本节中的示例生成了一个 RSA 密钥对。该密钥对用于对简单字符串进行签名和验证。此示例执行以下步骤：
定义密钥对象。
设置公钥模板。
设置私钥模板。
创建样例消息。
指定用于生成密钥对的 genmech 机制。
指定用于对密钥对进行签名的 smech 机制。
初始化 cryptoki 库。
通过用于生成和验证密钥对并对其进行签名的机制来查找插槽。
此任务将使用一个名为 getMySlot() 的函数来执行以下步骤：
调用 C_GetSlotList() 函数以获取可用插槽的列表。
与 PKCS #11 约定中所建议的一样，C_GetSlotList() 需要调用两次。第一次调用 C_GetSlotList() 用于获取进行内存分配的插槽数量，第二次调用 C_GetSlotList() 用于检索插槽。
查找可以提供所需机制的插槽。
对于每个插槽，该函数都会调用 GetMechanismInfo() 以查找可用于生成密钥对并对其进行签名的机制。如果插槽不支持这些机制，则 GetMechanismInfo() 将返回错误。如果 GetMechanismInfo() 成功返回，将检查机制标志，以确保这些机制可以执行所需的操作。
调用 C_OpenSession() 来打开会话。
关闭会话。
下面是签名和验证示例的源代码。
示例 9-3 使用 PKCS #11 函数对文本进行签名和验证#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/types.h>
#include <security/cryptoki.h>
#include <security/pkcs11.h>
#define BUFFERSIZ 8192
/* Define key template */
static CK_BBOOL truevalue = TRUE;
static CK_BBOOL falsevalue = FALSE;
static CK_ULONG modulusbits = 1024;
static CK_BYTE public_exponent[] = {3};
boolean_t GetMySlot(CK_MECHANISM_TYPE sv_mech, CK_MECHANISM_TYPE kpgen_mech,
CK_SLOT_ID_PTR pslot);
/* Example signs and verifies a simple string, using a public/private
* key pair. */
void
main(int argc, char **argv)
{
CK_RV rv;
CK_MECHANISM genmech, smech;
CK_SESSION_HANDLE hSession;
CK_SESSION_INFO sessInfo;
CK_SLOT_ID slotID;
int error, i = 0;
CK_OBJECT_HANDLE privatekey, publickey;
/* Set public key. */
CK_ATTRIBUTE publickey_template[] = {
{CKA_VERIFY, &truevalue, sizeof (truevalue)},
{CKA_MODULUS_BITS, &modulusbits, sizeof (modulusbits)},
{CKA_PUBLIC_EXPONENT, &public_exponent,
sizeof (public_exponent)}
};
/* Set private key. */
CK_ATTRIBUTE privatekey_template[] = {
{CKA_SIGN, &truevalue, sizeof (truevalue)},
{CKA_TOKEN, &falsevalue, sizeof (falsevalue)},
{CKA_SENSITIVE, &truevalue, sizeof (truevalue)},
{CKA_EXTRACTABLE, &truevalue, sizeof (truevalue)}
};
/* Create sample message. */
CK_ATTRIBUTE getattributes[] = {
{CKA_MODULUS_BITS, NULL_PTR, 0},
{CKA_MODULUS, NULL_PTR, 0},
{CKA_PUBLIC_EXPONENT, NULL_PTR, 0}
};
CK_ULONG messagelen, slen, template_size;
boolean_t found_slot = B_FALSE;
uchar_t *message = (uchar_t *)"Simple message for signing & verifying.";
uchar_t *modulus, *pub_exponent;
char sign[BUFFERSIZ];
slen = BUFFERSIZ;
messagelen = strlen((char *)message);
/* Set up mechanism for generating key pair */
genmech.mechanism = CKM_RSA_PKCS_KEY_PAIR_GEN;
genmech.pParameter = NULL_PTR;
genmech.ulParameterLen = 0;
/* Set up the signing mechanism */
smech.mechanism = CKM_RSA_PKCS;
smech.pParameter = NULL_PTR;
smech.ulParameterLen = 0;
/* Initialize the CRYPTOKI library */
rv = C_Initialize(NULL_PTR);
if (rv != CKR_OK) {
fprintf(stderr, "C_Initialize: Error = 0x%.8X\n", rv);
exit(1);
}
found_slot = GetMySlot(smech.mechanism, genmech.mechanism, &slotID);
if (!found_slot) {
fprintf(stderr, "No usable slot was found.\n");
goto exit_program;
}
fprintf(stdout, "selected slot: %d\n", slotID);
/* Open a session on the slot found */
rv = C_OpenSession(slotID, CKF_SERIAL_SESSION, NULL_PTR, NULL_PTR,
&hSession);
if (rv != CKR_OK) {
fprintf(stderr, "C_OpenSession: rv = 0x%.8X\n", rv);
error = 1;
goto exit_program;
}
fprintf(stdout, "Generating keypair....\n");
/* Generate Key pair for signing/verifying */
rv = C_GenerateKeyPair(hSession, &genmech, publickey_template,
(sizeof (publickey_template) / sizeof (CK_ATTRIBUTE)),
privatekey_template,
(sizeof (privatekey_template) / sizeof (CK_ATTRIBUTE)),
&publickey, &privatekey);
if (rv != CKR_OK) {
fprintf(stderr, "C_GenerateKeyPair: rv = 0x%.8X\n", rv);
error = 1;
goto exit_session;
}
/* Display the publickey. */
template_size = sizeof (getattributes) / sizeof (CK_ATTRIBUTE);
rv = C_GetAttributeValue(hSession, publickey, getattributes,
template_size);
if (rv != CKR_OK) {
/* not fatal, we can still sign/verify if this failed */
fprintf(stderr, "C_GetAttributeValue: rv = 0x%.8X\n", rv);
error = 1;
} else {
/* Allocate memory to hold the data we want */
