hQ+RUi0epoE6V3Hsn2/JQXdukBarhfFGVuIr2K9i5yLj+OvimlGiyjotmb0ifObn fNi3YCodRlD7daAr5zNnKTy0sYQ3uu0tnuim9UBoCJEZaJRYAK1HCakCrYvk+5Zm Rh1DtZCKCTHlzfHyIGR4SHTbbOpiQY5OHZR7hR+shi5KqMtvZ36OR9lDVLgtAtA+ 0zE1X8WrAgMBAAECggEAWybDCJJEHGgLdj22v5dE171RQgBf7aX2nkjg7/UfSiW0 0qz100gjTIOW9jXNPQNl7Vj/60NuryWYc+ufkIF2ROyxlr4CZpHQG4qhypRhlrBf fwnX6Sgeobby8EXUVkqjK1YftBStmzTYxlLYwzADN5R+0sHvsTr57LyB3dTJgKsn 4iAuJXfR4EthZ6iEM+D8FrmXt5lJ2d1FoMLKiC09M7nMuY9ARqR6O5Tr/Tq4vqfw La6Mv3mWrD2nIznyTJtxUkAxvCRi1tfHOw2YCl6u2JqqWRjLBeaGNyydhGeVH5PT utPHtDciCxpUgGuQ8wNBEstiGYXklpLJFS48+bWVCQKBgQDLC4DNeZ/Tc9g+WUFU ypVCTKfCYt2YmLcNeKDqIPdt14PmV3odIxZGJ1OWrNK1LA50pet0xxY1HRjcBsN+ XUIc5Xa/0nWazdz7c0nqzZgOpVYfPcApQ1K/dqsoWzRY+rlz2PEOYJwMaKW/kkVV 8EPEg38Ck/qr5iKsBYljTteHhQKBgQDCe+iKtPjlFPJ4WX8vTu5QVpRjYmqj87/j 4JFpSh7Lv2PsxSCGQR/7JoyB8Zaz9dyP+RV8/ySJuwGqSseU+W495h8oHe1DtIxU lTR1GB4YI4BU+txvydzQiaFyEUdEFqJblCxXg+XDAcwCUYESLbR661ljbVV/0Qep HMTeXgfnbwKBgDPMYHSK1ZItGHp3bKpD8CX0xktZy2xVcUV3g52XAWg9NcH6iQWL 4O/Oso1a03oynhF2DoZBD9JG9QOUmiTPh8E1bMDs4OG4KOrg83d6MZNy7HCV4ULl kOOVU369HbKha9Q5AO4JCWZFABvKJfQRkkg8v5cZxzY5RJkb5Hu4LlW9AoGACvxg 2GT8okQapj23934n7BXX7/1BNN2x+zdWP3JWZv/6rwc7nRnUqqU0zqpM7wF2YhOZ 6SOodrc/ktUCjSHB3nE/VU7LdkWen7CF9A9Ws9pdh29cQFxQwt7jZcQgGHKG3VFz Z8Yllmxlj8P23IYEaeUdeYZVjBDMs/rSDBWXsLUCgYEAw4TTKH/4BdnRIKhNLp63 n8oGo7Cc/idSQD8XbUVpPbLmychOs2no3Y0XT+xRTAuXjm0GYdmY3Sk3/polGMu5 NHmi5293eAxJ+9ikSD+bYCaLCXFI2PmgJkm+uS1WucqQOSAKOXS6mfsv2pn9YXKw QCMIqX4p7BmO7OD1CFEu6ho= -----END PRIVATE KEY-----
PEM_write_bio_RSAPrivateKey （PEM）。 通知开始BEGIN RSA PRIVATE KEY ：
$ cat rsa-private-3.pem -----BEGIN RSA PRIVATE KEY----- MIIEowIBAAKCAQEAtRZEW6EXwMv2j4mZOhPv3GHcVTi2k8rNlaHc//wUfIYxmNPE zzPd0JBUyT/dbRzwrPMrnmzgdFRidbpyplatCNhq+Httog+Cxd6MdxqGAqOI/X5p 6uxFK8/ptR7E84XpclUQSw+X8VxaG4SFDeMYAuGgw4bIezfFoIySdL16UVIjtSzj aRoG1R8kZFtfKONukoqmQUPwFpLvbxE0u6/pzWk873EiM9w6+zZ3c4NAc0ehzfzA 0maQfjbmVSRihplbocreRXLCaaCYUqAf0K3l4NOYBzVOxBeG03wzsZ0J+nWc5zIW