for (i = 0; i < template_size; i++) {
getattributes[i].pValue =
malloc (getattributes[i].ulValueLen *
sizeof(CK_VOID_PTR));
if (getattributes[i].pValue == NULL) {
int j;
for (j = 0; j < i; j++)
free(getattributes[j].pValue);
goto sign_cont;
}
}
/* Call again to get actual attributes */
rv = C_GetAttributeValue(hSession, publickey, getattributes,
template_size);
if (rv != CKR_OK) {
/* not fatal, we can still sign/verify if failed */
fprintf(stderr,
"C_GetAttributeValue: rv = 0x%.8X\n", rv);
error = 1;
} else {
/* Display public key values */
fprintf(stdout, "Public Key data:\n\tModulus bits: "
"%d\n",
*((CK_ULONG_PTR)(getattributes[0].pValue)));
fprintf(stdout, "\tModulus: ");
modulus = (uchar_t *)getattributes[1].pValue;
for (i = 0; i < getattributes[1].ulValueLen; i++) {
fprintf(stdout, "%.2x", modulus[i]);
}
fprintf(stdout, "\n\tPublic Exponent: ");
pub_exponent = (uchar_t *)getattributes[2].pValue;
for (i = 0; i< getattributes[2].ulValueLen; i++) {
fprintf(stdout, "%.2x", pub_exponent[i]);
}
fprintf(stdout, "\n");
}
}
sign_cont:
rv = C_SignInit(hSession, &smech, privatekey);
if (rv != CKR_OK) {
fprintf(stderr, "C_SignInit: rv = 0x%.8X\n", rv);
error = 1;
goto exit_session;
}
rv = C_Sign(hSession, (CK_BYTE_PTR)message, messagelen,
(CK_BYTE_PTR)sign, &slen);
if (rv != CKR_OK) {
fprintf(stderr, "C_Sign: rv = 0x%.8X\n", rv);
error = 1;
goto exit_session;
}
fprintf(stdout, "Message was successfully signed with private key!\n");
rv = C_VerifyInit(hSession, &smech, publickey);
if (rv != CKR_OK) {
fprintf(stderr, "C_VerifyInit: rv = 0x%.8X\n", rv);
error = 1;
goto exit_session;
}
rv = C_Verify(hSession, (CK_BYTE_PTR)message, messagelen,
(CK_BYTE_PTR)sign, slen);
if (rv != CKR_OK) {
fprintf(stderr, "C_Verify: rv = 0x%.8X\n", rv);
error = 1;
goto exit_session;
}
fprintf(stdout, "Message was successfully verified with public key!\n");
exit_session:
(void) C_CloseSession(hSession);
exit_program:
(void) C_Finalize(NULL_PTR);
for (i = 0; i < template_size; i++) {
if (getattributes[i].pValue != NULL)
free(getattributes[i].pValue);
}
exit(error);
}
/* Find a slot capable of:
* . signing and verifying with sv_mech
* . generating a key pair with kpgen_mech
* Returns B_TRUE when successful. */
boolean_t GetMySlot(CK_MECHANISM_TYPE sv_mech, CK_MECHANISM_TYPE kpgen_mech,
CK_SLOT_ID_PTR pSlotID)
{
CK_SLOT_ID_PTR pSlotList = NULL_PTR;
CK_SLOT_ID SlotID;
CK_ULONG ulSlotCount = 0;
CK_MECHANISM_INFO mech_info;
int i;
boolean_t returnval = B_FALSE;
CK_RV rv;
/* Get slot list for memory alloction */
rv = C_GetSlotList(0, NULL_PTR, &ulSlotCount);
if ((rv == CKR_OK) && (ulSlotCount > 0)) {
fprintf(stdout, "slotCount = %d\n", ulSlotCount);
pSlotList = malloc(ulSlotCount * sizeof (CK_SLOT_ID));
if (pSlotList == NULL) {
fprintf(stderr, "System error: unable to allocate "
"memory\n");
return (returnval);
}
/* Get the slot list for processing */
rv = C_GetSlotList(0, pSlotList, &ulSlotCount);
if (rv != CKR_OK) {
fprintf(stderr, "GetSlotList failed: unable to get "
"slot count.\n");
goto cleanup;
}
} else {
fprintf(stderr, "GetSlotList failed: unable to get slot "
"list.\n");
return (returnval);
}
/* Find a slot capable of specified mechanism */
for (i = 0; i < ulSlotCount; i++) {
SlotID = pSlotList[i];
/* Check if this slot is capable of signing and
* verifying with sv_mech. */
rv = C_GetMechanismInfo(SlotID, sv_mech, &mech_info);
if (rv != CKR_OK) {
continue;
}
if (!(mech_info.flags & CKF_SIGN &&
mech_info.flags & CKF_VERIFY)) {
continue;
}
/* Check if the slot is capable of key pair generation
* with kpgen_mech. */
rv = C_GetMechanismInfo(SlotID, kpgen_mech, &mech_info);
if (rv != CKR_OK) {
continue;
}
if (!(mech_info.flags & CKF_GENERATE_KEY_PAIR)) {
continue;
}
/* If we get this far, this slot supports our mechanisms. */
returnval = B_TRUE;
*pSlotID = SlotID;
break;
}
cleanup:
if (pSlotList)
free(pSlotList);
return (returnval);
}