b6auwqBYTO7gMRFXO5vFQZXKaSsEc+B/KwztUwIDAQABAoIBAQCjKDTe+f4Uz7CP E0LjeSMcRW/nuPmHn6orr3MXkWBD8gSt1d/1cJ3iVKiPyuMOdIzExzP9wctaBM3R lPPHu0CcP6Hh0BOveJoy/ZlBlrw3lHDRNRzpdYe9Oc8wSVDauUTkpo/PkXUtGjB1 qqjXIk14CyJ2CPKJUm7VgNJULIQQz5Uh7rMZjK1FvlcLU+v06nHHC4y0w9X/ygXq UoFKKlEADcPqHR/imhrozQxqC4wtn6xFiT/cDngazoGqMX5NCZpso1OZChu3vdAa PYOz/Wv22C+JIK0xgDIfgTh01IyAedeI2ABQeKrak0nU6Faer2Y6cMvHhidG95/v lmIfSqwBAoGBANroQDoZDVYQ7ToYPNd9MIgb217Ug7I6j/NEpGJjUktxeRzgZKDv U5rdbaAArhLXY4FZ0UTZ3WytN1wwV1yXo3Ey5l5CzCXN4GYmv41Z57D218fE7mnx T8OKD4SxznYcayCWtbjlTXC13rz3gYT3XgyKwTpuywabhOMjDpaos+wTAoGBANPF c2uTIPNq+RUouqTnxyBg+/ujwcF32F5n2Rad9cv1NdtZ22JdotKIpSEnvifqbtGG od7vWg5gWgtoG67852K5Q5oBELkcPz4r9PmbSo9H9VWuYotCwB3hvZnIA5GFkfW6 7pLY3j1gdLqMUm0yHPx4or53ScgU9pnYRFJ6UKHBAoGATTE05MfMwhq57JB7c+l7 YaOhGbGKtyCbfkcoSGGJtXzQHnSqR23dZ3DJpXBX8eDt/8DyYHsK77WtHd8WD1qR ketG/NpFLteIV702MtwPLYH92T4CbG1hmSxoCHzCtzeSNy2t6wNA6YvYfX4xt/ea vIV5WeeTxEK2+3lzPYFD4O0CgYA+KGJsXM77I5bgowfFh1JnKpBLmBEy3B5h91E8 1jhjGSIptAI0qQ81hG4TgTrLNIA6d63jZZWlSpqjZndZsVmpHH+/IDjsXGIjuXs6 GF6WF6Tm9Txva7RAERY5oP+LIw1odum3qHfyw/D/IFjBPEhNworiJNk/JQgMt/G1 07j/AQKBgHF2AoovqkCVx0TyggVkwBxwrQvR4jmUYmLKYWYc+IkDQzESXIUme61b OZ7OfbTKQHBTz7i8bXK5mWSbNgmhcVsKHnbPyXKIrL7p+j2b2gdSNAaP1c5XFI/l BvQSuumzUXbzQHbsYjn/4phOv3AK1xGLhnVI69QpaCYYuuPyfm1X -----END RSA PRIVATE KEY-----
i2d_RSAPublicKey_bio （ASN.1 / DER）：
$ dumpasn1 rsa-public.der 0 266: SEQUENCE { 4 257: INTEGER : 00 9A 40 FE 93 09 5B B2 6B F2 51 83 81 B9 59 32 : 58 3C 81 37 11 90 34 9A CA 51 9B BD ED 9F A1 04 : 6D CE 03 CE 5F 63 AA 15 09 DC A8 4F E2 83 9A D0 : 05 81 38 18 EF A2 91 90 75 58 40 7D C7 60 5A 5E : 73 9B CD A6 D2 C9 35 DE 8E 54 90 97 47 A3 45 51 : 1D 9B ED A1 CB 92 B7 AC AB 23 CC AC 01 CD 53 5E : B0 A7 CE 6A 74 70 0B 35 DE F6 12 85 0F 91 52 2D : 1E A6 81 3A 57 71 EC 9F 6F C9 41 77 6E 90 16 AB : [ Another 129 bytes skipped ] 265 3: INTEGER 65537 : } 0 warnings, 0 errors.
i2d_RSAPrivateKey_bio （ASN.1 / DER）：
$ dumpasn1 rsa-private.der 0 1187: SEQUENCE { 4 1: INTEGER 0 7 257: INTEGER : 00 9A 40 FE 93 09 5B B2 6B F2 51 83 81 B9 59 32 : 58 3C 81 37 11 90 34 9A CA 51 9B BD ED 9F A1 04 : 6D CE 03 CE 5F 63 AA 15 09 DC A8 4F E2 83 9A D0 : 05 81 38 18 EF A2 91 90 75 58 40 7D C7 60 5A 5E : 73 9B CD A6 D2 C9 35 DE 8E 54 90 97 47 A3 45 51 : 1D 9B ED A1 CB 92 B7 AC AB 23 CC AC 01 CD 53 5E : B0 A7 CE 6A 74 70 0B 35 DE F6 12 85 0F 91 52 2D : 1E A6 81 3A 57 71 EC 9F 6F C9 41 77 6E 90 16 AB : [ Another 129 bytes skipped ] 268 3: INTEGER 65537 273 256: INTEGER : 5B 26 C3 08 92 44 1C 68 0B 76 3D B6 BF 97 44 D7 : BD 51 42 00 5F ED A5 F6 9E 48 E0 EF F5 1F 4A 25 : B4 D2 AC F5 D3 48 23 4C 83 96 F6 35 CD 3D 03 65 : ED 58 FF EB 43 6E AF 25 98 73 EB 9F 90 81 76 44 : EC B1 96 BE 02 66 91 D0 1B 8A A1 CA 94 61 96 B0 : 5F 7F 09 D7 E9 28 1E A1 B6 F2 F0 45 D4 56 4A A3 : 2B 56 1F B4 14 AD 9B 34 D8 C6 52 D8 C3 30 03 37 : 94 7E D2 C1 EF B1 3A F9 EC BC 81 DD D4 C9 80 AB : [ Another 128 bytes skipped ] ...
该程序是用C ++编写的，即使你有一个C标签。 它允许我们避免大量的错误检查和清理，因为它是自动的。 而且它很容易转换回C.
#include <memory> using std::unique_ptr; #include <openssl/bn.h> #include <openssl/rsa.h> #include <openssl/pem.h> #include <openssl/bio.h> #include <openssl/x509.h> #include <cassert> #define ASSERT assert using BN_ptr = std::unique_ptr<BIGNUM, decltype(&::BN_free)>; using RSA_ptr = std::unique_ptr<RSA, decltype(&::RSA_free)>; using EVP_KEY_ptr = std::unique_ptr<EVP_PKEY, decltype(&::EVP_PKEY_free)>; using BIO_FILE_ptr = std::unique_ptr<BIO, decltype(&::BIO_free)>; int main(int argc, char* argv[]) { int rc; RSA_ptr rsa(RSA_new(), ::RSA_free); BN_ptr bn(BN_new(), ::BN_free); BIO_FILE_ptr pem1(BIO_new_file("rsa-public-1.pem", "w"), ::BIO_free); BIO_FILE_ptr pem2(BIO_new_file("rsa-public-2.pem", "w"), ::BIO_free); BIO_FILE_ptr pem3(BIO_new_file("rsa-private-1.pem", "w"), ::BIO_free); BIO_FILE_ptr pem4(BIO_new_file("rsa-private-2.pem", "w"), ::BIO_free); BIO_FILE_ptr pem5(BIO_new_file("rsa-private-3.pem", "w"), ::BIO_free); BIO_FILE_ptr der1(BIO_new_file("rsa-public.der", "w"), ::BIO_free); BIO_FILE_ptr der2(BIO_new_file("rsa-private.der", "w"), ::BIO_free); rc = BN_set_word(bn.get(), RSA_F4); ASSERT(rc == 1); // Generate key rc = RSA_generate_key_ex(rsa.get(), 2048, bn.get(), NULL); ASSERT(rc == 1); // Convert RSA to PKEY EVP_KEY_ptr pkey(EVP_PKEY_new(), ::EVP_PKEY_free); rc = EVP_PKEY_set1_RSA(pkey.get(), rsa.get()); ASSERT(rc == 1); ////////// // Write public key in ASN.1/DER rc = i2d_RSAPublicKey_bio(der1.get(), rsa.get()); ASSERT(rc == 1); // Write public key in PKCS PEM rc = PEM_write_bio_RSAPublicKey(pem1.get(), rsa.get()); ASSERT(rc == 1); // Write public key in Traditional PEM rc = PEM_write_bio_PUBKEY(pem2.get(), pkey.get()); ASSERT(rc == 1); ////////// // Write private key in ASN.1/DER rc = i2d_RSAPrivateKey_bio(der2.get(), rsa.get()); ASSERT(rc == 1); // Write private key in PKCS PEM. rc = PEM_write_bio_PrivateKey(pem3.get(), pkey.get(), NULL, NULL, 0, NULL, NULL); ASSERT(rc == 1); // Write private key in PKCS PEM rc = PEM_write_bio_PKCS8PrivateKey(pem4.get(), pkey.get(), NULL, NULL, 0, NULL, NULL); ASSERT(rc == 1); // Write private key in Traditional PEM rc = PEM_write_bio_RSAPrivateKey(pem5.get(), rsa.get(), NULL, NULL, 0, NULL, NULL); ASSERT(rc == 1); return 0; }
kExp = 3可以是安全漏洞，请使用65537代替。 这个问题被称为“小RSA指数”，见http://en.wikipedia.org/wiki/Coppersmith%27s_Attack和http://www.usna.edu/Users/math/wdj/book/node45.html请使用超过1024位。;
在使用RSA_generate_key_ex正确接种PRNG之后，您将使用RAND_add
